rootHEADmaster

18 files changed, 12004 insertions, 0 deletions

diff --git a/graphics/AudioManager.cpp b/graphics/AudioManager.cpp
new file mode 100644
index 0000000..5b89acd
--- /dev/null
+++ b/graphics/AudioManager.cpp
@@ -0,0 +1,65 @@
+#include "AudioManager.h"
+
+void AudioManager::playSound(std::string soundfile, float volume, bool looping)
+{
+	auto siter = sounds.find(soundfile);
+	if (siter == sounds.end())
+	{
+		Mix_Chunk * as = Mix_LoadWAV(soundfile.c_str());
+		if (as)
+		{
+			sounds.insert(std::pair<std::string, Mix_Chunk*>(soundfile, as));
+			Mix_VolumeChunk(as, (unsigned char)(MIX_MAX_VOLUME*volume));
+			Mix_PlayChannel(-1, as, looping ? -1 : 0);
+		}
+	}
+	else
+	{
+		Mix_VolumeChunk(siter->second, (unsigned char)(MIX_MAX_VOLUME*volume));
+		Mix_PlayChannel(-1, siter->second, looping ? -1 : 0);
+	}
+}
+
+void AudioManager::playMusic(std::string soundfile, float volume, bool looping, int fade_time)
+{
+	auto siter = scores.find(soundfile);
+	if (siter == scores.end())
+	{
+		Mix_Music * ms = Mix_LoadMUS(soundfile.c_str());
+		if (ms)
+		{
+			scores.insert(std::pair<std::string, Mix_Music*>(soundfile, ms));
+			Mix_VolumeMusic((unsigned char)(MIX_MAX_VOLUME*volume));
+			Mix_FadeInMusic(ms, looping ? -1 : 1, fade_time);
+		}
+	}
+	else
+	{
+		Mix_VolumeMusic((unsigned char)(MIX_MAX_VOLUME*volume));
+		Mix_FadeInMusic(siter->second, looping ? -1 : 1, fade_time);
+	}
+}
+
+void AudioManager::stopMusic(int fade_time)
+{
+	Mix_FadeOutMusic(fade_time);
+	
+}
+
+AudioManager::AudioManager()
+{
+	if (Mix_OpenAudio(44100, MIX_DEFAULT_FORMAT, 2, 4096) == -1)
+		return;
+	initialized = true;
+}
+
+AudioManager::~AudioManager()
+{
+	
+	for (auto sound : sounds)
+		Mix_FreeChunk(sound.second);
+	for (auto score : scores)
+		Mix_FreeMusic(score.second);
+
+	Mix_CloseAudio();
+}
diff --git a/graphics/AudioManager.h b/graphics/AudioManager.h
new file mode 100644
index 0000000..f323cc7
--- /dev/null
+++ b/graphics/AudioManager.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <unordered_map>
+#include <string>
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_mixer.h>
+
+class AudioManager
+{
+	std::unordered_map<std::string, Mix_Chunk*> sounds;
+	std::unordered_map<std::string, Mix_Music*> scores;
+	bool initialized = true;
+public:
+	void playSound(std::string soundfile, float volume, bool looping = false);
+	void playMusic(std::string soundfile, float volume, bool looping = true, int fade_time = 0);
+	void stopMusic(int fade_time = 0);
+	AudioManager();
+	~AudioManager();
+	
+};
\ No newline at end of file
diff --git a/graphics/GLbackend.cpp b/graphics/GLbackend.cpp
new file mode 100644
index 0000000..6c03277
--- /dev/null
+++ b/graphics/GLbackend.cpp
@@ -0,0 +1,887 @@
+#include <cstring>
+
+#include "GLbackend.h"
+#include <iostream>
+#include <string>
+#include <chrono>
+#include <cstdint>
+#include "glm/gtc/matrix_transform.hpp"
+#include "glm/gtx/transform.hpp"
+#include "commonshaders.h"
+#include "graphics.h"
+
+#ifdef __APPLE__
+#define sggBindVertexArray glBindVertexArrayAPPLE
+#define sggGenVertexArrays glGenVertexArraysAPPLE
+#else
+#define sggBindVertexArray glBindVertexArray
+#define sggGenVertexArrays glGenVertexArrays
+#endif
+
+namespace graphics
+{
+
+	const uint32_t delay = 5;  // update every delay ms.
+	float delta_time = 0.0f;
+
+	GLBackend::GLBackend(int w, int h, std::string title) :
+		m_width(w), m_height(h), m_title(title),
+		m_draw_callback(nullptr),
+		m_resize_callback(nullptr),
+		m_idle_callback(nullptr),
+		m_prev_time_tick()
+	{
+
+	}
+
+	void GLBackend::cleanup()
+	{
+
+		SDL_GL_DeleteContext(m_context);
+		SDL_DestroyWindow(m_window);
+		if (m_audio)
+			delete m_audio;
+		SDL_Quit();
+	}
+
+	void GLBackend::swap()
+	{
+		SDL_GL_SwapWindow(m_window);
+	}
+
+	GLBackend::~GLBackend()
+	{
+	}
+
+	void GLBackend::makeCurrent()
+	{
+		SDL_GL_MakeCurrent(m_window, m_context);
+	}
+
+	void GLBackend::show(bool s)
+	{
+		if (s)
+			SDL_ShowWindow(m_window);
+		else
+			SDL_HideWindow(m_window);
+	}
+
+	void GLBackend::setBackgroundColor(float r, float g, float b)
+	{
+		m_back_color = glm::vec3(r, g, b);
+	}
+
+	float GLBackend::getDeltaTime()
+	{
+		return m_delta_time;
+	}
+
+	float GLBackend::getGlobalTime()
+	{
+		return m_global_time;
+	}
+
+	void GLBackend::getMouseButtonPressed(bool * button_array)
+	{
+		button_array[0] = m_button_pressed[0];
+		button_array[1] = m_button_pressed[1];
+		button_array[2] = m_button_pressed[2];
+	}
+
+	void GLBackend::getMouseButtonReleased(bool * button_array)
+	{
+		button_array[0] = m_button_released[0];
+		button_array[1] = m_button_released[1];
+		button_array[2] = m_button_released[2];
+	}
+
+	void GLBackend::getMouseButtonState(bool * button_array)
+	{
+		button_array[0] = m_button_state[0];
+		button_array[1] = m_button_state[1];
+		button_array[2] = m_button_state[2];
+	}
+
+	void GLBackend::getMousePosition(int * x, int * y)
+	{
+		*x = m_mouse_pos.x;
+		*y = m_mouse_pos.y;
+	}
+
+	void GLBackend::getPrevMousePosition(int * x, int * y)
+	{
+		*x = m_prev_mouse_pos.x;
+		*y = m_prev_mouse_pos.y;
+	}
+
+	bool GLBackend::isMouseDragging()
+	{
+		return m_mouse_dragging;
+	}
+
+	void GLBackend::setCanvasMode(int m)
+	{
+		m_canvas_mode = m;
+		if (m == CANVAS_SCALE_WINDOW)
+			m_requested_canvas = glm::vec4(0.0f);
+	}
+
+	void GLBackend::setCanvasSize(float w, float h)
+	{
+		m_requested_canvas.z = w;
+		m_requested_canvas.w = h;
+	}
+
+	void GLBackend::setFullscreen(bool fs)
+	{
+		if (fs)
+		{
+			SDL_SetWindowFullscreen(m_window, SDL_WINDOW_FULLSCREEN_DESKTOP);
+		}
+		else
+		{
+			SDL_SetWindowFullscreen(m_window, 0);
+		}
+		SDL_GetWindowSize(m_window, &m_width, &m_height);
+		resize(m_width, m_height);
+	}
+
+	void GLBackend::playSound(std::string soundfile, float volume, bool looping)
+	{
+		m_audio->playSound(soundfile, volume, looping);
+	}
+
+	void GLBackend::playMusic(std::string soundfile, float volume, bool looping, int fade_time)
+	{
+		m_audio->playMusic(soundfile, volume, looping, fade_time);
+	}
+
+	void GLBackend::stopMusic(int fade_time)
+	{
+		m_audio->stopMusic(fade_time);
+	}
+
+
+	bool GLBackend::processEvent(SDL_Event event)
+	{
+		if (event.type == SDL_MOUSEMOTION)
+		{
+			m_prev_mouse_pos = m_mouse_pos;
+			m_mouse_pos.x = event.motion.x;
+			m_mouse_pos.y = event.motion.y;
+			m_mouse_dragging = (m_button_state[0] || m_button_state[1] || m_button_state[2]);
+		}
+		else if (event.type == SDL_MOUSEBUTTONDOWN || event.type == SDL_MOUSEBUTTONUP)
+		{
+			bool new_state = (event.type == SDL_MOUSEBUTTONDOWN);
+			switch (event.button.button)
+			{
+			case SDL_BUTTON_LEFT: m_button_state[0] = new_state;
+			case SDL_BUTTON_MIDDLE: m_button_state[1] = new_state;
+			case SDL_BUTTON_RIGHT: m_button_state[2] = new_state;
+			}
+			
+		}
+		else if (event.type == SDL_KEYDOWN)
+		{
+			switch (event.key.keysym.sym)
+			{
+			case SDLK_ESCAPE:
+				return false;
+
+			default:
+				break;
+			}
+		}
+		else if (event.type == SDL_WINDOWEVENT)
+		{
+			if (event.window.windowID == m_windowID)
+			{
+				if (event.window.event == SDL_WINDOWEVENT_RESIZED || event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED
+					|| event.window.event == SDL_WINDOWEVENT_MAXIMIZED)
+				{
+					if (event.window.data1 != 0 && event.window.data2 != 0)
+						resize(event.window.data1, event.window.data2);
+				}
+			}
+		}
+		
+		return true;
+	}
+
+	void GLBackend::advanceTime()
+	{
+		auto now = std::chrono::steady_clock::now();
+		std::chrono::duration<float> elapsed_seconds = now - m_prev_time_tick;
+		m_delta_time = elapsed_seconds.count()*1000.0f;
+		m_global_time += m_delta_time;
+		m_prev_time_tick = now;
+	}
+
+	void GLBackend::computeProjection()
+	{
+		float w, h;
+		float n = -1.0f, f = 1.0f;
+		float true_aspect = m_width / (float)m_height;
+		float req_aspect = m_requested_canvas.z / m_requested_canvas.w;
+
+		switch (m_canvas_mode)
+		{
+		case CANVAS_SCALE_STRETCH:
+			m_canvas = m_requested_canvas;
+			m_projection = glm::scale(glm::vec3(1, -1, 1)) * glm::ortho(0.0f, m_canvas.z, 0.0f, m_canvas.w, n, f);
+			break;
+		case CANVAS_SCALE_FIT:
+			
+			if (true_aspect > req_aspect)
+			{
+				m_canvas.z = (true_aspect / req_aspect) * m_requested_canvas.z;
+				m_canvas.w = m_requested_canvas.w;
+				m_canvas.x = -m_requested_canvas.z * (true_aspect / req_aspect-1.0f) / 2;
+				m_canvas.y = 0.0f;
+				m_canvas.z += m_canvas.x;
+			}
+			else
+			{
+				m_canvas.z = m_requested_canvas.z;
+				m_canvas.w = (req_aspect / true_aspect) * m_requested_canvas.w;
+				m_canvas.y = 0.0f;
+				m_canvas.x = 0.0f;
+				m_canvas.y = -m_requested_canvas.w * (req_aspect / true_aspect - 1.0f) / 2;
+				m_canvas.w += m_canvas.y;
+			}
+			m_projection = glm::scale(glm::vec3(1, -1, 1)) * glm::ortho(m_canvas.x, m_canvas.z, m_canvas.y, m_canvas.w, n, f);
+
+			break;
+		default:
+			m_canvas = glm::vec4(0.0f, 0.0f, (float)m_width, (float)m_height);
+			m_projection = glm::scale(glm::vec3(1, -1, 1)) * glm::ortho(0.0f, m_canvas.z, 0.0f, m_canvas.w, n, f);
+		}
+
+		
+	}
+
+	void GLBackend::initPrimitives()
+	{
+		glGetError();
+		const GLubyte * s = glewGetErrorString(glGetError());
+
+		m_flat_shader = Shader(__PrimitivesVertexShader, __SolidFragmentShader);
+		
+		if (!m_flat_shader.init())
+			return;
+		
+		GLfloat box[4][4] = {
+			{ -0.5f, 0.5f, 0, 1 },
+			{ 0.5f, 0.5f, 1, 1 },
+			{ -0.5f, -0.5f, 0, 0 },
+			{ 0.5f, -0.5f, 1, 0 }
+		};
+
+		GLfloat box_outline[4][4] = {
+			{ -0.5f, 0.5f, 0, 0 },
+			{ 0.5f, 0.5f, 1, 0 },
+			{ 0.5f, -0.5f, 1, 1 },
+			{ -0.5f, -0.5f, 0, 1 }
+		};
+
+		GLfloat line[2][4] = 
+		{
+			{0,0,0,1},
+			{1,1,1,1}
+		};
+
+		float sector_vertices[2 * CURVE_SUBDIVS][4];
+		float sector_outline_vertices[2 * CURVE_SUBDIVS][4];
+		float r1 = 0.0f, r2 = 1.0f;
+		for (int i = 0; i < CURVE_SUBDIVS; i++)
+		{
+			float s = i / (float)CURVE_SUBDIVS;
+			sector_vertices[i*2+0][0] = r1*sin(3.1415936f*s);
+			sector_vertices[i*2+0][1] = r1*cos(3.1415936f*s);
+			sector_vertices[i*2+0][2] = s;
+			sector_vertices[i*2+0][3] = 0.0f;
+			sector_vertices[i * 2 + 1][0] = r2 * sin(3.1415936f*s);
+			sector_vertices[i * 2 + 1][1] = r2 * cos(3.1415936f*s);
+			sector_vertices[i * 2 + 1][2] = s;
+			sector_vertices[i * 2 + 1][3] = 1.0f;
+		}
+		for (int i = 0; i < CURVE_SUBDIVS; i++)
+		{
+			float s = i / (float)CURVE_SUBDIVS;
+			sector_vertices[i][0] = r1 * sin(3.1415936f*s);
+			sector_vertices[i][1] = r1 * cos(3.1415936f*s);
+			sector_vertices[i][2] = s;
+			sector_vertices[i][3] = 0.0f;
+			sector_vertices[2 * CURVE_SUBDIVS - i - 1][0] = r2 * sin(3.1415936f*s);
+			sector_vertices[2 * CURVE_SUBDIVS - i - 1][1] = r2 * cos(3.1415936f*s);
+			sector_vertices[2 * CURVE_SUBDIVS - i - 1][2] = s;
+			sector_vertices[2 * CURVE_SUBDIVS - i - 1][3] = 1.0f;
+		}
+
+		sggGenVertexArrays(1, &m_sector_vao);
+		sggBindVertexArray(m_sector_vao);
+		glGenBuffers(1, &m_sector_vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, m_sector_vbo);
+		glBufferData(GL_ARRAY_BUFFER, sizeof sector_vertices, sector_vertices, GL_DYNAMIC_DRAW);
+
+		sggGenVertexArrays(1, &m_sector_outline_vao);
+		sggBindVertexArray(m_sector_outline_vao);
+		glGenBuffers(1, &m_sector_outline_vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, m_sector_outline_vbo);
+		glBufferData(GL_ARRAY_BUFFER, sizeof sector_outline_vertices, sector_outline_vertices, GL_DYNAMIC_DRAW);
+
+		sggGenVertexArrays(1, &m_line_vao);
+		sggBindVertexArray(m_line_vao);
+		glGenBuffers(1, &m_line_vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, m_line_vbo);
+		glBufferData(GL_ARRAY_BUFFER, sizeof line, line, GL_DYNAMIC_DRAW);
+		
+		sggGenVertexArrays(1, &m_rect_vao);
+		sggBindVertexArray(m_rect_vao);
+		glGenBuffers(1, &m_rect_vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, m_rect_vbo);
+		glBufferData(GL_ARRAY_BUFFER, sizeof box, box, GL_STATIC_DRAW);
+
+		sggGenVertexArrays(1, &m_rect_outline_vao);
+		sggBindVertexArray(m_rect_outline_vao);
+		glGenBuffers(1, &m_rect_outline_vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, m_rect_outline_vbo);
+		glBufferData(GL_ARRAY_BUFFER, sizeof box_outline, box_outline, GL_STATIC_DRAW);
+
+		unsigned int attrib_flat_position = m_flat_shader.getAttributeLocation("coord");
+		glEnableVertexAttribArray(attrib_flat_position);
+		glVertexAttribPointer(attrib_flat_position, 4, GL_FLOAT, GL_FALSE, 0, 0);
+		
+	}
+
+	void GLBackend::computeTransformation()
+	{
+		// note: rotation is CW, due to mirroring after projection.
+		m_transformation = glm::rotate(-3.1415936f*m_orientation / 180.0f, glm::vec3(0.f, 0.f, 1.f)) * glm::scale(m_scale);
+	}
+
+	void GLBackend::drawRect(float cx, float cy, float w, float h, const Brush & brush)
+	{
+
+		glEnable(GL_TEXTURE_2D);
+		glFrontFace(GL_CCW);
+		glPolygonMode(GL_FRONT, GL_FILL);
+		glm::mat4 mat = glm::translate(glm::vec3(cx, cy, 0.0f)) * 
+			m_transformation * glm::scale(glm::vec3(w, h, 1.0f));
+		m_flat_shader["gradient"] = glm::vec2(brush.gradient_dir_u, brush.gradient_dir_v);
+
+		// fill
+		if (brush.fill_opacity != 0.0f || brush.fill_secondary_opacity != 0.0f )
+		{
+			int tid = textures.getTexture(brush.texture);
+			if (tid > 0)
+			{
+				glActiveTexture(GL_TEXTURE0);
+				glBindTexture(GL_TEXTURE_2D, tid);
+				
+			}
+			
+			m_flat_shader["color1"] = glm::vec4(brush.fill_color[0], brush.fill_color[1], brush.fill_color[2], brush.fill_opacity);
+
+			if (brush.gradient)
+			{
+				m_flat_shader["color2"] = glm::vec4(brush.fill_secondary_color[0], brush.fill_secondary_color[1],
+					brush.fill_secondary_color[2], brush.fill_secondary_opacity);
+			}
+			else
+			{
+				m_flat_shader["color2"] = glm::vec4(brush.fill_color[0], brush.fill_color[1], brush.fill_color[2], brush.fill_opacity);
+			}
+				
+			m_flat_shader["MV"] = mat;
+			m_flat_shader["tex"] = 0;
+			if (tid>0) 
+				m_flat_shader["has_texture"] = 1;
+			else
+				m_flat_shader["has_texture"] = 0;
+
+			unsigned int attrib_flat_position = m_flat_shader.getAttributeLocation("coord");
+			sggBindVertexArray(m_rect_vao); 
+			glBindBuffer(GL_ARRAY_BUFFER, m_rect_vbo);
+			glEnableVertexAttribArray(attrib_flat_position);
+			glVertexAttribPointer(attrib_flat_position, 4, GL_FLOAT, GL_FALSE, 0, 0);
+			
+			glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+		}
+		glActiveTexture(GL_TEXTURE0);
+		glBindTexture(GL_TEXTURE_2D, 0);
+
+		if (brush.outline_opacity>0.0f)
+		{
+			m_flat_shader.use();
+			m_flat_shader["color1"] = glm::vec4(brush.outline_color[0], brush.outline_color[1], brush.outline_color[2], brush.outline_opacity);
+			m_flat_shader["color2"] = glm::vec4(brush.outline_color[0], brush.outline_color[1], brush.outline_color[2], brush.outline_opacity);
+			m_flat_shader["MV"] = mat;
+			m_flat_shader["has_texture"] = 0;
+			glLineWidth(brush.outline_width);
+			sggBindVertexArray(m_rect_outline_vao);
+			glBindBuffer(GL_ARRAY_BUFFER, m_rect_outline_vbo);
+			unsigned int attrib_flat_position = m_flat_shader.getAttributeLocation("coord");
+			glEnableVertexAttribArray(attrib_flat_position);
+			glVertexAttribPointer(attrib_flat_position, 4, GL_FLOAT, GL_FALSE, 0, 0);
+			glDrawArrays(GL_LINE_LOOP, 0, 4);
+			glLineWidth(1);
+
+		}
+		
+	}
+
+	void GLBackend::drawLine(float x_1, float y_1, float x_2, float y_2, const Brush & brush)
+	{
+		m_flat_shader["color1"] = glm::vec4(brush.outline_color[0], brush.outline_color[1], brush.outline_color[2], brush.outline_opacity);
+		m_flat_shader["MV"] = glm::mat4(1.0f);
+		m_flat_shader["gradient"] = glm::vec2(1.0f, 0.0f);
+		GLfloat line[2][4] = 
+		{
+			{ x_1, y_1, 0.0f, 1.0f},
+			{ x_2, y_2, 0.1f, 1.0f},
+		};
+
+		sggBindVertexArray(m_line_vao);
+		glBindBuffer(GL_ARRAY_BUFFER, m_line_vbo);
+		glBufferData(GL_ARRAY_BUFFER, sizeof line, line, GL_DYNAMIC_DRAW);
+		unsigned int attrib_flat_position = m_flat_shader.getAttributeLocation("coord");
+		glEnableVertexAttribArray(attrib_flat_position);
+		glVertexAttribPointer(attrib_flat_position, 4, GL_FLOAT, GL_FALSE, 0, 0);
+		glDrawArrays(GL_LINES, 0, 2);
+	}
+
+	void GLBackend::drawSector(float cx, float cy, float start_angle, float end_angle, float radius1, float radius2, const Brush & brush)
+	{
+		glEnable(GL_TEXTURE_2D);
+		glFrontFace(GL_CCW);
+		glPolygonMode(GL_FRONT, GL_FILL);
+		m_flat_shader["MV"] = glm::translate(glm::vec3(cx, cy, 0.0f)) * m_transformation;
+		m_flat_shader["gradient"] = glm::vec2(brush.gradient_dir_u,brush.gradient_dir_v);
+
+		float sector_vertices[2 * CURVE_SUBDIVS+2][4];
+		float sector_outline_vertices[2 * CURVE_SUBDIVS+2][4];
+		float r1 = radius1, r2 = radius2;
+		float arc_inc = 3.1415936f*(end_angle - start_angle) / (180.0f*CURVE_SUBDIVS);
+		for (int i = 0; i <= CURVE_SUBDIVS; i++)
+		{
+			float s = i / (float)CURVE_SUBDIVS;
+			sector_vertices[i * 2 + 0][0] = r1 * cos(3.1415936f*start_angle / 180.f + i * arc_inc);
+			sector_vertices[i * 2 + 0][1] = r1 * -sin(3.1415936f*start_angle / 180.f + i * arc_inc);
+			sector_vertices[i * 2 + 0][2] = s;
+			sector_vertices[i * 2 + 0][3] = 0.0f;
+			sector_vertices[i * 2 + 1][0] = r2 * cos(3.1415936f*start_angle / 180.f + i * arc_inc);
+			sector_vertices[i * 2 + 1][1] = r2 * -sin(3.1415936f*start_angle / 180.f + i * arc_inc);
+			sector_vertices[i * 2 + 1][2] = s;
+			sector_vertices[i * 2 + 1][3] = 1.0f;
+		}
+		for (int i = 0; i <= CURVE_SUBDIVS; i++)
+		{
+			float s = i / (float)CURVE_SUBDIVS;
+			sector_outline_vertices[i][0] = r1 * cos(3.1415936f*start_angle / 180.f + i * arc_inc);
+			sector_outline_vertices[i][1] = r1 * -sin(3.1415936f*start_angle / 180.f + i * arc_inc);
+			sector_outline_vertices[i][2] = s;
+			sector_outline_vertices[i][3] = 0.0f;
+		}
+		for (int i = CURVE_SUBDIVS; i >= 0; i--)
+		{
+			float s = (i) / (float)CURVE_SUBDIVS;
+			sector_outline_vertices[2*CURVE_SUBDIVS-i+1][0] = r2 * cos(3.1415936f*start_angle / 180.f + i * arc_inc);
+			sector_outline_vertices[2*CURVE_SUBDIVS-i+1][1] = r2 * -sin(3.1415936f*start_angle / 180.f + i * arc_inc);
+			sector_outline_vertices[2*CURVE_SUBDIVS-i+1][2] = s;
+			sector_outline_vertices[2*CURVE_SUBDIVS-i+1][3] = 1.0f;
+		}
+
+
+		// fill
+		if (brush.fill_opacity != 0.0f || brush.fill_secondary_opacity != 0.0f)
+		{
+			int tid = textures.getTexture(brush.texture);
+			if (tid > 0)
+			{
+				glActiveTexture(GL_TEXTURE0);
+				glBindTexture(GL_TEXTURE_2D, tid);
+
+			}
+
+			m_flat_shader["color1"] = glm::vec4(brush.fill_color[0], brush.fill_color[1], brush.fill_color[2], brush.fill_opacity);
+
+			if (brush.gradient)
+			{
+				m_flat_shader["color2"] = glm::vec4(brush.fill_secondary_color[0], brush.fill_secondary_color[1],
+					brush.fill_secondary_color[2], brush.fill_secondary_opacity);
+			}
+			else
+			{
+				m_flat_shader["color2"] = glm::vec4(brush.fill_color[0], brush.fill_color[1], brush.fill_color[2], brush.fill_opacity);
+			}
+
+			m_flat_shader["tex"] = 0;
+			if (tid > 0)
+				m_flat_shader["has_texture"] = 1;
+			else
+				m_flat_shader["has_texture"] = 0;
+
+			sggBindVertexArray(m_sector_vao);
+			glBindBuffer(GL_ARRAY_BUFFER, m_sector_vbo);
+			glBufferData(GL_ARRAY_BUFFER, sizeof sector_vertices, sector_vertices, GL_DYNAMIC_DRAW);
+			unsigned int attrib_flat_position = m_flat_shader.getAttributeLocation("coord");
+			glEnableVertexAttribArray(attrib_flat_position);
+			glVertexAttribPointer(attrib_flat_position, 4, GL_FLOAT, GL_FALSE, 0, 0);
+			glDrawArrays(GL_TRIANGLE_STRIP, 0, 2 * CURVE_SUBDIVS+2);
+
+		}
+		glActiveTexture(GL_TEXTURE0);
+		glBindTexture(GL_TEXTURE_2D, 0);
+
+		if (brush.outline_opacity > 0.0f)
+		{
+			m_flat_shader.use();
+			m_flat_shader["color1"] = glm::vec4(brush.outline_color[0], brush.outline_color[1], brush.outline_color[2], brush.outline_opacity);
+			m_flat_shader["color2"] = glm::vec4(brush.outline_color[0], brush.outline_color[1], brush.outline_color[2], brush.outline_opacity);
+			m_flat_shader["has_texture"] = 0;
+			glLineWidth(brush.outline_width);
+			
+			sggBindVertexArray(m_sector_outline_vao);
+			glBindBuffer(GL_ARRAY_BUFFER, m_sector_outline_vbo);
+			glBufferData(GL_ARRAY_BUFFER, sizeof sector_outline_vertices, sector_outline_vertices, GL_DYNAMIC_DRAW);
+			unsigned int attrib_flat_position = m_flat_shader.getAttributeLocation("coord");
+			glEnableVertexAttribArray(attrib_flat_position);
+			glVertexAttribPointer(attrib_flat_position, 4, GL_FLOAT, GL_FALSE, 0, 0);
+			if (fabs(end_angle-start_angle-360.0f)>0.000f)
+				glDrawArrays(GL_LINE_LOOP, 0, 2 * CURVE_SUBDIVS+2);
+			else
+				glDrawArrays(GL_LINE_LOOP, CURVE_SUBDIVS + 1, CURVE_SUBDIVS );
+			
+			glLineWidth(1);
+
+		}
+
+		
+
+	}
+
+	void GLBackend::drawText(float pos_x, float pos_y, float size, const std::string & text, const Brush & brush)
+	{
+		TextRecord entry;
+		entry.text = text;
+		entry.pos = glm::vec2(pos_x, pos_y);
+		entry.size = glm::vec2(size, size);
+		entry.color1 = glm::vec4(brush.fill_color[0], brush.fill_color[1], brush.fill_color[2], brush.fill_opacity);
+		entry.color2 = glm::vec4(brush.fill_secondary_color[0], brush.fill_secondary_color[1], brush.fill_secondary_color[2], brush.fill_secondary_opacity);
+		entry.gradient = glm::vec2(brush.gradient_dir_u, brush.gradient_dir_v);
+		entry.use_gradient = brush.gradient;
+		entry.mv = m_transformation;
+		entry.proj = m_projection;
+		m_fontlib.submitText(entry);
+	}
+
+	void GLBackend::setUserData(const void * user_data) {
+		m_user_data = user_data;
+	}
+
+	void* GLBackend::getUserData() {
+		/* Safely cast const away */
+		return const_cast<void*>(m_user_data);
+	}
+
+	void GLBackend::setScale(float sx, float sy, float sz)
+	{
+		m_scale = glm::vec3(sx,sy,sz);
+		computeTransformation();
+	}
+
+	void GLBackend::setOrientation(float degrees)
+	{
+		m_orientation = degrees;
+		computeTransformation();
+	}
+
+	void GLBackend::resetPose()
+	{
+		m_transformation = glm::mat4(1.0f);
+		m_scale = glm::vec3(1.0f);
+		m_orientation = 0.0f;
+	}
+
+	bool GLBackend::setFont(std::string fontname)
+	{
+		return m_fontlib.setCurrentFont(fontname);
+	}
+
+	bool GLBackend::getKeyState(scancode_t key)
+	{
+		int numkeys;
+		const uint8_t * keymap = SDL_GetKeyboardState(&numkeys);
+		return keymap[key];
+	}
+
+
+	bool GLBackend::processMessages()
+	{
+		SDL_Event event;
+		bool loop = true;
+		while (SDL_PollEvent(&event))
+		{
+			if (event.type == SDL_WINDOWEVENT_CLOSE || event.type == SDL_QUIT)
+			{
+				return false;
+			}
+			else
+			{
+				loop = processEvent(event);
+			}
+		}
+			update();
+			m_idle_callback(getDeltaTime());
+			draw();
+		advanceTime();
+		SDL_Delay(5);
+
+		return loop;
+	}
+
+	void GLBackend::update(float delta_time)
+	{
+		static bool prev_mouse_state[3] = { 0,0,0 };
+
+		m_button_pressed[0] = (m_button_state[0] && !prev_mouse_state[0]);
+		m_button_pressed[1] = (m_button_state[1] && !prev_mouse_state[1]);
+		m_button_pressed[2] = (m_button_state[2] && !prev_mouse_state[2]);
+
+		m_button_released[0] = (!m_button_state[0] && prev_mouse_state[0]);
+		m_button_released[1] = (!m_button_state[1] && prev_mouse_state[1]);
+		m_button_released[2] = (!m_button_state[2] && prev_mouse_state[2]);
+
+		prev_mouse_state[0] = m_button_state[0];
+		prev_mouse_state[1] = m_button_state[1];
+		prev_mouse_state[2] = m_button_state[2];
+
+	}
+
+	void GLBackend::resize(int w, int h)
+	{
+		m_width = w;
+		m_height = h;
+
+		if (m_resize_callback != nullptr)
+			m_resize_callback(w, h);
+
+		if (m_requested_canvas.z == 0 || m_requested_canvas.w == 0)
+		// default canvas is window-sized, in pixel units.
+			m_canvas = glm::vec4(0, 0, m_width, m_height);
+		else
+			m_canvas = m_requested_canvas;
+
+		float c_w = m_canvas.z;
+		float c_h = m_canvas.w;
+		float cr = c_w / c_h;
+		float wr = m_width / (float)m_height;
+
+		// calculate window to canvas unit conversion ratios
+		if (m_canvas_mode == CANVAS_SCALE_FIT)
+		{
+			if (cr > wr)
+			{
+				m_window_to_canvas_factors.x = c_w / m_width;
+				m_window_to_canvas_factors.y = 0.0f;
+				m_window_to_canvas_factors.z = c_w / m_width;
+				m_window_to_canvas_factors.w = c_h / 2.0f - 0.5 * m_height * c_w / m_width;
+			}
+			else
+			{
+				m_window_to_canvas_factors.z = c_h / m_height;
+				m_window_to_canvas_factors.w = 0.0f;
+				m_window_to_canvas_factors.x = c_h / m_height;
+				m_window_to_canvas_factors.y = c_w / 2.0f - 0.5 * m_width * c_h / m_height;
+			}
+		}
+		else 
+		{
+			m_window_to_canvas_factors.x = c_w / m_width;
+			m_window_to_canvas_factors.y = 0.0f;
+			m_window_to_canvas_factors.z = c_h / m_height;
+			m_window_to_canvas_factors.w = 0.0f;
+		}
+
+		computeProjection();
+		glViewport(0, 0, m_width, m_height);
+		//SDL_Delay(100);
+		draw();
+	}
+
+	float GLBackend::WindowToCanvasX(float x, bool clamped)
+	{
+		float coord = m_window_to_canvas_factors.x*x + m_window_to_canvas_factors.y;
+		return clamped?glm::clamp(coord, 0.0f, m_canvas.z) : coord;
+	}
+
+	float GLBackend::WindowToCanvasY(float y, bool clamped)
+	{
+		float coord = m_window_to_canvas_factors.z*y + m_window_to_canvas_factors.w;
+		return clamped?glm::clamp(coord, 0.0f, m_canvas.w) : coord;
+	}
+
+	void GLBackend::draw()
+	{
+		m_flat_shader.use();
+
+		// reset timers on first run
+		static bool first_time = true;
+		if (first_time)
+		{
+			advanceTime();
+			m_global_time = 0.0f;
+			m_delta_time = 0.0f;
+			first_time = false;
+
+			//force a call to resize to take canvas parameters set by the user.
+			resize(m_width, m_height);
+			return;
+		}
+
+		resetPose();
+				
+		glDepthMask(0.0f);
+		glDisable(GL_DEPTH_TEST);
+		glClearColor(0.0f, 0.0f, 0.f, 1.0);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		
+		if (m_canvas_mode == CANVAS_SCALE_FIT)
+		{
+			float true_aspect = m_width / (float)m_height;
+			float req_aspect = m_requested_canvas.z / m_requested_canvas.w;
+			glEnable(GL_SCISSOR_TEST);
+			glm::vec4 rect;
+			rect.x = (true_aspect > req_aspect ? (m_width - m_height * req_aspect) / 2.0f : 0.0f);
+			rect.y = (req_aspect > true_aspect ? (m_height - m_width / req_aspect)/2.0f : 0.0f);
+			rect.z = (true_aspect > req_aspect ? m_height * req_aspect : m_width);
+			rect.w = (req_aspect > true_aspect ? m_width / req_aspect : m_height);
+			glScissor(rect.x, rect.y, rect.z, rect.w);
+		}
+
+		Brush bck;
+		bck.fill_color[0] = m_back_color.r, bck.fill_color[1] = m_back_color.g, bck.fill_color[2] = m_back_color.b;
+		bck.outline_opacity = 0.0f;
+		drawRect(m_requested_canvas.z / 2, m_requested_canvas.w / 2, m_requested_canvas.z, m_requested_canvas.w, bck);
+		
+		glEnable(GL_BLEND);
+		glBlendEquation(GL_ADD);
+		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+		
+		m_flat_shader["P"] = m_projection;
+		glGetError();
+		if (m_draw_callback != nullptr)
+			m_draw_callback();
+
+		m_fontlib.setCanvas(glm::vec2(m_requested_canvas.z, m_requested_canvas.w));
+		m_fontlib.commitText();
+
+		glDisable(GL_SCISSOR_TEST);
+		swap();
+	}
+
+
+
+	void GLBackend::setDrawCallback(std::function<void()> drf)
+	{
+		m_draw_callback = drf;
+	}
+
+	void GLBackend::setIdleCallback(std::function<void(float)> idf)
+	{
+		m_idle_callback = idf;
+	}
+
+	void GLBackend::setResizeCallback(std::function<void(int, int)> rsf)
+	{
+		m_resize_callback = rsf;
+	}
+
+	bool GLBackend::init()
+	{
+		m_initialized = false;
+
+		if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_EVENTS | SDL_INIT_AUDIO) < 0)
+		{
+			std::cout << "Failed to init SDL\n";
+			return false;
+		}
+		
+		m_window = SDL_CreateWindow(m_title.c_str(), SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+			m_width, m_height, SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE );
+		m_windowID = SDL_GetWindowID(m_window);
+		m_audio = new AudioManager();
+
+		if (!m_window)
+		{
+			std::cout << "Unable to create window\n";
+			CheckSDLError(__LINE__);
+			return false;
+		}
+		
+		m_context = SDL_GL_CreateContext(m_window);
+
+		
+		//SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 4);
+		SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+		SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+		SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+		SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+		SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
+		SDL_GL_SetSwapInterval(0);
+		
+		glewExperimental = GL_TRUE;
+		glewInit();
+		glGetError();
+		glEnable(GL_DEPTH_TEST);
+		glDepthFunc(GL_LEQUAL);
+		glClearDepth(1.0f);
+		glDisable(GL_CULL_FACE);
+		glCullFace(GL_BACK);
+
+		if (!m_fontlib.init())
+		{
+			std::cout << "Unable to initialize font library\n";
+			CheckSDLError(__LINE__);
+			return false;
+		}
+		
+		initPrimitives();
+		computeProjection();
+		glViewport(0, 0, m_width, m_height);
+		
+		m_initialized = true;
+		return true;
+	}
+
+	
+
+	void CheckSDLError(int line = -1)
+	{
+		std::string error = SDL_GetError();
+
+		if (error != "")
+		{
+			std::cout << "SLD Error : " << error << std::endl;
+
+			if (line != -1)
+				std::cout << "\nLine : " << line << std::endl;
+
+			SDL_ClearError();
+		}
+	}
+
+	void PrintSDL_GL_Attributes()
+	{
+		int value = 0;
+		SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &value);
+		std::cout << "SDL_GL_CONTEXT_MAJOR_VERSION : " << value << std::endl;
+
+		SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &value);
+		std::cout << "SDL_GL_CONTEXT_MINOR_VERSION: " << value << std::endl;
+	}
+}
\ No newline at end of file
diff --git a/graphics/GLbackend.h b/graphics/GLbackend.h
new file mode 100644
index 0000000..7b00b90
--- /dev/null
+++ b/graphics/GLbackend.h
@@ -0,0 +1,140 @@
+#pragma once
+#define GL3_PROTOTYPES 1
+#include <GL/glew.h>
+#include <SDL2/SDL.h>
+#include <string>
+#include <thread>
+#include "shader.h"
+#include "fonts.h"
+#include <functional>
+#include <glm/vec3.hpp>
+#include "scancodes.h"
+#include "texture.h"
+#include "AudioManager.h"
+
+#define SGG_CHECK_GL() do {GLenum err;while((err = glGetError()) != GL_NO_ERROR){ printf("Error %s %d\n", (const char*)glewGetErrorString(err), err);exit(0);}printf("Pass\n");} while(0);
+
+constexpr auto CURVE_SUBDIVS = 64;
+
+//#undef main
+namespace graphics
+{
+	void PrintSDL_GL_Attributes();
+	void CheckSDLError(int line);
+
+	class GLBackend
+	{
+	protected:
+		int			  m_width,
+					  m_height;
+		std::string   m_title;
+		SDL_Window *  m_window;
+		uint32_t      m_windowID;
+		SDL_GLContext m_context;
+		bool		  m_initialized = false;
+		FontLib		  m_fontlib;
+		SDL_TimerID   m_idle_timer;
+		glm::vec3	  m_back_color = { 0.0f, 0.0f, 0.0f };
+
+		glm::ivec2	  m_mouse_pos = glm::ivec2();
+		glm::ivec2	  m_prev_mouse_pos = glm::ivec2();
+		bool		  m_button_state[3] = { 0, 0, 0 };
+		bool		  m_button_pressed[3] = { 0, 0, 0 };
+		bool		  m_button_released[3] = { 0, 0, 0 };
+		bool		  m_mouse_dragging = false;
+
+		glm::vec4	  m_requested_canvas = glm::vec4(0.0f);
+		glm::vec4	  m_canvas;
+		int			  m_canvas_mode = 0;
+
+		glm::mat4	  m_projection;
+		glm::mat4	  m_transformation = glm::mat4(1.0f);
+		float		  m_orientation = 0.0f;
+		glm::vec3	  m_scale = glm::vec3(1.0f);
+		Shader		  m_flat_shader;
+		
+		GLuint		m_rect_vbo;
+		GLuint		m_rect_vao;
+		GLuint		m_rect_outline_vbo;
+		GLuint		m_rect_outline_vao;
+		GLuint		m_line_vbo;
+		GLuint		m_line_vao;
+		GLuint		m_sector_vbo;
+		GLuint		m_sector_vao;
+		GLuint		m_sector_outline_vbo;
+		GLuint		m_sector_outline_vao;
+
+		glm::vec4	m_window_to_canvas_factors;
+
+		AudioManager * m_audio = nullptr;
+
+		TextureManager textures;
+
+		std::chrono::time_point<std::chrono::steady_clock> m_prev_time_tick;
+		float m_global_time = 0.0f;
+		float m_delta_time = 0.0f;
+
+		const void* m_user_data = nullptr;
+
+		bool processEvent(SDL_Event event);
+
+		void advanceTime();
+
+		void computeProjection();
+		void initPrimitives();
+		void computeTransformation();
+
+		std::function<void()> m_draw_callback = nullptr;
+		std::function<void(float ms)> m_idle_callback = nullptr;
+		std::function<void(int w, int h)> m_resize_callback = nullptr;
+
+	public:
+		void drawRect(float cx, float cy, float w, float h, const struct Brush & brush);
+		void drawLine(float x_1, float y_1, float x_2, float y_2, const struct Brush & brush);
+		void drawSector(float cx, float cy, float start_angle, float end_angle, float radius1, float radius2, const struct Brush & brush);
+		void drawText(float pos_x, float pos_y, float size, const std::string & text, const Brush & brush);
+		
+		void setUserData(const void* user_data);
+		void* getUserData();
+
+		void setScale(float sx, float sy, float sz);
+		void setOrientation(float degrees);
+		void resetPose();
+		bool setFont(std::string fontname);
+
+		bool getKeyState(scancode_t key);
+		void setDrawCallback(std::function<void()> drf);
+		void setIdleCallback(std::function<void(float ms)> idf);
+		void setResizeCallback(std::function<void(int w, int h)> rsf);
+		virtual bool init();
+		GLBackend(int w = 800, int h = 600, std::string title = "");
+		virtual void cleanup();
+		void swap();
+		bool processMessages();
+		virtual void update(float delta_time = 0.0f);
+		virtual void resize(int w, int h);
+		float WindowToCanvasX(float x, bool clamped = true);
+		float WindowToCanvasY(float y, bool clamped = true);
+		virtual void draw();
+		virtual ~GLBackend();
+		void makeCurrent();
+		void show(bool s);
+		void setBackgroundColor(float r, float g, float b);
+		float getDeltaTime();
+		float getGlobalTime();
+		void getMouseButtonPressed(bool * button_array);
+		void getMouseButtonReleased(bool * button_array);
+		void getMouseButtonState(bool * button_array);
+		void getMousePosition(int * x, int * y);
+		void getPrevMousePosition(int * x, int * y);
+		bool isMouseDragging();
+		void setCanvasMode(int m);
+		void setCanvasSize(float w, float h);
+		void setFullscreen(bool fs);
+
+		void playSound(std::string soundfile, float volume, bool looping = false);
+		void playMusic(std::string soundfile, float volume, bool looping = true, int fade_time = 0);
+		void stopMusic(int fade_time = 0);
+	};
+
+}
\ No newline at end of file
diff --git a/graphics/audio.cpp b/graphics/audio.cpp
new file mode 100644
index 0000000..1d74a9e
--- /dev/null
+++ b/graphics/audio.cpp
@@ -0,0 +1,459 @@
+/*
+ * Simple-SDL2-Audio
+ *
+ * Copyright 2016 Jake Besworth
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <memory.h>
+#include <SDL2/SDL.h>
+
+#include "audio.h"
+
+/*
+ * Native WAVE format
+ *
+ * On some GNU/Linux you can identify a files properties using:
+ *      mplayer -identify music.wav
+ *
+ * On some GNU/Linux to convert any music to this or another specified format use:
+ *      ffmpeg -i in.mp3 -acodec pcm_s16le -ac 2 -ar 48000 out.wav
+ */
+/* SDL_AudioFormat of files, such as s16 little endian */
+#define AUDIO_FORMAT AUDIO_S16LSB
+
+/* Frequency of the file */
+#define AUDIO_FREQUENCY 48000
+
+/* 1 mono, 2 stereo, 4 quad, 6 (5.1) */
+#define AUDIO_CHANNELS 2
+
+/* Specifies a unit of audio data to be used at a time. Must be a power of 2 */
+#define AUDIO_SAMPLES 4096
+
+/* Max number of sounds that can be in the audio queue at anytime, stops too much mixing */
+#define AUDIO_MAX_SOUNDS 25
+
+/* Flags OR'd together, which specify how SDL should behave when a device cannot offer a specific feature
+ * If flag is set, SDL will change the format in the actual audio file structure (as opposed to gDevice->want)
+ *
+ * Note: If you're having issues with Emscripten / EMCC play around with these flags
+ *
+ * 0                                    Allow no changes
+ * SDL_AUDIO_ALLOW_FREQUENCY_CHANGE     Allow frequency changes (e.g. AUDIO_FREQUENCY is 48k, but allow files to play at 44.1k
+ * SDL_AUDIO_ALLOW_FORMAT_CHANGE        Allow Format change (e.g. AUDIO_FORMAT may be S32LSB, but allow wave files of S16LSB to play)
+ * SDL_AUDIO_ALLOW_CHANNELS_CHANGE      Allow any number of channels (e.g. AUDIO_CHANNELS being 2, allow actual 1)
+ * SDL_AUDIO_ALLOW_ANY_CHANGE           Allow all changes above
+ */
+#define SDL_AUDIO_ALLOW_CHANGES SDL_AUDIO_ALLOW_ANY_CHANGE
+
+/*
+ * Definition for the game global sound device
+ *
+ */
+typedef struct privateAudioDevice
+{
+    SDL_AudioDeviceID device;
+    SDL_AudioSpec want;
+    uint8_t audioEnabled;
+} PrivateAudioDevice;
+
+/* File scope variables to persist data */
+static PrivateAudioDevice * gDevice;
+static uint32_t gSoundCount;
+
+/*
+ * Add a music to the queue, addAudio wrapper for music due to fade
+ *
+ * @param new       New Audio to add
+ *
+ */
+static void addMusic(Audio * root, Audio * news);
+
+/*
+ * Wrapper function for playMusic, playSound, playMusicFromMemory, playSoundFromMemory
+ *
+ * @param filename      Provide a filename to load WAV from, or NULL if using FromMemory
+ * @param audio         Provide an Audio object if copying from memory, or NULL if using a filename
+ * @param sound         1 if looping (music), 0 otherwise (sound)
+ * @param volume        See playSound for explanation
+ *
+ */
+static inline void playAudio(const char * filename, Audio * audio, uint8_t loop, int volume);
+
+/*
+ * Add a sound to the end of the queue
+ *
+ * @param root      Root of queue
+ * @param new       New Audio to add
+ *
+ */
+static void addAudio(Audio * root, Audio * news);
+
+/*
+ * Audio callback function for OpenAudioDevice
+ *
+ * @param userdata      Points to linked list of sounds to play, first being a placeholder
+ * @param stream        Stream to mix sound into
+ * @param len           Length of sound to play
+ *
+ */
+static inline void audioCallback(void * userdata, uint8_t * stream, int len);
+
+void playSound(const char * filename, int volume)
+{
+    playAudio(filename, NULL, 0, volume);
+}
+
+void playMusic(const char * filename, int volume)
+{
+    playAudio(filename, NULL, 1, volume);
+}
+
+void playSoundFromMemory(Audio * audio, int volume)
+{
+    playAudio(NULL, audio, 0, volume);
+}
+
+void playMusicFromMemory(Audio * audio, int volume)
+{
+    playAudio(NULL, audio, 1, volume);
+}
+
+void initAudio(void)
+{
+    Audio * global;
+    gDevice = (PrivateAudioDevice*)calloc(1, sizeof(PrivateAudioDevice));
+    gSoundCount = 0;
+
+    if(gDevice == NULL)
+    {
+        fprintf(stderr, "[%s: %d]Fatal Error: Memory c-allocation error\n", __FILE__, __LINE__);
+        return;
+    }
+
+    gDevice->audioEnabled = 0;
+
+    if(!(SDL_WasInit(SDL_INIT_AUDIO) & SDL_INIT_AUDIO))
+    {
+        fprintf(stderr, "[%s: %d]Error: SDL_INIT_AUDIO not initialized\n", __FILE__, __LINE__);
+        return;
+    }
+
+    SDL_memset(&(gDevice->want), 0, sizeof(gDevice->want));
+
+    (gDevice->want).freq = AUDIO_FREQUENCY;
+    (gDevice->want).format = AUDIO_FORMAT;
+    (gDevice->want).channels = AUDIO_CHANNELS;
+    (gDevice->want).samples = AUDIO_SAMPLES;
+    (gDevice->want).callback = audioCallback;
+    (gDevice->want).userdata = calloc(1, sizeof(Audio));
+
+    global = (Audio*)(gDevice->want).userdata;
+
+    if(global == NULL)
+    {
+        fprintf(stderr, "[%s: %d]Error: Memory allocation error\n", __FILE__, __LINE__);
+        return;
+    }
+
+    global->buffer = NULL;
+    global->next = NULL;
+
+    /* want.userdata = new; */
+    if((gDevice->device = SDL_OpenAudioDevice(NULL, 0, &(gDevice->want), NULL, SDL_AUDIO_ALLOW_CHANGES)) == 0)
+    {
+        fprintf(stderr, "[%s: %d]Warning: failed to open audio device: %s\n", __FILE__, __LINE__, SDL_GetError());
+    }
+    else
+    {
+        /* Set audio device enabled global flag */
+        gDevice->audioEnabled = 1;
+
+        /* Unpause active audio stream */
+        unpauseAudio();
+    }
+}
+
+void endAudio(void)
+{
+    if(gDevice->audioEnabled)
+    {
+        pauseAudio();
+
+        freeAudio((Audio *) (gDevice->want).userdata);
+
+        /* Close down audio */
+        SDL_CloseAudioDevice(gDevice->device);
+    }
+
+    free(gDevice);
+}
+
+void pauseAudio(void)
+{
+    if(gDevice->audioEnabled)
+    {
+        SDL_PauseAudioDevice(gDevice->device, 1);
+    }
+}
+
+void unpauseAudio(void)
+{
+    if(gDevice->audioEnabled)
+    {
+        SDL_PauseAudioDevice(gDevice->device, 0);
+    }
+}
+
+void freeAudio(Audio * audio)
+{
+    Audio * temp;
+
+    while(audio != NULL)
+    {
+        if(audio->free == 1)
+        {
+            SDL_FreeWAV(audio->bufferTrue);
+        }
+
+        temp = audio;
+        audio = audio->next;
+
+        free(temp);
+    }
+}
+
+Audio * createAudio(const char * filename, uint8_t loop, int volume)
+{
+    Audio * news = (Audio*)calloc(1, sizeof(Audio));
+
+    if(news == NULL)
+    {
+        fprintf(stderr, "[%s: %d]Error: Memory allocation error\n", __FILE__, __LINE__);
+        return NULL;
+    }
+
+    if(filename == NULL)
+    {
+        fprintf(stderr, "[%s: %d]Warning: filename NULL: %s\n", __FILE__, __LINE__, filename);
+        return NULL;
+    }
+
+    news->next = NULL;
+    news->loop = loop;
+    news->fade = 0;
+    news->free = 1;
+    news->volume = volume;
+
+    if(SDL_LoadWAV(filename, &(news->audio), &(news->bufferTrue), &(news->lengthTrue)) == NULL)
+    {
+        fprintf(stderr, "[%s: %d]Warning: failed to open wave file: %s error: %s\n", __FILE__, __LINE__, filename, SDL_GetError());
+        free(news);
+        return NULL;
+    }
+
+    news->buffer = news->bufferTrue;
+    news->length = news->lengthTrue;
+    (news->audio).callback = NULL;
+    (news->audio).userdata = NULL;
+
+    return news;
+}
+
+static inline void playAudio(const char * filename, Audio * audio, uint8_t loop, int volume)
+{
+    Audio * news;
+
+    /* Check if audio is enabled */
+    if(!gDevice->audioEnabled)
+    {
+        return;
+    }
+
+    /* If sound, check if under max number of sounds allowed, else don't play */
+    if(loop == 0)
+    {
+        if(gSoundCount >= AUDIO_MAX_SOUNDS)
+        {
+            return;
+        }
+        else
+        {
+            gSoundCount++;
+        }
+    }
+
+    /* Load from filename or from Memory */
+    if(filename != NULL)
+    {
+        /* Create new music sound with loop */
+        news = createAudio(filename, loop, volume);
+    }
+    else if(audio != NULL)
+    {
+        news = (Audio*)malloc(sizeof(Audio));
+
+        if(news == NULL)
+        {
+            fprintf(stderr, "[%s: %d]Fatal Error: Memory allocation error\n", __FILE__, __LINE__);
+            return;
+        }
+
+        memcpy(news, audio, sizeof(Audio));
+
+        news->volume = volume;
+        news->loop = loop;
+        news->free = 0;
+    }
+    else
+    {
+        fprintf(stderr, "[%s: %d]Warning: filename and Audio parameters NULL\n", __FILE__, __LINE__);
+        return;
+    }
+
+    /* Lock callback function */
+    SDL_LockAudioDevice(gDevice->device);
+
+    if(loop == 1)
+    {
+        addMusic((Audio *) (gDevice->want).userdata, news);
+    }
+    else
+    {
+        addAudio((Audio *) (gDevice->want).userdata, news);
+    }
+
+    SDL_UnlockAudioDevice(gDevice->device);
+
+}
+
+static void addMusic(Audio * root, Audio * news)
+{
+    uint8_t musicFound = 0;
+    Audio * rootNext = root->next;
+
+    /* Find any existing musics, 0, 1 or 2 and fade them out */
+    while(rootNext != NULL)
+    {
+        /* Phase out any current music */
+        if(rootNext->loop == 1 && rootNext->fade == 0)
+        {
+            if(musicFound)
+            {
+                rootNext->length = 0;
+                rootNext->volume = 0;
+            }
+
+            rootNext->fade = 1;
+        }
+        /* Set flag to remove any queued up music in favour of new music */
+        else if(rootNext->loop == 1 && rootNext->fade == 1)
+        {
+            musicFound = 1;
+        }
+
+        rootNext = rootNext->next;
+    }
+
+    addAudio(root, news);
+}
+
+static inline void audioCallback(void * userdata, uint8_t * stream, int len)
+{
+    Audio * audio = (Audio *) userdata;
+    Audio * previous = audio;
+    int tempLength;
+    uint8_t music = 0;
+
+    /* Silence the main buffer */
+    SDL_memset(stream, 0, len);
+
+    /* First one is place holder */
+    audio = audio->next;
+
+    while(audio != NULL)
+    {
+        if(audio->length > 0)
+        {
+            if(audio->fade == 1 && audio->loop == 1)
+            {
+                music = 1;
+
+                if(audio->volume > 0)
+                {
+                    audio->volume--;
+                }
+                else
+                {
+                    audio->length = 0;
+                }
+            }
+
+            if(music && audio->loop == 1 && audio->fade == 0)
+            {
+                tempLength = 0;
+            }
+            else
+            {
+                tempLength = ((uint32_t) len > audio->length) ? audio->length : (uint32_t) len;
+            }
+
+            SDL_MixAudioFormat(stream, audio->buffer, AUDIO_FORMAT, tempLength, audio->volume);
+
+            audio->buffer += tempLength;
+            audio->length -= tempLength;
+
+            previous = audio;
+            audio = audio->next;
+        }
+        else if(audio->loop == 1 && audio->fade == 0)
+        {
+            audio->buffer = audio->bufferTrue;
+            audio->length = audio->lengthTrue;
+        }
+        else
+        {
+            previous->next = audio->next;
+
+            if(audio->loop == 0)
+            {
+                gSoundCount--;
+            }
+
+            audio->next = NULL;
+            freeAudio(audio);
+
+            audio = previous->next;
+        }
+    }
+}
+
+static void addAudio(Audio * root, Audio * news)
+{
+    if(root == NULL)
+    {
+        return;
+    }
+
+    while(root->next != NULL)
+    {
+        root = root->next;
+    }
+
+    root->next = news;
+}
diff --git a/graphics/audio.h b/graphics/audio.h
new file mode 100644
index 0000000..55ddc8c
--- /dev/null
+++ b/graphics/audio.h
@@ -0,0 +1,143 @@
+/*
+ * Simple-SDL2-Audio
+ *
+ * Copyright 2016 Jake Besworth
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+/*
+ * audio.h
+ *
+ * All audio related functions go here
+ *
+ */
+#ifndef SIMPLE_AUDIO_
+#define SIMPLE_AUDIO_
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#include <SDL2/SDL.h>
+
+/*
+ * Queue structure for all loaded sounds
+ *
+ */
+typedef struct sound
+{
+    uint32_t length;
+    uint32_t lengthTrue;
+    uint8_t * bufferTrue;
+    uint8_t * buffer;
+    uint8_t loop;
+    uint8_t fade;
+    uint8_t free;
+    uint8_t volume;
+
+    SDL_AudioSpec audio;
+
+    struct sound * next;
+} Audio;
+
+/*
+ * Create a Audio object
+ *
+ * @param filename      Filename for the WAVE file to load
+ * @param loop          0 ends after playing once (sound), 1 repeats and fades when other music added (music)
+ * @param volume        Volume, read playSound()
+ *
+ * @return returns a new Audio or NULL on failure, you must call freeAudio() on return Audio
+ *
+ */
+Audio * createAudio(const char * filename, uint8_t loop, int volume);
+
+/*
+ * Frees as many chained Audios as given
+ *
+ * @param audio     Chain of sounds to free
+ *
+ */
+void freeAudio(Audio * audio);
+
+/*
+ * Play a wave file currently must be S16LE format 2 channel stereo
+ *
+ * @param filename      Filename to open, use getAbsolutePath
+ * @param volume        Volume 0 - 128. SDL_MIX_MAXVOLUME constant for max volume
+ *
+ */
+void playSound(const char * filename, int volume);
+
+/*
+ * Plays a new music, only 1 at a time plays
+ *
+ * @param filename      Filename of the WAVE file to load
+ * @param volume        Volume read playSound for moree
+ *
+ */
+void playMusic(const char * filename, int volume);
+
+/*
+ * Plays a sound from a createAudio object (clones), only 1 at a time plays
+ * Advantage to this method is no more disk reads, only once, data is stored and constantly reused
+ *
+ * @param audio         Audio object to clone and use
+ * @param volume        Volume read playSound for moree
+ *
+ */
+void playSoundFromMemory(Audio * audio, int volume);
+
+/*
+ * Plays a music from a createAudio object (clones), only 1 at a time plays
+ * Advantage to this method is no more disk reads, only once, data is stored and constantly reused
+ *
+ * @param audio         Audio object to clone and use
+ * @param volume        Volume read playSound for moree
+ *
+ */
+void playMusicFromMemory(Audio * audio, int volume);
+
+/*
+ * Free all audio related variables
+ * Note, this needs to be run even if initAudio fails, because it frees the global audio device
+ *
+ */
+void endAudio(void);
+
+/*
+ * Initialize Audio Variable
+ *
+ */
+void initAudio(void);
+
+/*
+ * Pause audio from playing
+ *
+ */
+void pauseAudio(void);
+
+/*
+ * Unpause audio from playing
+ *
+ */
+void unpauseAudio(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/graphics/commonshaders.h b/graphics/commonshaders.h
new file mode 100644
index 0000000..b5b423f
--- /dev/null
+++ b/graphics/commonshaders.h
@@ -0,0 +1,36 @@
+#pragma once
+
+const char* __PrimitivesVertexShader = R"(
+#version 120
+
+attribute vec4 coord;
+varying vec2 texcoord;
+uniform mat4 MV;
+uniform mat4 P;
+
+void main(void) {
+  gl_Position = P*MV*vec4(coord.xy, 0, 1);
+  texcoord = coord.zw;
+}
+)";
+
+
+const char* __SolidFragmentShader = R"(
+#version 120
+
+varying vec2 texcoord;
+uniform vec4 color1;
+uniform vec4 color2;
+uniform sampler2D tex;
+uniform int has_texture;
+uniform vec2 gradient;
+
+void main(void) {
+	vec4 color = mix( color1, color2, dot(texcoord,gradient));
+	vec4 tex_color = texture2D(tex, texcoord); 
+	if (has_texture>0)
+		gl_FragColor = color * tex_color;
+	else
+		gl_FragColor = color;
+}
+)";
diff --git a/graphics/fonts.cpp b/graphics/fonts.cpp
new file mode 100644
index 0000000..760e676
--- /dev/null
+++ b/graphics/fonts.cpp
@@ -0,0 +1,212 @@
+
+#include "fonts.h"
+#include <algorithm>
+#include "glm/gtc/matrix_transform.hpp"
+#include "glm/gtx/transform.hpp"
+
+#ifdef __APPLE__
+#define sggBindVertexArray glBindVertexArrayAPPLE
+#define sggGenVertexArrays glGenVertexArraysAPPLE
+#else
+#define sggBindVertexArray glBindVertexArray
+#define sggGenVertexArrays glGenVertexArrays
+#endif
+
+const char* __FontVertexShader = R"(
+#version 120
+
+attribute vec4 coord;
+varying vec2 texcoord;
+uniform mat4 projection;
+uniform mat4 modelview;
+
+void main(void) {
+  gl_Position = projection * modelview * vec4(coord.xy, 0, 1);
+  texcoord = coord.zw;
+}
+)";
+
+const char* __FontFragmentShader = R"(
+#version 120
+
+varying vec2 texcoord;
+uniform vec4 color1;
+uniform vec4 color2;
+uniform sampler2D tex;
+uniform vec2 gradient;
+
+void main(void) {
+	vec4 color = mix( color1, color2, dot(texcoord,gradient));
+	gl_FragColor = vec4(1, 1, 1, texture2D(tex, texcoord).r) * color;
+}
+)";
+
+
+
+bool FontLib::init()
+{
+	if (FT_Init_FreeType(&m_ft))
+	{
+		return false;
+	}
+	
+	glGetError();
+	const GLubyte * s = glewGetErrorString(glGetError());
+
+	m_font_shader = Shader(__FontVertexShader, __FontFragmentShader);
+		
+
+	if (!m_font_shader.init())
+		return false;
+	
+	unsigned int attrib_position = m_font_shader.getAttributeLocation("coord");
+		
+	sggGenVertexArrays(1, &m_font_vao);
+	sggBindVertexArray(m_font_vao);
+		
+	glGenBuffers(1, &m_font_vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, m_font_vbo);
+	glEnableVertexAttribArray(attrib_position); 
+	glVertexAttribPointer(attrib_position, 4, GL_FLOAT, GL_FALSE, 0, 0);
+
+	GLfloat box[4][4] = {
+		{ -1, 1    , 0, 0 },
+		{ 1, 1    , 1, 0 },
+		{ -1, -1, 0, 1 },
+		{ 1, -1, 1, 1 },
+	};
+	glBufferData(GL_ARRAY_BUFFER, sizeof box, box, GL_DYNAMIC_DRAW);
+
+	m_curr_font = m_fonts.end();
+
+	return true;
+}
+
+void FontLib::submitText(const TextRecord & text)
+{
+	m_content.push_back(text);
+}
+
+void FontLib::drawText(TextRecord entry)
+{
+	float x = 0.0f;  
+	float y = 0.0f;  
+	
+	const char *p;
+	if (m_curr_font == m_fonts.end())
+		return;
+	Font font = m_curr_font->second;
+	FT_GlyphSlot g = font.face->glyph;
+
+#ifndef __APPLE__
+	//glFrontFace(GL_CW);
+#endif
+	
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, font.font_tex);
+	static int c = 0;
+
+	m_font_shader.use();
+
+	m_font_shader["tex"] = 0;
+	
+	m_font_shader["color1"] = entry.color1;
+	m_font_shader["color2"] = (entry.use_gradient? entry.color2 : entry.color1);
+	m_font_shader["gradient"] = entry.gradient;
+	m_font_shader["projection"] = entry.proj;
+	   
+	for (p = entry.text.c_str(); *p; p++) {
+		if (FT_Load_Char(font.face, *p, FT_LOAD_RENDER))
+			continue;
+		
+		
+		glTexImage2D(
+			GL_TEXTURE_2D,
+			0,
+			GL_RED,
+			g->bitmap.width,
+			g->bitmap.rows,
+			0,
+			GL_RED,
+			GL_UNSIGNED_BYTE,
+			g->bitmap.buffer
+			);
+
+
+		float w = g->bitmap.width;
+		float h = g->bitmap.rows; 
+		w = entry.size.x * g->bitmap.width / (float)m_font_res;
+		h = entry.size.y * g->bitmap.rows / (float)m_font_res;
+		float b = g->metrics.horiBearingY/(64* (float)m_font_res)*entry.size.y - h;
+
+		GLfloat box[4][4] = {
+			{ x,     y-b    , 0, 1 },
+			{ x + w, y-b    , 1, 1 },
+			{ x,     y - h - b, 0, 0 },
+			{ x + w, y - h -b, 1, 0 },
+		};
+		
+		m_font_shader["modelview"] = glm::translate(glm::vec3(entry.pos.x, entry.pos.y, 0.0f)) * entry.mv;
+
+
+		sggBindVertexArray(m_font_vao);
+		glBindBuffer(GL_ARRAY_BUFFER, m_font_vbo);
+		glBufferData(GL_ARRAY_BUFFER, sizeof box, box, GL_DYNAMIC_DRAW);
+		
+		glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+		x += std::max(w+ entry.size.x*0.05f, entry.size.x*0.15f);
+		y += entry.size.y*1.1f*(g->advance.y);
+	}
+	
+	glBindTexture(GL_TEXTURE_2D, 0);
+	glFrontFace(GL_CCW);
+}
+
+void FontLib::commitText()
+{
+	m_font_shader.use();
+	glEnable(GL_SCISSOR_TEST);
+	for (auto item : m_content)
+	{
+		drawText(item);
+	}
+	m_content.clear();
+	
+}
+
+void FontLib::setCanvas(glm::vec2 sz)
+{
+	m_canvas = sz;
+}
+
+bool FontLib::setCurrentFont(std::string fontname)
+{
+	m_curr_font = m_fonts.find(fontname);
+	if (m_curr_font != m_fonts.end())
+		return true;
+
+	Font font;
+	if (FT_New_Face(m_ft, fontname.c_str(), 0, &font.face))
+	{
+		return false;
+	}
+	FT_Set_Pixel_Sizes(font.face, 0, m_font_res);
+
+	glActiveTexture(GL_TEXTURE0);
+	glGenTextures(1, &font.font_tex);
+	glBindTexture(GL_TEXTURE_2D, font.font_tex);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+
+	m_curr_font = m_fonts.insert(std::pair<std::string, Font>(fontname,font)).first;
+	return true;
+}
+
+
+
+FT_Library FontLib::m_ft = nullptr;
diff --git a/graphics/fonts.h b/graphics/fonts.h
new file mode 100644
index 0000000..2ddcd43
--- /dev/null
+++ b/graphics/fonts.h
@@ -0,0 +1,54 @@
+#pragma once
+#include <ft2build.h>
+#include FT_FREETYPE_H
+#include "GL/glew.h"
+#include "shader.h"
+#include <string>
+#include <vector>
+#include <unordered_map>
+
+struct Font
+{
+	std::string fontname;
+	FT_Face	face;
+	GLuint  font_tex;
+};
+
+struct TextRecord
+{
+	glm::vec2 pos;
+	glm::vec2 size;
+	std::string text;
+	glm::vec4 color1;
+	glm::vec4 color2;
+	glm::vec2 gradient;
+	bool use_gradient;
+	glm::mat4 mv;
+	glm::mat4 proj;
+};
+
+
+class FontLib
+{
+	static FT_Library	m_ft;
+	std::unordered_map<std::string, Font>::iterator m_curr_font;
+	std::unordered_map<std::string, Font> m_fonts;
+	Shader				m_font_shader;
+	GLuint				m_font_vbo;
+	GLuint				m_font_vao;
+	GLuint				m_font_res = 64;
+	std::vector<TextRecord> m_content;
+	
+	glm::vec2	  m_canvas;
+
+	void drawText(TextRecord entry);
+	
+public:
+	bool init();
+	void submitText(const TextRecord & text);
+	void commitText();
+	void setCanvas(glm::vec2 sz);
+	bool setCurrentFont(std::string fontname);
+	
+};
+
diff --git a/graphics/graphics.cpp b/graphics/graphics.cpp
new file mode 100644
index 0000000..d2a09e7
--- /dev/null
+++ b/graphics/graphics.cpp
@@ -0,0 +1,187 @@
+#include "graphics.h"
+#include "GLbackend.h"
+
+
+static graphics::GLBackend * engine = nullptr;
+
+namespace graphics
+{
+	float getDeltaTime()
+	{
+		return engine->getDeltaTime();
+	}
+
+	float getGlobalTime()
+	{
+		return engine->getGlobalTime();
+	}
+
+	void drawRect(float center_x, float center_y, float width, float height, const Brush & brush)
+	{
+		engine->drawRect(center_x, center_y, width, height, brush);
+	}
+
+	void drawLine(float x1, float y1, float x2, float y2, const Brush & brush)
+	{
+		engine->drawLine(x1, y1, x2, y2, brush);
+	}
+
+	bool setFont(std::string fontname)
+	{
+		return engine->setFont(fontname);
+	}
+
+	void drawText(float pos_x, float pos_y, float size, const std::string & text, const Brush & brush)
+	{
+		engine->drawText(pos_x, pos_y, size, text, brush);
+	}
+
+	void drawDisk(float x, float y, float radius, const Brush & brush)
+	{
+		engine->drawSector(x, y, 0, 360, 0.0f, radius, brush);
+	}
+
+	void drawSector(float cx, float cy, float radius1, float radius2, float start_angle, float end_angle, const Brush & brush)
+	{
+		engine->drawSector(cx, cy, start_angle, end_angle, radius1, radius2, brush);
+	}
+
+	void setOrientation(float angle)
+	{
+		engine->setOrientation(angle);
+	}
+
+	void setScale(float sx, float sy)
+	{
+		engine->setScale(sx, sy, 1.0f);
+	}
+
+	void resetPose()
+	{
+		engine->resetPose();
+	}
+
+	void playSound(std::string soundfile, float volume, bool looping)
+	{
+		engine->playSound(soundfile, volume, looping);
+	}
+
+	void stopMusic(int fade_time)
+	{
+		engine->stopMusic(fade_time);
+	}
+
+	void playMusic(std::string soundfile, float volume, bool looping, int fade_time )
+	{
+		engine->playMusic(soundfile, volume, looping, fade_time);
+	}
+
+	void createWindow(int width, int height, std::string title)
+	{
+		if (!engine)
+			engine = new GLBackend(width, height, title);
+		engine->init();
+		engine->show(true);
+	}
+
+	void setWindowBackground(Brush style)
+	{
+		engine->setBackgroundColor(style.fill_color[0], style.fill_color[1], style.fill_color[2]);
+	}
+
+	void destroyWindow()
+	{
+		engine->cleanup();
+		delete engine;
+		engine = nullptr;
+	}
+
+	void startMessageLoop()
+	{
+		bool running = true;
+		engine->draw();
+		while (running)
+		{
+			running = engine->processMessages();
+			
+		}
+	}
+
+	void setCanvasSize(float w, float h)
+	{
+		engine->setCanvasSize(w, h);
+	}
+
+	void setCanvasScaleMode(scale_mode_t sm)
+	{
+		engine->setCanvasMode((int)sm);
+	}
+
+	void setFullScreen(bool fs)
+	{
+		engine->setFullscreen(fs);
+	}
+
+	float windowToCanvasX(float x, bool clamped)
+	{
+		return engine->WindowToCanvasX(x, clamped);
+	}
+
+	float windowToCanvasY(float y, bool clamped)
+	{
+		return engine->WindowToCanvasY(y, clamped);
+	}
+
+	void setDrawFunction(std::function<void()> fdraw)
+	{
+		engine->setDrawCallback(fdraw);
+	}
+
+	void setUpdateFunction(std::function<void(float)> fupdate)
+	{
+		engine->setIdleCallback(fupdate);
+	}
+
+	void setResizeFunction(std::function<void(int, int)> fresize)
+	{
+		engine->setResizeCallback(fresize);
+	}
+
+	void setUserData(const void* user_data) {
+		engine->setUserData(user_data);
+	}
+
+	void* getUserData() {
+		return engine->getUserData();
+	}
+
+	void getMouseState(MouseState & ms)
+	{
+		ms.dragging = engine->isMouseDragging();
+		bool ba[3]; 
+		engine->getMouseButtonState(ba);
+		ms.button_left_down = ba[0];
+		ms.button_middle_down = ba[1];
+		ms.button_right_down = ba[2];
+		engine->getMouseButtonPressed(ba);
+		ms.button_left_pressed = ba[0];
+		ms.button_middle_pressed = ba[1];
+		ms.button_right_pressed = ba[2];
+		engine->getMouseButtonReleased(ba);
+		ms.button_left_released = ba[0];
+		ms.button_middle_released = ba[1];
+		ms.button_right_released = ba[2];
+		int x, y;
+		engine->getMousePosition(&x, &y);
+		ms.cur_pos_x = x;
+		ms.cur_pos_y = y;
+		engine->getPrevMousePosition(&x, &y);
+		ms.prev_pos_x = x;
+		ms.prev_pos_y = y;
+	}
+	bool getKeyState(scancode_t key)
+	{
+		return engine->getKeyState(key);
+	}
+}
+
diff --git a/graphics/graphics.h b/graphics/graphics.h
new file mode 100644
index 0000000..d10d198
--- /dev/null
+++ b/graphics/graphics.h
@@ -0,0 +1,742 @@
+#pragma once
+#include <string>
+#include <functional>
+#include "scancodes.h"
+
+/** \file graphics.h This is the *only* library header file that is required to be included by your application.
+	It contains the declaration of all SGG library functions and data structures.
+*/
+
+/** \namespace graphics includes all functions of the Simple Game Graphics library.
+*/
+namespace graphics
+{
+	/** The available modes for adapting the canvas to the application window.
+	*/
+	typedef enum {
+		CANVAS_SCALE_WINDOW = 0,
+		CANVAS_SCALE_STRETCH,
+		CANVAS_SCALE_FIT
+	}
+	scale_mode_t;
+
+	/** Encapsulates the superset of drawing attributes for all supported primitives and draw calls. These include 
+	    the primary fill color, the use of gradient fill or not, the secondary fill color and fill direction used 
+		by the gradient, a texture image to be blended with the underlying color, the outline color and width and 
+		the opacity for the fill and outline colors. The use of these attributes is demonstrated in the example 
+		image below:
+
+	    \image html brush1.jpg
+	*/
+	struct Brush
+	{
+		float fill_color[3] = {1.f,1.f,1.f};               ///< The primary fill color for shapes.
+														   ///<
+
+		float fill_secondary_color[3] = { 1.f,1.f,1.f };   ///< The fill color used as a secondary one when using a color gradient.
+														   ///<
+
+		float fill_opacity = 1.0f;                         ///< The opacity (1-transparency) of the primary fill color. A (maximum)
+														   ///< value of 1.0f means "fully opaque", while a value of 0.0f means 
+											               ///< fully transparent (invisible).
+		
+		float fill_secondary_opacity = 1.f;				   ///< The opacity of the second fill color, used for the gradient.
+														   ///<
+
+		float outline_color[3] = { 1.f,1.f,1.f };          ///< The color of the shape outline (where applicable). Most drawn
+														   ///< shapes, like disks, line segments and rectangles use this 
+														   ///< property to set the outline stroke color.
+
+		float outline_opacity = 1.f;                       ///< The opacity of the outline. Maximum value is 1.0f (fully opaque),
+														   ///< and the minimum value is 0.0f (fully transparent). 
+
+		float outline_width = 1.0f;						   ///< The stroke width in pixel units. Can accept fractional values. 
+														   ///< 
+
+		std::string texture = "";                          ///< The filename of a bitmap to project over and blend with the 
+														   ///< underlying color of the fill. The image is multiplicatively
+														   ///< combined with the entire fill motif, respecting also the opacity.
+														   ///< Currently, only PNG images are supported, with transparency. 
+														   ///< Images of arbitrary size are supported but are internally upscaled
+														   ///< to the nearest power of two in each dimension, using linear 
+														   ///< interpolation. The bitmap, regardless of its aspect ratio,
+														   ///< covers the entire shape end to end, according to its own 
+														   ///< parameterization. This means that a square image drawn on a non-square
+														   ///< rectangle will stretch the image. To avoid this, the drawn rectangle
+														   ///< should follow the aspect ratio of the image. By default, no image is 
+														   ///< used. When an image filename is provided, it is loaded once and 
+														   ///< internally cached for repeated use. 
+														   ///< 
+														   ///< Keep in mind that when using a bitmap on a drawable shape, the 
+														   ///< image parametric space (expressed as u,v coordinates in the image below)
+														   ///< is mapped to corresponding parameters of the underlying shape.
+														   ///< For example, for the disk shape, the horizontal axis of the image is 
+														   ///< mapped to the circumferance of the disk, while the height is mapped to
+														   ///< the disk radius. 
+														   ///< \image html uv.jpg
+
+		bool gradient = false;							   ///< Enables or disables the gradient fill of a shape.
+														   ///<
+
+		float gradient_dir_u = 0.0f;					   ///< The gradient by default uses the v dimension of the parametric shape.
+														   ///< In practice though, the calculation is as follows: s = u*gradient_dir_u + v*gradient_dir_v,
+														   ///< where s is the color mixing parameter, clamped to [0.0,1.0].
+														   ///< This means that we can change the linear parameters gradient_dir_u/v to bias the 
+														   ///< between the two parametric space axes. 
+														   ///< For example:
+														   ///< \image html gradient.jpg
+
+		float gradient_dir_v = 1.0f;					   ///< \see gradient_dir_u
+	};
+
+	/** Includes the state of the pointing device as polled by the message processing loop of the library. 
+	
+		This state can be polled using the getMouseState function. Typically, the mouse (and keyboard) events are
+		polled from within the update callback:
+
+		\code{.cpp}
+		graphics::MouseState mouse;
+		graphics::getMouseState(mouse);
+		if (mouse.button_left_pressed)
+		{
+			// call custom code here to respond to the left mouse button press.
+		}
+	    \endcode
+	*/
+	struct MouseState
+	{
+		bool button_left_pressed;	///< The left button went from an "depressed" state to a "pressed" one during the last poll cycle.
+		bool button_middle_pressed; ///< The middle button went from an "depressed" state to a "pressed" one during the last poll cycle.
+		bool button_right_pressed;  ///< The right went from an "depressed" state to a "pressed" one during the last poll cycle.
+		bool button_left_released;  ///< The left button went from an "pressed" state to a "released" one during the last poll cycle.
+		bool button_middle_released;///< The middle button went from an "pressed" state to a "released" one during the last poll cycle.
+		bool button_right_released; ///< The right button went from an "pressed" state to a "released" one during the last poll cycle.
+		bool button_left_down;		///< The left button is currently held down.
+		bool button_middle_down;	///< The middle button is currently held down.
+		bool button_right_down;	    ///< The right button is currently held down.
+		bool dragging;				///< The left button is currently held down and the cursor is moving.
+		int cur_pos_x;				///< The current x position in pixel units of the pointing device.
+		int cur_pos_y;				///< The current y position in pixel units of the pointing device.
+		int prev_pos_x;				///< The x position in pixel units of the pointing device in the previous update cycle.
+		int prev_pos_y;				///< The y position in pixel units of the pointing device in the previous update cycle.
+	};
+
+
+	/** \defgroup _WINDOW Window initialization and handling
+	* @{
+	*/
+	
+	/** Creates and shows a framed window with a title of specific dimensions.
+
+		This should be the first function call to the SGG API. Internally, it performs library initialization and graphics 
+		canvas allocation and displays the window.
+		
+		\param width is the window canvas width in pixel units.
+		\param height is the window canvas height in pixel units.
+		\param title is the title displayed on the window frame.
+	*/
+	void createWindow(int width, int height, std::string title);
+	
+	/** Sets the color to fill the background of the main window, including the area outside the drawing canvas extents.
+
+		The function can be called at any time (after creating a window). Typical use:
+
+	    \code{.cpp}
+		graphics::Brush br;
+		br.fill_color[0] = 0.2f;
+		br.fill_color[1] = 0.3f;
+		br.fill_color[2] = 0.6f;
+		graphics::setWindowBackground(br);
+		\endcode
+
+		\param style is the graphics::Brush structure defining the background color. Only the fill_color field is used.
+	*/
+	void setWindowBackground(Brush style);
+
+	/** Destroys the application window and clears all internal resources.
+
+	    This is typically the last SGG API call, before closing the application.
+	*/
+	void destroyWindow();
+
+	/** Starts the message pump loop of the application window.
+
+		The function processes all window and user interface events and is alos responsible for 
+		internally calling the draw callback defined by the user to refresh the visual content of the
+		window. The user also defines and provides an optional but typically present application state 
+		update function, where all input processing is performed along with time-dependent updates of the
+		application logic.
+
+	    The function should be called after all application initialization is done, including the 
+		setup of any callback functions to invoke upon the draw, state update and resizing events.
+		The function only returns when the application window signals a quit event or the ESC key
+		is pressed.
+
+		Typical usage:
+
+		\code{.cpp}
+		graphics::createWindow(960, 540, "Night of the Living Arkanoid");
+		graphics::setDrawFunction(draw);  // draw is a user-defined function 
+		                                  // that issues calls to the library's draw functions 
+										  // to paint the window canvas. 
+	    graphics::setUpdateFunction(update);  // update is a user-defined function to perform all 
+											  // user input polling and application state updates.
+
+		... // application initialization code.
+
+		graphics::startMessageLoop();
+		graphics::destroyWindow();
+		\endcode
+	*/
+	void startMessageLoop();
+
+	/** Defines the extents of the drawing canvas in the custom units used by the application.
+
+	    The function explicitly sets the desired width and height of the drawing canvas in the measurement units
+		used by the developer of the application, irrespectively of the actual window size and resolution. The 
+		contents of the drawing canvas are scaled to fit the window according to the modes available via the 
+		setCanvasScaleMode function. For example, the developer may define that the drawing canvas should be
+		30 X 20 application units (e.g. cm). The drawing canvas will be then scaled to correspond to the 
+		actual window client area, properly adapted to fill the window resolution. 
+
+		Please note that the canvas aspect ratio needs not correspond with the window aspect ratio. The fitting
+		is determined by the setCanvasScaleMode function, as mentioned above.
+
+		\param w is the canvas width in custom units.
+		\param h is the canvas height in custom units.
+	*/
+	void setCanvasSize(float w, float h);
+
+	/** Defines how the canvas scales to adapt to the actual window size. 
+
+		SGG supports 3 different modes of scaling the canvas to fit the window. The 3 modes are defined in the scale_mode_t enumeration.
+
+		\param sm is the scaling mode and is one of the following:
+
+		graphics::CANVAS_SCALE_WINDOW: The canvas size used for drawing corresponds to the current window size in pixel units. Custom canvas size 
+		provide via the setCanvasSize is ignored. Upon window size change, the canvas is adapted to be equal to the window client area 
+		resolution. This mode is useful if the graphics drawn must correspond to the specific image resolution of the window and should not
+		be dynamically scaled.
+
+		graphics::CANVAS_SCALE_STRETCH: The canvas is stretched to fill the entire window. When the aspect ratio of tyhe canvas as specified by the 
+		user does not match the window aspect ratio, the drawn contents will appear distorted (stretched or compressed).
+
+		 \image html resize2.jpg
+
+		graphics::CANVAS_SCALE_FIT: The canvas is scaled to maximally fit the window but its aspect ratio is not affected. This means that if there 
+		is an aspect ration mismatch between the canvas and the window, the canvas will leave equal gaps along the axis of mismatch 
+		(centered). The window background outside the canvas will be painted with the user-defined background color. The drawn contents 
+		of the canvas will be clipped at the borders of the canvas and will not cross over to the elastic guard space.
+		
+		\image html resize.jpg
+	
+	   	\see setWindowBackground
+		\see setCanvasSize
+	*/
+	void setCanvasScaleMode(scale_mode_t sm);
+	
+	/** Puts the application window in full screen mode.
+
+		This function must immediately follow the window creation, otherwise it may result in an unexpected behavior.
+
+		\param fs should be set to either true for full screen or false for windowed mode.
+	*/
+	void setFullScreen(bool fs);
+	
+	/** Converts the horizontal window coordinate of a point to the corresponding canvas coordinate.
+
+		This function is useful for translating window coordinates (e.g. from the MouseState reported position) to the canvas space.
+
+		\param x is the window x coordinate to convert.
+		\param clamped specifies whether the coordinates reported are clamped to the extents of the canvas.
+		\return the horizontal coordinate in canvas units.
+
+		\see windowToCanvasY
+	*/
+	float windowToCanvasX(float x, bool clamped = true);
+
+	/** Converts the vertical window coordinate of a point to the corresponding canvas coordinate.
+
+		This function is useful for translating window coordinates (e.g. from the MouseState reported position) to the canvas space.
+
+		\param y is the window y coordinate to convert.
+		\param clamped specifies whether the coordinates reported are clamped to the extents of the canvas.
+		\return the vertical coordinate in canvas units.
+
+		\see windowToCanvasX
+	*/
+	float windowToCanvasY(float y, bool clamped = true);
+
+	/** Specifies a user-provided pointer to be stored within the SGG Engine.
+
+	Typically, at the start of the application the user creates a class that holds the application's state. A pointer to this class can be passed to setUserData(). At any later point in the application's lifecycle, the stored pointer can be retrieved using getUserData(). This is very useful for retreiving application data during callbacks for update, draw and resize. 
+	
+	\param user_data is the pointer that the user wants to store within the SGG engine. This pointer can later be retrieved using getUserData(). 
+
+	\see getUserData
+
+	Potential usage:
+
+	\code{.cpp}
+	void resize(int new_w, int new_h)
+	{
+		...
+		Game* the_game = (Game*)graphics::getUserData();
+		...
+	}
+
+	void update(float ms)
+	{
+		...
+		Game* the_game = (Game*)graphics::getUserData();
+		...
+	}
+
+	void draw()
+	{
+		...
+		Game* the_game = (Game*)graphics::getUserData();
+		...
+	}
+
+	struct Game {
+		int data_a;
+		int data_b;
+		...
+		...
+	};
+
+	int main()
+	{
+		...
+		Game* the_game = new Game();
+
+		graphics::createWindow(960, 540, "Night of the Living Arkanoid");
+		graphics::setUserData(the_game);
+		...
+		return 0;
+	}
+	\endcode
+	*/
+	void setUserData(const void* user_data);
+
+	/** Returns the user-submitted pointer that was previously set with setUserData().
+
+	If the memory pointed to by the provided pointer is freed, the user should also be careful and use setUserData(nullptr) to avoid accessing invalid memory later.  
+
+	\return Returns the pointer that was previously submitted through setUserData(). The returned value is of type void*. The user is expected to know which the correct type is to cast it to. If no pointer was previously set, the function returns a nullptr.
+
+	\see setUserData
+
+	*/
+	void* getUserData();
+
+	/** @}*/
+
+	/** \defgroup _CALLBACK Callback setup
+	* @{
+	*/
+
+	/** Specifies a user-defined function to be called each time the window is to be redisplayed.
+
+		The custom draw function is the only one that should contain all SGG draw functions to be 
+		used for painting the contents of the canvas. Drawing occurs a) when a window size change is reported,
+		b) at predetermied and equally spaced intervals, triggered by the event processing loop of the SGG engine.
+
+		\param draw is the user-defined draw function passed. 
+
+		Typical usage:
+
+		\code{.cpp}
+		void draw()
+		{
+			the_game.render(); // here, "the_game" is a global static variable (class instance) of a custom
+							   // class that encapsulates the logic and state of a game.
+							   // We call its render() method to perform all relevant drawing.
+			
+			                   // In addition, here we also add some extra drawing commands on top.
+			graphics::Brush br;
+			graphics::drawLine(10.0f, 10.0f, 400.0f, 10.0f, br);
+		}
+
+		
+		void update(float ms)
+		{
+			... // update is a user-defined function to perform all
+			    // user input polling and application state updates.
+		}
+
+		int main()
+		{
+			graphics::createWindow(960, 540, "Night of the Living Arkanoid");
+			graphics::setDrawFunction(draw); 
+			graphics::setUpdateFunction(update);  
+
+			... // application initialization code.
+
+			graphics::startMessageLoop();
+			graphics::destroyWindow();
+			return 0;
+		}
+		\endcode
+	*/
+	void setDrawFunction(std::function<void()> draw);
+
+	/** Specifies a user-defined function to be called each time the state of the application needs to be updated.
+
+	This callback function is invoked a) when an input event is triggered in the event processing loop of the engine,
+	such as mouse state change or keyboard key press, b) at regularly timed intervals, so that time-dependent states
+	in the application (such as animations, collisions, simulations) may advance their values.
+
+	Typically, in the update callback function the developer places code for polling the input devices and using the 
+	time increment (passed as an argument) to update the application mechanics. Keep also in mind that the time increment 
+	passed in the callback is also globally available thoughout the code through the getDeltaTime() function.
+
+	\param update is the user-defined function passed. The callback function must accept a single parameter, the 
+	time passed in miliseconds from the last triggered update.
+
+	Typical usage:
+
+	\code{.cpp}
+	void draw()
+	{
+		... // includes all the draw calls for repainting the canvas.
+	}
+
+	bool toggle_help = false;
+
+	void update(float ms)
+	{
+		
+		the_game.update(); // here, "the_game" is a global static variable (class instance) of a custom
+						   // class that encapsulates the logic and state of a game.
+						   // We call its update() method to perform all relevant state changes in internal fields.
+						   // Please note here that the time increment ms is not passed to the update() method,
+						   // as it internally calls the graphics::getDeltaTime() itself for this purpose. 
+
+		// In addition, check whether the user pressed the F1 function key.
+		if (graphics::getKeyState(graphics::SCANCODE_F1))
+		{
+			// If pressed, toggle a global variable that enables the display of a help message overlay. 
+			toggle_help = !toggle_help;
+		}
+	}
+
+	int main()
+	{
+		graphics::createWindow(960, 540, "Night of the Living Arkanoid");
+		graphics::setDrawFunction(draw);
+		graphics::setUpdateFunction(update);
+		... // application initialization code.
+		graphics::startMessageLoop();
+		graphics::destroyWindow();
+		return 0;
+	}
+	\endcode
+	*/
+	void setUpdateFunction(std::function<void(float)> update );
+
+	/** Specifies a user-defined function to be called each time the window is resized.
+
+	Typically, there is no need to call this function in most situations, as the dimensions of the window and the drawing 
+	canvas are independent. Still, in some case, one may want to change what is displayed according to the available 
+	screen area, or adapt the aspect ratio of the canvas to match that of the host window. 
+
+	\param resize is the user-defined function passed. The callback function must accept two int parameters, the
+	new width and height of the window. 
+
+	Potential usage:
+
+	\code{.cpp}
+	void resize(int new_w, int new_h)
+	{
+		the_game.adjustCanvas(new_w, new_h); // here, "the_game" is a global static variable (class instance) of a custom
+						                     // class that encapsulates the logic and state of a game.
+						                     // We call its adjustCanvas() method here to rescale the canvas so that it 
+											 // matches the aspect ratio of the window. 
+		
+	}
+
+	int main()
+	{
+		...
+		graphics::createWindow(960, 540, "Night of the Living Arkanoid");
+		graphics::setResizeFunction(resize);
+		...
+		return 0;
+	}
+	\endcode
+	*/
+	void setResizeFunction(std::function<void(int, int)> resize);
+	/** @}*/
+
+	/** \defgroup _INPUT Input handling
+	* @{
+	*/
+	/** Polls the engine for the current state of the mouse.
+
+	    Stores in the user-provided MouseState record ms, the current status of all mouse events. For more information on what 
+		data can be obtained, see the MouseState structure. Typically, this function is used from within the update callback
+		of the application.
+
+		\param ms is the user-provided record to update with the current status of the mouse cursor button and higher-level information
+		such as mouse "dragging" and button "pressed / released".
+
+		\see MouseState
+		\see setUpdateFunction
+	*/
+	void getMouseState(MouseState & ms);
+
+
+	/** Polls the engine for the current state of a specific key.
+		
+		Since buttons can be queried individually, multiple pressed keys can be detected, by querying each one of them. The 
+		function shall return true if a button has been reported as pressed by a window event between the previous call to
+		the update function and the current call to getKeyState().
+
+		\param key is the scancode ID of the key to query. The available scancodes are listed in the [scancodes.h](@ref scancodes.h)  file.
+
+		\return true if the key is pressed, false otherwise.
+
+		\see setUpdateFunction
+	*/
+	bool getKeyState(scancode_t key);
+	/** @}*/
+
+	/** \defgroup _TIME Time reporting
+	* @{
+	*/
+
+	/** Returns the time passed from the previous engine state update.
+
+		The function reports the time passed in miliseconds between the current internal state update and the previous one.
+		If a user-defined update callback is provided, the time also corresponds to the interval between successive callback
+		invocations.
+
+		\return the time elapsed from the previous engine update (coinsides also with the "frame" update interval) in miliseconds.
+	*/
+	float getDeltaTime();
+
+	/** Reports the absolute application execution time.
+
+	    The time starts counting from the call to create the window. 
+
+		\return the elapsed time passed from the launch of the application window in miliseconds. 
+	*/
+	float getGlobalTime();
+	/** @}*/
+
+	/** \defgroup _GRAPHICS Graphics output
+	* @{
+	*/
+
+	/** Draws a rectangle.
+
+		Draws a rectangle of size width X height, centered at (center_x, center_y).
+		The shape outline and fill attributes are provided in the brush parameter. 
+
+		\param center_x is the x coordinate of the rectangle center in canvas units.
+		\param center_y is the y coordinate of the rectangle center in canvas units.
+		\param width is the horizontal size of the rectangle center in canvas units.
+		\param height is the vertical size of the rectangle center in canvas units.
+		\param brush specifies the drawing attributes to use for the outline and fill of the shape.
+
+		\see Brush
+	*/
+	void drawRect(float center_x, float center_y, float width, float height, const Brush & brush);
+
+	/** Draws a line segment.
+
+		Draws a linear segment between two points on the canvas.
+		The outline attributes are specified in the brush parameter.
+
+		\param x1 is the x coordinate of the first point in canvas units.
+		\param y1 is the y coordinate of the first point in canvas units.
+		\param x2 is the x coordinate of the second point in canvas units.
+		\param y2 is the y coordinate of the second point in canvas units.
+		\param brush specifies the drawing attributes to use for the outline and fill of the shape.
+
+		\see Brush
+	*/
+	void drawLine(float x1, float y1, float x2, float y2, const Brush & brush);
+
+	/** Draws a disk.
+
+		Draws a disk (or circle, if fill opacity is set to 0) of certain radius and centered at (cx, cy).
+		The outline and fill attributes are specified in the brush parameter.
+
+		\param cx is the x coordinate of the center of the disk in canvas units.
+		\param cy is the y coordinate of the center of the disk in canvas units.
+		\param radius is the radius of the disk in canvas units.
+		\param brush specifies the drawing attributes to use for the outline and fill of the shape.
+
+		\see Brush
+	*/
+	void drawDisk(float cx, float cy, float radius, const Brush & brush);
+
+	/** Draws a sector of a disk.
+
+		Draws a sector of a disk between an inner and outer radius and two angles. 
+		The outline and fill attributes are specified in the brush parameter.
+
+		\code{.cpp}
+		// In the draw callback function:
+		graphics::Brush br;
+		br.fill_color[0] = 1.0f;
+		br.fill_color[1] = 0.1f;
+		br.fill_color[2] = 0.0f;
+		br.fill_secondary_color[0] = 0.0f;
+		br.fill_secondary_color[1] = 0.2f;
+		br.fill_secondary_color[2] = 1.f;
+		br.gradient = true;
+		br.gradient_dir_u = 1.0f;
+		br.gradient_dir_v = 0.0f;
+
+		graphics::drawSector(20, 20, 5, 10, 0, 90, br);
+		\endcode
+
+		\image html sector.jpg
+
+		\param cx is the x coordinate of the center of the disk sector in canvas units.
+		\param cy is the y coordinate of the center of the disk sector in canvas units.
+		\param radius1 is the inner radius of the disk sector in canvas units.
+		\param radius2 is the outer radius of the disk sector in canvas units.
+	*/
+	void drawSector(float cx, float cy, float radius1, float radius2, float start_angle, float end_angle, const Brush & brush);
+
+	/** Sets the current font for text rendering.
+
+		Notifies the SGG engine to prepare and make current the font typeface in the filename supplied as argument. If the 
+		font is not already loaded into SGG, it loads the SGG and builds all necessary information for it. If the font name
+		supplied does not correspond to a valid path to a TrueType typeface, the operation is silently aborted and no font 
+		is loaded or made active for text rendering. After loading the font, it is made current and all subsequent text drawing
+		calls use this font for text rendering. If the font is already loaded into SGG, it is just made active for rendering. This 
+		operation does not incur any measurable overhead, as all resource allocation and convesion processes occur once, during the 
+		first call to load a specific font. 
+
+		\param fontname is a valid path to the filename of the TrueType font (.ttf extension) to use.
+
+		\return true if the operation was successful, false otherwise.
+
+		\see drawText
+	*/
+	bool setFont(std::string fontname);
+
+	/** Draws a string of text at a user-provided location on the canvas, using the current font.
+
+		The function displays the glyphs for the text provided, in a left-aligned manner. The coordinates
+		passed to the function correspond to the lower left corner of the text box and the height of the 
+		glyphs is indicated by the size parameter. If there is no active font (or the setFont function failed),
+		no text is drawn. 
+
+		\param pos_x is the horizontal coordinate of the lower left corner of the text in canvas units.
+		
+		\param pos_y is the vertical coordinate of the lower left corner of the text in canvas units.
+		
+		\param size is the glyph height of the text to be drawn.
+		
+		\param text is the string of text to display.
+		
+		\param brush contains the drawing attributes. Only the fill parameters of the provided brush are
+		used for drawing, including any gradient.
+
+	    \see setFont
+	*/
+	void drawText(float pos_x, float pos_y, float size, const std::string & text, const Brush & brush);
+	
+	/** Sets the current orientation that all subsequent draw calls will use for the displayed shapes.
+
+	    SGG maintains a current orientation (default value 0.0f - no rotation) according to which it 
+		displays the shape of draw calls. Once set, the orientation is respected by all subsequent
+		draw calls, until set to a new value or reset via a call to resetPose(). The rotation of the 
+		drawn shape in accordance with the orientation value occurs using a pivot point specific to
+		the drawn shape. For rectangles, disks and sections, the pivot point is their center. For 
+		text, it is the lower left corner of the text bounds. Line segments are not rotated, since
+		it is simpler to redefine their end-points.
+
+		\param angle is the angle of rotation for the shapes to draw in degrees. Positive angles correspond
+		to counter-clockwise rotations.
+	*/
+	void setOrientation(float angle);
+
+	/** Sets the current scale that all subsequent draw calls will use for the displayed shapes.
+
+		SGG maintains a current scale (default value 1.0f - no scaling) according to which it
+		displays the shape of draw calls. Once set, the scale is respected by all subsequent
+		draw calls, until set to a new value or reset via a call to resetPose(). 
+
+		The scaling is defined by two scaling factors, one for each dimension of the shape. Setting
+		an equal value for both parameters corresponds to a uniform scale (no distortion). 
+		Scaling factors greater than 1 mean shape magnification, while values less than 1 result in shrinking. 
+		Never set the scaling factor to 0.
+		
+		The change of scale of the
+		drawn shape along its X and Y dimension is performed prior to the rotation, using a pivot point specific to
+		the drawn shape. For rectangles, disks and sections, the pivot point is their center. For
+		text, it is the lower left corner of the text bounds. Line segments are not scaled, since
+		it is simpler to redefine their end-points.
+
+		\param sx is the scale factor along the local X axis of the shape. 1 means no scaling.
+
+		\param sy is the scale factor along the local Y axis of the shape. 1 means no scaling.
+	*/
+	void setScale(float sx, float sy);
+
+	/** Restores both the orientation and scaling to their default values for subsequent draw calls.
+	*/
+	void resetPose();
+	/** @}*/
+
+	/** \defgroup _AUDIO Audio output
+	* @{
+	*/
+
+	/** Plays a sound sample.
+
+	    The function plays a sound file provided in mp3, ogg or wav format at specified volume level, with the 
+		option to indefinately loop it. If the provided sound file is successfully loaded into memory, it is set to play 
+		immediately. The sound data are kept in memory, therefore future attempts to play the sample, do not 
+		reload the file. If the sound file is not found, no sound is played.
+
+		\param soundfile is the path to the file of the sound sample. WAV, MP3 or OGG file formats are supported.
+		
+		\param volume is the volume of the played sound sample with values in the range [0,1]
+
+		\param looping sets the sound to indefinately loop. Default value is false;
+	*/
+	void playSound(std::string soundfile, float volume, bool looping = false);
+
+	/** Starts playing an audio file as a stream.
+
+	    The function plays a sound file provided in mp3, ogg or wav format at specified volume level, with the 
+		option to indefinately loop it. The file is loaded in chunks, in order to support large audio files
+		and therefore, the function is suitable for reproducing large pieces of music. 
+		If the provided sound file is successfully loaded, it is set to play 
+		immediately. If the sound file is not found, no sound is played. There is also the option to set a 
+		fade in/out time for a smooth transition to a subsequent call to the function using a different sound.
+		The same fade effect applies to the beggining of the play cycle. Only one audio file can be
+		played as "music" at any one time. A subsequent call to playMusic, simply fades in a new audio stream
+		and eventually stops the currently played one.
+
+		\params soundfile is the music file to load in MP3, OGG or WAV format. 
+
+		\param volume is the volume of the played sound sample with values in the range [0,1]
+
+		\param looping sets the sound to indefinately loop. Default value is true;
+
+		\param fade_time is the fade-in/-out time for the audio file in miliseconds. Default value is 0.
+		
+	*/
+	void playMusic(std::string soundfile, float volume, bool looping = true, int fade_time = 0);
+
+	/** Stops any music that is being played.
+
+		This operation only applies to audio files played with the playMusic function. The function 
+		also takes as optional argument a fade-out time. 
+
+		\params fade_time is the fade-out time for the currently playing sound.
+	*/
+	void stopMusic(int fade_time = 0);
+	/** @}*/
+	
+}
\ No newline at end of file
diff --git a/graphics/lodepng.cpp b/graphics/lodepng.cpp
new file mode 100644
index 0000000..ee8cf33
--- /dev/null
+++ b/graphics/lodepng.cpp
@@ -0,0 +1,6410 @@
+/*
+LodePNG version 20200306
+
+Copyright (c) 2005-2020 Lode Vandevenne
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgment in the product documentation would be
+    appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution.
+*/
+
+/*
+The manual and changelog are in the header file "lodepng.h"
+Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C.
+*/
+
+#include "lodepng.h"
+
+#ifdef LODEPNG_COMPILE_DISK
+#include <limits.h> /* LONG_MAX */
+#include <stdio.h> /* file handling */
+#endif /* LODEPNG_COMPILE_DISK */
+
+#ifdef LODEPNG_COMPILE_ALLOCATORS
+#include <stdlib.h> /* allocations */
+#endif /* LODEPNG_COMPILE_ALLOCATORS */
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1310) /*Visual Studio: A few warning types are not desired here.*/
+#pragma warning( disable : 4244 ) /*implicit conversions: not warned by gcc -Wall -Wextra and requires too much casts*/
+#pragma warning( disable : 4996 ) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/
+#endif /*_MSC_VER */
+
+const char* LODEPNG_VERSION_STRING = "20200306";
+
+/*
+This source file is built up in the following large parts. The code sections
+with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way.
+-Tools for C and common code for PNG and Zlib
+-C Code for Zlib (huffman, deflate, ...)
+-C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...)
+-The C++ wrapper around all of the above
+*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // Tools for C, and common code for PNG and Zlib.                       // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*The malloc, realloc and free functions defined here with "lodepng_" in front
+of the name, so that you can easily change them to others related to your
+platform if needed. Everything else in the code calls these. Pass
+-DLODEPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out
+#define LODEPNG_COMPILE_ALLOCATORS in the header, to disable the ones here and
+define them in your own project's source files without needing to change
+lodepng source code. Don't forget to remove "static" if you copypaste them
+from here.*/
+
+#ifdef LODEPNG_COMPILE_ALLOCATORS
+static void* lodepng_malloc(size_t size) {
+#ifdef LODEPNG_MAX_ALLOC
+  if(size > LODEPNG_MAX_ALLOC) return 0;
+#endif
+  return malloc(size);
+}
+
+/* NOTE: when realloc returns NULL, it leaves the original memory untouched */
+static void* lodepng_realloc(void* ptr, size_t new_size) {
+#ifdef LODEPNG_MAX_ALLOC
+  if(new_size > LODEPNG_MAX_ALLOC) return 0;
+#endif
+  return realloc(ptr, new_size);
+}
+
+static void lodepng_free(void* ptr) {
+  free(ptr);
+}
+#else /*LODEPNG_COMPILE_ALLOCATORS*/
+/* TODO: support giving additional void* payload to the custom allocators */
+void* lodepng_malloc(size_t size);
+void* lodepng_realloc(void* ptr, size_t new_size);
+void lodepng_free(void* ptr);
+#endif /*LODEPNG_COMPILE_ALLOCATORS*/
+
+/* convince the compiler to inline a function, for use when this measurably improves performance */
+/* inline is not available in C90, but use it when supported by the compiler */
+#if (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)) || (defined(__cplusplus) && (__cplusplus >= 199711L))
+#define LODEPNG_INLINE inline
+#else
+#define LODEPNG_INLINE /* not available */
+#endif
+
+/* restrict is not available in C90, but use it when supported by the compiler */
+#if (defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))) ||\
+    (defined(_MSC_VER) && (_MSC_VER >= 1400)) || \
+    (defined(__WATCOMC__) && (__WATCOMC__ >= 1250) && !defined(__cplusplus))
+#define LODEPNG_RESTRICT __restrict
+#else
+#define LODEPNG_RESTRICT /* not available */
+#endif
+
+/* Replacements for C library functions such as memcpy and strlen, to support platforms
+where a full C library is not available. The compiler can recognize them and compile
+to something as fast. */
+
+static void lodepng_memcpy(void* LODEPNG_RESTRICT dst,
+                           const void* LODEPNG_RESTRICT src, size_t size) {
+  size_t i;
+  for(i = 0; i < size; i++) ((char*)dst)[i] = ((const char*)src)[i];
+}
+
+static void lodepng_memset(void* LODEPNG_RESTRICT dst,
+                           int value, size_t num) {
+  size_t i;
+  for(i = 0; i < num; i++) ((char*)dst)[i] = (char)value;
+}
+
+/* does not check memory out of bounds, do not use on untrusted data */
+static size_t lodepng_strlen(const char* a) {
+  const char* orig = a;
+  /* avoid warning about unused function in case of disabled COMPILE... macros */
+  (void)(&lodepng_strlen);
+  while(*a) a++;
+  return (size_t)(a - orig);
+}
+
+#define LODEPNG_MAX(a, b) (((a) > (b)) ? (a) : (b))
+#define LODEPNG_MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define LODEPNG_ABS(x) ((x) < 0 ? -(x) : (x))
+
+#if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_DECODER)
+/* Safely check if adding two integers will overflow (no undefined
+behavior, compiler removing the code, etc...) and output result. */
+static int lodepng_addofl(size_t a, size_t b, size_t* result) {
+  *result = a + b; /* Unsigned addition is well defined and safe in C90 */
+  return *result < a;
+}
+#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_DECODER)*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+/* Safely check if multiplying two integers will overflow (no undefined
+behavior, compiler removing the code, etc...) and output result. */
+static int lodepng_mulofl(size_t a, size_t b, size_t* result) {
+  *result = a * b; /* Unsigned multiplication is well defined and safe in C90 */
+  return (a != 0 && *result / a != b);
+}
+
+#ifdef LODEPNG_COMPILE_ZLIB
+/* Safely check if a + b > c, even if overflow could happen. */
+static int lodepng_gtofl(size_t a, size_t b, size_t c) {
+  size_t d;
+  if(lodepng_addofl(a, b, &d)) return 1;
+  return d > c;
+}
+#endif /*LODEPNG_COMPILE_ZLIB*/
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+
+/*
+Often in case of an error a value is assigned to a variable and then it breaks
+out of a loop (to go to the cleanup phase of a function). This macro does that.
+It makes the error handling code shorter and more readable.
+
+Example: if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83);
+*/
+#define CERROR_BREAK(errorvar, code){\
+  errorvar = code;\
+  break;\
+}
+
+/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/
+#define ERROR_BREAK(code) CERROR_BREAK(error, code)
+
+/*Set error var to the error code, and return it.*/
+#define CERROR_RETURN_ERROR(errorvar, code){\
+  errorvar = code;\
+  return code;\
+}
+
+/*Try the code, if it returns error, also return the error.*/
+#define CERROR_TRY_RETURN(call){\
+  unsigned error = call;\
+  if(error) return error;\
+}
+
+/*Set error var to the error code, and return from the void function.*/
+#define CERROR_RETURN(errorvar, code){\
+  errorvar = code;\
+  return;\
+}
+
+/*
+About uivector, ucvector and string:
+-All of them wrap dynamic arrays or text strings in a similar way.
+-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
+-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
+-They're not used in the interface, only internally in this file as static functions.
+-As with many other structs in this file, the init and cleanup functions serve as ctor and dtor.
+*/
+
+#ifdef LODEPNG_COMPILE_ZLIB
+#ifdef LODEPNG_COMPILE_ENCODER
+/*dynamic vector of unsigned ints*/
+typedef struct uivector {
+  unsigned* data;
+  size_t size; /*size in number of unsigned longs*/
+  size_t allocsize; /*allocated size in bytes*/
+} uivector;
+
+static void uivector_cleanup(void* p) {
+  ((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
+  lodepng_free(((uivector*)p)->data);
+  ((uivector*)p)->data = NULL;
+}
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_resize(uivector* p, size_t size) {
+  size_t allocsize = size * sizeof(unsigned);
+  if(allocsize > p->allocsize) {
+    size_t newsize = allocsize + (p->allocsize >> 1u);
+    void* data = lodepng_realloc(p->data, newsize);
+    if(data) {
+      p->allocsize = newsize;
+      p->data = (unsigned*)data;
+    }
+    else return 0; /*error: not enough memory*/
+  }
+  p->size = size;
+  return 1; /*success*/
+}
+
+static void uivector_init(uivector* p) {
+  p->data = NULL;
+  p->size = p->allocsize = 0;
+}
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_push_back(uivector* p, unsigned c) {
+  if(!uivector_resize(p, p->size + 1)) return 0;
+  p->data[p->size - 1] = c;
+  return 1;
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+/* /////////////////////////////////////////////////////////////////////////// */
+
+/*dynamic vector of unsigned chars*/
+typedef struct ucvector {
+  unsigned char* data;
+  size_t size; /*used size*/
+  size_t allocsize; /*allocated size*/
+} ucvector;
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned ucvector_resize(ucvector* p, size_t size) {
+  if(size > p->allocsize) {
+    size_t newsize = size + (p->allocsize >> 1u);
+    void* data = lodepng_realloc(p->data, newsize);
+    if(data) {
+      p->allocsize = newsize;
+      p->data = (unsigned char*)data;
+    }
+    else return 0; /*error: not enough memory*/
+  }
+  p->size = size;
+  return 1; /*success*/
+}
+
+static ucvector ucvector_init(unsigned char* buffer, size_t size) {
+  ucvector v;
+  v.data = buffer;
+  v.allocsize = v.size = size;
+  return v;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_PNG
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+
+/*free string pointer and set it to NULL*/
+static void string_cleanup(char** out) {
+  lodepng_free(*out);
+  *out = NULL;
+}
+
+static char* alloc_string_sized(const char* in, size_t insize) {
+  char* out = (char*)lodepng_malloc(insize + 1);
+  if(out) {
+    lodepng_memcpy(out, in, insize);
+    out[insize] = 0;
+  }
+  return out;
+}
+
+/* dynamically allocates a new string with a copy of the null terminated input text */
+static char* alloc_string(const char* in) {
+  return alloc_string_sized(in, lodepng_strlen(in));
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_PNG)
+static unsigned lodepng_read32bitInt(const unsigned char* buffer) {
+  return (((unsigned)buffer[0] << 24u) | ((unsigned)buffer[1] << 16u) |
+         ((unsigned)buffer[2] << 8u) | (unsigned)buffer[3]);
+}
+#endif /*defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_PNG)*/
+
+#if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)
+/*buffer must have at least 4 allocated bytes available*/
+static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) {
+  buffer[0] = (unsigned char)((value >> 24) & 0xff);
+  buffer[1] = (unsigned char)((value >> 16) & 0xff);
+  buffer[2] = (unsigned char)((value >>  8) & 0xff);
+  buffer[3] = (unsigned char)((value      ) & 0xff);
+}
+#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / File IO                                                                / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_DISK
+
+/* returns negative value on error. This should be pure C compatible, so no fstat. */
+static long lodepng_filesize(const char* filename) {
+  FILE* file;
+  long size;
+  file = fopen(filename, "rb");
+  if(!file) return -1;
+
+  if(fseek(file, 0, SEEK_END) != 0) {
+    fclose(file);
+    return -1;
+  }
+
+  size = ftell(file);
+  /* It may give LONG_MAX as directory size, this is invalid for us. */
+  if(size == LONG_MAX) size = -1;
+
+  fclose(file);
+  return size;
+}
+
+/* load file into buffer that already has the correct allocated size. Returns error code.*/
+static unsigned lodepng_buffer_file(unsigned char* out, size_t size, const char* filename) {
+  FILE* file;
+  size_t readsize;
+  file = fopen(filename, "rb");
+  if(!file) return 78;
+
+  readsize = fread(out, 1, size, file);
+  fclose(file);
+
+  if(readsize != size) return 78;
+  return 0;
+}
+
+unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) {
+  long size = lodepng_filesize(filename);
+  if(size < 0) return 78;
+  *outsize = (size_t)size;
+
+  *out = (unsigned char*)lodepng_malloc((size_t)size);
+  if(!(*out) && size > 0) return 83; /*the above malloc failed*/
+
+  return lodepng_buffer_file(*out, (size_t)size, filename);
+}
+
+/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
+unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename) {
+  FILE* file;
+  file = fopen(filename, "wb" );
+  if(!file) return 79;
+  fwrite(buffer, 1, buffersize, file);
+  fclose(file);
+  return 0;
+}
+
+#endif /*LODEPNG_COMPILE_DISK*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of common code and tools. Begin of Zlib related code.            // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ZLIB
+#ifdef LODEPNG_COMPILE_ENCODER
+
+typedef struct {
+  ucvector* data;
+  unsigned char bp; /*ok to overflow, indicates bit pos inside byte*/
+} LodePNGBitWriter;
+
+static void LodePNGBitWriter_init(LodePNGBitWriter* writer, ucvector* data) {
+  writer->data = data;
+  writer->bp = 0;
+}
+
+/*TODO: this ignores potential out of memory errors*/
+#define WRITEBIT(writer, bit){\
+  /* append new byte */\
+  if(((writer->bp) & 7u) == 0) {\
+    if(!ucvector_resize(writer->data, writer->data->size + 1)) return;\
+    writer->data->data[writer->data->size - 1] = 0;\
+  }\
+  (writer->data->data[writer->data->size - 1]) |= (bit << ((writer->bp) & 7u));\
+  ++writer->bp;\
+}
+
+/* LSB of value is written first, and LSB of bytes is used first */
+static void writeBits(LodePNGBitWriter* writer, unsigned value, size_t nbits) {
+  if(nbits == 1) { /* compiler should statically compile this case if nbits == 1 */
+    WRITEBIT(writer, value);
+  } else {
+    /* TODO: increase output size only once here rather than in each WRITEBIT */
+    size_t i;
+    for(i = 0; i != nbits; ++i) {
+      WRITEBIT(writer, (unsigned char)((value >> i) & 1));
+    }
+  }
+}
+
+/* This one is to use for adding huffman symbol, the value bits are written MSB first */
+static void writeBitsReversed(LodePNGBitWriter* writer, unsigned value, size_t nbits) {
+  size_t i;
+  for(i = 0; i != nbits; ++i) {
+    /* TODO: increase output size only once here rather than in each WRITEBIT */
+    WRITEBIT(writer, (unsigned char)((value >> (nbits - 1u - i)) & 1u));
+  }
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+typedef struct {
+  const unsigned char* data;
+  size_t size; /*size of data in bytes*/
+  size_t bitsize; /*size of data in bits, end of valid bp values, should be 8*size*/
+  size_t bp;
+  unsigned buffer; /*buffer for reading bits. NOTE: 'unsigned' must support at least 32 bits*/
+} LodePNGBitReader;
+
+/* data size argument is in bytes. Returns error if size too large causing overflow */
+static unsigned LodePNGBitReader_init(LodePNGBitReader* reader, const unsigned char* data, size_t size) {
+  size_t temp;
+  reader->data = data;
+  reader->size = size;
+  /* size in bits, return error if overflow (if size_t is 32 bit this supports up to 500MB)  */
+  if(lodepng_mulofl(size, 8u, &reader->bitsize)) return 105;
+  /*ensure incremented bp can be compared to bitsize without overflow even when it would be incremented 32 too much and
+  trying to ensure 32 more bits*/
+  if(lodepng_addofl(reader->bitsize, 64u, &temp)) return 105;
+  reader->bp = 0;
+  reader->buffer = 0;
+  return 0; /*ok*/
+}
+
+/*
+ensureBits functions:
+Ensures the reader can at least read nbits bits in one or more readBits calls,
+safely even if not enough bits are available.
+Returns 1 if there are enough bits available, 0 if not.
+*/
+
+/*See ensureBits documentation above. This one ensures exactly 1 bit */
+/*static unsigned ensureBits1(LodePNGBitReader* reader) {
+  if(reader->bp >= reader->bitsize) return 0;
+  reader->buffer = (unsigned)reader->data[reader->bp >> 3u] >> (reader->bp & 7u);
+  return 1;
+}*/
+
+/*See ensureBits documentation above. This one ensures up to 9 bits */
+static unsigned ensureBits9(LodePNGBitReader* reader, size_t nbits) {
+  size_t start = reader->bp >> 3u;
+  size_t size = reader->size;
+  if(start + 1u < size) {
+    reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u);
+    reader->buffer >>= (reader->bp & 7u);
+    return 1;
+  } else {
+    reader->buffer = 0;
+    if(start + 0u < size) reader->buffer |= reader->data[start + 0];
+    reader->buffer >>= (reader->bp & 7u);
+    return reader->bp + nbits <= reader->bitsize;
+  }
+}
+
+/*See ensureBits documentation above. This one ensures up to 17 bits */
+static unsigned ensureBits17(LodePNGBitReader* reader, size_t nbits) {
+  size_t start = reader->bp >> 3u;
+  size_t size = reader->size;
+  if(start + 2u < size) {
+    reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) |
+                     ((unsigned)reader->data[start + 2] << 16u);
+    reader->buffer >>= (reader->bp & 7u);
+    return 1;
+  } else {
+    reader->buffer = 0;
+    if(start + 0u < size) reader->buffer |= reader->data[start + 0];
+    if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
+    reader->buffer >>= (reader->bp & 7u);
+    return reader->bp + nbits <= reader->bitsize;
+  }
+}
+
+/*See ensureBits documentation above. This one ensures up to 25 bits */
+static LODEPNG_INLINE unsigned ensureBits25(LodePNGBitReader* reader, size_t nbits) {
+  size_t start = reader->bp >> 3u;
+  size_t size = reader->size;
+  if(start + 3u < size) {
+    reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) |
+                     ((unsigned)reader->data[start + 2] << 16u) | ((unsigned)reader->data[start + 3] << 24u);
+    reader->buffer >>= (reader->bp & 7u);
+    return 1;
+  } else {
+    reader->buffer = 0;
+    if(start + 0u < size) reader->buffer |= reader->data[start + 0];
+    if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
+    if(start + 2u < size) reader->buffer |= ((unsigned)reader->data[start + 2] << 16u);
+    reader->buffer >>= (reader->bp & 7u);
+    return reader->bp + nbits <= reader->bitsize;
+  }
+}
+
+/*See ensureBits documentation above. This one ensures up to 32 bits */
+static LODEPNG_INLINE unsigned ensureBits32(LodePNGBitReader* reader, size_t nbits) {
+  size_t start = reader->bp >> 3u;
+  size_t size = reader->size;
+  if(start + 4u < size) {
+    reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) |
+                     ((unsigned)reader->data[start + 2] << 16u) | ((unsigned)reader->data[start + 3] << 24u);
+    reader->buffer >>= (reader->bp & 7u);
+    reader->buffer |= (((unsigned)reader->data[start + 4] << 24u) << (8u - (reader->bp & 7u)));
+    return 1;
+  } else {
+    reader->buffer = 0;
+    if(start + 0u < size) reader->buffer |= reader->data[start + 0];
+    if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
+    if(start + 2u < size) reader->buffer |= ((unsigned)reader->data[start + 2] << 16u);
+    if(start + 3u < size) reader->buffer |= ((unsigned)reader->data[start + 3] << 24u);
+    reader->buffer >>= (reader->bp & 7u);
+    return reader->bp + nbits <= reader->bitsize;
+  }
+}
+
+/* Get bits without advancing the bit pointer. Must have enough bits available with ensureBits. Max nbits is 31. */
+static unsigned peekBits(LodePNGBitReader* reader, size_t nbits) {
+  /* The shift allows nbits to be only up to 31. */
+  return reader->buffer & ((1u << nbits) - 1u);
+}
+
+/* Must have enough bits available with ensureBits */
+static void advanceBits(LodePNGBitReader* reader, size_t nbits) {
+  reader->buffer >>= nbits;
+  reader->bp += nbits;
+}
+
+/* Must have enough bits available with ensureBits */
+static unsigned readBits(LodePNGBitReader* reader, size_t nbits) {
+  unsigned result = peekBits(reader, nbits);
+  advanceBits(reader, nbits);
+  return result;
+}
+
+/* Public for testing only. steps and result must have numsteps values. */
+unsigned lode_png_test_bitreader(const unsigned char* data, size_t size,
+                                 size_t numsteps, const size_t* steps, unsigned* result) {
+  size_t i;
+  LodePNGBitReader reader;
+  unsigned error = LodePNGBitReader_init(&reader, data, size);
+  if(error) return 0;
+  for(i = 0; i < numsteps; i++) {
+    size_t step = steps[i];
+    unsigned ok;
+    if(step > 25) ok = ensureBits32(&reader, step);
+    else if(step > 17) ok = ensureBits25(&reader, step);
+    else if(step > 9) ok = ensureBits17(&reader, step);
+    else ok = ensureBits9(&reader, step);
+    if(!ok) return 0;
+    result[i] = readBits(&reader, step);
+  }
+  return 1;
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+static unsigned reverseBits(unsigned bits, unsigned num) {
+  /*TODO: implement faster lookup table based version when needed*/
+  unsigned i, result = 0;
+  for(i = 0; i < num; i++) result |= ((bits >> (num - i - 1u)) & 1u) << i;
+  return result;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Deflate - Huffman                                                      / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#define FIRST_LENGTH_CODE_INDEX 257
+#define LAST_LENGTH_CODE_INDEX 285
+/*256 literals, the end code, some length codes, and 2 unused codes*/
+#define NUM_DEFLATE_CODE_SYMBOLS 288
+/*the distance codes have their own symbols, 30 used, 2 unused*/
+#define NUM_DISTANCE_SYMBOLS 32
+/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/
+#define NUM_CODE_LENGTH_CODES 19
+
+/*the base lengths represented by codes 257-285*/
+static const unsigned LENGTHBASE[29]
+  = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
+     67, 83, 99, 115, 131, 163, 195, 227, 258};
+
+/*the extra bits used by codes 257-285 (added to base length)*/
+static const unsigned LENGTHEXTRA[29]
+  = {0, 0, 0, 0, 0, 0, 0,  0,  1,  1,  1,  1,  2,  2,  2,  2,  3,  3,  3,  3,
+      4,  4,  4,   4,   5,   5,   5,   5,   0};
+
+/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/
+static const unsigned DISTANCEBASE[30]
+  = {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
+     769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
+
+/*the extra bits of backwards distances (added to base)*/
+static const unsigned DISTANCEEXTRA[30]
+  = {0, 0, 0, 0, 1, 1, 2,  2,  3,  3,  4,  4,  5,  5,   6,   6,   7,   7,   8,
+       8,    9,    9,   10,   10,   11,   11,   12,    12,    13,    13};
+
+/*the order in which "code length alphabet code lengths" are stored as specified by deflate, out of this the huffman
+tree of the dynamic huffman tree lengths is generated*/
+static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES]
+  = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+Huffman tree struct, containing multiple representations of the tree
+*/
+typedef struct HuffmanTree {
+  unsigned* codes; /*the huffman codes (bit patterns representing the symbols)*/
+  unsigned* lengths; /*the lengths of the huffman codes*/
+  unsigned maxbitlen; /*maximum number of bits a single code can get*/
+  unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
+  /* for reading only */
+  unsigned char* table_len; /*length of symbol from lookup table, or max length if secondary lookup needed*/
+  unsigned short* table_value; /*value of symbol from lookup table, or pointer to secondary table if needed*/
+} HuffmanTree;
+
+static void HuffmanTree_init(HuffmanTree* tree) {
+  tree->codes = 0;
+  tree->lengths = 0;
+  tree->table_len = 0;
+  tree->table_value = 0;
+}
+
+static void HuffmanTree_cleanup(HuffmanTree* tree) {
+  lodepng_free(tree->codes);
+  lodepng_free(tree->lengths);
+  lodepng_free(tree->table_len);
+  lodepng_free(tree->table_value);
+}
+
+/* amount of bits for first huffman table lookup (aka root bits), see HuffmanTree_makeTable and huffmanDecodeSymbol.*/
+/* values 8u and 9u work the fastest */
+#define FIRSTBITS 9u
+
+/* a symbol value too big to represent any valid symbol, to indicate reading disallowed huffman bits combination,
+which is possible in case of only 0 or 1 present symbols. */
+#define INVALIDSYMBOL 65535u
+
+/* make table for huffman decoding */
+static unsigned HuffmanTree_makeTable(HuffmanTree* tree) {
+  static const unsigned headsize = 1u << FIRSTBITS; /*size of the first table*/
+  static const unsigned mask = (1u << FIRSTBITS) /*headsize*/ - 1u;
+  size_t i, numpresent, pointer, size; /*total table size*/
+  unsigned* maxlens = (unsigned*)lodepng_malloc(headsize * sizeof(unsigned));
+  if(!maxlens) return 83; /*alloc fail*/
+
+  /* compute maxlens: max total bit length of symbols sharing prefix in the first table*/
+  lodepng_memset(maxlens, 0, headsize * sizeof(*maxlens));
+  for(i = 0; i < tree->numcodes; i++) {
+    unsigned symbol = tree->codes[i];
+    unsigned l = tree->lengths[i];
+    unsigned index;
+    if(l <= FIRSTBITS) continue; /*symbols that fit in first table don't increase secondary table size*/
+    /*get the FIRSTBITS MSBs, the MSBs of the symbol are encoded first. See later comment about the reversing*/
+    index = reverseBits(symbol >> (l - FIRSTBITS), FIRSTBITS);
+    maxlens[index] = LODEPNG_MAX(maxlens[index], l);
+  }
+  /* compute total table size: size of first table plus all secondary tables for symbols longer than FIRSTBITS */
+  size = headsize;
+  for(i = 0; i < headsize; ++i) {
+    unsigned l = maxlens[i];
+    if(l > FIRSTBITS) size += (1u << (l - FIRSTBITS));
+  }
+  tree->table_len = (unsigned char*)lodepng_malloc(size * sizeof(*tree->table_len));
+  tree->table_value = (unsigned short*)lodepng_malloc(size * sizeof(*tree->table_value));
+  if(!tree->table_len || !tree->table_value) {
+    lodepng_free(maxlens);
+    /* freeing tree->table values is done at a higher scope */
+    return 83; /*alloc fail*/
+  }
+  /*initialize with an invalid length to indicate unused entries*/
+  for(i = 0; i < size; ++i) tree->table_len[i] = 16;
+
+  /*fill in the first table for long symbols: max prefix size and pointer to secondary tables*/
+  pointer = headsize;
+  for(i = 0; i < headsize; ++i) {
+    unsigned l = maxlens[i];
+    if(l <= FIRSTBITS) continue;
+    tree->table_len[i] = l;
+    tree->table_value[i] = pointer;
+    pointer += (1u << (l - FIRSTBITS));
+  }
+  lodepng_free(maxlens);
+
+  /*fill in the first table for short symbols, or secondary table for long symbols*/
+  numpresent = 0;
+  for(i = 0; i < tree->numcodes; ++i) {
+    unsigned l = tree->lengths[i];
+    unsigned symbol = tree->codes[i]; /*the huffman bit pattern. i itself is the value.*/
+    /*reverse bits, because the huffman bits are given in MSB first order but the bit reader reads LSB first*/
+    unsigned reverse = reverseBits(symbol, l);
+    if(l == 0) continue;
+    numpresent++;
+
+    if(l <= FIRSTBITS) {
+      /*short symbol, fully in first table, replicated num times if l < FIRSTBITS*/
+      unsigned num = 1u << (FIRSTBITS - l);
+      unsigned j;
+      for(j = 0; j < num; ++j) {
+        /*bit reader will read the l bits of symbol first, the remaining FIRSTBITS - l bits go to the MSB's*/
+        unsigned index = reverse | (j << l);
+        if(tree->table_len[index] != 16) return 55; /*invalid tree: long symbol shares prefix with short symbol*/
+        tree->table_len[index] = l;
+        tree->table_value[index] = i;
+      }
+    } else {
+      /*long symbol, shares prefix with other long symbols in first lookup table, needs second lookup*/
+      /*the FIRSTBITS MSBs of the symbol are the first table index*/
+      unsigned index = reverse & mask;
+      unsigned maxlen = tree->table_len[index];
+      /*log2 of secondary table length, should be >= l - FIRSTBITS*/
+      unsigned tablelen = maxlen - FIRSTBITS;
+      unsigned start = tree->table_value[index]; /*starting index in secondary table*/
+      unsigned num = 1u << (tablelen - (l - FIRSTBITS)); /*amount of entries of this symbol in secondary table*/
+      unsigned j;
+      if(maxlen < l) return 55; /*invalid tree: long symbol shares prefix with short symbol*/
+      for(j = 0; j < num; ++j) {
+        unsigned reverse2 = reverse >> FIRSTBITS; /* l - FIRSTBITS bits */
+        unsigned index2 = start + (reverse2 | (j << (l - FIRSTBITS)));
+        tree->table_len[index2] = l;
+        tree->table_value[index2] = i;
+      }
+    }
+  }
+
+  if(numpresent < 2) {
+    /* In case of exactly 1 symbol, in theory the huffman symbol needs 0 bits,
+    but deflate uses 1 bit instead. In case of 0 symbols, no symbols can
+    appear at all, but such huffman tree could still exist (e.g. if distance
+    codes are never used). In both cases, not all symbols of the table will be
+    filled in. Fill them in with an invalid symbol value so returning them from
+    huffmanDecodeSymbol will cause error. */
+    for(i = 0; i < size; ++i) {
+      if(tree->table_len[i] == 16) {
+        /* As length, use a value smaller than FIRSTBITS for the head table,
+        and a value larger than FIRSTBITS for the secondary table, to ensure
+        valid behavior for advanceBits when reading this symbol. */
+        tree->table_len[i] = (i < headsize) ? 1 : (FIRSTBITS + 1);
+        tree->table_value[i] = INVALIDSYMBOL;
+      }
+    }
+  } else {
+    /* A good huffman tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
+    If that is not the case (due to too long length codes), the table will not
+    have been fully used, and this is an error (not all bit combinations can be
+    decoded): an oversubscribed huffman tree, indicated by error 55. */
+    for(i = 0; i < size; ++i) {
+      if(tree->table_len[i] == 16) return 55;
+    }
+  }
+
+  return 0;
+}
+
+/*
+Second step for the ...makeFromLengths and ...makeFromFrequencies functions.
+numcodes, lengths and maxbitlen must already be filled in correctly. return
+value is error.
+*/
+static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) {
+  unsigned* blcount;
+  unsigned* nextcode;
+  unsigned error = 0;
+  unsigned bits, n;
+
+  tree->codes = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned));
+  blcount = (unsigned*)lodepng_malloc((tree->maxbitlen + 1) * sizeof(unsigned));
+  nextcode = (unsigned*)lodepng_malloc((tree->maxbitlen + 1) * sizeof(unsigned));
+  if(!tree->codes || !blcount || !nextcode) error = 83; /*alloc fail*/
+
+  if(!error) {
+    for(n = 0; n != tree->maxbitlen + 1; n++) blcount[n] = nextcode[n] = 0;
+    /*step 1: count number of instances of each code length*/
+    for(bits = 0; bits != tree->numcodes; ++bits) ++blcount[tree->lengths[bits]];
+    /*step 2: generate the nextcode values*/
+    for(bits = 1; bits <= tree->maxbitlen; ++bits) {
+      nextcode[bits] = (nextcode[bits - 1] + blcount[bits - 1]) << 1u;
+    }
+    /*step 3: generate all the codes*/
+    for(n = 0; n != tree->numcodes; ++n) {
+      if(tree->lengths[n] != 0) {
+        tree->codes[n] = nextcode[tree->lengths[n]]++;
+        /*remove superfluous bits from the code*/
+        tree->codes[n] &= ((1u << tree->lengths[n]) - 1u);
+      }
+    }
+  }
+
+  lodepng_free(blcount);
+  lodepng_free(nextcode);
+
+  if(!error) error = HuffmanTree_makeTable(tree);
+  return error;
+}
+
+/*
+given the code lengths (as stored in the PNG file), generate the tree as defined
+by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
+return value is error.
+*/
+static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen,
+                                            size_t numcodes, unsigned maxbitlen) {
+  unsigned i;
+  tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned));
+  if(!tree->lengths) return 83; /*alloc fail*/
+  for(i = 0; i != numcodes; ++i) tree->lengths[i] = bitlen[i];
+  tree->numcodes = (unsigned)numcodes; /*number of symbols*/
+  tree->maxbitlen = maxbitlen;
+  return HuffmanTree_makeFromLengths2(tree);
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+/*BPM: Boundary Package Merge, see "A Fast and Space-Economical Algorithm for Length-Limited Coding",
+Jyrki Katajainen, Alistair Moffat, Andrew Turpin, 1995.*/
+
+/*chain node for boundary package merge*/
+typedef struct BPMNode {
+  int weight; /*the sum of all weights in this chain*/
+  unsigned index; /*index of this leaf node (called "count" in the paper)*/
+  struct BPMNode* tail; /*the next nodes in this chain (null if last)*/
+  int in_use;
+} BPMNode;
+
+/*lists of chains*/
+typedef struct BPMLists {
+  /*memory pool*/
+  unsigned memsize;
+  BPMNode* memory;
+  unsigned numfree;
+  unsigned nextfree;
+  BPMNode** freelist;
+  /*two heads of lookahead chains per list*/
+  unsigned listsize;
+  BPMNode** chains0;
+  BPMNode** chains1;
+} BPMLists;
+
+/*creates a new chain node with the given parameters, from the memory in the lists */
+static BPMNode* bpmnode_create(BPMLists* lists, int weight, unsigned index, BPMNode* tail) {
+  unsigned i;
+  BPMNode* result;
+
+  /*memory full, so garbage collect*/
+  if(lists->nextfree >= lists->numfree) {
+    /*mark only those that are in use*/
+    for(i = 0; i != lists->memsize; ++i) lists->memory[i].in_use = 0;
+    for(i = 0; i != lists->listsize; ++i) {
+      BPMNode* node;
+      for(node = lists->chains0[i]; node != 0; node = node->tail) node->in_use = 1;
+      for(node = lists->chains1[i]; node != 0; node = node->tail) node->in_use = 1;
+    }
+    /*collect those that are free*/
+    lists->numfree = 0;
+    for(i = 0; i != lists->memsize; ++i) {
+      if(!lists->memory[i].in_use) lists->freelist[lists->numfree++] = &lists->memory[i];
+    }
+    lists->nextfree = 0;
+  }
+
+  result = lists->freelist[lists->nextfree++];
+  result->weight = weight;
+  result->index = index;
+  result->tail = tail;
+  return result;
+}
+
+/*sort the leaves with stable mergesort*/
+static void bpmnode_sort(BPMNode* leaves, size_t num) {
+  BPMNode* mem = (BPMNode*)lodepng_malloc(sizeof(*leaves) * num);
+  size_t width, counter = 0;
+  for(width = 1; width < num; width *= 2) {
+    BPMNode* a = (counter & 1) ? mem : leaves;
+    BPMNode* b = (counter & 1) ? leaves : mem;
+    size_t p;
+    for(p = 0; p < num; p += 2 * width) {
+      size_t q = (p + width > num) ? num : (p + width);
+      size_t r = (p + 2 * width > num) ? num : (p + 2 * width);
+      size_t i = p, j = q, k;
+      for(k = p; k < r; k++) {
+        if(i < q && (j >= r || a[i].weight <= a[j].weight)) b[k] = a[i++];
+        else b[k] = a[j++];
+      }
+    }
+    counter++;
+  }
+  if(counter & 1) lodepng_memcpy(leaves, mem, sizeof(*leaves) * num);
+  lodepng_free(mem);
+}
+
+/*Boundary Package Merge step, numpresent is the amount of leaves, and c is the current chain.*/
+static void boundaryPM(BPMLists* lists, BPMNode* leaves, size_t numpresent, int c, int num) {
+  unsigned lastindex = lists->chains1[c]->index;
+
+  if(c == 0) {
+    if(lastindex >= numpresent) return;
+    lists->chains0[c] = lists->chains1[c];
+    lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, 0);
+  } else {
+    /*sum of the weights of the head nodes of the previous lookahead chains.*/
+    int sum = lists->chains0[c - 1]->weight + lists->chains1[c - 1]->weight;
+    lists->chains0[c] = lists->chains1[c];
+    if(lastindex < numpresent && sum > leaves[lastindex].weight) {
+      lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, lists->chains1[c]->tail);
+      return;
+    }
+    lists->chains1[c] = bpmnode_create(lists, sum, lastindex, lists->chains1[c - 1]);
+    /*in the end we are only interested in the chain of the last list, so no
+    need to recurse if we're at the last one (this gives measurable speedup)*/
+    if(num + 1 < (int)(2 * numpresent - 2)) {
+      boundaryPM(lists, leaves, numpresent, c - 1, num);
+      boundaryPM(lists, leaves, numpresent, c - 1, num);
+    }
+  }
+}
+
+unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
+                                      size_t numcodes, unsigned maxbitlen) {
+  unsigned error = 0;
+  unsigned i;
+  size_t numpresent = 0; /*number of symbols with non-zero frequency*/
+  BPMNode* leaves; /*the symbols, only those with > 0 frequency*/
+
+  if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
+  if((1u << maxbitlen) < (unsigned)numcodes) return 80; /*error: represent all symbols*/
+
+  leaves = (BPMNode*)lodepng_malloc(numcodes * sizeof(*leaves));
+  if(!leaves) return 83; /*alloc fail*/
+
+  for(i = 0; i != numcodes; ++i) {
+    if(frequencies[i] > 0) {
+      leaves[numpresent].weight = (int)frequencies[i];
+      leaves[numpresent].index = i;
+      ++numpresent;
+    }
+  }
+
+  lodepng_memset(lengths, 0, numcodes * sizeof(*lengths));
+
+  /*ensure at least two present symbols. There should be at least one symbol
+  according to RFC 1951 section 3.2.7. Some decoders incorrectly require two. To
+  make these work as well ensure there are at least two symbols. The
+  Package-Merge code below also doesn't work correctly if there's only one
+  symbol, it'd give it the theoretical 0 bits but in practice zlib wants 1 bit*/
+  if(numpresent == 0) {
+    lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/
+  } else if(numpresent == 1) {
+    lengths[leaves[0].index] = 1;
+    lengths[leaves[0].index == 0 ? 1 : 0] = 1;
+  } else {
+    BPMLists lists;
+    BPMNode* node;
+
+    bpmnode_sort(leaves, numpresent);
+
+    lists.listsize = maxbitlen;
+    lists.memsize = 2 * maxbitlen * (maxbitlen + 1);
+    lists.nextfree = 0;
+    lists.numfree = lists.memsize;
+    lists.memory = (BPMNode*)lodepng_malloc(lists.memsize * sizeof(*lists.memory));
+    lists.freelist = (BPMNode**)lodepng_malloc(lists.memsize * sizeof(BPMNode*));
+    lists.chains0 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*));
+    lists.chains1 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*));
+    if(!lists.memory || !lists.freelist || !lists.chains0 || !lists.chains1) error = 83; /*alloc fail*/
+
+    if(!error) {
+      for(i = 0; i != lists.memsize; ++i) lists.freelist[i] = &lists.memory[i];
+
+      bpmnode_create(&lists, leaves[0].weight, 1, 0);
+      bpmnode_create(&lists, leaves[1].weight, 2, 0);
+
+      for(i = 0; i != lists.listsize; ++i) {
+        lists.chains0[i] = &lists.memory[0];
+        lists.chains1[i] = &lists.memory[1];
+      }
+
+      /*each boundaryPM call adds one chain to the last list, and we need 2 * numpresent - 2 chains.*/
+      for(i = 2; i != 2 * numpresent - 2; ++i) boundaryPM(&lists, leaves, numpresent, (int)maxbitlen - 1, (int)i);
+
+      for(node = lists.chains1[maxbitlen - 1]; node; node = node->tail) {
+        for(i = 0; i != node->index; ++i) ++lengths[leaves[i].index];
+      }
+    }
+
+    lodepng_free(lists.memory);
+    lodepng_free(lists.freelist);
+    lodepng_free(lists.chains0);
+    lodepng_free(lists.chains1);
+  }
+
+  lodepng_free(leaves);
+  return error;
+}
+
+/*Create the Huffman tree given the symbol frequencies*/
+static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies,
+                                                size_t mincodes, size_t numcodes, unsigned maxbitlen) {
+  unsigned error = 0;
+  while(!frequencies[numcodes - 1] && numcodes > mincodes) --numcodes; /*trim zeroes*/
+  tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned));
+  if(!tree->lengths) return 83; /*alloc fail*/
+  tree->maxbitlen = maxbitlen;
+  tree->numcodes = (unsigned)numcodes; /*number of symbols*/
+
+  error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen);
+  if(!error) error = HuffmanTree_makeFromLengths2(tree);
+  return error;
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+/*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/
+static unsigned generateFixedLitLenTree(HuffmanTree* tree) {
+  unsigned i, error = 0;
+  unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
+  if(!bitlen) return 83; /*alloc fail*/
+
+  /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
+  for(i =   0; i <= 143; ++i) bitlen[i] = 8;
+  for(i = 144; i <= 255; ++i) bitlen[i] = 9;
+  for(i = 256; i <= 279; ++i) bitlen[i] = 7;
+  for(i = 280; i <= 287; ++i) bitlen[i] = 8;
+
+  error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15);
+
+  lodepng_free(bitlen);
+  return error;
+}
+
+/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
+static unsigned generateFixedDistanceTree(HuffmanTree* tree) {
+  unsigned i, error = 0;
+  unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
+  if(!bitlen) return 83; /*alloc fail*/
+
+  /*there are 32 distance codes, but 30-31 are unused*/
+  for(i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen[i] = 5;
+  error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15);
+
+  lodepng_free(bitlen);
+  return error;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+/*
+returns the code. The bit reader must already have been ensured at least 15 bits
+*/
+static unsigned huffmanDecodeSymbol(LodePNGBitReader* reader, const HuffmanTree* codetree) {
+  unsigned short code = peekBits(reader, FIRSTBITS);
+  unsigned short l = codetree->table_len[code];
+  unsigned short value = codetree->table_value[code];
+  if(l <= FIRSTBITS) {
+    advanceBits(reader, l);
+    return value;
+  } else {
+    unsigned index2;
+    advanceBits(reader, FIRSTBITS);
+    index2 = value + peekBits(reader, l - FIRSTBITS);
+    advanceBits(reader, codetree->table_len[index2] - FIRSTBITS);
+    return codetree->table_value[index2];
+  }
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Inflator (Decompressor)                                                / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*get the tree of a deflated block with fixed tree, as specified in the deflate specification
+Returns error code.*/
+static unsigned getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d) {
+  unsigned error = generateFixedLitLenTree(tree_ll);
+  if(error) return error;
+  return generateFixedDistanceTree(tree_d);
+}
+
+/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
+static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
+                                      LodePNGBitReader* reader) {
+  /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
+  unsigned error = 0;
+  unsigned n, HLIT, HDIST, HCLEN, i;
+
+  /*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
+  unsigned* bitlen_ll = 0; /*lit,len code lengths*/
+  unsigned* bitlen_d = 0; /*dist code lengths*/
+  /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
+  unsigned* bitlen_cl = 0;
+  HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
+
+  if(!ensureBits17(reader, 14)) return 49; /*error: the bit pointer is or will go past the memory*/
+
+  /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
+  HLIT =  readBits(reader, 5) + 257;
+  /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
+  HDIST = readBits(reader, 5) + 1;
+  /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
+  HCLEN = readBits(reader, 4) + 4;
+
+  bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned));
+  if(!bitlen_cl) return 83 /*alloc fail*/;
+
+  HuffmanTree_init(&tree_cl);
+
+  while(!error) {
+    /*read the code length codes out of 3 * (amount of code length codes) bits*/
+    if(lodepng_gtofl(reader->bp, HCLEN * 3, reader->bitsize)) {
+      ERROR_BREAK(50); /*error: the bit pointer is or will go past the memory*/
+    }
+    for(i = 0; i != HCLEN; ++i) {
+      ensureBits9(reader, 3); /*out of bounds already checked above */
+      bitlen_cl[CLCL_ORDER[i]] = readBits(reader, 3);
+    }
+    for(i = HCLEN; i != NUM_CODE_LENGTH_CODES; ++i) {
+      bitlen_cl[CLCL_ORDER[i]] = 0;
+    }
+
+    error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7);
+    if(error) break;
+
+    /*now we can use this tree to read the lengths for the tree that this function will return*/
+    bitlen_ll = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
+    bitlen_d = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
+    if(!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/);
+    lodepng_memset(bitlen_ll, 0, NUM_DEFLATE_CODE_SYMBOLS * sizeof(*bitlen_ll));
+    lodepng_memset(bitlen_d, 0, NUM_DISTANCE_SYMBOLS * sizeof(*bitlen_d));
+
+    /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
+    i = 0;
+    while(i < HLIT + HDIST) {
+      unsigned code;
+      ensureBits25(reader, 22); /* up to 15 bits for huffman code, up to 7 extra bits below*/
+      code = huffmanDecodeSymbol(reader, &tree_cl);
+      if(code <= 15) /*a length code*/ {
+        if(i < HLIT) bitlen_ll[i] = code;
+        else bitlen_d[i - HLIT] = code;
+        ++i;
+      } else if(code == 16) /*repeat previous*/ {
+        unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/
+        unsigned value; /*set value to the previous code*/
+
+        if(i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/
+
+        replength += readBits(reader, 2);
+
+        if(i < HLIT + 1) value = bitlen_ll[i - 1];
+        else value = bitlen_d[i - HLIT - 1];
+        /*repeat this value in the next lengths*/
+        for(n = 0; n < replength; ++n) {
+          if(i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/
+          if(i < HLIT) bitlen_ll[i] = value;
+          else bitlen_d[i - HLIT] = value;
+          ++i;
+        }
+      } else if(code == 17) /*repeat "0" 3-10 times*/ {
+        unsigned replength = 3; /*read in the bits that indicate repeat length*/
+        replength += readBits(reader, 3);
+
+        /*repeat this value in the next lengths*/
+        for(n = 0; n < replength; ++n) {
+          if(i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/
+
+          if(i < HLIT) bitlen_ll[i] = 0;
+          else bitlen_d[i - HLIT] = 0;
+          ++i;
+        }
+      } else if(code == 18) /*repeat "0" 11-138 times*/ {
+        unsigned replength = 11; /*read in the bits that indicate repeat length*/
+        replength += readBits(reader, 7);
+
+        /*repeat this value in the next lengths*/
+        for(n = 0; n < replength; ++n) {
+          if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/
+
+          if(i < HLIT) bitlen_ll[i] = 0;
+          else bitlen_d[i - HLIT] = 0;
+          ++i;
+        }
+      } else /*if(code == INVALIDSYMBOL)*/ {
+        ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
+      }
+      /*check if any of the ensureBits above went out of bounds*/
+      if(reader->bp > reader->bitsize) {
+        /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+        (10=no endcode, 11=wrong jump outside of tree)*/
+        /* TODO: revise error codes 10,11,50: the above comment is no longer valid */
+        ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+      }
+    }
+    if(error) break;
+
+    if(bitlen_ll[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/
+
+    /*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
+    error = HuffmanTree_makeFromLengths(tree_ll, bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 15);
+    if(error) break;
+    error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15);
+
+    break; /*end of error-while*/
+  }
+
+  lodepng_free(bitlen_cl);
+  lodepng_free(bitlen_ll);
+  lodepng_free(bitlen_d);
+  HuffmanTree_cleanup(&tree_cl);
+
+  return error;
+}
+
+/*inflate a block with dynamic of fixed Huffman tree. btype must be 1 or 2.*/
+static unsigned inflateHuffmanBlock(ucvector* out, LodePNGBitReader* reader,
+                                    unsigned btype) {
+  unsigned error = 0;
+  HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
+  HuffmanTree tree_d; /*the huffman tree for distance codes*/
+
+  HuffmanTree_init(&tree_ll);
+  HuffmanTree_init(&tree_d);
+
+  if(btype == 1) error = getTreeInflateFixed(&tree_ll, &tree_d);
+  else /*if(btype == 2)*/ error = getTreeInflateDynamic(&tree_ll, &tree_d, reader);
+
+  while(!error) /*decode all symbols until end reached, breaks at end code*/ {
+    /*code_ll is literal, length or end code*/
+    unsigned code_ll;
+    ensureBits25(reader, 20); /* up to 15 for the huffman symbol, up to 5 for the length extra bits */
+    code_ll = huffmanDecodeSymbol(reader, &tree_ll);
+    if(code_ll <= 255) /*literal symbol*/ {
+      if(!ucvector_resize(out, out->size + 1)) ERROR_BREAK(83 /*alloc fail*/);
+      out->data[out->size - 1] = (unsigned char)code_ll;
+    } else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/ {
+      unsigned code_d, distance;
+      unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/
+      size_t start, backward, length;
+
+      /*part 1: get length base*/
+      length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX];
+
+      /*part 2: get extra bits and add the value of that to length*/
+      numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX];
+      if(numextrabits_l != 0) {
+        /* bits already ensured above */
+        length += readBits(reader, numextrabits_l);
+      }
+
+      /*part 3: get distance code*/
+      ensureBits32(reader, 28); /* up to 15 for the huffman symbol, up to 13 for the extra bits */
+      code_d = huffmanDecodeSymbol(reader, &tree_d);
+      if(code_d > 29) {
+        if(code_d <= 31) {
+          ERROR_BREAK(18); /*error: invalid distance code (30-31 are never used)*/
+        } else /* if(code_d == INVALIDSYMBOL) */{
+          ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
+        }
+      }
+      distance = DISTANCEBASE[code_d];
+
+      /*part 4: get extra bits from distance*/
+      numextrabits_d = DISTANCEEXTRA[code_d];
+      if(numextrabits_d != 0) {
+        /* bits already ensured above */
+        distance += readBits(reader, numextrabits_d);
+      }
+
+      /*part 5: fill in all the out[n] values based on the length and dist*/
+      start = out->size;
+      if(distance > start) ERROR_BREAK(52); /*too long backward distance*/
+      backward = start - distance;
+
+      if(!ucvector_resize(out, out->size + length)) ERROR_BREAK(83 /*alloc fail*/);
+      if(distance < length) {
+        size_t forward;
+        lodepng_memcpy(out->data + start, out->data + backward, distance);
+        start += distance;
+        for(forward = distance; forward < length; ++forward) {
+          out->data[start++] = out->data[backward++];
+        }
+      } else {
+        lodepng_memcpy(out->data + start, out->data + backward, length);
+      }
+    } else if(code_ll == 256) {
+      break; /*end code, break the loop*/
+    } else /*if(code_ll == INVALIDSYMBOL)*/ {
+      ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
+    }
+    /*check if any of the ensureBits above went out of bounds*/
+    if(reader->bp > reader->bitsize) {
+      /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+      (10=no endcode, 11=wrong jump outside of tree)*/
+      /* TODO: revise error codes 10,11,50: the above comment is no longer valid */
+      ERROR_BREAK(51); /*error, bit pointer jumps past memory*/
+    }
+  }
+
+  HuffmanTree_cleanup(&tree_ll);
+  HuffmanTree_cleanup(&tree_d);
+
+  return error;
+}
+
+static unsigned inflateNoCompression(ucvector* out, LodePNGBitReader* reader,
+                                     const LodePNGDecompressSettings* settings) {
+  size_t bytepos;
+  size_t size = reader->size;
+  unsigned LEN, NLEN, error = 0;
+
+  /*go to first boundary of byte*/
+  bytepos = (reader->bp + 7u) >> 3u;
+
+  /*read LEN (2 bytes) and NLEN (2 bytes)*/
+  if(bytepos + 4 >= size) return 52; /*error, bit pointer will jump past memory*/
+  LEN = (unsigned)reader->data[bytepos] + ((unsigned)reader->data[bytepos + 1] << 8u); bytepos += 2;
+  NLEN = (unsigned)reader->data[bytepos] + ((unsigned)reader->data[bytepos + 1] << 8u); bytepos += 2;
+
+  /*check if 16-bit NLEN is really the one's complement of LEN*/
+  if(!settings->ignore_nlen && LEN + NLEN != 65535) {
+    return 21; /*error: NLEN is not one's complement of LEN*/
+  }
+
+  if(!ucvector_resize(out, out->size + LEN)) return 83; /*alloc fail*/
+
+  /*read the literal data: LEN bytes are now stored in the out buffer*/
+  if(bytepos + LEN > size) return 23; /*error: reading outside of in buffer*/
+
+  lodepng_memcpy(out->data + out->size - LEN, reader->data + bytepos, LEN);
+  bytepos += LEN;
+
+  reader->bp = bytepos << 3u;
+
+  return error;
+}
+
+static unsigned lodepng_inflatev(ucvector* out,
+                                 const unsigned char* in, size_t insize,
+                                 const LodePNGDecompressSettings* settings) {
+  unsigned BFINAL = 0;
+  LodePNGBitReader reader;
+  unsigned error = LodePNGBitReader_init(&reader, in, insize);
+
+  if(error) return error;
+
+  while(!BFINAL) {
+    unsigned BTYPE;
+    if(!ensureBits9(&reader, 3)) return 52; /*error, bit pointer will jump past memory*/
+    BFINAL = readBits(&reader, 1);
+    BTYPE = readBits(&reader, 2);
+
+    if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
+    else if(BTYPE == 0) error = inflateNoCompression(out, &reader, settings); /*no compression*/
+    else error = inflateHuffmanBlock(out, &reader, BTYPE); /*compression, BTYPE 01 or 10*/
+
+    if(error) return error;
+  }
+
+  return error;
+}
+
+unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
+                         const unsigned char* in, size_t insize,
+                         const LodePNGDecompressSettings* settings) {
+  ucvector v = ucvector_init(*out, *outsize);
+  unsigned error = lodepng_inflatev(&v, in, insize, settings);
+  *out = v.data;
+  *outsize = v.size;
+  return error;
+}
+
+static unsigned inflatev(ucvector* out, const unsigned char* in, size_t insize,
+                        const LodePNGDecompressSettings* settings) {
+  if(settings->custom_inflate) {
+    unsigned error = settings->custom_inflate(&out->data, &out->size, in, insize, settings);
+    out->allocsize = out->size;
+    return error;
+  } else {
+    return lodepng_inflatev(out, in, insize, settings);
+  }
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Deflator (Compressor)                                                  / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258;
+
+/*search the index in the array, that has the largest value smaller than or equal to the given value,
+given array must be sorted (if no value is smaller, it returns the size of the given array)*/
+static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value) {
+  /*binary search (only small gain over linear). TODO: use CPU log2 instruction for getting symbols instead*/
+  size_t left = 1;
+  size_t right = array_size - 1;
+
+  while(left <= right) {
+    size_t mid = (left + right) >> 1;
+    if(array[mid] >= value) right = mid - 1;
+    else left = mid + 1;
+  }
+  if(left >= array_size || array[left] > value) left--;
+  return left;
+}
+
+static void addLengthDistance(uivector* values, size_t length, size_t distance) {
+  /*values in encoded vector are those used by deflate:
+  0-255: literal bytes
+  256: end
+  257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits)
+  286-287: invalid*/
+
+  unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length);
+  unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]);
+  unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance);
+  unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]);
+
+  size_t pos = values->size;
+  /*TODO: return error when this fails (out of memory)*/
+  unsigned ok = uivector_resize(values, values->size + 4);
+  if(ok) {
+    values->data[pos + 0] = length_code + FIRST_LENGTH_CODE_INDEX;
+    values->data[pos + 1] = extra_length;
+    values->data[pos + 2] = dist_code;
+    values->data[pos + 3] = extra_distance;
+  }
+}
+
+/*3 bytes of data get encoded into two bytes. The hash cannot use more than 3
+bytes as input because 3 is the minimum match length for deflate*/
+static const unsigned HASH_NUM_VALUES = 65536;
+static const unsigned HASH_BIT_MASK = 65535; /*HASH_NUM_VALUES - 1, but C90 does not like that as initializer*/
+
+typedef struct Hash {
+  int* head; /*hash value to head circular pos - can be outdated if went around window*/
+  /*circular pos to prev circular pos*/
+  unsigned short* chain;
+  int* val; /*circular pos to hash value*/
+
+  /*TODO: do this not only for zeros but for any repeated byte. However for PNG
+  it's always going to be the zeros that dominate, so not important for PNG*/
+  int* headz; /*similar to head, but for chainz*/
+  unsigned short* chainz; /*those with same amount of zeros*/
+  unsigned short* zeros; /*length of zeros streak, used as a second hash chain*/
+} Hash;
+
+static unsigned hash_init(Hash* hash, unsigned windowsize) {
+  unsigned i;
+  hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES);
+  hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize);
+  hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
+
+  hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
+  hash->headz = (int*)lodepng_malloc(sizeof(int) * (MAX_SUPPORTED_DEFLATE_LENGTH + 1));
+  hash->chainz = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
+
+  if(!hash->head || !hash->chain || !hash->val  || !hash->headz|| !hash->chainz || !hash->zeros) {
+    return 83; /*alloc fail*/
+  }
+
+  /*initialize hash table*/
+  for(i = 0; i != HASH_NUM_VALUES; ++i) hash->head[i] = -1;
+  for(i = 0; i != windowsize; ++i) hash->val[i] = -1;
+  for(i = 0; i != windowsize; ++i) hash->chain[i] = i; /*same value as index indicates uninitialized*/
+
+  for(i = 0; i <= MAX_SUPPORTED_DEFLATE_LENGTH; ++i) hash->headz[i] = -1;
+  for(i = 0; i != windowsize; ++i) hash->chainz[i] = i; /*same value as index indicates uninitialized*/
+
+  return 0;
+}
+
+static void hash_cleanup(Hash* hash) {
+  lodepng_free(hash->head);
+  lodepng_free(hash->val);
+  lodepng_free(hash->chain);
+
+  lodepng_free(hash->zeros);
+  lodepng_free(hash->headz);
+  lodepng_free(hash->chainz);
+}
+
+
+
+static unsigned getHash(const unsigned char* data, size_t size, size_t pos) {
+  unsigned result = 0;
+  if(pos + 2 < size) {
+    /*A simple shift and xor hash is used. Since the data of PNGs is dominated
+    by zeroes due to the filters, a better hash does not have a significant
+    effect on speed in traversing the chain, and causes more time spend on
+    calculating the hash.*/
+    result ^= ((unsigned)data[pos + 0] << 0u);
+    result ^= ((unsigned)data[pos + 1] << 4u);
+    result ^= ((unsigned)data[pos + 2] << 8u);
+  } else {
+    size_t amount, i;
+    if(pos >= size) return 0;
+    amount = size - pos;
+    for(i = 0; i != amount; ++i) result ^= ((unsigned)data[pos + i] << (i * 8u));
+  }
+  return result & HASH_BIT_MASK;
+}
+
+static unsigned countZeros(const unsigned char* data, size_t size, size_t pos) {
+  const unsigned char* start = data + pos;
+  const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH;
+  if(end > data + size) end = data + size;
+  data = start;
+  while(data != end && *data == 0) ++data;
+  /*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/
+  return (unsigned)(data - start);
+}
+
+/*wpos = pos & (windowsize - 1)*/
+static void updateHashChain(Hash* hash, size_t wpos, unsigned hashval, unsigned short numzeros) {
+  hash->val[wpos] = (int)hashval;
+  if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval];
+  hash->head[hashval] = (int)wpos;
+
+  hash->zeros[wpos] = numzeros;
+  if(hash->headz[numzeros] != -1) hash->chainz[wpos] = hash->headz[numzeros];
+  hash->headz[numzeros] = (int)wpos;
+}
+
+/*
+LZ77-encode the data. Return value is error code. The input are raw bytes, the output
+is in the form of unsigned integers with codes representing for example literal bytes, or
+length/distance pairs.
+It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a
+sliding window (of windowsize) is used, and all past bytes in that window can be used as
+the "dictionary". A brute force search through all possible distances would be slow, and
+this hash technique is one out of several ways to speed this up.
+*/
+static unsigned encodeLZ77(uivector* out, Hash* hash,
+                           const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize,
+                           unsigned minmatch, unsigned nicematch, unsigned lazymatching) {
+  size_t pos;
+  unsigned i, error = 0;
+  /*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/
+  unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8u;
+  unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64;
+
+  unsigned usezeros = 1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/
+  unsigned numzeros = 0;
+
+  unsigned offset; /*the offset represents the distance in LZ77 terminology*/
+  unsigned length;
+  unsigned lazy = 0;
+  unsigned lazylength = 0, lazyoffset = 0;
+  unsigned hashval;
+  unsigned current_offset, current_length;
+  unsigned prev_offset;
+  const unsigned char *lastptr, *foreptr, *backptr;
+  unsigned hashpos;
+
+  if(windowsize == 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/
+  if((windowsize & (windowsize - 1)) != 0) return 90; /*error: must be power of two*/
+
+  if(nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH;
+
+  for(pos = inpos; pos < insize; ++pos) {
+    size_t wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/
+    unsigned chainlength = 0;
+
+    hashval = getHash(in, insize, pos);
+
+    if(usezeros && hashval == 0) {
+      if(numzeros == 0) numzeros = countZeros(in, insize, pos);
+      else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros;
+    } else {
+      numzeros = 0;
+    }
+
+    updateHashChain(hash, wpos, hashval, numzeros);
+
+    /*the length and offset found for the current position*/
+    length = 0;
+    offset = 0;
+
+    hashpos = hash->chain[wpos];
+
+    lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH];
+
+    /*search for the longest string*/
+    prev_offset = 0;
+    for(;;) {
+      if(chainlength++ >= maxchainlength) break;
+      current_offset = (unsigned)(hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize);
+
+      if(current_offset < prev_offset) break; /*stop when went completely around the circular buffer*/
+      prev_offset = current_offset;
+      if(current_offset > 0) {
+        /*test the next characters*/
+        foreptr = &in[pos];
+        backptr = &in[pos - current_offset];
+
+        /*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/
+        if(numzeros >= 3) {
+          unsigned skip = hash->zeros[hashpos];
+          if(skip > numzeros) skip = numzeros;
+          backptr += skip;
+          foreptr += skip;
+        }
+
+        while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/ {
+          ++backptr;
+          ++foreptr;
+        }
+        current_length = (unsigned)(foreptr - &in[pos]);
+
+        if(current_length > length) {
+          length = current_length; /*the longest length*/
+          offset = current_offset; /*the offset that is related to this longest length*/
+          /*jump out once a length of max length is found (speed gain). This also jumps
+          out if length is MAX_SUPPORTED_DEFLATE_LENGTH*/
+          if(current_length >= nicematch) break;
+        }
+      }
+
+      if(hashpos == hash->chain[hashpos]) break;
+
+      if(numzeros >= 3 && length > numzeros) {
+        hashpos = hash->chainz[hashpos];
+        if(hash->zeros[hashpos] != numzeros) break;
+      } else {
+        hashpos = hash->chain[hashpos];
+        /*outdated hash value, happens if particular value was not encountered in whole last window*/
+        if(hash->val[hashpos] != (int)hashval) break;
+      }
+    }
+
+    if(lazymatching) {
+      if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH) {
+        lazy = 1;
+        lazylength = length;
+        lazyoffset = offset;
+        continue; /*try the next byte*/
+      }
+      if(lazy) {
+        lazy = 0;
+        if(pos == 0) ERROR_BREAK(81);
+        if(length > lazylength + 1) {
+          /*push the previous character as literal*/
+          if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/);
+        } else {
+          length = lazylength;
+          offset = lazyoffset;
+          hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/
+          hash->headz[numzeros] = -1; /*idem*/
+          --pos;
+        }
+      }
+    }
+    if(length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/);
+
+    /*encode it as length/distance pair or literal value*/
+    if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ {
+      if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
+    } else if(length < minmatch || (length == 3 && offset > 4096)) {
+      /*compensate for the fact that longer offsets have more extra bits, a
+      length of only 3 may be not worth it then*/
+      if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
+    } else {
+      addLengthDistance(out, length, offset);
+      for(i = 1; i < length; ++i) {
+        ++pos;
+        wpos = pos & (windowsize - 1);
+        hashval = getHash(in, insize, pos);
+        if(usezeros && hashval == 0) {
+          if(numzeros == 0) numzeros = countZeros(in, insize, pos);
+          else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros;
+        } else {
+          numzeros = 0;
+        }
+        updateHashChain(hash, wpos, hashval, numzeros);
+      }
+    }
+  } /*end of the loop through each character of input*/
+
+  return error;
+}
+
+/* /////////////////////////////////////////////////////////////////////////// */
+
+static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize) {
+  /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte,
+  2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
+
+  size_t i, numdeflateblocks = (datasize + 65534u) / 65535u;
+  unsigned datapos = 0;
+  for(i = 0; i != numdeflateblocks; ++i) {
+    unsigned BFINAL, BTYPE, LEN, NLEN;
+    unsigned char firstbyte;
+    size_t pos = out->size;
+
+    BFINAL = (i == numdeflateblocks - 1);
+    BTYPE = 0;
+
+    LEN = 65535;
+    if(datasize - datapos < 65535u) LEN = (unsigned)datasize - datapos;
+    NLEN = 65535 - LEN;
+
+    if(!ucvector_resize(out, out->size + LEN + 5)) return 83; /*alloc fail*/
+
+    firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1u) << 1u) + ((BTYPE & 2u) << 1u));
+    out->data[pos + 0] = firstbyte;
+    out->data[pos + 1] = (unsigned char)(LEN & 255);
+    out->data[pos + 2] = (unsigned char)(LEN >> 8u);
+    out->data[pos + 3] = (unsigned char)(NLEN & 255);
+    out->data[pos + 4] = (unsigned char)(NLEN >> 8u);
+    lodepng_memcpy(out->data + pos + 5, data + datapos, LEN);
+    datapos += LEN;
+  }
+
+  return 0;
+}
+
+/*
+write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees.
+tree_ll: the tree for lit and len codes.
+tree_d: the tree for distance codes.
+*/
+static void writeLZ77data(LodePNGBitWriter* writer, const uivector* lz77_encoded,
+                          const HuffmanTree* tree_ll, const HuffmanTree* tree_d) {
+  size_t i = 0;
+  for(i = 0; i != lz77_encoded->size; ++i) {
+    unsigned val = lz77_encoded->data[i];
+    writeBitsReversed(writer, tree_ll->codes[val], tree_ll->lengths[val]);
+    if(val > 256) /*for a length code, 3 more things have to be added*/ {
+      unsigned length_index = val - FIRST_LENGTH_CODE_INDEX;
+      unsigned n_length_extra_bits = LENGTHEXTRA[length_index];
+      unsigned length_extra_bits = lz77_encoded->data[++i];
+
+      unsigned distance_code = lz77_encoded->data[++i];
+
+      unsigned distance_index = distance_code;
+      unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index];
+      unsigned distance_extra_bits = lz77_encoded->data[++i];
+
+      writeBits(writer, length_extra_bits, n_length_extra_bits);
+      writeBitsReversed(writer, tree_d->codes[distance_code], tree_d->lengths[distance_code]);
+      writeBits(writer, distance_extra_bits, n_distance_extra_bits);
+    }
+  }
+}
+
+/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
+static unsigned deflateDynamic(LodePNGBitWriter* writer, Hash* hash,
+                               const unsigned char* data, size_t datapos, size_t dataend,
+                               const LodePNGCompressSettings* settings, unsigned final) {
+  unsigned error = 0;
+
+  /*
+  A block is compressed as follows: The PNG data is lz77 encoded, resulting in
+  literal bytes and length/distance pairs. This is then huffman compressed with
+  two huffman trees. One huffman tree is used for the lit and len values ("ll"),
+  another huffman tree is used for the dist values ("d"). These two trees are
+  stored using their code lengths, and to compress even more these code lengths
+  are also run-length encoded and huffman compressed. This gives a huffman tree
+  of code lengths "cl". The code lengths used to describe this third tree are
+  the code length code lengths ("clcl").
+  */
+
+  /*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/
+  uivector lz77_encoded;
+  HuffmanTree tree_ll; /*tree for lit,len values*/
+  HuffmanTree tree_d; /*tree for distance codes*/
+  HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/
+  unsigned* frequencies_ll = 0; /*frequency of lit,len codes*/
+  unsigned* frequencies_d = 0; /*frequency of dist codes*/
+  unsigned* frequencies_cl = 0; /*frequency of code length codes*/
+  unsigned* bitlen_lld = 0; /*lit,len,dist code lengths (int bits), literally (without repeat codes).*/
+  unsigned* bitlen_lld_e = 0; /*bitlen_lld encoded with repeat codes (this is a rudimentary run length compression)*/
+  size_t datasize = dataend - datapos;
+
+  /*
+  If we could call "bitlen_cl" the the code length code lengths ("clcl"), that is the bit lengths of codes to represent
+  tree_cl in CLCL_ORDER, then due to the huffman compression of huffman tree representations ("two levels"), there are
+  some analogies:
+  bitlen_lld is to tree_cl what data is to tree_ll and tree_d.
+  bitlen_lld_e is to bitlen_lld what lz77_encoded is to data.
+  bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded.
+  */
+
+  unsigned BFINAL = final;
+  size_t i;
+  size_t numcodes_ll, numcodes_d, numcodes_lld, numcodes_lld_e, numcodes_cl;
+  unsigned HLIT, HDIST, HCLEN;
+
+  uivector_init(&lz77_encoded);
+  HuffmanTree_init(&tree_ll);
+  HuffmanTree_init(&tree_d);
+  HuffmanTree_init(&tree_cl);
+  /* could fit on stack, but >1KB is on the larger side so allocate instead */
+  frequencies_ll = (unsigned*)lodepng_malloc(286 * sizeof(*frequencies_ll));
+  frequencies_d = (unsigned*)lodepng_malloc(30 * sizeof(*frequencies_d));
+  frequencies_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(*frequencies_cl));
+
+  if(!frequencies_ll || !frequencies_d || !frequencies_cl) error = 83; /*alloc fail*/
+
+  /*This while loop never loops due to a break at the end, it is here to
+  allow breaking out of it to the cleanup phase on error conditions.*/
+  while(!error) {
+    lodepng_memset(frequencies_ll, 0, 286 * sizeof(*frequencies_ll));
+    lodepng_memset(frequencies_d, 0, 30 * sizeof(*frequencies_d));
+    lodepng_memset(frequencies_cl, 0, NUM_CODE_LENGTH_CODES * sizeof(*frequencies_cl));
+
+    if(settings->use_lz77) {
+      error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
+                         settings->minmatch, settings->nicematch, settings->lazymatching);
+      if(error) break;
+    } else {
+      if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/);
+      for(i = datapos; i < dataend; ++i) lz77_encoded.data[i - datapos] = data[i]; /*no LZ77, but still will be Huffman compressed*/
+    }
+
+    /*Count the frequencies of lit, len and dist codes*/
+    for(i = 0; i != lz77_encoded.size; ++i) {
+      unsigned symbol = lz77_encoded.data[i];
+      ++frequencies_ll[symbol];
+      if(symbol > 256) {
+        unsigned dist = lz77_encoded.data[i + 2];
+        ++frequencies_d[dist];
+        i += 3;
+      }
+    }
+    frequencies_ll[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
+
+    /*Make both huffman trees, one for the lit and len codes, one for the dist codes*/
+    error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll, 257, 286, 15);
+    if(error) break;
+    /*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/
+    error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d, 2, 30, 15);
+    if(error) break;
+
+    numcodes_ll = LODEPNG_MIN(tree_ll.numcodes, 286);
+    numcodes_d = LODEPNG_MIN(tree_d.numcodes, 30);
+    /*store the code lengths of both generated trees in bitlen_lld*/
+    numcodes_lld = numcodes_ll + numcodes_d;
+    bitlen_lld = (unsigned*)lodepng_malloc(numcodes_lld * sizeof(*bitlen_lld));
+    /*numcodes_lld_e never needs more size than bitlen_lld*/
+    bitlen_lld_e = (unsigned*)lodepng_malloc(numcodes_lld * sizeof(*bitlen_lld_e));
+    if(!bitlen_lld || !bitlen_lld_e) ERROR_BREAK(83); /*alloc fail*/
+    numcodes_lld_e = 0;
+
+    for(i = 0; i != numcodes_ll; ++i) bitlen_lld[i] = tree_ll.lengths[i];
+    for(i = 0; i != numcodes_d; ++i) bitlen_lld[numcodes_ll + i] = tree_d.lengths[i];
+
+    /*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times),
+    17 (3-10 zeroes), 18 (11-138 zeroes)*/
+    for(i = 0; i != numcodes_lld; ++i) {
+      unsigned j = 0; /*amount of repetitions*/
+      while(i + j + 1 < numcodes_lld && bitlen_lld[i + j + 1] == bitlen_lld[i]) ++j;
+
+      if(bitlen_lld[i] == 0 && j >= 2) /*repeat code for zeroes*/ {
+        ++j; /*include the first zero*/
+        if(j <= 10) /*repeat code 17 supports max 10 zeroes*/ {
+          bitlen_lld_e[numcodes_lld_e++] = 17;
+          bitlen_lld_e[numcodes_lld_e++] = j - 3;
+        } else /*repeat code 18 supports max 138 zeroes*/ {
+          if(j > 138) j = 138;
+          bitlen_lld_e[numcodes_lld_e++] = 18;
+          bitlen_lld_e[numcodes_lld_e++] = j - 11;
+        }
+        i += (j - 1);
+      } else if(j >= 3) /*repeat code for value other than zero*/ {
+        size_t k;
+        unsigned num = j / 6u, rest = j % 6u;
+        bitlen_lld_e[numcodes_lld_e++] = bitlen_lld[i];
+        for(k = 0; k < num; ++k) {
+          bitlen_lld_e[numcodes_lld_e++] = 16;
+          bitlen_lld_e[numcodes_lld_e++] = 6 - 3;
+        }
+        if(rest >= 3) {
+          bitlen_lld_e[numcodes_lld_e++] = 16;
+          bitlen_lld_e[numcodes_lld_e++] = rest - 3;
+        }
+        else j -= rest;
+        i += j;
+      } else /*too short to benefit from repeat code*/ {
+        bitlen_lld_e[numcodes_lld_e++] = bitlen_lld[i];
+      }
+    }
+
+    /*generate tree_cl, the huffmantree of huffmantrees*/
+    for(i = 0; i != numcodes_lld_e; ++i) {
+      ++frequencies_cl[bitlen_lld_e[i]];
+      /*after a repeat code come the bits that specify the number of repetitions,
+      those don't need to be in the frequencies_cl calculation*/
+      if(bitlen_lld_e[i] >= 16) ++i;
+    }
+
+    error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl,
+                                            NUM_CODE_LENGTH_CODES, NUM_CODE_LENGTH_CODES, 7);
+    if(error) break;
+
+    /*compute amount of code-length-code-lengths to output*/
+    numcodes_cl = NUM_CODE_LENGTH_CODES;
+    /*trim zeros at the end (using CLCL_ORDER), but minimum size must be 4 (see HCLEN below)*/
+    while(numcodes_cl > 4u && tree_cl.lengths[CLCL_ORDER[numcodes_cl - 1u]] == 0) {
+      numcodes_cl--;
+    }
+
+    /*
+    Write everything into the output
+
+    After the BFINAL and BTYPE, the dynamic block consists out of the following:
+    - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
+    - (HCLEN+4)*3 bits code lengths of code length alphabet
+    - HLIT + 257 code lengths of lit/length alphabet (encoded using the code length
+      alphabet, + possible repetition codes 16, 17, 18)
+    - HDIST + 1 code lengths of distance alphabet (encoded using the code length
+      alphabet, + possible repetition codes 16, 17, 18)
+    - compressed data
+    - 256 (end code)
+    */
+
+    /*Write block type*/
+    writeBits(writer, BFINAL, 1);
+    writeBits(writer, 0, 1); /*first bit of BTYPE "dynamic"*/
+    writeBits(writer, 1, 1); /*second bit of BTYPE "dynamic"*/
+
+    /*write the HLIT, HDIST and HCLEN values*/
+    /*all three sizes take trimmed ending zeroes into account, done either by HuffmanTree_makeFromFrequencies
+    or in the loop for numcodes_cl above, which saves space. */
+    HLIT = (unsigned)(numcodes_ll - 257);
+    HDIST = (unsigned)(numcodes_d - 1);
+    HCLEN = (unsigned)(numcodes_cl - 4);
+    writeBits(writer, HLIT, 5);
+    writeBits(writer, HDIST, 5);
+    writeBits(writer, HCLEN, 4);
+
+    /*write the code lengths of the code length alphabet ("bitlen_cl")*/
+    for(i = 0; i != numcodes_cl; ++i) writeBits(writer, tree_cl.lengths[CLCL_ORDER[i]], 3);
+
+    /*write the lengths of the lit/len AND the dist alphabet*/
+    for(i = 0; i != numcodes_lld_e; ++i) {
+      writeBitsReversed(writer, tree_cl.codes[bitlen_lld_e[i]], tree_cl.lengths[bitlen_lld_e[i]]);
+      /*extra bits of repeat codes*/
+      if(bitlen_lld_e[i] == 16) writeBits(writer, bitlen_lld_e[++i], 2);
+      else if(bitlen_lld_e[i] == 17) writeBits(writer, bitlen_lld_e[++i], 3);
+      else if(bitlen_lld_e[i] == 18) writeBits(writer, bitlen_lld_e[++i], 7);
+    }
+
+    /*write the compressed data symbols*/
+    writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d);
+    /*error: the length of the end code 256 must be larger than 0*/
+    if(tree_ll.lengths[256] == 0) ERROR_BREAK(64);
+
+    /*write the end code*/
+    writeBitsReversed(writer, tree_ll.codes[256], tree_ll.lengths[256]);
+
+    break; /*end of error-while*/
+  }
+
+  /*cleanup*/
+  uivector_cleanup(&lz77_encoded);
+  HuffmanTree_cleanup(&tree_ll);
+  HuffmanTree_cleanup(&tree_d);
+  HuffmanTree_cleanup(&tree_cl);
+  lodepng_free(frequencies_ll);
+  lodepng_free(frequencies_d);
+  lodepng_free(frequencies_cl);
+  lodepng_free(bitlen_lld);
+  lodepng_free(bitlen_lld_e);
+
+  return error;
+}
+
+static unsigned deflateFixed(LodePNGBitWriter* writer, Hash* hash,
+                             const unsigned char* data,
+                             size_t datapos, size_t dataend,
+                             const LodePNGCompressSettings* settings, unsigned final) {
+  HuffmanTree tree_ll; /*tree for literal values and length codes*/
+  HuffmanTree tree_d; /*tree for distance codes*/
+
+  unsigned BFINAL = final;
+  unsigned error = 0;
+  size_t i;
+
+  HuffmanTree_init(&tree_ll);
+  HuffmanTree_init(&tree_d);
+
+  error = generateFixedLitLenTree(&tree_ll);
+  if(!error) error = generateFixedDistanceTree(&tree_d);
+
+  if(!error) {
+    writeBits(writer, BFINAL, 1);
+    writeBits(writer, 1, 1); /*first bit of BTYPE*/
+    writeBits(writer, 0, 1); /*second bit of BTYPE*/
+
+    if(settings->use_lz77) /*LZ77 encoded*/ {
+      uivector lz77_encoded;
+      uivector_init(&lz77_encoded);
+      error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
+                         settings->minmatch, settings->nicematch, settings->lazymatching);
+      if(!error) writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d);
+      uivector_cleanup(&lz77_encoded);
+    } else /*no LZ77, but still will be Huffman compressed*/ {
+      for(i = datapos; i < dataend; ++i) {
+        writeBitsReversed(writer, tree_ll.codes[data[i]], tree_ll.lengths[data[i]]);
+      }
+    }
+    /*add END code*/
+    if(!error) writeBitsReversed(writer,tree_ll.codes[256], tree_ll.lengths[256]);
+  }
+
+  /*cleanup*/
+  HuffmanTree_cleanup(&tree_ll);
+  HuffmanTree_cleanup(&tree_d);
+
+  return error;
+}
+
+static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize,
+                                 const LodePNGCompressSettings* settings) {
+  unsigned error = 0;
+  size_t i, blocksize, numdeflateblocks;
+  Hash hash;
+  LodePNGBitWriter writer;
+
+  LodePNGBitWriter_init(&writer, out);
+
+  if(settings->btype > 2) return 61;
+  else if(settings->btype == 0) return deflateNoCompression(out, in, insize);
+  else if(settings->btype == 1) blocksize = insize;
+  else /*if(settings->btype == 2)*/ {
+    /*on PNGs, deflate blocks of 65-262k seem to give most dense encoding*/
+    blocksize = insize / 8u + 8;
+    if(blocksize < 65536) blocksize = 65536;
+    if(blocksize > 262144) blocksize = 262144;
+  }
+
+  numdeflateblocks = (insize + blocksize - 1) / blocksize;
+  if(numdeflateblocks == 0) numdeflateblocks = 1;
+
+  error = hash_init(&hash, settings->windowsize);
+
+  if(!error) {
+    for(i = 0; i != numdeflateblocks && !error; ++i) {
+      unsigned final = (i == numdeflateblocks - 1);
+      size_t start = i * blocksize;
+      size_t end = start + blocksize;
+      if(end > insize) end = insize;
+
+      if(settings->btype == 1) error = deflateFixed(&writer, &hash, in, start, end, settings, final);
+      else if(settings->btype == 2) error = deflateDynamic(&writer, &hash, in, start, end, settings, final);
+    }
+  }
+
+  hash_cleanup(&hash);
+
+  return error;
+}
+
+unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
+                         const unsigned char* in, size_t insize,
+                         const LodePNGCompressSettings* settings) {
+  ucvector v = ucvector_init(*out, *outsize);
+  unsigned error = lodepng_deflatev(&v, in, insize, settings);
+  *out = v.data;
+  *outsize = v.size;
+  return error;
+}
+
+static unsigned deflate(unsigned char** out, size_t* outsize,
+                        const unsigned char* in, size_t insize,
+                        const LodePNGCompressSettings* settings) {
+  if(settings->custom_deflate) {
+    return settings->custom_deflate(out, outsize, in, insize, settings);
+  } else {
+    return lodepng_deflate(out, outsize, in, insize, settings);
+  }
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Adler32                                                                / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) {
+  unsigned s1 = adler & 0xffffu;
+  unsigned s2 = (adler >> 16u) & 0xffffu;
+
+  while(len != 0u) {
+    unsigned i;
+    /*at least 5552 sums can be done before the sums overflow, saving a lot of module divisions*/
+    unsigned amount = len > 5552u ? 5552u : len;
+    len -= amount;
+    for(i = 0; i != amount; ++i) {
+      s1 += (*data++);
+      s2 += s1;
+    }
+    s1 %= 65521u;
+    s2 %= 65521u;
+  }
+
+  return (s2 << 16u) | s1;
+}
+
+/*Return the adler32 of the bytes data[0..len-1]*/
+static unsigned adler32(const unsigned char* data, unsigned len) {
+  return update_adler32(1u, data, len);
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Zlib                                                                   / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+static unsigned lodepng_zlib_decompressv(ucvector* out,
+                                         const unsigned char* in, size_t insize,
+                                         const LodePNGDecompressSettings* settings) {
+  unsigned error = 0;
+  unsigned CM, CINFO, FDICT;
+
+  if(insize < 2) return 53; /*error, size of zlib data too small*/
+  /*read information from zlib header*/
+  if((in[0] * 256 + in[1]) % 31 != 0) {
+    /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/
+    return 24;
+  }
+
+  CM = in[0] & 15;
+  CINFO = (in[0] >> 4) & 15;
+  /*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/
+  FDICT = (in[1] >> 5) & 1;
+  /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
+
+  if(CM != 8 || CINFO > 7) {
+    /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
+    return 25;
+  }
+  if(FDICT != 0) {
+    /*error: the specification of PNG says about the zlib stream:
+      "The additional flags shall not specify a preset dictionary."*/
+    return 26;
+  }
+
+  error = inflatev(out, in + 2, insize - 2, settings);
+  if(error) return error;
+
+  if(!settings->ignore_adler32) {
+    unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]);
+    unsigned checksum = adler32(out->data, (unsigned)(out->size));
+    if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
+  }
+
+  return 0; /*no error*/
+}
+
+
+unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                                 size_t insize, const LodePNGDecompressSettings* settings) {
+  ucvector v = ucvector_init(*out, *outsize);
+  unsigned error = lodepng_zlib_decompressv(&v, in, insize, settings);
+  *out = v.data;
+  *outsize = v.size;
+  return error;
+}
+
+/*expected_size is expected output size, to avoid intermediate allocations. Set to 0 if not known. */
+static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t expected_size,
+                                const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings) {
+  if(settings->custom_zlib) {
+    return settings->custom_zlib(out, outsize, in, insize, settings);
+  } else {
+    unsigned error;
+    ucvector v = ucvector_init(*out, *outsize);
+    if(expected_size) {
+      /*reserve the memory to avoid intermediate reallocations*/
+      ucvector_resize(&v, *outsize + expected_size);
+      v.size = *outsize;
+    }
+    error = lodepng_zlib_decompressv(&v, in, insize, settings);
+    *out = v.data;
+    *outsize = v.size;
+    return error;
+  }
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                               size_t insize, const LodePNGCompressSettings* settings) {
+  size_t i;
+  unsigned error;
+  unsigned char* deflatedata = 0;
+  size_t deflatesize = 0;
+
+  error = deflate(&deflatedata, &deflatesize, in, insize, settings);
+
+  *out = NULL;
+  *outsize = 0;
+  if(!error) {
+    *outsize = deflatesize + 6;
+    *out = (unsigned char*)lodepng_malloc(*outsize);
+    if(!*out) error = 83; /*alloc fail*/
+  }
+
+  if(!error) {
+    unsigned ADLER32 = adler32(in, (unsigned)insize);
+    /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
+    unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
+    unsigned FLEVEL = 0;
+    unsigned FDICT = 0;
+    unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
+    unsigned FCHECK = 31 - CMFFLG % 31;
+    CMFFLG += FCHECK;
+
+    (*out)[0] = (unsigned char)(CMFFLG >> 8);
+    (*out)[1] = (unsigned char)(CMFFLG & 255);
+    for(i = 0; i != deflatesize; ++i) (*out)[i + 2] = deflatedata[i];
+    lodepng_set32bitInt(&(*out)[*outsize - 4], ADLER32);
+  }
+
+  lodepng_free(deflatedata);
+  return error;
+}
+
+/* compress using the default or custom zlib function */
+static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                              size_t insize, const LodePNGCompressSettings* settings) {
+  if(settings->custom_zlib) {
+    return settings->custom_zlib(out, outsize, in, insize, settings);
+  } else {
+    return lodepng_zlib_compress(out, outsize, in, insize, settings);
+  }
+}
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#else /*no LODEPNG_COMPILE_ZLIB*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t expected_size,
+                                const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings) {
+  if(!settings->custom_zlib) return 87; /*no custom zlib function provided */
+  (void)expected_size;
+  return settings->custom_zlib(out, outsize, in, insize, settings);
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+#ifdef LODEPNG_COMPILE_ENCODER
+static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                              size_t insize, const LodePNGCompressSettings* settings) {
+  if(!settings->custom_zlib) return 87; /*no custom zlib function provided */
+  return settings->custom_zlib(out, outsize, in, insize, settings);
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+/*this is a good tradeoff between speed and compression ratio*/
+#define DEFAULT_WINDOWSIZE 2048
+
+void lodepng_compress_settings_init(LodePNGCompressSettings* settings) {
+  /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
+  settings->btype = 2;
+  settings->use_lz77 = 1;
+  settings->windowsize = DEFAULT_WINDOWSIZE;
+  settings->minmatch = 3;
+  settings->nicematch = 128;
+  settings->lazymatching = 1;
+
+  settings->custom_zlib = 0;
+  settings->custom_deflate = 0;
+  settings->custom_context = 0;
+}
+
+const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0, 0, 0};
+
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) {
+  settings->ignore_adler32 = 0;
+  settings->ignore_nlen = 0;
+
+  settings->custom_zlib = 0;
+  settings->custom_inflate = 0;
+  settings->custom_context = 0;
+}
+
+const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0, 0};
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of Zlib related code. Begin of PNG related code.                 // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_PNG
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / CRC32                                                                  / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+
+#ifndef LODEPNG_NO_COMPILE_CRC
+/* CRC polynomial: 0xedb88320 */
+static unsigned lodepng_crc32_table[256] = {
+           0u, 1996959894u, 3993919788u, 2567524794u,  124634137u, 1886057615u, 3915621685u, 2657392035u,
+   249268274u, 2044508324u, 3772115230u, 2547177864u,  162941995u, 2125561021u, 3887607047u, 2428444049u,
+   498536548u, 1789927666u, 4089016648u, 2227061214u,  450548861u, 1843258603u, 4107580753u, 2211677639u,
+   325883990u, 1684777152u, 4251122042u, 2321926636u,  335633487u, 1661365465u, 4195302755u, 2366115317u,
+   997073096u, 1281953886u, 3579855332u, 2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u,
+   901097722u, 1119000684u, 3686517206u, 2898065728u,  853044451u, 1172266101u, 3705015759u, 2882616665u,
+   651767980u, 1373503546u, 3369554304u, 3218104598u,  565507253u, 1454621731u, 3485111705u, 3099436303u,
+   671266974u, 1594198024u, 3322730930u, 2970347812u,  795835527u, 1483230225u, 3244367275u, 3060149565u,
+  1994146192u,   31158534u, 2563907772u, 4023717930u, 1907459465u,  112637215u, 2680153253u, 3904427059u,
+  2013776290u,  251722036u, 2517215374u, 3775830040u, 2137656763u,  141376813u, 2439277719u, 3865271297u,
+  1802195444u,  476864866u, 2238001368u, 4066508878u, 1812370925u,  453092731u, 2181625025u, 4111451223u,
+  1706088902u,  314042704u, 2344532202u, 4240017532u, 1658658271u,  366619977u, 2362670323u, 4224994405u,
+  1303535960u,  984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u,
+  1131014506u,  879679996u, 2909243462u, 3663771856u, 1141124467u,  855842277u, 2852801631u, 3708648649u,
+  1342533948u,  654459306u, 3188396048u, 3373015174u, 1466479909u,  544179635u, 3110523913u, 3462522015u,
+  1591671054u,  702138776u, 2966460450u, 3352799412u, 1504918807u,  783551873u, 3082640443u, 3233442989u,
+  3988292384u, 2596254646u,   62317068u, 1957810842u, 3939845945u, 2647816111u,   81470997u, 1943803523u,
+  3814918930u, 2489596804u,  225274430u, 2053790376u, 3826175755u, 2466906013u,  167816743u, 2097651377u,
+  4027552580u, 2265490386u,  503444072u, 1762050814u, 4150417245u, 2154129355u,  426522225u, 1852507879u,
+  4275313526u, 2312317920u,  282753626u, 1742555852u, 4189708143u, 2394877945u,  397917763u, 1622183637u,
+  3604390888u, 2714866558u,  953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u,
+  3624741850u, 2936675148u,  906185462u, 1090812512u, 3747672003u, 2825379669u,  829329135u, 1181335161u,
+  3412177804u, 3160834842u,  628085408u, 1382605366u, 3423369109u, 3138078467u,  570562233u, 1426400815u,
+  3317316542u, 2998733608u,  733239954u, 1555261956u, 3268935591u, 3050360625u,  752459403u, 1541320221u,
+  2607071920u, 3965973030u, 1969922972u,   40735498u, 2617837225u, 3943577151u, 1913087877u,   83908371u,
+  2512341634u, 3803740692u, 2075208622u,  213261112u, 2463272603u, 3855990285u, 2094854071u,  198958881u,
+  2262029012u, 4057260610u, 1759359992u,  534414190u, 2176718541u, 4139329115u, 1873836001u,  414664567u,
+  2282248934u, 4279200368u, 1711684554u,  285281116u, 2405801727u, 4167216745u, 1634467795u,  376229701u,
+  2685067896u, 3608007406u, 1308918612u,  956543938u, 2808555105u, 3495958263u, 1231636301u, 1047427035u,
+  2932959818u, 3654703836u, 1088359270u,  936918000u, 2847714899u, 3736837829u, 1202900863u,  817233897u,
+  3183342108u, 3401237130u, 1404277552u,  615818150u, 3134207493u, 3453421203u, 1423857449u,  601450431u,
+  3009837614u, 3294710456u, 1567103746u,  711928724u, 3020668471u, 3272380065u, 1510334235u,  755167117u
+};
+
+/*Return the CRC of the bytes buf[0..len-1].*/
+unsigned lodepng_crc32(const unsigned char* data, size_t length) {
+  unsigned r = 0xffffffffu;
+  size_t i;
+  for(i = 0; i < length; ++i) {
+    r = lodepng_crc32_table[(r ^ data[i]) & 0xffu] ^ (r >> 8u);
+  }
+  return r ^ 0xffffffffu;
+}
+#else /* !LODEPNG_NO_COMPILE_CRC */
+unsigned lodepng_crc32(const unsigned char* data, size_t length);
+#endif /* !LODEPNG_NO_COMPILE_CRC */
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Reading and writing PNG color channel bits                             / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/* The color channel bits of less-than-8-bit pixels are read with the MSB of bytes first,
+so LodePNGBitWriter and LodePNGBitReader can't be used for those. */
+
+static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream) {
+  unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
+  ++(*bitpointer);
+  return result;
+}
+
+/* TODO: make this faster */
+static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) {
+  unsigned result = 0;
+  size_t i;
+  for(i = 0 ; i < nbits; ++i) {
+    result <<= 1u;
+    result |= (unsigned)readBitFromReversedStream(bitpointer, bitstream);
+  }
+  return result;
+}
+
+static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) {
+  /*the current bit in bitstream may be 0 or 1 for this to work*/
+  if(bit == 0) bitstream[(*bitpointer) >> 3u] &=  (unsigned char)(~(1u << (7u - ((*bitpointer) & 7u))));
+  else         bitstream[(*bitpointer) >> 3u] |=  (1u << (7u - ((*bitpointer) & 7u)));
+  ++(*bitpointer);
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / PNG chunks                                                             / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+unsigned lodepng_chunk_length(const unsigned char* chunk) {
+  return lodepng_read32bitInt(&chunk[0]);
+}
+
+void lodepng_chunk_type(char type[5], const unsigned char* chunk) {
+  unsigned i;
+  for(i = 0; i != 4; ++i) type[i] = (char)chunk[4 + i];
+  type[4] = 0; /*null termination char*/
+}
+
+unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type) {
+  if(lodepng_strlen(type) != 4) return 0;
+  return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
+}
+
+unsigned char lodepng_chunk_ancillary(const unsigned char* chunk) {
+  return((chunk[4] & 32) != 0);
+}
+
+unsigned char lodepng_chunk_private(const unsigned char* chunk) {
+  return((chunk[6] & 32) != 0);
+}
+
+unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) {
+  return((chunk[7] & 32) != 0);
+}
+
+unsigned char* lodepng_chunk_data(unsigned char* chunk) {
+  return &chunk[8];
+}
+
+const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) {
+  return &chunk[8];
+}
+
+unsigned lodepng_chunk_check_crc(const unsigned char* chunk) {
+  unsigned length = lodepng_chunk_length(chunk);
+  unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]);
+  /*the CRC is taken of the data and the 4 chunk type letters, not the length*/
+  unsigned checksum = lodepng_crc32(&chunk[4], length + 4);
+  if(CRC != checksum) return 1;
+  else return 0;
+}
+
+void lodepng_chunk_generate_crc(unsigned char* chunk) {
+  unsigned length = lodepng_chunk_length(chunk);
+  unsigned CRC = lodepng_crc32(&chunk[4], length + 4);
+  lodepng_set32bitInt(chunk + 8 + length, CRC);
+}
+
+unsigned char* lodepng_chunk_next(unsigned char* chunk, unsigned char* end) {
+  if(chunk >= end || end - chunk < 12) return end; /*too small to contain a chunk*/
+  if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47
+    && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) {
+    /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */
+    return chunk + 8;
+  } else {
+    size_t total_chunk_length;
+    unsigned char* result;
+    if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return end;
+    result = chunk + total_chunk_length;
+    if(result < chunk) return end; /*pointer overflow*/
+    return result;
+  }
+}
+
+const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk, const unsigned char* end) {
+  if(chunk >= end || end - chunk < 12) return end; /*too small to contain a chunk*/
+  if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47
+    && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) {
+    /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */
+    return chunk + 8;
+  } else {
+    size_t total_chunk_length;
+    const unsigned char* result;
+    if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return end;
+    result = chunk + total_chunk_length;
+    if(result < chunk) return end; /*pointer overflow*/
+    return result;
+  }
+}
+
+unsigned char* lodepng_chunk_find(unsigned char* chunk, unsigned char* end, const char type[5]) {
+  for(;;) {
+    if(chunk >= end || end - chunk < 12) return 0; /* past file end: chunk + 12 > end */
+    if(lodepng_chunk_type_equals(chunk, type)) return chunk;
+    chunk = lodepng_chunk_next(chunk, end);
+  }
+}
+
+const unsigned char* lodepng_chunk_find_const(const unsigned char* chunk, const unsigned char* end, const char type[5]) {
+  for(;;) {
+    if(chunk >= end || end - chunk < 12) return 0; /* past file end: chunk + 12 > end */
+    if(lodepng_chunk_type_equals(chunk, type)) return chunk;
+    chunk = lodepng_chunk_next_const(chunk, end);
+  }
+}
+
+unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk) {
+  unsigned i;
+  size_t total_chunk_length, new_length;
+  unsigned char *chunk_start, *new_buffer;
+
+  if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return 77;
+  if(lodepng_addofl(*outsize, total_chunk_length, &new_length)) return 77;
+
+  new_buffer = (unsigned char*)lodepng_realloc(*out, new_length);
+  if(!new_buffer) return 83; /*alloc fail*/
+  (*out) = new_buffer;
+  (*outsize) = new_length;
+  chunk_start = &(*out)[new_length - total_chunk_length];
+
+  for(i = 0; i != total_chunk_length; ++i) chunk_start[i] = chunk[i];
+
+  return 0;
+}
+
+/*Sets length and name and allocates the space for data and crc but does not
+set data or crc yet. Returns the start of the chunk in chunk. The start of
+the data is at chunk + 8. To finalize chunk, add the data, then use
+lodepng_chunk_generate_crc */
+static unsigned lodepng_chunk_init(unsigned char** chunk,
+                                   ucvector* out,
+                                   unsigned length, const char* type) {
+  size_t new_length = out->size;
+  if(lodepng_addofl(new_length, length, &new_length)) return 77;
+  if(lodepng_addofl(new_length, 12, &new_length)) return 77;
+  if(!ucvector_resize(out, new_length)) return 83; /*alloc fail*/
+  *chunk = out->data + new_length - length - 12u;
+
+  /*1: length*/
+  lodepng_set32bitInt(*chunk, length);
+
+  /*2: chunk name (4 letters)*/
+  lodepng_memcpy(*chunk + 4, type, 4);
+
+  return 0;
+}
+
+/* like lodepng_chunk_create but with custom allocsize */
+static unsigned lodepng_chunk_createv(ucvector* out,
+                                      unsigned length, const char* type, const unsigned char* data) {
+  unsigned char* chunk;
+  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, length, type));
+
+  /*3: the data*/
+  lodepng_memcpy(chunk + 8, data, length);
+
+  /*4: CRC (of the chunkname characters and the data)*/
+  lodepng_chunk_generate_crc(chunk);
+
+  return 0;
+}
+
+unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize,
+                              unsigned length, const char* type, const unsigned char* data) {
+  ucvector v = ucvector_init(*out, *outsize);
+  unsigned error = lodepng_chunk_createv(&v, length, type, data);
+  *out = v.data;
+  *outsize = v.size;
+  return error;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Color types, channels, bits                                            / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*checks if the colortype is valid and the bitdepth bd is allowed for this colortype.
+Return value is a LodePNG error code.*/
+static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) {
+  switch(colortype) {
+    case LCT_GREY:       if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break;
+    case LCT_RGB:        if(!(                                 bd == 8 || bd == 16)) return 37; break;
+    case LCT_PALETTE:    if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8            )) return 37; break;
+    case LCT_GREY_ALPHA: if(!(                                 bd == 8 || bd == 16)) return 37; break;
+    case LCT_RGBA:       if(!(                                 bd == 8 || bd == 16)) return 37; break;
+    case LCT_MAX_OCTET_VALUE: return 31; /* invalid color type */
+    default: return 31; /* invalid color type */
+  }
+  return 0; /*allowed color type / bits combination*/
+}
+
+static unsigned getNumColorChannels(LodePNGColorType colortype) {
+  switch(colortype) {
+    case LCT_GREY: return 1;
+    case LCT_RGB: return 3;
+    case LCT_PALETTE: return 1;
+    case LCT_GREY_ALPHA: return 2;
+    case LCT_RGBA: return 4;
+    case LCT_MAX_OCTET_VALUE: return 0; /* invalid color type */
+    default: return 0; /*invalid color type*/
+  }
+}
+
+static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth) {
+  /*bits per pixel is amount of channels * bits per channel*/
+  return getNumColorChannels(colortype) * bitdepth;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+void lodepng_color_mode_init(LodePNGColorMode* info) {
+  info->key_defined = 0;
+  info->key_r = info->key_g = info->key_b = 0;
+  info->colortype = LCT_RGBA;
+  info->bitdepth = 8;
+  info->palette = 0;
+  info->palettesize = 0;
+}
+
+/*allocates palette memory if needed, and initializes all colors to black*/
+static void lodepng_color_mode_alloc_palette(LodePNGColorMode* info) {
+  size_t i;
+  /*if the palette is already allocated, it will have size 1024 so no reallocation needed in that case*/
+  /*the palette must have room for up to 256 colors with 4 bytes each.*/
+  if(!info->palette) info->palette = (unsigned char*)lodepng_malloc(1024);
+  if(!info->palette) return; /*alloc fail*/
+  for(i = 0; i != 256; ++i) {
+    /*Initialize all unused colors with black, the value used for invalid palette indices.
+    This is an error according to the PNG spec, but common PNG decoders make it black instead.
+    That makes color conversion slightly faster due to no error handling needed.*/
+    info->palette[i * 4 + 0] = 0;
+    info->palette[i * 4 + 1] = 0;
+    info->palette[i * 4 + 2] = 0;
+    info->palette[i * 4 + 3] = 255;
+  }
+}
+
+void lodepng_color_mode_cleanup(LodePNGColorMode* info) {
+  lodepng_palette_clear(info);
+}
+
+unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) {
+  lodepng_color_mode_cleanup(dest);
+  lodepng_memcpy(dest, source, sizeof(LodePNGColorMode));
+  if(source->palette) {
+    dest->palette = (unsigned char*)lodepng_malloc(1024);
+    if(!dest->palette && source->palettesize) return 83; /*alloc fail*/
+    lodepng_memcpy(dest->palette, source->palette, source->palettesize * 4);
+  }
+  return 0;
+}
+
+LodePNGColorMode lodepng_color_mode_make(LodePNGColorType colortype, unsigned bitdepth) {
+  LodePNGColorMode result;
+  lodepng_color_mode_init(&result);
+  result.colortype = colortype;
+  result.bitdepth = bitdepth;
+  return result;
+}
+
+static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b) {
+  size_t i;
+  if(a->colortype != b->colortype) return 0;
+  if(a->bitdepth != b->bitdepth) return 0;
+  if(a->key_defined != b->key_defined) return 0;
+  if(a->key_defined) {
+    if(a->key_r != b->key_r) return 0;
+    if(a->key_g != b->key_g) return 0;
+    if(a->key_b != b->key_b) return 0;
+  }
+  if(a->palettesize != b->palettesize) return 0;
+  for(i = 0; i != a->palettesize * 4; ++i) {
+    if(a->palette[i] != b->palette[i]) return 0;
+  }
+  return 1;
+}
+
+void lodepng_palette_clear(LodePNGColorMode* info) {
+  if(info->palette) lodepng_free(info->palette);
+  info->palette = 0;
+  info->palettesize = 0;
+}
+
+unsigned lodepng_palette_add(LodePNGColorMode* info,
+                             unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
+  if(!info->palette) /*allocate palette if empty*/ {
+    lodepng_color_mode_alloc_palette(info);
+    if(!info->palette) return 83; /*alloc fail*/
+  }
+  if(info->palettesize >= 256) {
+    return 108; /*too many palette values*/
+  }
+  info->palette[4 * info->palettesize + 0] = r;
+  info->palette[4 * info->palettesize + 1] = g;
+  info->palette[4 * info->palettesize + 2] = b;
+  info->palette[4 * info->palettesize + 3] = a;
+  ++info->palettesize;
+  return 0;
+}
+
+/*calculate bits per pixel out of colortype and bitdepth*/
+unsigned lodepng_get_bpp(const LodePNGColorMode* info) {
+  return lodepng_get_bpp_lct(info->colortype, info->bitdepth);
+}
+
+unsigned lodepng_get_channels(const LodePNGColorMode* info) {
+  return getNumColorChannels(info->colortype);
+}
+
+unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info) {
+  return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA;
+}
+
+unsigned lodepng_is_alpha_type(const LodePNGColorMode* info) {
+  return (info->colortype & 4) != 0; /*4 or 6*/
+}
+
+unsigned lodepng_is_palette_type(const LodePNGColorMode* info) {
+  return info->colortype == LCT_PALETTE;
+}
+
+unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) {
+  size_t i;
+  for(i = 0; i != info->palettesize; ++i) {
+    if(info->palette[i * 4 + 3] < 255) return 1;
+  }
+  return 0;
+}
+
+unsigned lodepng_can_have_alpha(const LodePNGColorMode* info) {
+  return info->key_defined
+      || lodepng_is_alpha_type(info)
+      || lodepng_has_palette_alpha(info);
+}
+
+static size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) {
+  size_t bpp = lodepng_get_bpp_lct(colortype, bitdepth);
+  size_t n = (size_t)w * (size_t)h;
+  return ((n / 8u) * bpp) + ((n & 7u) * bpp + 7u) / 8u;
+}
+
+size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color) {
+  return lodepng_get_raw_size_lct(w, h, color->colortype, color->bitdepth);
+}
+
+
+#ifdef LODEPNG_COMPILE_PNG
+
+/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer,
+and in addition has one extra byte per line: the filter byte. So this gives a larger
+result than lodepng_get_raw_size. Set h to 1 to get the size of 1 row including filter byte. */
+static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, unsigned bpp) {
+  /* + 1 for the filter byte, and possibly plus padding bits per line. */
+  /* Ignoring casts, the expression is equal to (w * bpp + 7) / 8 + 1, but avoids overflow of w * bpp */
+  size_t line = ((size_t)(w / 8u) * bpp) + 1u + ((w & 7u) * bpp + 7u) / 8u;
+  return (size_t)h * line;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*Safely checks whether size_t overflow can be caused due to amount of pixels.
+This check is overcautious rather than precise. If this check indicates no overflow,
+you can safely compute in a size_t (but not an unsigned):
+-(size_t)w * (size_t)h * 8
+-amount of bytes in IDAT (including filter, padding and Adam7 bytes)
+-amount of bytes in raw color model
+Returns 1 if overflow possible, 0 if not.
+*/
+static int lodepng_pixel_overflow(unsigned w, unsigned h,
+                                  const LodePNGColorMode* pngcolor, const LodePNGColorMode* rawcolor) {
+  size_t bpp = LODEPNG_MAX(lodepng_get_bpp(pngcolor), lodepng_get_bpp(rawcolor));
+  size_t numpixels, total;
+  size_t line; /* bytes per line in worst case */
+
+  if(lodepng_mulofl((size_t)w, (size_t)h, &numpixels)) return 1;
+  if(lodepng_mulofl(numpixels, 8, &total)) return 1; /* bit pointer with 8-bit color, or 8 bytes per channel color */
+
+  /* Bytes per scanline with the expression "(w / 8u) * bpp) + ((w & 7u) * bpp + 7u) / 8u" */
+  if(lodepng_mulofl((size_t)(w / 8u), bpp, &line)) return 1;
+  if(lodepng_addofl(line, ((w & 7u) * bpp + 7u) / 8u, &line)) return 1;
+
+  if(lodepng_addofl(line, 5, &line)) return 1; /* 5 bytes overhead per line: 1 filterbyte, 4 for Adam7 worst case */
+  if(lodepng_mulofl(line, h, &total)) return 1; /* Total bytes in worst case */
+
+  return 0; /* no overflow */
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+
+static void LodePNGUnknownChunks_init(LodePNGInfo* info) {
+  unsigned i;
+  for(i = 0; i != 3; ++i) info->unknown_chunks_data[i] = 0;
+  for(i = 0; i != 3; ++i) info->unknown_chunks_size[i] = 0;
+}
+
+static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info) {
+  unsigned i;
+  for(i = 0; i != 3; ++i) lodepng_free(info->unknown_chunks_data[i]);
+}
+
+static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src) {
+  unsigned i;
+
+  LodePNGUnknownChunks_cleanup(dest);
+
+  for(i = 0; i != 3; ++i) {
+    size_t j;
+    dest->unknown_chunks_size[i] = src->unknown_chunks_size[i];
+    dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]);
+    if(!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/
+    for(j = 0; j < src->unknown_chunks_size[i]; ++j) {
+      dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j];
+    }
+  }
+
+  return 0;
+}
+
+/******************************************************************************/
+
+static void LodePNGText_init(LodePNGInfo* info) {
+  info->text_num = 0;
+  info->text_keys = NULL;
+  info->text_strings = NULL;
+}
+
+static void LodePNGText_cleanup(LodePNGInfo* info) {
+  size_t i;
+  for(i = 0; i != info->text_num; ++i) {
+    string_cleanup(&info->text_keys[i]);
+    string_cleanup(&info->text_strings[i]);
+  }
+  lodepng_free(info->text_keys);
+  lodepng_free(info->text_strings);
+}
+
+static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source) {
+  size_t i = 0;
+  dest->text_keys = 0;
+  dest->text_strings = 0;
+  dest->text_num = 0;
+  for(i = 0; i != source->text_num; ++i) {
+    CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i]));
+  }
+  return 0;
+}
+
+static unsigned lodepng_add_text_sized(LodePNGInfo* info, const char* key, const char* str, size_t size) {
+  char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1)));
+  char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1)));
+
+  if(new_keys) info->text_keys = new_keys;
+  if(new_strings) info->text_strings = new_strings;
+
+  if(!new_keys || !new_strings) return 83; /*alloc fail*/
+
+  ++info->text_num;
+  info->text_keys[info->text_num - 1] = alloc_string(key);
+  info->text_strings[info->text_num - 1] = alloc_string_sized(str, size);
+  if(!info->text_keys[info->text_num - 1] || !info->text_strings[info->text_num - 1]) return 83; /*alloc fail*/
+
+  return 0;
+}
+
+unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str) {
+  return lodepng_add_text_sized(info, key, str, lodepng_strlen(str));
+}
+
+void lodepng_clear_text(LodePNGInfo* info) {
+  LodePNGText_cleanup(info);
+}
+
+/******************************************************************************/
+
+static void LodePNGIText_init(LodePNGInfo* info) {
+  info->itext_num = 0;
+  info->itext_keys = NULL;
+  info->itext_langtags = NULL;
+  info->itext_transkeys = NULL;
+  info->itext_strings = NULL;
+}
+
+static void LodePNGIText_cleanup(LodePNGInfo* info) {
+  size_t i;
+  for(i = 0; i != info->itext_num; ++i) {
+    string_cleanup(&info->itext_keys[i]);
+    string_cleanup(&info->itext_langtags[i]);
+    string_cleanup(&info->itext_transkeys[i]);
+    string_cleanup(&info->itext_strings[i]);
+  }
+  lodepng_free(info->itext_keys);
+  lodepng_free(info->itext_langtags);
+  lodepng_free(info->itext_transkeys);
+  lodepng_free(info->itext_strings);
+}
+
+static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source) {
+  size_t i = 0;
+  dest->itext_keys = 0;
+  dest->itext_langtags = 0;
+  dest->itext_transkeys = 0;
+  dest->itext_strings = 0;
+  dest->itext_num = 0;
+  for(i = 0; i != source->itext_num; ++i) {
+    CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i],
+                                        source->itext_transkeys[i], source->itext_strings[i]));
+  }
+  return 0;
+}
+
+void lodepng_clear_itext(LodePNGInfo* info) {
+  LodePNGIText_cleanup(info);
+}
+
+static unsigned lodepng_add_itext_sized(LodePNGInfo* info, const char* key, const char* langtag,
+                                        const char* transkey, const char* str, size_t size) {
+  char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1)));
+  char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1)));
+  char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1)));
+  char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1)));
+
+  if(new_keys) info->itext_keys = new_keys;
+  if(new_langtags) info->itext_langtags = new_langtags;
+  if(new_transkeys) info->itext_transkeys = new_transkeys;
+  if(new_strings) info->itext_strings = new_strings;
+
+  if(!new_keys || !new_langtags || !new_transkeys || !new_strings) return 83; /*alloc fail*/
+
+  ++info->itext_num;
+
+  info->itext_keys[info->itext_num - 1] = alloc_string(key);
+  info->itext_langtags[info->itext_num - 1] = alloc_string(langtag);
+  info->itext_transkeys[info->itext_num - 1] = alloc_string(transkey);
+  info->itext_strings[info->itext_num - 1] = alloc_string_sized(str, size);
+
+  return 0;
+}
+
+unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
+                           const char* transkey, const char* str) {
+  return lodepng_add_itext_sized(info, key, langtag, transkey, str, lodepng_strlen(str));
+}
+
+/* same as set but does not delete */
+static unsigned lodepng_assign_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size) {
+  if(profile_size == 0) return 100; /*invalid ICC profile size*/
+
+  info->iccp_name = alloc_string(name);
+  info->iccp_profile = (unsigned char*)lodepng_malloc(profile_size);
+
+  if(!info->iccp_name || !info->iccp_profile) return 83; /*alloc fail*/
+
+  lodepng_memcpy(info->iccp_profile, profile, profile_size);
+  info->iccp_profile_size = profile_size;
+
+  return 0; /*ok*/
+}
+
+unsigned lodepng_set_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size) {
+  if(info->iccp_name) lodepng_clear_icc(info);
+  info->iccp_defined = 1;
+
+  return lodepng_assign_icc(info, name, profile, profile_size);
+}
+
+void lodepng_clear_icc(LodePNGInfo* info) {
+  string_cleanup(&info->iccp_name);
+  lodepng_free(info->iccp_profile);
+  info->iccp_profile = NULL;
+  info->iccp_profile_size = 0;
+  info->iccp_defined = 0;
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+void lodepng_info_init(LodePNGInfo* info) {
+  lodepng_color_mode_init(&info->color);
+  info->interlace_method = 0;
+  info->compression_method = 0;
+  info->filter_method = 0;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  info->background_defined = 0;
+  info->background_r = info->background_g = info->background_b = 0;
+
+  LodePNGText_init(info);
+  LodePNGIText_init(info);
+
+  info->time_defined = 0;
+  info->phys_defined = 0;
+
+  info->gama_defined = 0;
+  info->chrm_defined = 0;
+  info->srgb_defined = 0;
+  info->iccp_defined = 0;
+  info->iccp_name = NULL;
+  info->iccp_profile = NULL;
+
+  LodePNGUnknownChunks_init(info);
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+}
+
+void lodepng_info_cleanup(LodePNGInfo* info) {
+  lodepng_color_mode_cleanup(&info->color);
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  LodePNGText_cleanup(info);
+  LodePNGIText_cleanup(info);
+
+  lodepng_clear_icc(info);
+
+  LodePNGUnknownChunks_cleanup(info);
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+}
+
+unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) {
+  lodepng_info_cleanup(dest);
+  lodepng_memcpy(dest, source, sizeof(LodePNGInfo));
+  lodepng_color_mode_init(&dest->color);
+  CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color));
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  CERROR_TRY_RETURN(LodePNGText_copy(dest, source));
+  CERROR_TRY_RETURN(LodePNGIText_copy(dest, source));
+  if(source->iccp_defined) {
+    CERROR_TRY_RETURN(lodepng_assign_icc(dest, source->iccp_name, source->iccp_profile, source->iccp_profile_size));
+  }
+
+  LodePNGUnknownChunks_init(dest);
+  CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source));
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+  return 0;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/
+static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in) {
+  unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/
+  /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/
+  unsigned p = index & m;
+  in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/
+  in = in << (bits * (m - p));
+  if(p == 0) out[index * bits / 8u] = in;
+  else out[index * bits / 8u] |= in;
+}
+
+typedef struct ColorTree ColorTree;
+
+/*
+One node of a color tree
+This is the data structure used to count the number of unique colors and to get a palette
+index for a color. It's like an octree, but because the alpha channel is used too, each
+node has 16 instead of 8 children.
+*/
+struct ColorTree {
+  ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/
+  int index; /*the payload. Only has a meaningful value if this is in the last level*/
+};
+
+static void color_tree_init(ColorTree* tree) {
+  lodepng_memset(tree->children, 0, 16 * sizeof(*tree->children));
+  tree->index = -1;
+}
+
+static void color_tree_cleanup(ColorTree* tree) {
+  int i;
+  for(i = 0; i != 16; ++i) {
+    if(tree->children[i]) {
+      color_tree_cleanup(tree->children[i]);
+      lodepng_free(tree->children[i]);
+    }
+  }
+}
+
+/*returns -1 if color not present, its index otherwise*/
+static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
+  int bit = 0;
+  for(bit = 0; bit < 8; ++bit) {
+    int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
+    if(!tree->children[i]) return -1;
+    else tree = tree->children[i];
+  }
+  return tree ? tree->index : -1;
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
+  return color_tree_get(tree, r, g, b, a) >= 0;
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+/*color is not allowed to already exist.
+Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")
+Returns error code, or 0 if ok*/
+static unsigned color_tree_add(ColorTree* tree,
+                               unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index) {
+  int bit;
+  for(bit = 0; bit < 8; ++bit) {
+    int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
+    if(!tree->children[i]) {
+      tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree));
+      if(!tree->children[i]) return 83; /*alloc fail*/
+      color_tree_init(tree->children[i]);
+    }
+    tree = tree->children[i];
+  }
+  tree->index = (int)index;
+  return 0;
+}
+
+/*put a pixel, given its RGBA color, into image of any color type*/
+static unsigned rgba8ToPixel(unsigned char* out, size_t i,
+                             const LodePNGColorMode* mode, ColorTree* tree /*for palette*/,
+                             unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
+  if(mode->colortype == LCT_GREY) {
+    unsigned char gray = r; /*((unsigned short)r + g + b) / 3u;*/
+    if(mode->bitdepth == 8) out[i] = gray;
+    else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = gray;
+    else {
+      /*take the most significant bits of gray*/
+      gray = ((unsigned)gray >> (8u - mode->bitdepth)) & ((1u << mode->bitdepth) - 1u);
+      addColorBits(out, i, mode->bitdepth, gray);
+    }
+  } else if(mode->colortype == LCT_RGB) {
+    if(mode->bitdepth == 8) {
+      out[i * 3 + 0] = r;
+      out[i * 3 + 1] = g;
+      out[i * 3 + 2] = b;
+    } else {
+      out[i * 6 + 0] = out[i * 6 + 1] = r;
+      out[i * 6 + 2] = out[i * 6 + 3] = g;
+      out[i * 6 + 4] = out[i * 6 + 5] = b;
+    }
+  } else if(mode->colortype == LCT_PALETTE) {
+    int index = color_tree_get(tree, r, g, b, a);
+    if(index < 0) return 82; /*color not in palette*/
+    if(mode->bitdepth == 8) out[i] = index;
+    else addColorBits(out, i, mode->bitdepth, (unsigned)index);
+  } else if(mode->colortype == LCT_GREY_ALPHA) {
+    unsigned char gray = r; /*((unsigned short)r + g + b) / 3u;*/
+    if(mode->bitdepth == 8) {
+      out[i * 2 + 0] = gray;
+      out[i * 2 + 1] = a;
+    } else if(mode->bitdepth == 16) {
+      out[i * 4 + 0] = out[i * 4 + 1] = gray;
+      out[i * 4 + 2] = out[i * 4 + 3] = a;
+    }
+  } else if(mode->colortype == LCT_RGBA) {
+    if(mode->bitdepth == 8) {
+      out[i * 4 + 0] = r;
+      out[i * 4 + 1] = g;
+      out[i * 4 + 2] = b;
+      out[i * 4 + 3] = a;
+    } else {
+      out[i * 8 + 0] = out[i * 8 + 1] = r;
+      out[i * 8 + 2] = out[i * 8 + 3] = g;
+      out[i * 8 + 4] = out[i * 8 + 5] = b;
+      out[i * 8 + 6] = out[i * 8 + 7] = a;
+    }
+  }
+
+  return 0; /*no error*/
+}
+
+/*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/
+static void rgba16ToPixel(unsigned char* out, size_t i,
+                         const LodePNGColorMode* mode,
+                         unsigned short r, unsigned short g, unsigned short b, unsigned short a) {
+  if(mode->colortype == LCT_GREY) {
+    unsigned short gray = r; /*((unsigned)r + g + b) / 3u;*/
+    out[i * 2 + 0] = (gray >> 8) & 255;
+    out[i * 2 + 1] = gray & 255;
+  } else if(mode->colortype == LCT_RGB) {
+    out[i * 6 + 0] = (r >> 8) & 255;
+    out[i * 6 + 1] = r & 255;
+    out[i * 6 + 2] = (g >> 8) & 255;
+    out[i * 6 + 3] = g & 255;
+    out[i * 6 + 4] = (b >> 8) & 255;
+    out[i * 6 + 5] = b & 255;
+  } else if(mode->colortype == LCT_GREY_ALPHA) {
+    unsigned short gray = r; /*((unsigned)r + g + b) / 3u;*/
+    out[i * 4 + 0] = (gray >> 8) & 255;
+    out[i * 4 + 1] = gray & 255;
+    out[i * 4 + 2] = (a >> 8) & 255;
+    out[i * 4 + 3] = a & 255;
+  } else if(mode->colortype == LCT_RGBA) {
+    out[i * 8 + 0] = (r >> 8) & 255;
+    out[i * 8 + 1] = r & 255;
+    out[i * 8 + 2] = (g >> 8) & 255;
+    out[i * 8 + 3] = g & 255;
+    out[i * 8 + 4] = (b >> 8) & 255;
+    out[i * 8 + 5] = b & 255;
+    out[i * 8 + 6] = (a >> 8) & 255;
+    out[i * 8 + 7] = a & 255;
+  }
+}
+
+/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/
+static void getPixelColorRGBA8(unsigned char* r, unsigned char* g,
+                               unsigned char* b, unsigned char* a,
+                               const unsigned char* in, size_t i,
+                               const LodePNGColorMode* mode) {
+  if(mode->colortype == LCT_GREY) {
+    if(mode->bitdepth == 8) {
+      *r = *g = *b = in[i];
+      if(mode->key_defined && *r == mode->key_r) *a = 0;
+      else *a = 255;
+    } else if(mode->bitdepth == 16) {
+      *r = *g = *b = in[i * 2 + 0];
+      if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
+      else *a = 255;
+    } else {
+      unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
+      size_t j = i * mode->bitdepth;
+      unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
+      *r = *g = *b = (value * 255) / highest;
+      if(mode->key_defined && value == mode->key_r) *a = 0;
+      else *a = 255;
+    }
+  } else if(mode->colortype == LCT_RGB) {
+    if(mode->bitdepth == 8) {
+      *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2];
+      if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0;
+      else *a = 255;
+    } else {
+      *r = in[i * 6 + 0];
+      *g = in[i * 6 + 2];
+      *b = in[i * 6 + 4];
+      if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
+         && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
+         && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
+      else *a = 255;
+    }
+  } else if(mode->colortype == LCT_PALETTE) {
+    unsigned index;
+    if(mode->bitdepth == 8) index = in[i];
+    else {
+      size_t j = i * mode->bitdepth;
+      index = readBitsFromReversedStream(&j, in, mode->bitdepth);
+    }
+    /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
+    *r = mode->palette[index * 4 + 0];
+    *g = mode->palette[index * 4 + 1];
+    *b = mode->palette[index * 4 + 2];
+    *a = mode->palette[index * 4 + 3];
+  } else if(mode->colortype == LCT_GREY_ALPHA) {
+    if(mode->bitdepth == 8) {
+      *r = *g = *b = in[i * 2 + 0];
+      *a = in[i * 2 + 1];
+    } else {
+      *r = *g = *b = in[i * 4 + 0];
+      *a = in[i * 4 + 2];
+    }
+  } else if(mode->colortype == LCT_RGBA) {
+    if(mode->bitdepth == 8) {
+      *r = in[i * 4 + 0];
+      *g = in[i * 4 + 1];
+      *b = in[i * 4 + 2];
+      *a = in[i * 4 + 3];
+    } else {
+      *r = in[i * 8 + 0];
+      *g = in[i * 8 + 2];
+      *b = in[i * 8 + 4];
+      *a = in[i * 8 + 6];
+    }
+  }
+}
+
+/*Similar to getPixelColorRGBA8, but with all the for loops inside of the color
+mode test cases, optimized to convert the colors much faster, when converting
+to the common case of RGBA with 8 bit per channel. buffer must be RGBA with
+enough memory.*/
+static void getPixelColorsRGBA8(unsigned char* LODEPNG_RESTRICT buffer, size_t numpixels,
+                                const unsigned char* LODEPNG_RESTRICT in,
+                                const LodePNGColorMode* mode) {
+  unsigned num_channels = 4;
+  size_t i;
+  if(mode->colortype == LCT_GREY) {
+    if(mode->bitdepth == 8) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = buffer[1] = buffer[2] = in[i];
+        buffer[3] = 255;
+      }
+      if(mode->key_defined) {
+        buffer -= numpixels * num_channels;
+        for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+          if(buffer[0] == mode->key_r) buffer[3] = 0;
+        }
+      }
+    } else if(mode->bitdepth == 16) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 2];
+        buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255;
+      }
+    } else {
+      unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
+      size_t j = 0;
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
+        buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
+        buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255;
+      }
+    }
+  } else if(mode->colortype == LCT_RGB) {
+    if(mode->bitdepth == 8) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        lodepng_memcpy(buffer, &in[i * 3], 3);
+        buffer[3] = 255;
+      }
+      if(mode->key_defined) {
+        buffer -= numpixels * num_channels;
+        for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+          if(buffer[0] == mode->key_r && buffer[1]== mode->key_g && buffer[2] == mode->key_b) buffer[3] = 0;
+        }
+      }
+    } else {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = in[i * 6 + 0];
+        buffer[1] = in[i * 6 + 2];
+        buffer[2] = in[i * 6 + 4];
+        buffer[3] = mode->key_defined
+           && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
+           && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
+           && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255;
+      }
+    }
+  } else if(mode->colortype == LCT_PALETTE) {
+    if(mode->bitdepth == 8) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        unsigned index = in[i];
+        /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
+        lodepng_memcpy(buffer, &mode->palette[index * 4], 4);
+      }
+    } else {
+      size_t j = 0;
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        unsigned index = readBitsFromReversedStream(&j, in, mode->bitdepth);
+        /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
+        lodepng_memcpy(buffer, &mode->palette[index * 4], 4);
+      }
+    }
+  } else if(mode->colortype == LCT_GREY_ALPHA) {
+    if(mode->bitdepth == 8) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
+        buffer[3] = in[i * 2 + 1];
+      }
+    } else {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
+        buffer[3] = in[i * 4 + 2];
+      }
+    }
+  } else if(mode->colortype == LCT_RGBA) {
+    if(mode->bitdepth == 8) {
+      lodepng_memcpy(buffer, in, numpixels * 4);
+    } else {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = in[i * 8 + 0];
+        buffer[1] = in[i * 8 + 2];
+        buffer[2] = in[i * 8 + 4];
+        buffer[3] = in[i * 8 + 6];
+      }
+    }
+  }
+}
+
+/*Similar to getPixelColorsRGBA8, but with 3-channel RGB output.*/
+static void getPixelColorsRGB8(unsigned char* LODEPNG_RESTRICT buffer, size_t numpixels,
+                               const unsigned char* LODEPNG_RESTRICT in,
+                               const LodePNGColorMode* mode) {
+  const unsigned num_channels = 3;
+  size_t i;
+  if(mode->colortype == LCT_GREY) {
+    if(mode->bitdepth == 8) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = buffer[1] = buffer[2] = in[i];
+      }
+    } else if(mode->bitdepth == 16) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 2];
+      }
+    } else {
+      unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
+      size_t j = 0;
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
+        buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
+      }
+    }
+  } else if(mode->colortype == LCT_RGB) {
+    if(mode->bitdepth == 8) {
+      lodepng_memcpy(buffer, in, numpixels * 3);
+    } else {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = in[i * 6 + 0];
+        buffer[1] = in[i * 6 + 2];
+        buffer[2] = in[i * 6 + 4];
+      }
+    }
+  } else if(mode->colortype == LCT_PALETTE) {
+    if(mode->bitdepth == 8) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        unsigned index = in[i];
+        /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
+        lodepng_memcpy(buffer, &mode->palette[index * 4], 3);
+      }
+    } else {
+      size_t j = 0;
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        unsigned index = readBitsFromReversedStream(&j, in, mode->bitdepth);
+        /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
+        lodepng_memcpy(buffer, &mode->palette[index * 4], 3);
+      }
+    }
+  } else if(mode->colortype == LCT_GREY_ALPHA) {
+    if(mode->bitdepth == 8) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
+      }
+    } else {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
+      }
+    }
+  } else if(mode->colortype == LCT_RGBA) {
+    if(mode->bitdepth == 8) {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        lodepng_memcpy(buffer, &in[i * 4], 3);
+      }
+    } else {
+      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+        buffer[0] = in[i * 8 + 0];
+        buffer[1] = in[i * 8 + 2];
+        buffer[2] = in[i * 8 + 4];
+      }
+    }
+  }
+}
+
+/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with
+given color type, but the given color type must be 16-bit itself.*/
+static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a,
+                                const unsigned char* in, size_t i, const LodePNGColorMode* mode) {
+  if(mode->colortype == LCT_GREY) {
+    *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1];
+    if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
+    else *a = 65535;
+  } else if(mode->colortype == LCT_RGB) {
+    *r = 256u * in[i * 6 + 0] + in[i * 6 + 1];
+    *g = 256u * in[i * 6 + 2] + in[i * 6 + 3];
+    *b = 256u * in[i * 6 + 4] + in[i * 6 + 5];
+    if(mode->key_defined
+       && 256u * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
+       && 256u * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
+       && 256u * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
+    else *a = 65535;
+  } else if(mode->colortype == LCT_GREY_ALPHA) {
+    *r = *g = *b = 256u * in[i * 4 + 0] + in[i * 4 + 1];
+    *a = 256u * in[i * 4 + 2] + in[i * 4 + 3];
+  } else if(mode->colortype == LCT_RGBA) {
+    *r = 256u * in[i * 8 + 0] + in[i * 8 + 1];
+    *g = 256u * in[i * 8 + 2] + in[i * 8 + 3];
+    *b = 256u * in[i * 8 + 4] + in[i * 8 + 5];
+    *a = 256u * in[i * 8 + 6] + in[i * 8 + 7];
+  }
+}
+
+unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
+                         const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
+                         unsigned w, unsigned h) {
+  size_t i;
+  ColorTree tree;
+  size_t numpixels = (size_t)w * (size_t)h;
+  unsigned error = 0;
+
+  if(mode_in->colortype == LCT_PALETTE && !mode_in->palette) {
+    return 107; /* error: must provide palette if input mode is palette */
+  }
+
+  if(lodepng_color_mode_equal(mode_out, mode_in)) {
+    size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
+    lodepng_memcpy(out, in, numbytes);
+    return 0;
+  }
+
+  if(mode_out->colortype == LCT_PALETTE) {
+    size_t palettesize = mode_out->palettesize;
+    const unsigned char* palette = mode_out->palette;
+    size_t palsize = (size_t)1u << mode_out->bitdepth;
+    /*if the user specified output palette but did not give the values, assume
+    they want the values of the input color type (assuming that one is palette).
+    Note that we never create a new palette ourselves.*/
+    if(palettesize == 0) {
+      palettesize = mode_in->palettesize;
+      palette = mode_in->palette;
+      /*if the input was also palette with same bitdepth, then the color types are also
+      equal, so copy literally. This to preserve the exact indices that were in the PNG
+      even in case there are duplicate colors in the palette.*/
+      if(mode_in->colortype == LCT_PALETTE && mode_in->bitdepth == mode_out->bitdepth) {
+        size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
+        lodepng_memcpy(out, in, numbytes);
+        return 0;
+      }
+    }
+    if(palettesize < palsize) palsize = palettesize;
+    color_tree_init(&tree);
+    for(i = 0; i != palsize; ++i) {
+      const unsigned char* p = &palette[i * 4];
+      error = color_tree_add(&tree, p[0], p[1], p[2], p[3], (unsigned)i);
+      if(error) break;
+    }
+  }
+
+  if(!error) {
+    if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16) {
+      for(i = 0; i != numpixels; ++i) {
+        unsigned short r = 0, g = 0, b = 0, a = 0;
+        getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
+        rgba16ToPixel(out, i, mode_out, r, g, b, a);
+      }
+    } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) {
+      getPixelColorsRGBA8(out, numpixels, in, mode_in);
+    } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) {
+      getPixelColorsRGB8(out, numpixels, in, mode_in);
+    } else {
+      unsigned char r = 0, g = 0, b = 0, a = 0;
+      for(i = 0; i != numpixels; ++i) {
+        getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
+        error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a);
+        if(error) break;
+      }
+    }
+  }
+
+  if(mode_out->colortype == LCT_PALETTE) {
+    color_tree_cleanup(&tree);
+  }
+
+  return error;
+}
+
+
+/* Converts a single rgb color without alpha from one type to another, color bits truncated to
+their bitdepth. In case of single channel (gray or palette), only the r channel is used. Slow
+function, do not use to process all pixels of an image. Alpha channel not supported on purpose:
+this is for bKGD, supporting alpha may prevent it from finding a color in the palette, from the
+specification it looks like bKGD should ignore the alpha values of the palette since it can use
+any palette index but doesn't have an alpha channel. Idem with ignoring color key. */
+unsigned lodepng_convert_rgb(
+    unsigned* r_out, unsigned* g_out, unsigned* b_out,
+    unsigned r_in, unsigned g_in, unsigned b_in,
+    const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in) {
+  unsigned r = 0, g = 0, b = 0;
+  unsigned mul = 65535 / ((1u << mode_in->bitdepth) - 1u); /*65535, 21845, 4369, 257, 1*/
+  unsigned shift = 16 - mode_out->bitdepth;
+
+  if(mode_in->colortype == LCT_GREY || mode_in->colortype == LCT_GREY_ALPHA) {
+    r = g = b = r_in * mul;
+  } else if(mode_in->colortype == LCT_RGB || mode_in->colortype == LCT_RGBA) {
+    r = r_in * mul;
+    g = g_in * mul;
+    b = b_in * mul;
+  } else if(mode_in->colortype == LCT_PALETTE) {
+    if(r_in >= mode_in->palettesize) return 82;
+    r = mode_in->palette[r_in * 4 + 0] * 257u;
+    g = mode_in->palette[r_in * 4 + 1] * 257u;
+    b = mode_in->palette[r_in * 4 + 2] * 257u;
+  } else {
+    return 31;
+  }
+
+  /* now convert to output format */
+  if(mode_out->colortype == LCT_GREY || mode_out->colortype == LCT_GREY_ALPHA) {
+    *r_out = r >> shift ;
+  } else if(mode_out->colortype == LCT_RGB || mode_out->colortype == LCT_RGBA) {
+    *r_out = r >> shift ;
+    *g_out = g >> shift ;
+    *b_out = b >> shift ;
+  } else if(mode_out->colortype == LCT_PALETTE) {
+    unsigned i;
+    /* a 16-bit color cannot be in the palette */
+    if((r >> 8) != (r & 255) || (g >> 8) != (g & 255) || (b >> 8) != (b & 255)) return 82;
+    for(i = 0; i < mode_out->palettesize; i++) {
+      unsigned j = i * 4;
+      if((r >> 8) == mode_out->palette[j + 0] && (g >> 8) == mode_out->palette[j + 1] &&
+          (b >> 8) == mode_out->palette[j + 2]) {
+        *r_out = i;
+        return 0;
+      }
+    }
+    return 82;
+  } else {
+    return 31;
+  }
+
+  return 0;
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+void lodepng_color_stats_init(LodePNGColorStats* stats) {
+  /*stats*/
+  stats->colored = 0;
+  stats->key = 0;
+  stats->key_r = stats->key_g = stats->key_b = 0;
+  stats->alpha = 0;
+  stats->numcolors = 0;
+  stats->bits = 1;
+  stats->numpixels = 0;
+  /*settings*/
+  stats->allow_palette = 1;
+  stats->allow_greyscale = 1;
+}
+
+/*function used for debug purposes with C++*/
+/*void printColorStats(LodePNGColorStats* p) {
+  std::cout << "colored: " << (int)p->colored << ", ";
+  std::cout << "key: " << (int)p->key << ", ";
+  std::cout << "key_r: " << (int)p->key_r << ", ";
+  std::cout << "key_g: " << (int)p->key_g << ", ";
+  std::cout << "key_b: " << (int)p->key_b << ", ";
+  std::cout << "alpha: " << (int)p->alpha << ", ";
+  std::cout << "numcolors: " << (int)p->numcolors << ", ";
+  std::cout << "bits: " << (int)p->bits << std::endl;
+}*/
+
+/*Returns how many bits needed to represent given value (max 8 bit)*/
+static unsigned getValueRequiredBits(unsigned char value) {
+  if(value == 0 || value == 255) return 1;
+  /*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/
+  if(value % 17 == 0) return value % 85 == 0 ? 2 : 4;
+  return 8;
+}
+
+/*stats must already have been inited. */
+unsigned lodepng_compute_color_stats(LodePNGColorStats* stats,
+                                     const unsigned char* in, unsigned w, unsigned h,
+                                     const LodePNGColorMode* mode_in) {
+  size_t i;
+  ColorTree tree;
+  size_t numpixels = (size_t)w * (size_t)h;
+  unsigned error = 0;
+
+  /* mark things as done already if it would be impossible to have a more expensive case */
+  unsigned colored_done = lodepng_is_greyscale_type(mode_in) ? 1 : 0;
+  unsigned alpha_done = lodepng_can_have_alpha(mode_in) ? 0 : 1;
+  unsigned numcolors_done = 0;
+  unsigned bpp = lodepng_get_bpp(mode_in);
+  unsigned bits_done = (stats->bits == 1 && bpp == 1) ? 1 : 0;
+  unsigned sixteen = 0; /* whether the input image is 16 bit */
+  unsigned maxnumcolors = 257;
+  if(bpp <= 8) maxnumcolors = LODEPNG_MIN(257, stats->numcolors + (1u << bpp));
+
+  stats->numpixels += numpixels;
+
+  /*if palette not allowed, no need to compute numcolors*/
+  if(!stats->allow_palette) numcolors_done = 1;
+
+  color_tree_init(&tree);
+
+  /*If the stats was already filled in from previous data, fill its palette in tree
+  and mark things as done already if we know they are the most expensive case already*/
+  if(stats->alpha) alpha_done = 1;
+  if(stats->colored) colored_done = 1;
+  if(stats->bits == 16) numcolors_done = 1;
+  if(stats->bits >= bpp) bits_done = 1;
+  if(stats->numcolors >= maxnumcolors) numcolors_done = 1;
+
+  if(!numcolors_done) {
+    for(i = 0; i < stats->numcolors; i++) {
+      const unsigned char* color = &stats->palette[i * 4];
+      error = color_tree_add(&tree, color[0], color[1], color[2], color[3], i);
+      if(error) goto cleanup;
+    }
+  }
+
+  /*Check if the 16-bit input is truly 16-bit*/
+  if(mode_in->bitdepth == 16 && !sixteen) {
+    unsigned short r = 0, g = 0, b = 0, a = 0;
+    for(i = 0; i != numpixels; ++i) {
+      getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
+      if((r & 255) != ((r >> 8) & 255) || (g & 255) != ((g >> 8) & 255) ||
+         (b & 255) != ((b >> 8) & 255) || (a & 255) != ((a >> 8) & 255)) /*first and second byte differ*/ {
+        stats->bits = 16;
+        sixteen = 1;
+        bits_done = 1;
+        numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/
+        break;
+      }
+    }
+  }
+
+  if(sixteen) {
+    unsigned short r = 0, g = 0, b = 0, a = 0;
+
+    for(i = 0; i != numpixels; ++i) {
+      getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
+
+      if(!colored_done && (r != g || r != b)) {
+        stats->colored = 1;
+        colored_done = 1;
+      }
+
+      if(!alpha_done) {
+        unsigned matchkey = (r == stats->key_r && g == stats->key_g && b == stats->key_b);
+        if(a != 65535 && (a != 0 || (stats->key && !matchkey))) {
+          stats->alpha = 1;
+          stats->key = 0;
+          alpha_done = 1;
+        } else if(a == 0 && !stats->alpha && !stats->key) {
+          stats->key = 1;
+          stats->key_r = r;
+          stats->key_g = g;
+          stats->key_b = b;
+        } else if(a == 65535 && stats->key && matchkey) {
+          /* Color key cannot be used if an opaque pixel also has that RGB color. */
+          stats->alpha = 1;
+          stats->key = 0;
+          alpha_done = 1;
+        }
+      }
+      if(alpha_done && numcolors_done && colored_done && bits_done) break;
+    }
+
+    if(stats->key && !stats->alpha) {
+      for(i = 0; i != numpixels; ++i) {
+        getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
+        if(a != 0 && r == stats->key_r && g == stats->key_g && b == stats->key_b) {
+          /* Color key cannot be used if an opaque pixel also has that RGB color. */
+          stats->alpha = 1;
+          stats->key = 0;
+          alpha_done = 1;
+        }
+      }
+    }
+  } else /* < 16-bit */ {
+    unsigned char r = 0, g = 0, b = 0, a = 0;
+    for(i = 0; i != numpixels; ++i) {
+      getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
+
+      if(!bits_done && stats->bits < 8) {
+        /*only r is checked, < 8 bits is only relevant for grayscale*/
+        unsigned bits = getValueRequiredBits(r);
+        if(bits > stats->bits) stats->bits = bits;
+      }
+      bits_done = (stats->bits >= bpp);
+
+      if(!colored_done && (r != g || r != b)) {
+        stats->colored = 1;
+        colored_done = 1;
+        if(stats->bits < 8) stats->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/
+      }
+
+      if(!alpha_done) {
+        unsigned matchkey = (r == stats->key_r && g == stats->key_g && b == stats->key_b);
+        if(a != 255 && (a != 0 || (stats->key && !matchkey))) {
+          stats->alpha = 1;
+          stats->key = 0;
+          alpha_done = 1;
+          if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
+        } else if(a == 0 && !stats->alpha && !stats->key) {
+          stats->key = 1;
+          stats->key_r = r;
+          stats->key_g = g;
+          stats->key_b = b;
+        } else if(a == 255 && stats->key && matchkey) {
+          /* Color key cannot be used if an opaque pixel also has that RGB color. */
+          stats->alpha = 1;
+          stats->key = 0;
+          alpha_done = 1;
+          if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
+        }
+      }
+
+      if(!numcolors_done) {
+        if(!color_tree_has(&tree, r, g, b, a)) {
+          error = color_tree_add(&tree, r, g, b, a, stats->numcolors);
+          if(error) goto cleanup;
+          if(stats->numcolors < 256) {
+            unsigned char* p = stats->palette;
+            unsigned n = stats->numcolors;
+            p[n * 4 + 0] = r;
+            p[n * 4 + 1] = g;
+            p[n * 4 + 2] = b;
+            p[n * 4 + 3] = a;
+          }
+          ++stats->numcolors;
+          numcolors_done = stats->numcolors >= maxnumcolors;
+        }
+      }
+
+      if(alpha_done && numcolors_done && colored_done && bits_done) break;
+    }
+
+    if(stats->key && !stats->alpha) {
+      for(i = 0; i != numpixels; ++i) {
+        getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
+        if(a != 0 && r == stats->key_r && g == stats->key_g && b == stats->key_b) {
+          /* Color key cannot be used if an opaque pixel also has that RGB color. */
+          stats->alpha = 1;
+          stats->key = 0;
+          alpha_done = 1;
+          if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
+        }
+      }
+    }
+
+    /*make the stats's key always 16-bit for consistency - repeat each byte twice*/
+    stats->key_r += (stats->key_r << 8);
+    stats->key_g += (stats->key_g << 8);
+    stats->key_b += (stats->key_b << 8);
+  }
+
+cleanup:
+  color_tree_cleanup(&tree);
+  return error;
+}
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*Adds a single color to the color stats. The stats must already have been inited. The color must be given as 16-bit
+(with 2 bytes repeating for 8-bit and 65535 for opaque alpha channel). This function is expensive, do not call it for
+all pixels of an image but only for a few additional values. */
+static unsigned lodepng_color_stats_add(LodePNGColorStats* stats,
+                                        unsigned r, unsigned g, unsigned b, unsigned a) {
+  unsigned error = 0;
+  unsigned char image[8];
+  LodePNGColorMode mode;
+  lodepng_color_mode_init(&mode);
+  image[0] = r >> 8; image[1] = r; image[2] = g >> 8; image[3] = g;
+  image[4] = b >> 8; image[5] = b; image[6] = a >> 8; image[7] = a;
+  mode.bitdepth = 16;
+  mode.colortype = LCT_RGBA;
+  error = lodepng_compute_color_stats(stats, image, 1, 1, &mode);
+  lodepng_color_mode_cleanup(&mode);
+  return error;
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+/*Computes a minimal PNG color model that can contain all colors as indicated by the stats.
+The stats should be computed with lodepng_compute_color_stats.
+mode_in is raw color profile of the image the stats were computed on, to copy palette order from when relevant.
+Minimal PNG color model means the color type and bit depth that gives smallest amount of bits in the output image,
+e.g. gray if only grayscale pixels, palette if less than 256 colors, color key if only single transparent color, ...
+This is used if auto_convert is enabled (it is by default).
+*/
+static unsigned auto_choose_color(LodePNGColorMode* mode_out,
+                                  const LodePNGColorMode* mode_in,
+                                  const LodePNGColorStats* stats) {
+  unsigned error = 0;
+  unsigned palettebits;
+  size_t i, n;
+  size_t numpixels = stats->numpixels;
+  unsigned palette_ok, gray_ok;
+
+  unsigned alpha = stats->alpha;
+  unsigned key = stats->key;
+  unsigned bits = stats->bits;
+
+  mode_out->key_defined = 0;
+
+  if(key && numpixels <= 16) {
+    alpha = 1; /*too few pixels to justify tRNS chunk overhead*/
+    key = 0;
+    if(bits < 8) bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
+  }
+
+  gray_ok = !stats->colored;
+  if(!stats->allow_greyscale) gray_ok = 0;
+  if(!gray_ok && bits < 8) bits = 8;
+
+  n = stats->numcolors;
+  palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8));
+  palette_ok = n <= 256 && bits <= 8 && n != 0; /*n==0 means likely numcolors wasn't computed*/
+  if(numpixels < n * 2) palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/
+  if(gray_ok && !alpha && bits <= palettebits) palette_ok = 0; /*gray is less overhead*/
+  if(!stats->allow_palette) palette_ok = 0;
+
+  if(palette_ok) {
+    const unsigned char* p = stats->palette;
+    lodepng_palette_clear(mode_out); /*remove potential earlier palette*/
+    for(i = 0; i != stats->numcolors; ++i) {
+      error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]);
+      if(error) break;
+    }
+
+    mode_out->colortype = LCT_PALETTE;
+    mode_out->bitdepth = palettebits;
+
+    if(mode_in->colortype == LCT_PALETTE && mode_in->palettesize >= mode_out->palettesize
+        && mode_in->bitdepth == mode_out->bitdepth) {
+      /*If input should have same palette colors, keep original to preserve its order and prevent conversion*/
+      lodepng_color_mode_cleanup(mode_out);
+      lodepng_color_mode_copy(mode_out, mode_in);
+    }
+  } else /*8-bit or 16-bit per channel*/ {
+    mode_out->bitdepth = bits;
+    mode_out->colortype = alpha ? (gray_ok ? LCT_GREY_ALPHA : LCT_RGBA)
+                                : (gray_ok ? LCT_GREY : LCT_RGB);
+    if(key) {
+      unsigned mask = (1u << mode_out->bitdepth) - 1u; /*stats always uses 16-bit, mask converts it*/
+      mode_out->key_r = stats->key_r & mask;
+      mode_out->key_g = stats->key_g & mask;
+      mode_out->key_b = stats->key_b & mask;
+      mode_out->key_defined = 1;
+    }
+  }
+
+  return error;
+}
+
+#endif /* #ifdef LODEPNG_COMPILE_ENCODER */
+
+/*
+Paeth predictor, used by PNG filter type 4
+The parameters are of type short, but should come from unsigned chars, the shorts
+are only needed to make the paeth calculation correct.
+*/
+static unsigned char paethPredictor(short a, short b, short c) {
+  short pa = LODEPNG_ABS(b - c);
+  short pb = LODEPNG_ABS(a - c);
+  short pc = LODEPNG_ABS(a + b - c - c);
+  /* return input value associated with smallest of pa, pb, pc (with certain priority if equal) */
+  if(pb < pa) { a = b; pa = pb; }
+  return (pc < pa) ? c : a;
+}
+
+/*shared values used by multiple Adam7 related functions*/
+
+static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
+static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/
+static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
+static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
+
+/*
+Outputs various dimensions and positions in the image related to the Adam7 reduced images.
+passw: output containing the width of the 7 passes
+passh: output containing the height of the 7 passes
+filter_passstart: output containing the index of the start and end of each
+ reduced image with filter bytes
+padded_passstart output containing the index of the start and end of each
+ reduced image when without filter bytes but with padded scanlines
+passstart: output containing the index of the start and end of each reduced
+ image without padding between scanlines, but still padding between the images
+w, h: width and height of non-interlaced image
+bpp: bits per pixel
+"padded" is only relevant if bpp is less than 8 and a scanline or image does not
+ end at a full byte
+*/
+static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8],
+                                size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp) {
+  /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/
+  unsigned i;
+
+  /*calculate width and height in pixels of each pass*/
+  for(i = 0; i != 7; ++i) {
+    passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
+    passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
+    if(passw[i] == 0) passh[i] = 0;
+    if(passh[i] == 0) passw[i] = 0;
+  }
+
+  filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
+  for(i = 0; i != 7; ++i) {
+    /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/
+    filter_passstart[i + 1] = filter_passstart[i]
+                            + ((passw[i] && passh[i]) ? passh[i] * (1u + (passw[i] * bpp + 7u) / 8u) : 0);
+    /*bits padded if needed to fill full byte at end of each scanline*/
+    padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7u) / 8u);
+    /*only padded at end of reduced image*/
+    passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7u) / 8u;
+  }
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / PNG Decoder                                                            / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*read the information from the header and store it in the LodePNGInfo. return value is error*/
+unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state,
+                         const unsigned char* in, size_t insize) {
+  unsigned width, height;
+  LodePNGInfo* info = &state->info_png;
+  if(insize == 0 || in == 0) {
+    CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/
+  }
+  if(insize < 33) {
+    CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/
+  }
+
+  /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
+  /* TODO: remove this. One should use a new LodePNGState for new sessions */
+  lodepng_info_cleanup(info);
+  lodepng_info_init(info);
+
+  if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71
+     || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) {
+    CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/
+  }
+  if(lodepng_chunk_length(in + 8) != 13) {
+    CERROR_RETURN_ERROR(state->error, 94); /*error: header size must be 13 bytes*/
+  }
+  if(!lodepng_chunk_type_equals(in + 8, "IHDR")) {
+    CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/
+  }
+
+  /*read the values given in the header*/
+  width = lodepng_read32bitInt(&in[16]);
+  height = lodepng_read32bitInt(&in[20]);
+  /*TODO: remove the undocumented feature that allows to give null pointers to width or height*/
+  if(w) *w = width;
+  if(h) *h = height;
+  info->color.bitdepth = in[24];
+  info->color.colortype = (LodePNGColorType)in[25];
+  info->compression_method = in[26];
+  info->filter_method = in[27];
+  info->interlace_method = in[28];
+
+  /*errors returned only after the parsing so other values are still output*/
+
+  /*error: invalid image size*/
+  if(width == 0 || height == 0) CERROR_RETURN_ERROR(state->error, 93);
+  /*error: invalid colortype or bitdepth combination*/
+  state->error = checkColorValidity(info->color.colortype, info->color.bitdepth);
+  if(state->error) return state->error;
+  /*error: only compression method 0 is allowed in the specification*/
+  if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32);
+  /*error: only filter method 0 is allowed in the specification*/
+  if(info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33);
+  /*error: only interlace methods 0 and 1 exist in the specification*/
+  if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34);
+
+  if(!state->decoder.ignore_crc) {
+    unsigned CRC = lodepng_read32bitInt(&in[29]);
+    unsigned checksum = lodepng_crc32(&in[12], 17);
+    if(CRC != checksum) {
+      CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/
+    }
+  }
+
+  return state->error;
+}
+
+static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon,
+                                 size_t bytewidth, unsigned char filterType, size_t length) {
+  /*
+  For PNG filter method 0
+  unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte,
+  the filter works byte per byte (bytewidth = 1)
+  precon is the previous unfiltered scanline, recon the result, scanline the current one
+  the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead
+  recon and scanline MAY be the same memory address! precon must be disjoint.
+  */
+
+  size_t i;
+  switch(filterType) {
+    case 0:
+      for(i = 0; i != length; ++i) recon[i] = scanline[i];
+      break;
+    case 1:
+      for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i];
+      for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + recon[i - bytewidth];
+      break;
+    case 2:
+      if(precon) {
+        for(i = 0; i != length; ++i) recon[i] = scanline[i] + precon[i];
+      } else {
+        for(i = 0; i != length; ++i) recon[i] = scanline[i];
+      }
+      break;
+    case 3:
+      if(precon) {
+        for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i] + (precon[i] >> 1u);
+        for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1u);
+      } else {
+        for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i];
+        for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1u);
+      }
+      break;
+    case 4:
+      if(precon) {
+        for(i = 0; i != bytewidth; ++i) {
+          recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/
+        }
+
+        /* Unroll independent paths of the paeth predictor. A 6x and 8x version would also be possible but that
+        adds too much code. Whether this actually speeds anything up at all depends on compiler and settings. */
+        if(bytewidth >= 4) {
+          for(; i + 3 < length; i += 4) {
+            size_t j = i - bytewidth;
+            unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1], s2 = scanline[i + 2], s3 = scanline[i + 3];
+            unsigned char r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2], r3 = recon[j + 3];
+            unsigned char p0 = precon[i + 0], p1 = precon[i + 1], p2 = precon[i + 2], p3 = precon[i + 3];
+            unsigned char q0 = precon[j + 0], q1 = precon[j + 1], q2 = precon[j + 2], q3 = precon[j + 3];
+            recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
+            recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
+            recon[i + 2] = s2 + paethPredictor(r2, p2, q2);
+            recon[i + 3] = s3 + paethPredictor(r3, p3, q3);
+          }
+        } else if(bytewidth >= 3) {
+          for(; i + 2 < length; i += 3) {
+            size_t j = i - bytewidth;
+            unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1], s2 = scanline[i + 2];
+            unsigned char r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2];
+            unsigned char p0 = precon[i + 0], p1 = precon[i + 1], p2 = precon[i + 2];
+            unsigned char q0 = precon[j + 0], q1 = precon[j + 1], q2 = precon[j + 2];
+            recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
+            recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
+            recon[i + 2] = s2 + paethPredictor(r2, p2, q2);
+          }
+        } else if(bytewidth >= 2) {
+          for(; i + 1 < length; i += 2) {
+            size_t j = i - bytewidth;
+            unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1];
+            unsigned char r0 = recon[j + 0], r1 = recon[j + 1];
+            unsigned char p0 = precon[i + 0], p1 = precon[i + 1];
+            unsigned char q0 = precon[j + 0], q1 = precon[j + 1];
+            recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
+            recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
+          }
+        }
+
+        for(; i != length; ++i) {
+          recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth]));
+        }
+      } else {
+        for(i = 0; i != bytewidth; ++i) {
+          recon[i] = scanline[i];
+        }
+        for(i = bytewidth; i < length; ++i) {
+          /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/
+          recon[i] = (scanline[i] + recon[i - bytewidth]);
+        }
+      }
+      break;
+    default: return 36; /*error: invalid filter type given*/
+  }
+  return 0;
+}
+
+static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) {
+  /*
+  For PNG filter method 0
+  this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times)
+  out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline
+  w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel
+  in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes)
+  */
+
+  unsigned y;
+  unsigned char* prevline = 0;
+
+  /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
+  size_t bytewidth = (bpp + 7u) / 8u;
+  /*the width of a scanline in bytes, not including the filter type*/
+  size_t linebytes = lodepng_get_raw_size_idat(w, 1, bpp) - 1u;
+
+  for(y = 0; y < h; ++y) {
+    size_t outindex = linebytes * y;
+    size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
+    unsigned char filterType = in[inindex];
+
+    CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes));
+
+    prevline = &out[outindex];
+  }
+
+  return 0;
+}
+
+/*
+in: Adam7 interlaced image, with no padding bits between scanlines, but between
+ reduced images so that each reduced image starts at a byte.
+out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h
+bpp: bits per pixel
+out has the following size in bits: w * h * bpp.
+in is possibly bigger due to padding bits between reduced images.
+out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation
+(because that's likely a little bit faster)
+NOTE: comments about padding bits are only relevant if bpp < 8
+*/
+static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) {
+  unsigned passw[7], passh[7];
+  size_t filter_passstart[8], padded_passstart[8], passstart[8];
+  unsigned i;
+
+  Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
+
+  if(bpp >= 8) {
+    for(i = 0; i != 7; ++i) {
+      unsigned x, y, b;
+      size_t bytewidth = bpp / 8u;
+      for(y = 0; y < passh[i]; ++y)
+      for(x = 0; x < passw[i]; ++x) {
+        size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth;
+        size_t pixeloutstart = ((ADAM7_IY[i] + (size_t)y * ADAM7_DY[i]) * (size_t)w
+                             + ADAM7_IX[i] + (size_t)x * ADAM7_DX[i]) * bytewidth;
+        for(b = 0; b < bytewidth; ++b) {
+          out[pixeloutstart + b] = in[pixelinstart + b];
+        }
+      }
+    }
+  } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ {
+    for(i = 0; i != 7; ++i) {
+      unsigned x, y, b;
+      unsigned ilinebits = bpp * passw[i];
+      unsigned olinebits = bpp * w;
+      size_t obp, ibp; /*bit pointers (for out and in buffer)*/
+      for(y = 0; y < passh[i]; ++y)
+      for(x = 0; x < passw[i]; ++x) {
+        ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
+        obp = (ADAM7_IY[i] + (size_t)y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + (size_t)x * ADAM7_DX[i]) * bpp;
+        for(b = 0; b < bpp; ++b) {
+          unsigned char bit = readBitFromReversedStream(&ibp, in);
+          setBitOfReversedStream(&obp, out, bit);
+        }
+      }
+    }
+  }
+}
+
+static void removePaddingBits(unsigned char* out, const unsigned char* in,
+                              size_t olinebits, size_t ilinebits, unsigned h) {
+  /*
+  After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need
+  to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers
+  for the Adam7 code, the color convert code and the output to the user.
+  in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must
+  have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
+  also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
+  only useful if (ilinebits - olinebits) is a value in the range 1..7
+  */
+  unsigned y;
+  size_t diff = ilinebits - olinebits;
+  size_t ibp = 0, obp = 0; /*input and output bit pointers*/
+  for(y = 0; y < h; ++y) {
+    size_t x;
+    for(x = 0; x < olinebits; ++x) {
+      unsigned char bit = readBitFromReversedStream(&ibp, in);
+      setBitOfReversedStream(&obp, out, bit);
+    }
+    ibp += diff;
+  }
+}
+
+/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from
+the IDAT chunks (with filter index bytes and possible padding bits)
+return value is error*/
+static unsigned postProcessScanlines(unsigned char* out, unsigned char* in,
+                                     unsigned w, unsigned h, const LodePNGInfo* info_png) {
+  /*
+  This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype.
+  Steps:
+  *) if no Adam7: 1) unfilter 2) remove padding bits (= possible extra bits per scanline if bpp < 8)
+  *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
+  NOTE: the in buffer will be overwritten with intermediate data!
+  */
+  unsigned bpp = lodepng_get_bpp(&info_png->color);
+  if(bpp == 0) return 31; /*error: invalid colortype*/
+
+  if(info_png->interlace_method == 0) {
+    if(bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) {
+      CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp));
+      removePaddingBits(out, in, w * bpp, ((w * bpp + 7u) / 8u) * 8u, h);
+    }
+    /*we can immediately filter into the out buffer, no other steps needed*/
+    else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp));
+  } else /*interlace_method is 1 (Adam7)*/ {
+    unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
+    unsigned i;
+
+    Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
+
+    for(i = 0; i != 7; ++i) {
+      CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp));
+      /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline,
+      move bytes instead of bits or move not at all*/
+      if(bpp < 8) {
+        /*remove padding bits in scanlines; after this there still may be padding
+        bits between the different reduced images: each reduced image still starts nicely at a byte*/
+        removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp,
+                          ((passw[i] * bpp + 7u) / 8u) * 8u, passh[i]);
+      }
+    }
+
+    Adam7_deinterlace(out, in, w, h, bpp);
+  }
+
+  return 0;
+}
+
+static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) {
+  unsigned pos = 0, i;
+  color->palettesize = chunkLength / 3u;
+  if(color->palettesize == 0 || color->palettesize > 256) return 38; /*error: palette too small or big*/
+  lodepng_color_mode_alloc_palette(color);
+  if(!color->palette && color->palettesize) {
+    color->palettesize = 0;
+    return 83; /*alloc fail*/
+  }
+
+  for(i = 0; i != color->palettesize; ++i) {
+    color->palette[4 * i + 0] = data[pos++]; /*R*/
+    color->palette[4 * i + 1] = data[pos++]; /*G*/
+    color->palette[4 * i + 2] = data[pos++]; /*B*/
+    color->palette[4 * i + 3] = 255; /*alpha*/
+  }
+
+  return 0; /* OK */
+}
+
+static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) {
+  unsigned i;
+  if(color->colortype == LCT_PALETTE) {
+    /*error: more alpha values given than there are palette entries*/
+    if(chunkLength > color->palettesize) return 39;
+
+    for(i = 0; i != chunkLength; ++i) color->palette[4 * i + 3] = data[i];
+  } else if(color->colortype == LCT_GREY) {
+    /*error: this chunk must be 2 bytes for grayscale image*/
+    if(chunkLength != 2) return 30;
+
+    color->key_defined = 1;
+    color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1];
+  } else if(color->colortype == LCT_RGB) {
+    /*error: this chunk must be 6 bytes for RGB image*/
+    if(chunkLength != 6) return 41;
+
+    color->key_defined = 1;
+    color->key_r = 256u * data[0] + data[1];
+    color->key_g = 256u * data[2] + data[3];
+    color->key_b = 256u * data[4] + data[5];
+  }
+  else return 42; /*error: tRNS chunk not allowed for other color models*/
+
+  return 0; /* OK */
+}
+
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*background color chunk (bKGD)*/
+static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+  if(info->color.colortype == LCT_PALETTE) {
+    /*error: this chunk must be 1 byte for indexed color image*/
+    if(chunkLength != 1) return 43;
+
+    /*error: invalid palette index, or maybe this chunk appeared before PLTE*/
+    if(data[0] >= info->color.palettesize) return 103;
+
+    info->background_defined = 1;
+    info->background_r = info->background_g = info->background_b = data[0];
+  } else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) {
+    /*error: this chunk must be 2 bytes for grayscale image*/
+    if(chunkLength != 2) return 44;
+
+    /*the values are truncated to bitdepth in the PNG file*/
+    info->background_defined = 1;
+    info->background_r = info->background_g = info->background_b = 256u * data[0] + data[1];
+  } else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) {
+    /*error: this chunk must be 6 bytes for grayscale image*/
+    if(chunkLength != 6) return 45;
+
+    /*the values are truncated to bitdepth in the PNG file*/
+    info->background_defined = 1;
+    info->background_r = 256u * data[0] + data[1];
+    info->background_g = 256u * data[2] + data[3];
+    info->background_b = 256u * data[4] + data[5];
+  }
+
+  return 0; /* OK */
+}
+
+/*text chunk (tEXt)*/
+static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+  unsigned error = 0;
+  char *key = 0, *str = 0;
+
+  while(!error) /*not really a while loop, only used to break on error*/ {
+    unsigned length, string2_begin;
+
+    length = 0;
+    while(length < chunkLength && data[length] != 0) ++length;
+    /*even though it's not allowed by the standard, no error is thrown if
+    there's no null termination char, if the text is empty*/
+    if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
+
+    key = (char*)lodepng_malloc(length + 1);
+    if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    lodepng_memcpy(key, data, length);
+    key[length] = 0;
+
+    string2_begin = length + 1; /*skip keyword null terminator*/
+
+    length = (unsigned)(chunkLength < string2_begin ? 0 : chunkLength - string2_begin);
+    str = (char*)lodepng_malloc(length + 1);
+    if(!str) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    lodepng_memcpy(str, data + string2_begin, length);
+    str[length] = 0;
+
+    error = lodepng_add_text(info, key, str);
+
+    break;
+  }
+
+  lodepng_free(key);
+  lodepng_free(str);
+
+  return error;
+}
+
+/*compressed text chunk (zTXt)*/
+static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
+                               const unsigned char* data, size_t chunkLength) {
+  unsigned error = 0;
+
+  unsigned length, string2_begin;
+  char *key = 0;
+  unsigned char* str = 0;
+  size_t size = 0;
+
+  while(!error) /*not really a while loop, only used to break on error*/ {
+    for(length = 0; length < chunkLength && data[length] != 0; ++length) ;
+    if(length + 2 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
+    if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
+
+    key = (char*)lodepng_malloc(length + 1);
+    if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    lodepng_memcpy(key, data, length);
+    key[length] = 0;
+
+    if(data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
+
+    string2_begin = length + 2;
+    if(string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
+
+    length = (unsigned)chunkLength - string2_begin;
+    /*will fail if zlib error, e.g. if length is too small*/
+    error = zlib_decompress(&str, &size, 0, &data[string2_begin],
+                            length, zlibsettings);
+    if(error) break;
+    error = lodepng_add_text_sized(info, key, (char*)str, size);
+
+    break;
+  }
+
+  lodepng_free(key);
+  lodepng_free(str);
+
+  return error;
+}
+
+/*international text chunk (iTXt)*/
+static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
+                               const unsigned char* data, size_t chunkLength) {
+  unsigned error = 0;
+  unsigned i;
+
+  unsigned length, begin, compressed;
+  char *key = 0, *langtag = 0, *transkey = 0;
+
+  while(!error) /*not really a while loop, only used to break on error*/ {
+    /*Quick check if the chunk length isn't too small. Even without check
+    it'd still fail with other error checks below if it's too short. This just gives a different error code.*/
+    if(chunkLength < 5) CERROR_BREAK(error, 30); /*iTXt chunk too short*/
+
+    /*read the key*/
+    for(length = 0; length < chunkLength && data[length] != 0; ++length) ;
+    if(length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/
+    if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
+
+    key = (char*)lodepng_malloc(length + 1);
+    if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    lodepng_memcpy(key, data, length);
+    key[length] = 0;
+
+    /*read the compression method*/
+    compressed = data[length + 1];
+    if(data[length + 2] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
+
+    /*even though it's not allowed by the standard, no error is thrown if
+    there's no null termination char, if the text is empty for the next 3 texts*/
+
+    /*read the langtag*/
+    begin = length + 3;
+    length = 0;
+    for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length;
+
+    langtag = (char*)lodepng_malloc(length + 1);
+    if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    lodepng_memcpy(langtag, data + begin, length);
+    langtag[length] = 0;
+
+    /*read the transkey*/
+    begin += length + 1;
+    length = 0;
+    for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length;
+
+    transkey = (char*)lodepng_malloc(length + 1);
+    if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    lodepng_memcpy(transkey, data + begin, length);
+    transkey[length] = 0;
+
+    /*read the actual text*/
+    begin += length + 1;
+
+    length = (unsigned)chunkLength < begin ? 0 : (unsigned)chunkLength - begin;
+
+    if(compressed) {
+      unsigned char* str = 0;
+      size_t size = 0;
+      /*will fail if zlib error, e.g. if length is too small*/
+      error = zlib_decompress(&str, &size, 0, &data[begin],
+                              length, zlibsettings);
+      if(!error) error = lodepng_add_itext_sized(info, key, langtag, transkey, (char*)str, size);
+      lodepng_free(str);
+    } else {
+      error = lodepng_add_itext_sized(info, key, langtag, transkey, (char*)(data + begin), length);
+    }
+
+    break;
+  }
+
+  lodepng_free(key);
+  lodepng_free(langtag);
+  lodepng_free(transkey);
+
+  return error;
+}
+
+static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+  if(chunkLength != 7) return 73; /*invalid tIME chunk size*/
+
+  info->time_defined = 1;
+  info->time.year = 256u * data[0] + data[1];
+  info->time.month = data[2];
+  info->time.day = data[3];
+  info->time.hour = data[4];
+  info->time.minute = data[5];
+  info->time.second = data[6];
+
+  return 0; /* OK */
+}
+
+static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+  if(chunkLength != 9) return 74; /*invalid pHYs chunk size*/
+
+  info->phys_defined = 1;
+  info->phys_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
+  info->phys_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7];
+  info->phys_unit = data[8];
+
+  return 0; /* OK */
+}
+
+static unsigned readChunk_gAMA(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+  if(chunkLength != 4) return 96; /*invalid gAMA chunk size*/
+
+  info->gama_defined = 1;
+  info->gama_gamma = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
+
+  return 0; /* OK */
+}
+
+static unsigned readChunk_cHRM(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+  if(chunkLength != 32) return 97; /*invalid cHRM chunk size*/
+
+  info->chrm_defined = 1;
+  info->chrm_white_x = 16777216u * data[ 0] + 65536u * data[ 1] + 256u * data[ 2] + data[ 3];
+  info->chrm_white_y = 16777216u * data[ 4] + 65536u * data[ 5] + 256u * data[ 6] + data[ 7];
+  info->chrm_red_x   = 16777216u * data[ 8] + 65536u * data[ 9] + 256u * data[10] + data[11];
+  info->chrm_red_y   = 16777216u * data[12] + 65536u * data[13] + 256u * data[14] + data[15];
+  info->chrm_green_x = 16777216u * data[16] + 65536u * data[17] + 256u * data[18] + data[19];
+  info->chrm_green_y = 16777216u * data[20] + 65536u * data[21] + 256u * data[22] + data[23];
+  info->chrm_blue_x  = 16777216u * data[24] + 65536u * data[25] + 256u * data[26] + data[27];
+  info->chrm_blue_y  = 16777216u * data[28] + 65536u * data[29] + 256u * data[30] + data[31];
+
+  return 0; /* OK */
+}
+
+static unsigned readChunk_sRGB(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+  if(chunkLength != 1) return 98; /*invalid sRGB chunk size (this one is never ignored)*/
+
+  info->srgb_defined = 1;
+  info->srgb_intent = data[0];
+
+  return 0; /* OK */
+}
+
+static unsigned readChunk_iCCP(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
+                               const unsigned char* data, size_t chunkLength) {
+  unsigned error = 0;
+  unsigned i;
+  size_t size = 0;
+
+  unsigned length, string2_begin;
+
+  info->iccp_defined = 1;
+  if(info->iccp_name) lodepng_clear_icc(info);
+
+  for(length = 0; length < chunkLength && data[length] != 0; ++length) ;
+  if(length + 2 >= chunkLength) return 75; /*no null termination, corrupt?*/
+  if(length < 1 || length > 79) return 89; /*keyword too short or long*/
+
+  info->iccp_name = (char*)lodepng_malloc(length + 1);
+  if(!info->iccp_name) return 83; /*alloc fail*/
+
+  info->iccp_name[length] = 0;
+  for(i = 0; i != length; ++i) info->iccp_name[i] = (char)data[i];
+
+  if(data[length + 1] != 0) return 72; /*the 0 byte indicating compression must be 0*/
+
+  string2_begin = length + 2;
+  if(string2_begin > chunkLength) return 75; /*no null termination, corrupt?*/
+
+  length = (unsigned)chunkLength - string2_begin;
+  error = zlib_decompress(&info->iccp_profile, &size, 0,
+                          &data[string2_begin],
+                          length, zlibsettings);
+  info->iccp_profile_size = size;
+  if(!error && !info->iccp_profile_size) error = 100; /*invalid ICC profile size*/
+  return error;
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos,
+                               const unsigned char* in, size_t insize) {
+  const unsigned char* chunk = in + pos;
+  unsigned chunkLength;
+  const unsigned char* data;
+  unsigned unhandled = 0;
+  unsigned error = 0;
+
+  if(pos + 4 > insize) return 30;
+  chunkLength = lodepng_chunk_length(chunk);
+  if(chunkLength > 2147483647) return 63;
+  data = lodepng_chunk_data_const(chunk);
+  if(data + chunkLength + 4 > in + insize) return 30;
+
+  if(lodepng_chunk_type_equals(chunk, "PLTE")) {
+    error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "tRNS")) {
+    error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  } else if(lodepng_chunk_type_equals(chunk, "bKGD")) {
+    error = readChunk_bKGD(&state->info_png, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "tEXt")) {
+    error = readChunk_tEXt(&state->info_png, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "zTXt")) {
+    error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "iTXt")) {
+    error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "tIME")) {
+    error = readChunk_tIME(&state->info_png, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "pHYs")) {
+    error = readChunk_pHYs(&state->info_png, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "gAMA")) {
+    error = readChunk_gAMA(&state->info_png, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "cHRM")) {
+    error = readChunk_cHRM(&state->info_png, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "sRGB")) {
+    error = readChunk_sRGB(&state->info_png, data, chunkLength);
+  } else if(lodepng_chunk_type_equals(chunk, "iCCP")) {
+    error = readChunk_iCCP(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+  } else {
+    /* unhandled chunk is ok (is not an error) */
+    unhandled = 1;
+  }
+
+  if(!error && !unhandled && !state->decoder.ignore_crc) {
+    if(lodepng_chunk_check_crc(chunk)) return 57; /*invalid CRC*/
+  }
+
+  return error;
+}
+
+/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
+static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
+                          LodePNGState* state,
+                          const unsigned char* in, size_t insize) {
+  unsigned char IEND = 0;
+  const unsigned char* chunk;
+  unsigned char* idat; /*the data from idat chunks, zlib compressed*/
+  size_t idatsize = 0;
+  unsigned char* scanlines = 0;
+  size_t scanlines_size = 0, expected_size = 0;
+  size_t outsize = 0;
+
+  /*for unknown chunk order*/
+  unsigned unknown = 0;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+
+  /* safe output values in case error happens */
+  *out = 0;
+  *w = *h = 0;
+
+  state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/
+  if(state->error) return;
+
+  if(lodepng_pixel_overflow(*w, *h, &state->info_png.color, &state->info_raw)) {
+    CERROR_RETURN(state->error, 92); /*overflow possible due to amount of pixels*/
+  }
+
+  /*the input filesize is a safe upper bound for the sum of idat chunks size*/
+  idat = (unsigned char*)lodepng_malloc(insize);
+  if(!idat) CERROR_RETURN(state->error, 83); /*alloc fail*/
+
+  chunk = &in[33]; /*first byte of the first chunk after the header*/
+
+  /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
+  IDAT data is put at the start of the in buffer*/
+  while(!IEND && !state->error) {
+    unsigned chunkLength;
+    const unsigned char* data; /*the data in the chunk*/
+
+    /*error: size of the in buffer too small to contain next chunk*/
+    if((size_t)((chunk - in) + 12) > insize || chunk < in) {
+      if(state->decoder.ignore_end) break; /*other errors may still happen though*/
+      CERROR_BREAK(state->error, 30);
+    }
+
+    /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
+    chunkLength = lodepng_chunk_length(chunk);
+    /*error: chunk length larger than the max PNG chunk size*/
+    if(chunkLength > 2147483647) {
+      if(state->decoder.ignore_end) break; /*other errors may still happen though*/
+      CERROR_BREAK(state->error, 63);
+    }
+
+    if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) {
+      CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/
+    }
+
+    data = lodepng_chunk_data_const(chunk);
+
+    unknown = 0;
+
+    /*IDAT chunk, containing compressed image data*/
+    if(lodepng_chunk_type_equals(chunk, "IDAT")) {
+      size_t newsize;
+      if(lodepng_addofl(idatsize, chunkLength, &newsize)) CERROR_BREAK(state->error, 95);
+      if(newsize > insize) CERROR_BREAK(state->error, 95);
+      lodepng_memcpy(idat + idatsize, data, chunkLength);
+      idatsize += chunkLength;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+      critical_pos = 3;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    } else if(lodepng_chunk_type_equals(chunk, "IEND")) {
+      /*IEND chunk*/
+      IEND = 1;
+    } else if(lodepng_chunk_type_equals(chunk, "PLTE")) {
+      /*palette chunk (PLTE)*/
+      state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
+      if(state->error) break;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+      critical_pos = 2;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    } else if(lodepng_chunk_type_equals(chunk, "tRNS")) {
+      /*palette transparency chunk (tRNS). Even though this one is an ancillary chunk , it is still compiled
+      in without 'LODEPNG_COMPILE_ANCILLARY_CHUNKS' because it contains essential color information that
+      affects the alpha channel of pixels. */
+      state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
+      if(state->error) break;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+      /*background color chunk (bKGD)*/
+    } else if(lodepng_chunk_type_equals(chunk, "bKGD")) {
+      state->error = readChunk_bKGD(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    } else if(lodepng_chunk_type_equals(chunk, "tEXt")) {
+      /*text chunk (tEXt)*/
+      if(state->decoder.read_text_chunks) {
+        state->error = readChunk_tEXt(&state->info_png, data, chunkLength);
+        if(state->error) break;
+      }
+    } else if(lodepng_chunk_type_equals(chunk, "zTXt")) {
+      /*compressed text chunk (zTXt)*/
+      if(state->decoder.read_text_chunks) {
+        state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
+        if(state->error) break;
+      }
+    } else if(lodepng_chunk_type_equals(chunk, "iTXt")) {
+      /*international text chunk (iTXt)*/
+      if(state->decoder.read_text_chunks) {
+        state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
+        if(state->error) break;
+      }
+    } else if(lodepng_chunk_type_equals(chunk, "tIME")) {
+      state->error = readChunk_tIME(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    } else if(lodepng_chunk_type_equals(chunk, "pHYs")) {
+      state->error = readChunk_pHYs(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    } else if(lodepng_chunk_type_equals(chunk, "gAMA")) {
+      state->error = readChunk_gAMA(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    } else if(lodepng_chunk_type_equals(chunk, "cHRM")) {
+      state->error = readChunk_cHRM(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    } else if(lodepng_chunk_type_equals(chunk, "sRGB")) {
+      state->error = readChunk_sRGB(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    } else if(lodepng_chunk_type_equals(chunk, "iCCP")) {
+      state->error = readChunk_iCCP(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
+      if(state->error) break;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    } else /*it's not an implemented chunk type, so ignore it: skip over the data*/ {
+      /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
+      if(!state->decoder.ignore_critical && !lodepng_chunk_ancillary(chunk)) {
+        CERROR_BREAK(state->error, 69);
+      }
+
+      unknown = 1;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+      if(state->decoder.remember_unknown_chunks) {
+        state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1],
+                                            &state->info_png.unknown_chunks_size[critical_pos - 1], chunk);
+        if(state->error) break;
+      }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    }
+
+    if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/ {
+      if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/
+    }
+
+    if(!IEND) chunk = lodepng_chunk_next_const(chunk, in + insize);
+  }
+
+  if(state->info_png.color.colortype == LCT_PALETTE && !state->info_png.color.palette) {
+    state->error = 106; /* error: PNG file must have PLTE chunk if color type is palette */
+  }
+
+  if(!state->error) {
+    /*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation.
+    If the decompressed size does not match the prediction, the image must be corrupt.*/
+    if(state->info_png.interlace_method == 0) {
+      size_t bpp = lodepng_get_bpp(&state->info_png.color);
+      expected_size = lodepng_get_raw_size_idat(*w, *h, bpp);
+    } else {
+      size_t bpp = lodepng_get_bpp(&state->info_png.color);
+      /*Adam-7 interlaced: expected size is the sum of the 7 sub-images sizes*/
+      expected_size = 0;
+      expected_size += lodepng_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, bpp);
+      if(*w > 4) expected_size += lodepng_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, bpp);
+      expected_size += lodepng_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, bpp);
+      if(*w > 2) expected_size += lodepng_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, bpp);
+      expected_size += lodepng_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, bpp);
+      if(*w > 1) expected_size += lodepng_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, bpp);
+      expected_size += lodepng_get_raw_size_idat((*w + 0), (*h + 0) >> 1, bpp);
+    }
+
+    state->error = zlib_decompress(&scanlines, &scanlines_size, expected_size, idat, idatsize, &state->decoder.zlibsettings);
+  }
+  if(!state->error && scanlines_size != expected_size) state->error = 91; /*decompressed size doesn't match prediction*/
+  lodepng_free(idat);
+
+  if(!state->error) {
+    outsize = lodepng_get_raw_size(*w, *h, &state->info_png.color);
+    *out = (unsigned char*)lodepng_malloc(outsize);
+    if(!*out) state->error = 83; /*alloc fail*/
+  }
+  if(!state->error) {
+    lodepng_memset(*out, 0, outsize);
+    state->error = postProcessScanlines(*out, scanlines, *w, *h, &state->info_png);
+  }
+  lodepng_free(scanlines);
+}
+
+unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
+                        LodePNGState* state,
+                        const unsigned char* in, size_t insize) {
+  *out = 0;
+  decodeGeneric(out, w, h, state, in, insize);
+  if(state->error) return state->error;
+  if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color)) {
+    /*same color type, no copying or converting of data needed*/
+    /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype
+    the raw image has to the end user*/
+    if(!state->decoder.color_convert) {
+      state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color);
+      if(state->error) return state->error;
+    }
+  } else { /*color conversion needed*/
+    unsigned char* data = *out;
+    size_t outsize;
+
+    /*TODO: check if this works according to the statement in the documentation: "The converter can convert
+    from grayscale input color type, to 8-bit grayscale or grayscale with alpha"*/
+    if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA)
+       && !(state->info_raw.bitdepth == 8)) {
+      return 56; /*unsupported color mode conversion*/
+    }
+
+    outsize = lodepng_get_raw_size(*w, *h, &state->info_raw);
+    *out = (unsigned char*)lodepng_malloc(outsize);
+    if(!(*out)) {
+      state->error = 83; /*alloc fail*/
+    }
+    else state->error = lodepng_convert(*out, data, &state->info_raw,
+                                        &state->info_png.color, *w, *h);
+    lodepng_free(data);
+  }
+  return state->error;
+}
+
+unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in,
+                               size_t insize, LodePNGColorType colortype, unsigned bitdepth) {
+  unsigned error;
+  LodePNGState state;
+  lodepng_state_init(&state);
+  state.info_raw.colortype = colortype;
+  state.info_raw.bitdepth = bitdepth;
+  error = lodepng_decode(out, w, h, &state, in, insize);
+  lodepng_state_cleanup(&state);
+  return error;
+}
+
+unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) {
+  return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8);
+}
+
+unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) {
+  return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8);
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename,
+                             LodePNGColorType colortype, unsigned bitdepth) {
+  unsigned char* buffer = 0;
+  size_t buffersize;
+  unsigned error;
+  /* safe output values in case error happens */
+  *out = 0;
+  *w = *h = 0;
+  error = lodepng_load_file(&buffer, &buffersize, filename);
+  if(!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth);
+  lodepng_free(buffer);
+  return error;
+}
+
+unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) {
+  return lodepng_decode_file(out, w, h, filename, LCT_RGBA, 8);
+}
+
+unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) {
+  return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8);
+}
+#endif /*LODEPNG_COMPILE_DISK*/
+
+void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) {
+  settings->color_convert = 1;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  settings->read_text_chunks = 1;
+  settings->remember_unknown_chunks = 0;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+  settings->ignore_crc = 0;
+  settings->ignore_critical = 0;
+  settings->ignore_end = 0;
+  lodepng_decompress_settings_init(&settings->zlibsettings);
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
+
+void lodepng_state_init(LodePNGState* state) {
+#ifdef LODEPNG_COMPILE_DECODER
+  lodepng_decoder_settings_init(&state->decoder);
+#endif /*LODEPNG_COMPILE_DECODER*/
+#ifdef LODEPNG_COMPILE_ENCODER
+  lodepng_encoder_settings_init(&state->encoder);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+  lodepng_color_mode_init(&state->info_raw);
+  lodepng_info_init(&state->info_png);
+  state->error = 1;
+}
+
+void lodepng_state_cleanup(LodePNGState* state) {
+  lodepng_color_mode_cleanup(&state->info_raw);
+  lodepng_info_cleanup(&state->info_png);
+}
+
+void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) {
+  lodepng_state_cleanup(dest);
+  *dest = *source;
+  lodepng_color_mode_init(&dest->info_raw);
+  lodepng_info_init(&dest->info_png);
+  dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if(dest->error) return;
+  dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if(dest->error) return;
+}
+
+#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / PNG Encoder                                                            / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+
+static unsigned writeSignature(ucvector* out) {
+  size_t pos = out->size;
+  const unsigned char signature[] = {137, 80, 78, 71, 13, 10, 26, 10};
+  /*8 bytes PNG signature, aka the magic bytes*/
+  if(!ucvector_resize(out, out->size + 8)) return 83; /*alloc fail*/
+  lodepng_memcpy(out->data + pos, signature, 8);
+  return 0;
+}
+
+static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h,
+                              LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method) {
+  unsigned char *chunk, *data;
+  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 13, "IHDR"));
+  data = chunk + 8;
+
+  lodepng_set32bitInt(data + 0, w); /*width*/
+  lodepng_set32bitInt(data + 4, h); /*height*/
+  data[8] = (unsigned char)bitdepth; /*bit depth*/
+  data[9] = (unsigned char)colortype; /*color type*/
+  data[10] = 0; /*compression method*/
+  data[11] = 0; /*filter method*/
+  data[12] = interlace_method; /*interlace method*/
+
+  lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+/* only adds the chunk if needed (there is a key or palette with alpha) */
+static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info) {
+  unsigned char* chunk;
+  size_t i, j = 8;
+
+  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, info->palettesize * 3, "PLTE"));
+
+  for(i = 0; i != info->palettesize; ++i) {
+    /*add all channels except alpha channel*/
+    chunk[j++] = info->palette[i * 4 + 0];
+    chunk[j++] = info->palette[i * 4 + 1];
+    chunk[j++] = info->palette[i * 4 + 2];
+  }
+
+  lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info) {
+  unsigned char* chunk = 0;
+
+  if(info->colortype == LCT_PALETTE) {
+    size_t i, amount = info->palettesize;
+    /*the tail of palette values that all have 255 as alpha, does not have to be encoded*/
+    for(i = info->palettesize; i != 0; --i) {
+      if(info->palette[4 * (i - 1) + 3] != 255) break;
+      --amount;
+    }
+    if(amount) {
+      CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, amount, "tRNS"));
+      /*add the alpha channel values from the palette*/
+      for(i = 0; i != amount; ++i) chunk[8 + i] = info->palette[4 * i + 3];
+    }
+  } else if(info->colortype == LCT_GREY) {
+    if(info->key_defined) {
+      CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 2, "tRNS"));
+      chunk[8] = (unsigned char)(info->key_r >> 8);
+      chunk[9] = (unsigned char)(info->key_r & 255);
+    }
+  } else if(info->colortype == LCT_RGB) {
+    if(info->key_defined) {
+      CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 6, "tRNS"));
+      chunk[8] = (unsigned char)(info->key_r >> 8);
+      chunk[9] = (unsigned char)(info->key_r & 255);
+      chunk[10] = (unsigned char)(info->key_g >> 8);
+      chunk[11] = (unsigned char)(info->key_g & 255);
+      chunk[12] = (unsigned char)(info->key_b >> 8);
+      chunk[13] = (unsigned char)(info->key_b & 255);
+    }
+  }
+
+  if(chunk) lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize,
+                              LodePNGCompressSettings* zlibsettings) {
+  unsigned error = 0;
+  unsigned char* zlib = 0;
+  size_t zlibsize = 0;
+
+  error = zlib_compress(&zlib, &zlibsize, data, datasize, zlibsettings);
+  if(!error) {
+    error = lodepng_chunk_createv(out, zlibsize, "IDAT", zlib);
+  }
+  lodepng_free(zlib);
+  return error;
+}
+
+static unsigned addChunk_IEND(ucvector* out) {
+  return lodepng_chunk_createv(out, 0, "IEND", 0);
+}
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+
+static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) {
+  unsigned char* chunk = 0;
+  size_t keysize = lodepng_strlen(keyword), textsize = lodepng_strlen(textstring);
+  size_t size = keysize + 1 + textsize;
+  if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/
+  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, size, "tEXt"));
+  lodepng_memcpy(chunk + 8, keyword, keysize);
+  chunk[8 + keysize] = 0; /*null termination char*/
+  lodepng_memcpy(chunk + 9 + keysize, textstring, textsize);
+  lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring,
+                              LodePNGCompressSettings* zlibsettings) {
+  unsigned error = 0;
+  unsigned char* chunk = 0;
+  unsigned char* compressed = 0;
+  size_t compressedsize = 0;
+  size_t textsize = lodepng_strlen(textstring);
+  size_t keysize = lodepng_strlen(keyword);
+  if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/
+
+  error = zlib_compress(&compressed, &compressedsize,
+                        (const unsigned char*)textstring, textsize, zlibsettings);
+  if(!error) {
+    size_t size = keysize + 2 + compressedsize;
+    error = lodepng_chunk_init(&chunk, out, size, "zTXt");
+  }
+  if(!error) {
+    lodepng_memcpy(chunk + 8, keyword, keysize);
+    chunk[8 + keysize] = 0; /*null termination char*/
+    chunk[9 + keysize] = 0; /*compression method: 0*/
+    lodepng_memcpy(chunk + 10 + keysize, compressed, compressedsize);
+    lodepng_chunk_generate_crc(chunk);
+  }
+
+  lodepng_free(compressed);
+  return error;
+}
+
+static unsigned addChunk_iTXt(ucvector* out, unsigned compress, const char* keyword, const char* langtag,
+                              const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings) {
+  unsigned error = 0;
+  unsigned char* chunk = 0;
+  unsigned char* compressed = 0;
+  size_t compressedsize = 0;
+  size_t textsize = lodepng_strlen(textstring);
+  size_t keysize = lodepng_strlen(keyword), langsize = lodepng_strlen(langtag), transsize = lodepng_strlen(transkey);
+
+  if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/
+
+  if(compress) {
+    error = zlib_compress(&compressed, &compressedsize,
+                          (const unsigned char*)textstring, textsize, zlibsettings);
+  }
+  if(!error) {
+    size_t size = keysize + 3 + langsize + 1 + transsize + 1 + (compress ? compressedsize : textsize);
+    error = lodepng_chunk_init(&chunk, out, size, "iTXt");
+  }
+  if(!error) {
+    size_t pos = 8;
+    lodepng_memcpy(chunk + pos, keyword, keysize);
+    pos += keysize;
+    chunk[pos++] = 0; /*null termination char*/
+    chunk[pos++] = (compress ? 1 : 0); /*compression flag*/
+    chunk[pos++] = 0; /*compression method: 0*/
+    lodepng_memcpy(chunk + pos, langtag, langsize);
+    pos += langsize;
+    chunk[pos++] = 0; /*null termination char*/
+    lodepng_memcpy(chunk + pos, transkey, transsize);
+    pos += transsize;
+    chunk[pos++] = 0; /*null termination char*/
+    if(compress) {
+      lodepng_memcpy(chunk + pos, compressed, compressedsize);
+    } else {
+      lodepng_memcpy(chunk + pos, textstring, textsize);
+    }
+    lodepng_chunk_generate_crc(chunk);
+  }
+
+  lodepng_free(compressed);
+  return error;
+}
+
+static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info) {
+  unsigned char* chunk = 0;
+  if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) {
+    CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 2, "bKGD"));
+    chunk[8] = (unsigned char)(info->background_r >> 8);
+    chunk[9] = (unsigned char)(info->background_r & 255);
+  } else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) {
+    CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 6, "bKGD"));
+    chunk[8] = (unsigned char)(info->background_r >> 8);
+    chunk[9] = (unsigned char)(info->background_r & 255);
+    chunk[10] = (unsigned char)(info->background_g >> 8);
+    chunk[11] = (unsigned char)(info->background_g & 255);
+    chunk[12] = (unsigned char)(info->background_b >> 8);
+    chunk[13] = (unsigned char)(info->background_b & 255);
+  } else if(info->color.colortype == LCT_PALETTE) {
+    CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 1, "bKGD"));
+    chunk[8] = (unsigned char)(info->background_r & 255); /*palette index*/
+  }
+  if(chunk) lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time) {
+  unsigned char* chunk;
+  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 7, "tIME"));
+  chunk[8] = (unsigned char)(time->year >> 8);
+  chunk[9] = (unsigned char)(time->year & 255);
+  chunk[10] = (unsigned char)time->month;
+  chunk[11] = (unsigned char)time->day;
+  chunk[12] = (unsigned char)time->hour;
+  chunk[13] = (unsigned char)time->minute;
+  chunk[14] = (unsigned char)time->second;
+  lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info) {
+  unsigned char* chunk;
+  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 9, "pHYs"));
+  lodepng_set32bitInt(chunk + 8, info->phys_x);
+  lodepng_set32bitInt(chunk + 12, info->phys_y);
+  chunk[16] = info->phys_unit;
+  lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+static unsigned addChunk_gAMA(ucvector* out, const LodePNGInfo* info) {
+  unsigned char* chunk;
+  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 4, "gAMA"));
+  lodepng_set32bitInt(chunk + 8, info->gama_gamma);
+  lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+static unsigned addChunk_cHRM(ucvector* out, const LodePNGInfo* info) {
+  unsigned char* chunk;
+  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 32, "cHRM"));
+  lodepng_set32bitInt(chunk + 8, info->chrm_white_x);
+  lodepng_set32bitInt(chunk + 12, info->chrm_white_y);
+  lodepng_set32bitInt(chunk + 16, info->chrm_red_x);
+  lodepng_set32bitInt(chunk + 20, info->chrm_red_y);
+  lodepng_set32bitInt(chunk + 24, info->chrm_green_x);
+  lodepng_set32bitInt(chunk + 28, info->chrm_green_y);
+  lodepng_set32bitInt(chunk + 32, info->chrm_blue_x);
+  lodepng_set32bitInt(chunk + 36, info->chrm_blue_y);
+  lodepng_chunk_generate_crc(chunk);
+  return 0;
+}
+
+static unsigned addChunk_sRGB(ucvector* out, const LodePNGInfo* info) {
+  unsigned char data = info->srgb_intent;
+  return lodepng_chunk_createv(out, 1, "sRGB", &data);
+}
+
+static unsigned addChunk_iCCP(ucvector* out, const LodePNGInfo* info, LodePNGCompressSettings* zlibsettings) {
+  unsigned error = 0;
+  unsigned char* chunk = 0;
+  unsigned char* compressed = 0;
+  size_t compressedsize = 0;
+  size_t keysize = lodepng_strlen(info->iccp_name);
+
+  if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/
+  error = zlib_compress(&compressed, &compressedsize,
+                        info->iccp_profile, info->iccp_profile_size, zlibsettings);
+  if(!error) {
+    size_t size = keysize + 2 + compressedsize;
+    error = lodepng_chunk_init(&chunk, out, size, "iCCP");
+  }
+  if(!error) {
+    lodepng_memcpy(chunk + 8, info->iccp_name, keysize);
+    chunk[8 + keysize] = 0; /*null termination char*/
+    chunk[9 + keysize] = 0; /*compression method: 0*/
+    lodepng_memcpy(chunk + 10 + keysize, compressed, compressedsize);
+    lodepng_chunk_generate_crc(chunk);
+  }
+
+  lodepng_free(compressed);
+  return error;
+}
+
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline,
+                           size_t length, size_t bytewidth, unsigned char filterType) {
+  size_t i;
+  switch(filterType) {
+    case 0: /*None*/
+      for(i = 0; i != length; ++i) out[i] = scanline[i];
+      break;
+    case 1: /*Sub*/
+      for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
+      for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - scanline[i - bytewidth];
+      break;
+    case 2: /*Up*/
+      if(prevline) {
+        for(i = 0; i != length; ++i) out[i] = scanline[i] - prevline[i];
+      } else {
+        for(i = 0; i != length; ++i) out[i] = scanline[i];
+      }
+      break;
+    case 3: /*Average*/
+      if(prevline) {
+        for(i = 0; i != bytewidth; ++i) out[i] = scanline[i] - (prevline[i] >> 1);
+        for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) >> 1);
+      } else {
+        for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
+        for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - (scanline[i - bytewidth] >> 1);
+      }
+      break;
+    case 4: /*Paeth*/
+      if(prevline) {
+        /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/
+        for(i = 0; i != bytewidth; ++i) out[i] = (scanline[i] - prevline[i]);
+        for(i = bytewidth; i < length; ++i) {
+          out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth]));
+        }
+      } else {
+        for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
+        /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/
+        for(i = bytewidth; i < length; ++i) out[i] = (scanline[i] - scanline[i - bytewidth]);
+      }
+      break;
+    default: return; /*invalid filter type given*/
+  }
+}
+
+/* integer binary logarithm, max return value is 31 */
+static size_t ilog2(size_t i) {
+  size_t result = 0;
+  if(i >= 65536) { result += 16; i >>= 16; }
+  if(i >= 256) { result += 8; i >>= 8; }
+  if(i >= 16) { result += 4; i >>= 4; }
+  if(i >= 4) { result += 2; i >>= 2; }
+  if(i >= 2) { result += 1; /*i >>= 1;*/ }
+  return result;
+}
+
+/* integer approximation for i * log2(i), helper function for LFS_ENTROPY */
+static size_t ilog2i(size_t i) {
+  size_t l;
+  if(i == 0) return 0;
+  l = ilog2(i);
+  /* approximate i*log2(i): l is integer logarithm, ((i - (1u << l)) << 1u)
+  linearly approximates the missing fractional part multiplied by i */
+  return i * l + ((i - (1u << l)) << 1u);
+}
+
+static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h,
+                       const LodePNGColorMode* color, const LodePNGEncoderSettings* settings) {
+  /*
+  For PNG filter method 0
+  out must be a buffer with as size: h + (w * h * bpp + 7u) / 8u, because there are
+  the scanlines with 1 extra byte per scanline
+  */
+
+  unsigned bpp = lodepng_get_bpp(color);
+  /*the width of a scanline in bytes, not including the filter type*/
+  size_t linebytes = lodepng_get_raw_size_idat(w, 1, bpp) - 1u;
+
+  /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
+  size_t bytewidth = (bpp + 7u) / 8u;
+  const unsigned char* prevline = 0;
+  unsigned x, y;
+  unsigned error = 0;
+  LodePNGFilterStrategy strategy = settings->filter_strategy;
+
+  /*
+  There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard:
+   *  If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e.
+      use fixed filtering, with the filter None).
+   * (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is
+     not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply
+     all five filters and select the filter that produces the smallest sum of absolute values per row.
+  This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true.
+
+  If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed,
+  but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum
+  heuristic is used.
+  */
+  if(settings->filter_palette_zero &&
+     (color->colortype == LCT_PALETTE || color->bitdepth < 8)) strategy = LFS_ZERO;
+
+  if(bpp == 0) return 31; /*error: invalid color type*/
+
+  if(strategy >= LFS_ZERO && strategy <= LFS_FOUR) {
+    unsigned char type = (unsigned char)strategy;
+    for(y = 0; y != h; ++y) {
+      size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
+      size_t inindex = linebytes * y;
+      out[outindex] = type; /*filter type byte*/
+      filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type);
+      prevline = &in[inindex];
+    }
+  } else if(strategy == LFS_MINSUM) {
+    /*adaptive filtering*/
+    unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/
+    size_t smallest = 0;
+    unsigned char type, bestType = 0;
+
+    for(type = 0; type != 5; ++type) {
+      attempt[type] = (unsigned char*)lodepng_malloc(linebytes);
+      if(!attempt[type]) error = 83; /*alloc fail*/
+    }
+
+    if(!error) {
+      for(y = 0; y != h; ++y) {
+        /*try the 5 filter types*/
+        for(type = 0; type != 5; ++type) {
+          size_t sum = 0;
+          filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type);
+
+          /*calculate the sum of the result*/
+          if(type == 0) {
+            for(x = 0; x != linebytes; ++x) sum += (unsigned char)(attempt[type][x]);
+          } else {
+            for(x = 0; x != linebytes; ++x) {
+              /*For differences, each byte should be treated as signed, values above 127 are negative
+              (converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there.
+              This means filtertype 0 is almost never chosen, but that is justified.*/
+              unsigned char s = attempt[type][x];
+              sum += s < 128 ? s : (255U - s);
+            }
+          }
+
+          /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
+          if(type == 0 || sum < smallest) {
+            bestType = type;
+            smallest = sum;
+          }
+        }
+
+        prevline = &in[y * linebytes];
+
+        /*now fill the out values*/
+        out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
+        for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
+      }
+    }
+
+    for(type = 0; type != 5; ++type) lodepng_free(attempt[type]);
+  } else if(strategy == LFS_ENTROPY) {
+    unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/
+    size_t bestSum = 0;
+    unsigned type, bestType = 0;
+    unsigned count[256];
+
+    for(type = 0; type != 5; ++type) {
+      attempt[type] = (unsigned char*)lodepng_malloc(linebytes);
+      if(!attempt[type]) error = 83; /*alloc fail*/
+    }
+
+    if(!error) {
+      for(y = 0; y != h; ++y) {
+        /*try the 5 filter types*/
+        for(type = 0; type != 5; ++type) {
+          size_t sum = 0;
+          filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type);
+          lodepng_memset(count, 0, 256 * sizeof(*count));
+          for(x = 0; x != linebytes; ++x) ++count[attempt[type][x]];
+          ++count[type]; /*the filter type itself is part of the scanline*/
+          for(x = 0; x != 256; ++x) {
+            sum += ilog2i(count[x]);
+          }
+          /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
+          if(type == 0 || sum > bestSum) {
+            bestType = type;
+            bestSum = sum;
+          }
+        }
+
+        prevline = &in[y * linebytes];
+
+        /*now fill the out values*/
+        out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
+        for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
+      }
+    }
+
+    for(type = 0; type != 5; ++type) lodepng_free(attempt[type]);
+  } else if(strategy == LFS_PREDEFINED) {
+    for(y = 0; y != h; ++y) {
+      size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
+      size_t inindex = linebytes * y;
+      unsigned char type = settings->predefined_filters[y];
+      out[outindex] = type; /*filter type byte*/
+      filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type);
+      prevline = &in[inindex];
+    }
+  } else if(strategy == LFS_BRUTE_FORCE) {
+    /*brute force filter chooser.
+    deflate the scanline after every filter attempt to see which one deflates best.
+    This is very slow and gives only slightly smaller, sometimes even larger, result*/
+    size_t size[5];
+    unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/
+    size_t smallest = 0;
+    unsigned type = 0, bestType = 0;
+    unsigned char* dummy;
+    LodePNGCompressSettings zlibsettings;
+    lodepng_memcpy(&zlibsettings, &settings->zlibsettings, sizeof(LodePNGCompressSettings));
+    /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose,
+    to simulate the true case where the tree is the same for the whole image. Sometimes it gives
+    better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare
+    cases better compression. It does make this a bit less slow, so it's worth doing this.*/
+    zlibsettings.btype = 1;
+    /*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG
+    images only, so disable it*/
+    zlibsettings.custom_zlib = 0;
+    zlibsettings.custom_deflate = 0;
+    for(type = 0; type != 5; ++type) {
+      attempt[type] = (unsigned char*)lodepng_malloc(linebytes);
+      if(!attempt[type]) error = 83; /*alloc fail*/
+    }
+    if(!error) {
+      for(y = 0; y != h; ++y) /*try the 5 filter types*/ {
+        for(type = 0; type != 5; ++type) {
+          unsigned testsize = (unsigned)linebytes;
+          /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/
+
+          filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type);
+          size[type] = 0;
+          dummy = 0;
+          zlib_compress(&dummy, &size[type], attempt[type], testsize, &zlibsettings);
+          lodepng_free(dummy);
+          /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
+          if(type == 0 || size[type] < smallest) {
+            bestType = type;
+            smallest = size[type];
+          }
+        }
+        prevline = &in[y * linebytes];
+        out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
+        for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
+      }
+    }
+    for(type = 0; type != 5; ++type) lodepng_free(attempt[type]);
+  }
+  else return 88; /* unknown filter strategy */
+
+  return error;
+}
+
+static void addPaddingBits(unsigned char* out, const unsigned char* in,
+                           size_t olinebits, size_t ilinebits, unsigned h) {
+  /*The opposite of the removePaddingBits function
+  olinebits must be >= ilinebits*/
+  unsigned y;
+  size_t diff = olinebits - ilinebits;
+  size_t obp = 0, ibp = 0; /*bit pointers*/
+  for(y = 0; y != h; ++y) {
+    size_t x;
+    for(x = 0; x < ilinebits; ++x) {
+      unsigned char bit = readBitFromReversedStream(&ibp, in);
+      setBitOfReversedStream(&obp, out, bit);
+    }
+    /*obp += diff; --> no, fill in some value in the padding bits too, to avoid
+    "Use of uninitialised value of size ###" warning from valgrind*/
+    for(x = 0; x != diff; ++x) setBitOfReversedStream(&obp, out, 0);
+  }
+}
+
+/*
+in: non-interlaced image with size w*h
+out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with
+ no padding bits between scanlines, but between reduced images so that each
+ reduced image starts at a byte.
+bpp: bits per pixel
+there are no padding bits, not between scanlines, not between reduced images
+in has the following size in bits: w * h * bpp.
+out is possibly bigger due to padding bits between reduced images
+NOTE: comments about padding bits are only relevant if bpp < 8
+*/
+static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) {
+  unsigned passw[7], passh[7];
+  size_t filter_passstart[8], padded_passstart[8], passstart[8];
+  unsigned i;
+
+  Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
+
+  if(bpp >= 8) {
+    for(i = 0; i != 7; ++i) {
+      unsigned x, y, b;
+      size_t bytewidth = bpp / 8u;
+      for(y = 0; y < passh[i]; ++y)
+      for(x = 0; x < passw[i]; ++x) {
+        size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
+        size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth;
+        for(b = 0; b < bytewidth; ++b) {
+          out[pixeloutstart + b] = in[pixelinstart + b];
+        }
+      }
+    }
+  } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ {
+    for(i = 0; i != 7; ++i) {
+      unsigned x, y, b;
+      unsigned ilinebits = bpp * passw[i];
+      unsigned olinebits = bpp * w;
+      size_t obp, ibp; /*bit pointers (for out and in buffer)*/
+      for(y = 0; y < passh[i]; ++y)
+      for(x = 0; x < passw[i]; ++x) {
+        ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
+        obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
+        for(b = 0; b < bpp; ++b) {
+          unsigned char bit = readBitFromReversedStream(&ibp, in);
+          setBitOfReversedStream(&obp, out, bit);
+        }
+      }
+    }
+  }
+}
+
+/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image.
+return value is error**/
+static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in,
+                                    unsigned w, unsigned h,
+                                    const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings) {
+  /*
+  This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
+  *) if no Adam7: 1) add padding bits (= possible extra bits per scanline if bpp < 8) 2) filter
+  *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter
+  */
+  unsigned bpp = lodepng_get_bpp(&info_png->color);
+  unsigned error = 0;
+
+  if(info_png->interlace_method == 0) {
+    *outsize = h + (h * ((w * bpp + 7u) / 8u)); /*image size plus an extra byte per scanline + possible padding bits*/
+    *out = (unsigned char*)lodepng_malloc(*outsize);
+    if(!(*out) && (*outsize)) error = 83; /*alloc fail*/
+
+    if(!error) {
+      /*non multiple of 8 bits per scanline, padding bits needed per scanline*/
+      if(bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) {
+        unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7u) / 8u));
+        if(!padded) error = 83; /*alloc fail*/
+        if(!error) {
+          addPaddingBits(padded, in, ((w * bpp + 7u) / 8u) * 8u, w * bpp, h);
+          error = filter(*out, padded, w, h, &info_png->color, settings);
+        }
+        lodepng_free(padded);
+      } else {
+        /*we can immediately filter into the out buffer, no other steps needed*/
+        error = filter(*out, in, w, h, &info_png->color, settings);
+      }
+    }
+  } else /*interlace_method is 1 (Adam7)*/ {
+    unsigned passw[7], passh[7];
+    size_t filter_passstart[8], padded_passstart[8], passstart[8];
+    unsigned char* adam7;
+
+    Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
+
+    *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/
+    *out = (unsigned char*)lodepng_malloc(*outsize);
+    if(!(*out)) error = 83; /*alloc fail*/
+
+    adam7 = (unsigned char*)lodepng_malloc(passstart[7]);
+    if(!adam7 && passstart[7]) error = 83; /*alloc fail*/
+
+    if(!error) {
+      unsigned i;
+
+      Adam7_interlace(adam7, in, w, h, bpp);
+      for(i = 0; i != 7; ++i) {
+        if(bpp < 8) {
+          unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]);
+          if(!padded) ERROR_BREAK(83); /*alloc fail*/
+          addPaddingBits(padded, &adam7[passstart[i]],
+                         ((passw[i] * bpp + 7u) / 8u) * 8u, passw[i] * bpp, passh[i]);
+          error = filter(&(*out)[filter_passstart[i]], padded,
+                         passw[i], passh[i], &info_png->color, settings);
+          lodepng_free(padded);
+        } else {
+          error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]],
+                         passw[i], passh[i], &info_png->color, settings);
+        }
+
+        if(error) break;
+      }
+    }
+
+    lodepng_free(adam7);
+  }
+
+  return error;
+}
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) {
+  unsigned char* inchunk = data;
+  while((size_t)(inchunk - data) < datasize) {
+    CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk));
+    out->allocsize = out->size; /*fix the allocsize again*/
+    inchunk = lodepng_chunk_next(inchunk, data + datasize);
+  }
+  return 0;
+}
+
+static unsigned isGrayICCProfile(const unsigned char* profile, unsigned size) {
+  /*
+  It is a gray profile if bytes 16-19 are "GRAY", rgb profile if bytes 16-19
+  are "RGB ". We do not perform any full parsing of the ICC profile here, other
+  than check those 4 bytes to grayscale profile. Other than that, validity of
+  the profile is not checked. This is needed only because the PNG specification
+  requires using a non-gray color model if there is an ICC profile with "RGB "
+  (sadly limiting compression opportunities if the input data is grayscale RGB
+  data), and requires using a gray color model if it is "GRAY".
+  */
+  if(size < 20) return 0;
+  return profile[16] == 'G' &&  profile[17] == 'R' &&  profile[18] == 'A' &&  profile[19] == 'Y';
+}
+
+static unsigned isRGBICCProfile(const unsigned char* profile, unsigned size) {
+  /* See comment in isGrayICCProfile*/
+  if(size < 20) return 0;
+  return profile[16] == 'R' &&  profile[17] == 'G' &&  profile[18] == 'B' &&  profile[19] == ' ';
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+unsigned lodepng_encode(unsigned char** out, size_t* outsize,
+                        const unsigned char* image, unsigned w, unsigned h,
+                        LodePNGState* state) {
+  unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
+  size_t datasize = 0;
+  ucvector outv = ucvector_init(NULL, 0);
+  LodePNGInfo info;
+  const LodePNGInfo* info_png = &state->info_png;
+
+  lodepng_info_init(&info);
+
+  /*provide some proper output values if error will happen*/
+  *out = 0;
+  *outsize = 0;
+  state->error = 0;
+
+  /*check input values validity*/
+  if((info_png->color.colortype == LCT_PALETTE || state->encoder.force_palette)
+      && (info_png->color.palettesize == 0 || info_png->color.palettesize > 256)) {
+    state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/
+    goto cleanup;
+  }
+  if(state->encoder.zlibsettings.btype > 2) {
+    state->error = 61; /*error: invalid btype*/
+    goto cleanup;
+  }
+  if(info_png->interlace_method > 1) {
+    state->error = 71; /*error: invalid interlace mode*/
+    goto cleanup;
+  }
+  state->error = checkColorValidity(info_png->color.colortype, info_png->color.bitdepth);
+  if(state->error) goto cleanup; /*error: invalid color type given*/
+  state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth);
+  if(state->error) goto cleanup; /*error: invalid color type given*/
+
+  /* color convert and compute scanline filter types */
+  lodepng_info_copy(&info, &state->info_png);
+  if(state->encoder.auto_convert) {
+    LodePNGColorStats stats;
+    lodepng_color_stats_init(&stats);
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    if(info_png->iccp_defined &&
+        isGrayICCProfile(info_png->iccp_profile, info_png->iccp_profile_size)) {
+      /*the PNG specification does not allow to use palette with a GRAY ICC profile, even
+      if the palette has only gray colors, so disallow it.*/
+      stats.allow_palette = 0;
+    }
+    if(info_png->iccp_defined &&
+        isRGBICCProfile(info_png->iccp_profile, info_png->iccp_profile_size)) {
+      /*the PNG specification does not allow to use grayscale color with RGB ICC profile, so disallow gray.*/
+      stats.allow_greyscale = 0;
+    }
+#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */
+    state->error = lodepng_compute_color_stats(&stats, image, w, h, &state->info_raw);
+    if(state->error) goto cleanup;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    if(info_png->background_defined) {
+      /*the background chunk's color must be taken into account as well*/
+      unsigned r = 0, g = 0, b = 0;
+      LodePNGColorMode mode16 = lodepng_color_mode_make(LCT_RGB, 16);
+      lodepng_convert_rgb(&r, &g, &b, info_png->background_r, info_png->background_g, info_png->background_b, &mode16, &info_png->color);
+      state->error = lodepng_color_stats_add(&stats, r, g, b, 65535);
+      if(state->error) goto cleanup;
+    }
+#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */
+    state->error = auto_choose_color(&info.color, &state->info_raw, &stats);
+    if(state->error) goto cleanup;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    /*also convert the background chunk*/
+    if(info_png->background_defined) {
+      if(lodepng_convert_rgb(&info.background_r, &info.background_g, &info.background_b,
+          info_png->background_r, info_png->background_g, info_png->background_b, &info.color, &info_png->color)) {
+        state->error = 104;
+        goto cleanup;
+      }
+    }
+#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */
+  }
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  if(info_png->iccp_defined) {
+    unsigned gray_icc = isGrayICCProfile(info_png->iccp_profile, info_png->iccp_profile_size);
+    unsigned rgb_icc = isRGBICCProfile(info_png->iccp_profile, info_png->iccp_profile_size);
+    unsigned gray_png = info.color.colortype == LCT_GREY || info.color.colortype == LCT_GREY_ALPHA;
+    if(!gray_icc && !rgb_icc) {
+      state->error = 100; /* Disallowed profile color type for PNG */
+      goto cleanup;
+    }
+    if(gray_icc != gray_png) {
+      /*Not allowed to use RGB/RGBA/palette with GRAY ICC profile or vice versa,
+      or in case of auto_convert, it wasn't possible to find appropriate model*/
+      state->error = state->encoder.auto_convert ? 102 : 101;
+      goto cleanup;
+    }
+  }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+  if(!lodepng_color_mode_equal(&state->info_raw, &info.color)) {
+    unsigned char* converted;
+    size_t size = ((size_t)w * (size_t)h * (size_t)lodepng_get_bpp(&info.color) + 7u) / 8u;
+
+    converted = (unsigned char*)lodepng_malloc(size);
+    if(!converted && size) state->error = 83; /*alloc fail*/
+    if(!state->error) {
+      state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h);
+    }
+    if(!state->error) {
+      state->error = preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder);
+    }
+    lodepng_free(converted);
+    if(state->error) goto cleanup;
+  } else {
+    state->error = preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder);
+    if(state->error) goto cleanup;
+  }
+
+  /* output all PNG chunks */ {
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    size_t i;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    /*write signature and chunks*/
+    state->error = writeSignature(&outv);
+    if(state->error) goto cleanup;
+    /*IHDR*/
+    state->error = addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method);
+    if(state->error) goto cleanup;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    /*unknown chunks between IHDR and PLTE*/
+    if(info.unknown_chunks_data[0]) {
+      state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]);
+      if(state->error) goto cleanup;
+    }
+    /*color profile chunks must come before PLTE */
+    if(info.iccp_defined) {
+      state->error = addChunk_iCCP(&outv, &info, &state->encoder.zlibsettings);
+      if(state->error) goto cleanup;
+    }
+    if(info.srgb_defined) {
+      state->error = addChunk_sRGB(&outv, &info);
+      if(state->error) goto cleanup;
+    }
+    if(info.gama_defined) {
+      state->error = addChunk_gAMA(&outv, &info);
+      if(state->error) goto cleanup;
+    }
+    if(info.chrm_defined) {
+      state->error = addChunk_cHRM(&outv, &info);
+      if(state->error) goto cleanup;
+    }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    /*PLTE*/
+    if(info.color.colortype == LCT_PALETTE) {
+      state->error = addChunk_PLTE(&outv, &info.color);
+      if(state->error) goto cleanup;
+    }
+    if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) {
+      /*force_palette means: write suggested palette for truecolor in PLTE chunk*/
+      state->error = addChunk_PLTE(&outv, &info.color);
+      if(state->error) goto cleanup;
+    }
+    /*tRNS (this will only add if when necessary) */
+    state->error = addChunk_tRNS(&outv, &info.color);
+    if(state->error) goto cleanup;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    /*bKGD (must come between PLTE and the IDAt chunks*/
+    if(info.background_defined) {
+      state->error = addChunk_bKGD(&outv, &info);
+      if(state->error) goto cleanup;
+    }
+    /*pHYs (must come before the IDAT chunks)*/
+    if(info.phys_defined) {
+      state->error = addChunk_pHYs(&outv, &info);
+      if(state->error) goto cleanup;
+    }
+
+    /*unknown chunks between PLTE and IDAT*/
+    if(info.unknown_chunks_data[1]) {
+      state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]);
+      if(state->error) goto cleanup;
+    }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    /*IDAT (multiple IDAT chunks must be consecutive)*/
+    state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings);
+    if(state->error) goto cleanup;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    /*tIME*/
+    if(info.time_defined) {
+      state->error = addChunk_tIME(&outv, &info.time);
+      if(state->error) goto cleanup;
+    }
+    /*tEXt and/or zTXt*/
+    for(i = 0; i != info.text_num; ++i) {
+      if(lodepng_strlen(info.text_keys[i]) > 79) {
+        state->error = 66; /*text chunk too large*/
+        goto cleanup;
+      }
+      if(lodepng_strlen(info.text_keys[i]) < 1) {
+        state->error = 67; /*text chunk too small*/
+        goto cleanup;
+      }
+      if(state->encoder.text_compression) {
+        state->error = addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings);
+        if(state->error) goto cleanup;
+      } else {
+        state->error = addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]);
+        if(state->error) goto cleanup;
+      }
+    }
+    /*LodePNG version id in text chunk*/
+    if(state->encoder.add_id) {
+      unsigned already_added_id_text = 0;
+      for(i = 0; i != info.text_num; ++i) {
+        const char* k = info.text_keys[i];
+        /* Could use strcmp, but we're not calling or reimplementing this C library function for this use only */
+        if(k[0] == 'L' && k[1] == 'o' && k[2] == 'd' && k[3] == 'e' &&
+           k[4] == 'P' && k[5] == 'N' && k[6] == 'G' && k[7] == '\0') {
+          already_added_id_text = 1;
+          break;
+        }
+      }
+      if(already_added_id_text == 0) {
+        state->error = addChunk_tEXt(&outv, "LodePNG", LODEPNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
+        if(state->error) goto cleanup;
+      }
+    }
+    /*iTXt*/
+    for(i = 0; i != info.itext_num; ++i) {
+      if(lodepng_strlen(info.itext_keys[i]) > 79) {
+        state->error = 66; /*text chunk too large*/
+        goto cleanup;
+      }
+      if(lodepng_strlen(info.itext_keys[i]) < 1) {
+        state->error = 67; /*text chunk too small*/
+        goto cleanup;
+      }
+      state->error = addChunk_iTXt(
+          &outv, state->encoder.text_compression,
+          info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i],
+          &state->encoder.zlibsettings);
+      if(state->error) goto cleanup;
+    }
+
+    /*unknown chunks between IDAT and IEND*/
+    if(info.unknown_chunks_data[2]) {
+      state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]);
+      if(state->error) goto cleanup;
+    }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    state->error = addChunk_IEND(&outv);
+    if(state->error) goto cleanup;
+  }
+
+cleanup:
+  lodepng_info_cleanup(&info);
+  lodepng_free(data);
+
+  /*instead of cleaning the vector up, give it to the output*/
+  *out = outv.data;
+  *outsize = outv.size;
+
+  return state->error;
+}
+
+unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image,
+                               unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) {
+  unsigned error;
+  LodePNGState state;
+  lodepng_state_init(&state);
+  state.info_raw.colortype = colortype;
+  state.info_raw.bitdepth = bitdepth;
+  state.info_png.color.colortype = colortype;
+  state.info_png.color.bitdepth = bitdepth;
+  lodepng_encode(out, outsize, image, w, h, &state);
+  error = state.error;
+  lodepng_state_cleanup(&state);
+  return error;
+}
+
+unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) {
+  return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8);
+}
+
+unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) {
+  return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8);
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h,
+                             LodePNGColorType colortype, unsigned bitdepth) {
+  unsigned char* buffer;
+  size_t buffersize;
+  unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth);
+  if(!error) error = lodepng_save_file(buffer, buffersize, filename);
+  lodepng_free(buffer);
+  return error;
+}
+
+unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) {
+  return lodepng_encode_file(filename, image, w, h, LCT_RGBA, 8);
+}
+
+unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) {
+  return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8);
+}
+#endif /*LODEPNG_COMPILE_DISK*/
+
+void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) {
+  lodepng_compress_settings_init(&settings->zlibsettings);
+  settings->filter_palette_zero = 1;
+  settings->filter_strategy = LFS_MINSUM;
+  settings->auto_convert = 1;
+  settings->force_palette = 0;
+  settings->predefined_filters = 0;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  settings->add_id = 0;
+  settings->text_compression = 1;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+}
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ERROR_TEXT
+/*
+This returns the description of a numerical error code in English. This is also
+the documentation of all the error codes.
+*/
+const char* lodepng_error_text(unsigned code) {
+  switch(code) {
+    case 0: return "no error, everything went ok";
+    case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/
+    case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/
+    case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/
+    case 13: return "problem while processing dynamic deflate block";
+    case 14: return "problem while processing dynamic deflate block";
+    case 15: return "problem while processing dynamic deflate block";
+    /*this error could happen if there are only 0 or 1 symbols present in the huffman code:*/
+    case 16: return "invalid code while processing dynamic deflate block";
+    case 17: return "end of out buffer memory reached while inflating";
+    case 18: return "invalid distance code while inflating";
+    case 19: return "end of out buffer memory reached while inflating";
+    case 20: return "invalid deflate block BTYPE encountered while decoding";
+    case 21: return "NLEN is not ones complement of LEN in a deflate block";
+
+    /*end of out buffer memory reached while inflating:
+    This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
+    all the pixels of the image, given the color depth and image dimensions. Something that doesn't
+    happen in a normal, well encoded, PNG image.*/
+    case 22: return "end of out buffer memory reached while inflating";
+    case 23: return "end of in buffer memory reached while inflating";
+    case 24: return "invalid FCHECK in zlib header";
+    case 25: return "invalid compression method in zlib header";
+    case 26: return "FDICT encountered in zlib header while it's not used for PNG";
+    case 27: return "PNG file is smaller than a PNG header";
+    /*Checks the magic file header, the first 8 bytes of the PNG file*/
+    case 28: return "incorrect PNG signature, it's no PNG or corrupted";
+    case 29: return "first chunk is not the header chunk";
+    case 30: return "chunk length too large, chunk broken off at end of file";
+    case 31: return "illegal PNG color type or bpp";
+    case 32: return "illegal PNG compression method";
+    case 33: return "illegal PNG filter method";
+    case 34: return "illegal PNG interlace method";
+    case 35: return "chunk length of a chunk is too large or the chunk too small";
+    case 36: return "illegal PNG filter type encountered";
+    case 37: return "illegal bit depth for this color type given";
+    case 38: return "the palette is too small or too big"; /*0, or more than 256 colors*/
+    case 39: return "tRNS chunk before PLTE or has more entries than palette size";
+    case 40: return "tRNS chunk has wrong size for grayscale image";
+    case 41: return "tRNS chunk has wrong size for RGB image";
+    case 42: return "tRNS chunk appeared while it was not allowed for this color type";
+    case 43: return "bKGD chunk has wrong size for palette image";
+    case 44: return "bKGD chunk has wrong size for grayscale image";
+    case 45: return "bKGD chunk has wrong size for RGB image";
+    case 48: return "empty input buffer given to decoder. Maybe caused by non-existing file?";
+    case 49: return "jumped past memory while generating dynamic huffman tree";
+    case 50: return "jumped past memory while generating dynamic huffman tree";
+    case 51: return "jumped past memory while inflating huffman block";
+    case 52: return "jumped past memory while inflating";
+    case 53: return "size of zlib data too small";
+    case 54: return "repeat symbol in tree while there was no value symbol yet";
+    /*jumped past tree while generating huffman tree, this could be when the
+    tree will have more leaves than symbols after generating it out of the
+    given lengths. They call this an oversubscribed dynamic bit lengths tree in zlib.*/
+    case 55: return "jumped past tree while generating huffman tree";
+    case 56: return "given output image colortype or bitdepth not supported for color conversion";
+    case 57: return "invalid CRC encountered (checking CRC can be disabled)";
+    case 58: return "invalid ADLER32 encountered (checking ADLER32 can be disabled)";
+    case 59: return "requested color conversion not supported";
+    case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)";
+    case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)";
+    /*LodePNG leaves the choice of RGB to grayscale conversion formula to the user.*/
+    case 62: return "conversion from color to grayscale not supported";
+    /*(2^31-1)*/
+    case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk";
+    /*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/
+    case 64: return "the length of the END symbol 256 in the Huffman tree is 0";
+    case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes";
+    case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte";
+    case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors";
+    case 69: return "unknown chunk type with 'critical' flag encountered by the decoder";
+    case 71: return "invalid interlace mode given to encoder (must be 0 or 1)";
+    case 72: return "while decoding, invalid compression method encountering in zTXt or iTXt chunk (it must be 0)";
+    case 73: return "invalid tIME chunk size";
+    case 74: return "invalid pHYs chunk size";
+    /*length could be wrong, or data chopped off*/
+    case 75: return "no null termination char found while decoding text chunk";
+    case 76: return "iTXt chunk too short to contain required bytes";
+    case 77: return "integer overflow in buffer size";
+    case 78: return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/
+    case 79: return "failed to open file for writing";
+    case 80: return "tried creating a tree of 0 symbols";
+    case 81: return "lazy matching at pos 0 is impossible";
+    case 82: return "color conversion to palette requested while a color isn't in palette, or index out of bounds";
+    case 83: return "memory allocation failed";
+    case 84: return "given image too small to contain all pixels to be encoded";
+    case 86: return "impossible offset in lz77 encoding (internal bug)";
+    case 87: return "must provide custom zlib function pointer if LODEPNG_COMPILE_ZLIB is not defined";
+    case 88: return "invalid filter strategy given for LodePNGEncoderSettings.filter_strategy";
+    case 89: return "text chunk keyword too short or long: must have size 1-79";
+    /*the windowsize in the LodePNGCompressSettings. Requiring POT(==> & instead of %) makes encoding 12% faster.*/
+    case 90: return "windowsize must be a power of two";
+    case 91: return "invalid decompressed idat size";
+    case 92: return "integer overflow due to too many pixels";
+    case 93: return "zero width or height is invalid";
+    case 94: return "header chunk must have a size of 13 bytes";
+    case 95: return "integer overflow with combined idat chunk size";
+    case 96: return "invalid gAMA chunk size";
+    case 97: return "invalid cHRM chunk size";
+    case 98: return "invalid sRGB chunk size";
+    case 99: return "invalid sRGB rendering intent";
+    case 100: return "invalid ICC profile color type, the PNG specification only allows RGB or GRAY";
+    case 101: return "PNG specification does not allow RGB ICC profile on gray color types and vice versa";
+    case 102: return "not allowed to set grayscale ICC profile with colored pixels by PNG specification";
+    case 103: return "invalid palette index in bKGD chunk. Maybe it came before PLTE chunk?";
+    case 104: return "invalid bKGD color while encoding (e.g. palette index out of range)";
+    case 105: return "integer overflow of bitsize";
+    case 106: return "PNG file must have PLTE chunk if color type is palette";
+    case 107: return "color convert from palette mode requested without setting the palette data in it";
+    case 108: return "tried to add more than 256 values to a palette";
+  }
+  return "unknown error code";
+}
+#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // C++ Wrapper                                                          // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_CPP
+namespace lodepng {
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned load_file(std::vector<unsigned char>& buffer, const std::string& filename) {
+  long size = lodepng_filesize(filename.c_str());
+  if(size < 0) return 78;
+  buffer.resize((size_t)size);
+  return size == 0 ? 0 : lodepng_buffer_file(&buffer[0], (size_t)size, filename.c_str());
+}
+
+/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
+unsigned save_file(const std::vector<unsigned char>& buffer, const std::string& filename) {
+  return lodepng_save_file(buffer.empty() ? 0 : &buffer[0], buffer.size(), filename.c_str());
+}
+#endif /* LODEPNG_COMPILE_DISK */
+
+#ifdef LODEPNG_COMPILE_ZLIB
+#ifdef LODEPNG_COMPILE_DECODER
+unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
+                    const LodePNGDecompressSettings& settings) {
+  unsigned char* buffer = 0;
+  size_t buffersize = 0;
+  unsigned error = zlib_decompress(&buffer, &buffersize, 0, in, insize, &settings);
+  if(buffer) {
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+                    const LodePNGDecompressSettings& settings) {
+  return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings);
+}
+#endif /* LODEPNG_COMPILE_DECODER */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
+                  const LodePNGCompressSettings& settings) {
+  unsigned char* buffer = 0;
+  size_t buffersize = 0;
+  unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings);
+  if(buffer) {
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+                  const LodePNGCompressSettings& settings) {
+  return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
+}
+#endif /* LODEPNG_COMPILE_ENCODER */
+#endif /* LODEPNG_COMPILE_ZLIB */
+
+
+#ifdef LODEPNG_COMPILE_PNG
+
+State::State() {
+  lodepng_state_init(this);
+}
+
+State::State(const State& other) {
+  lodepng_state_init(this);
+  lodepng_state_copy(this, &other);
+}
+
+State::~State() {
+  lodepng_state_cleanup(this);
+}
+
+State& State::operator=(const State& other) {
+  lodepng_state_copy(this, &other);
+  return *this;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in,
+                size_t insize, LodePNGColorType colortype, unsigned bitdepth) {
+  unsigned char* buffer = 0;
+  unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth);
+  if(buffer && !error) {
+    State state;
+    state.info_raw.colortype = colortype;
+    state.info_raw.bitdepth = bitdepth;
+    size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+  }
+  lodepng_free(buffer);
+  return error;
+}
+
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth) {
+  return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth);
+}
+
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                State& state,
+                const unsigned char* in, size_t insize) {
+  unsigned char* buffer = NULL;
+  unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize);
+  if(buffer && !error) {
+    size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+  }
+  lodepng_free(buffer);
+  return error;
+}
+
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                State& state,
+                const std::vector<unsigned char>& in) {
+  return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size());
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename,
+                LodePNGColorType colortype, unsigned bitdepth) {
+  std::vector<unsigned char> buffer;
+  /* safe output values in case error happens */
+  w = h = 0;
+  unsigned error = load_file(buffer, filename);
+  if(error) return error;
+  return decode(out, w, h, buffer, colortype, bitdepth);
+}
+#endif /* LODEPNG_COMPILE_DECODER */
+#endif /* LODEPNG_COMPILE_DISK */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h,
+                LodePNGColorType colortype, unsigned bitdepth) {
+  unsigned char* buffer;
+  size_t buffersize;
+  unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth);
+  if(buffer) {
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned encode(std::vector<unsigned char>& out,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                LodePNGColorType colortype, unsigned bitdepth) {
+  if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
+  return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
+}
+
+unsigned encode(std::vector<unsigned char>& out,
+                const unsigned char* in, unsigned w, unsigned h,
+                State& state) {
+  unsigned char* buffer;
+  size_t buffersize;
+  unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state);
+  if(buffer) {
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned encode(std::vector<unsigned char>& out,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                State& state) {
+  if(lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84;
+  return encode(out, in.empty() ? 0 : &in[0], w, h, state);
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned encode(const std::string& filename,
+                const unsigned char* in, unsigned w, unsigned h,
+                LodePNGColorType colortype, unsigned bitdepth) {
+  std::vector<unsigned char> buffer;
+  unsigned error = encode(buffer, in, w, h, colortype, bitdepth);
+  if(!error) error = save_file(buffer, filename);
+  return error;
+}
+
+unsigned encode(const std::string& filename,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                LodePNGColorType colortype, unsigned bitdepth) {
+  if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
+  return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
+}
+#endif /* LODEPNG_COMPILE_DISK */
+#endif /* LODEPNG_COMPILE_ENCODER */
+#endif /* LODEPNG_COMPILE_PNG */
+} /* namespace lodepng */
+#endif /*LODEPNG_COMPILE_CPP*/
diff --git a/graphics/lodepng.h b/graphics/lodepng.h
new file mode 100644
index 0000000..a386459
--- /dev/null
+++ b/graphics/lodepng.h
@@ -0,0 +1,1945 @@
+/*
+LodePNG version 20200306
+
+Copyright (c) 2005-2020 Lode Vandevenne
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgment in the product documentation would be
+    appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution.
+*/
+
+#ifndef LODEPNG_H
+#define LODEPNG_H
+
+#include <string.h> /*for size_t*/
+
+extern const char* LODEPNG_VERSION_STRING;
+
+/*
+The following #defines are used to create code sections. They can be disabled
+to disable code sections, which can give faster compile time and smaller binary.
+The "NO_COMPILE" defines are designed to be used to pass as defines to the
+compiler command to disable them without modifying this header, e.g.
+-DLODEPNG_NO_COMPILE_ZLIB for gcc.
+In addition to those below, you can also define LODEPNG_NO_COMPILE_CRC to
+allow implementing a custom lodepng_crc32.
+*/
+/*deflate & zlib. If disabled, you must specify alternative zlib functions in
+the custom_zlib field of the compress and decompress settings*/
+#ifndef LODEPNG_NO_COMPILE_ZLIB
+#define LODEPNG_COMPILE_ZLIB
+#endif
+
+/*png encoder and png decoder*/
+#ifndef LODEPNG_NO_COMPILE_PNG
+#define LODEPNG_COMPILE_PNG
+#endif
+
+/*deflate&zlib decoder and png decoder*/
+#ifndef LODEPNG_NO_COMPILE_DECODER
+#define LODEPNG_COMPILE_DECODER
+#endif
+
+/*deflate&zlib encoder and png encoder*/
+#ifndef LODEPNG_NO_COMPILE_ENCODER
+#define LODEPNG_COMPILE_ENCODER
+#endif
+
+/*the optional built in harddisk file loading and saving functions*/
+#ifndef LODEPNG_NO_COMPILE_DISK
+#define LODEPNG_COMPILE_DISK
+#endif
+
+/*support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks*/
+#ifndef LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS
+#define LODEPNG_COMPILE_ANCILLARY_CHUNKS
+#endif
+
+/*ability to convert error numerical codes to English text string*/
+#ifndef LODEPNG_NO_COMPILE_ERROR_TEXT
+#define LODEPNG_COMPILE_ERROR_TEXT
+#endif
+
+/*Compile the default allocators (C's free, malloc and realloc). If you disable this,
+you can define the functions lodepng_free, lodepng_malloc and lodepng_realloc in your
+source files with custom allocators.*/
+#ifndef LODEPNG_NO_COMPILE_ALLOCATORS
+#define LODEPNG_COMPILE_ALLOCATORS
+#endif
+
+/*compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)*/
+#ifdef __cplusplus
+#ifndef LODEPNG_NO_COMPILE_CPP
+#define LODEPNG_COMPILE_CPP
+#endif
+#endif
+
+#ifdef LODEPNG_COMPILE_CPP
+#include <vector>
+#include <string>
+#endif /*LODEPNG_COMPILE_CPP*/
+
+#ifdef LODEPNG_COMPILE_PNG
+/*The PNG color types (also used for raw image).*/
+typedef enum LodePNGColorType {
+  LCT_GREY = 0, /*grayscale: 1,2,4,8,16 bit*/
+  LCT_RGB = 2, /*RGB: 8,16 bit*/
+  LCT_PALETTE = 3, /*palette: 1,2,4,8 bit*/
+  LCT_GREY_ALPHA = 4, /*grayscale with alpha: 8,16 bit*/
+  LCT_RGBA = 6, /*RGB with alpha: 8,16 bit*/
+  /*LCT_MAX_OCTET_VALUE lets the compiler allow this enum to represent any invalid
+  byte value from 0 to 255 that could be present in an invalid PNG file header. Do
+  not use, compare with or set the name LCT_MAX_OCTET_VALUE, instead either use
+  the valid color type names above, or numeric values like 1 or 7 when checking for
+  particular disallowed color type byte values, or cast to integer to print it.*/
+  LCT_MAX_OCTET_VALUE = 255
+} LodePNGColorType;
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*
+Converts PNG data in memory to raw pixel data.
+out: Output parameter. Pointer to buffer that will contain the raw pixel data.
+     After decoding, its size is w * h * (bytes per pixel) bytes larger than
+     initially. Bytes per pixel depends on colortype and bitdepth.
+     Must be freed after usage with free(*out).
+     Note: for 16-bit per channel colors, uses big endian format like PNG does.
+w: Output parameter. Pointer to width of pixel data.
+h: Output parameter. Pointer to height of pixel data.
+in: Memory buffer with the PNG file.
+insize: size of the in buffer.
+colortype: the desired color type for the raw output image. See explanation on PNG color types.
+bitdepth: the desired bit depth for the raw output image. See explanation on PNG color types.
+Return value: LodePNG error code (0 means no error).
+*/
+unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h,
+                               const unsigned char* in, size_t insize,
+                               LodePNGColorType colortype, unsigned bitdepth);
+
+/*Same as lodepng_decode_memory, but always decodes to 32-bit RGBA raw image*/
+unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h,
+                          const unsigned char* in, size_t insize);
+
+/*Same as lodepng_decode_memory, but always decodes to 24-bit RGB raw image*/
+unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h,
+                          const unsigned char* in, size_t insize);
+
+#ifdef LODEPNG_COMPILE_DISK
+/*
+Load PNG from disk, from file with given name.
+Same as the other decode functions, but instead takes a filename as input.
+*/
+unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h,
+                             const char* filename,
+                             LodePNGColorType colortype, unsigned bitdepth);
+
+/*Same as lodepng_decode_file, but always decodes to 32-bit RGBA raw image.*/
+unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h,
+                               const char* filename);
+
+/*Same as lodepng_decode_file, but always decodes to 24-bit RGB raw image.*/
+unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h,
+                               const char* filename);
+#endif /*LODEPNG_COMPILE_DISK*/
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*
+Converts raw pixel data into a PNG image in memory. The colortype and bitdepth
+  of the output PNG image cannot be chosen, they are automatically determined
+  by the colortype, bitdepth and content of the input pixel data.
+  Note: for 16-bit per channel colors, needs big endian format like PNG does.
+out: Output parameter. Pointer to buffer that will contain the PNG image data.
+     Must be freed after usage with free(*out).
+outsize: Output parameter. Pointer to the size in bytes of the out buffer.
+image: The raw pixel data to encode. The size of this buffer should be
+       w * h * (bytes per pixel), bytes per pixel depends on colortype and bitdepth.
+w: width of the raw pixel data in pixels.
+h: height of the raw pixel data in pixels.
+colortype: the color type of the raw input image. See explanation on PNG color types.
+bitdepth: the bit depth of the raw input image. See explanation on PNG color types.
+Return value: LodePNG error code (0 means no error).
+*/
+unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize,
+                               const unsigned char* image, unsigned w, unsigned h,
+                               LodePNGColorType colortype, unsigned bitdepth);
+
+/*Same as lodepng_encode_memory, but always encodes from 32-bit RGBA raw image.*/
+unsigned lodepng_encode32(unsigned char** out, size_t* outsize,
+                          const unsigned char* image, unsigned w, unsigned h);
+
+/*Same as lodepng_encode_memory, but always encodes from 24-bit RGB raw image.*/
+unsigned lodepng_encode24(unsigned char** out, size_t* outsize,
+                          const unsigned char* image, unsigned w, unsigned h);
+
+#ifdef LODEPNG_COMPILE_DISK
+/*
+Converts raw pixel data into a PNG file on disk.
+Same as the other encode functions, but instead takes a filename as output.
+NOTE: This overwrites existing files without warning!
+*/
+unsigned lodepng_encode_file(const char* filename,
+                             const unsigned char* image, unsigned w, unsigned h,
+                             LodePNGColorType colortype, unsigned bitdepth);
+
+/*Same as lodepng_encode_file, but always encodes from 32-bit RGBA raw image.*/
+unsigned lodepng_encode32_file(const char* filename,
+                               const unsigned char* image, unsigned w, unsigned h);
+
+/*Same as lodepng_encode_file, but always encodes from 24-bit RGB raw image.*/
+unsigned lodepng_encode24_file(const char* filename,
+                               const unsigned char* image, unsigned w, unsigned h);
+#endif /*LODEPNG_COMPILE_DISK*/
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+
+#ifdef LODEPNG_COMPILE_CPP
+namespace lodepng {
+#ifdef LODEPNG_COMPILE_DECODER
+/*Same as lodepng_decode_memory, but decodes to an std::vector. The colortype
+is the format to output the pixels to. Default is RGBA 8-bit per channel.*/
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                const unsigned char* in, size_t insize,
+                LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                const std::vector<unsigned char>& in,
+                LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
+#ifdef LODEPNG_COMPILE_DISK
+/*
+Converts PNG file from disk to raw pixel data in memory.
+Same as the other decode functions, but instead takes a filename as input.
+*/
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                const std::string& filename,
+                LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
+#endif /* LODEPNG_COMPILE_DISK */
+#endif /* LODEPNG_COMPILE_DECODER */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*Same as lodepng_encode_memory, but encodes to an std::vector. colortype
+is that of the raw input data. The output PNG color type will be auto chosen.*/
+unsigned encode(std::vector<unsigned char>& out,
+                const unsigned char* in, unsigned w, unsigned h,
+                LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
+unsigned encode(std::vector<unsigned char>& out,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
+#ifdef LODEPNG_COMPILE_DISK
+/*
+Converts 32-bit RGBA raw pixel data into a PNG file on disk.
+Same as the other encode functions, but instead takes a filename as output.
+NOTE: This overwrites existing files without warning!
+*/
+unsigned encode(const std::string& filename,
+                const unsigned char* in, unsigned w, unsigned h,
+                LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
+unsigned encode(const std::string& filename,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
+#endif /* LODEPNG_COMPILE_DISK */
+#endif /* LODEPNG_COMPILE_ENCODER */
+} /* namespace lodepng */
+#endif /*LODEPNG_COMPILE_CPP*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ERROR_TEXT
+/*Returns an English description of the numerical error code.*/
+const char* lodepng_error_text(unsigned code);
+#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*Settings for zlib decompression*/
+typedef struct LodePNGDecompressSettings LodePNGDecompressSettings;
+struct LodePNGDecompressSettings {
+  /* Check LodePNGDecoderSettings for more ignorable errors such as ignore_crc */
+  unsigned ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/
+  unsigned ignore_nlen; /*ignore complement of len checksum in uncompressed blocks*/
+
+  /*use custom zlib decoder instead of built in one (default: null)*/
+  unsigned (*custom_zlib)(unsigned char**, size_t*,
+                          const unsigned char*, size_t,
+                          const LodePNGDecompressSettings*);
+  /*use custom deflate decoder instead of built in one (default: null)
+  if custom_zlib is not null, custom_inflate is ignored (the zlib format uses deflate)*/
+  unsigned (*custom_inflate)(unsigned char**, size_t*,
+                             const unsigned char*, size_t,
+                             const LodePNGDecompressSettings*);
+
+  const void* custom_context; /*optional custom settings for custom functions*/
+};
+
+extern const LodePNGDecompressSettings lodepng_default_decompress_settings;
+void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings);
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*
+Settings for zlib compression. Tweaking these settings tweaks the balance
+between speed and compression ratio.
+*/
+typedef struct LodePNGCompressSettings LodePNGCompressSettings;
+struct LodePNGCompressSettings /*deflate = compress*/ {
+  /*LZ77 related settings*/
+  unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/
+  unsigned use_lz77; /*whether or not to use LZ77. Should be 1 for proper compression.*/
+  unsigned windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Default value: 2048.*/
+  unsigned minmatch; /*minimum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/
+  unsigned nicematch; /*stop searching if >= this length found. Set to 258 for best compression. Default: 128*/
+  unsigned lazymatching; /*use lazy matching: better compression but a bit slower. Default: true*/
+
+  /*use custom zlib encoder instead of built in one (default: null)*/
+  unsigned (*custom_zlib)(unsigned char**, size_t*,
+                          const unsigned char*, size_t,
+                          const LodePNGCompressSettings*);
+  /*use custom deflate encoder instead of built in one (default: null)
+  if custom_zlib is used, custom_deflate is ignored since only the built in
+  zlib function will call custom_deflate*/
+  unsigned (*custom_deflate)(unsigned char**, size_t*,
+                             const unsigned char*, size_t,
+                             const LodePNGCompressSettings*);
+
+  const void* custom_context; /*optional custom settings for custom functions*/
+};
+
+extern const LodePNGCompressSettings lodepng_default_compress_settings;
+void lodepng_compress_settings_init(LodePNGCompressSettings* settings);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_PNG
+/*
+Color mode of an image. Contains all information required to decode the pixel
+bits to RGBA colors. This information is the same as used in the PNG file
+format, and is used both for PNG and raw image data in LodePNG.
+*/
+typedef struct LodePNGColorMode {
+  /*header (IHDR)*/
+  LodePNGColorType colortype; /*color type, see PNG standard or documentation further in this header file*/
+  unsigned bitdepth;  /*bits per sample, see PNG standard or documentation further in this header file*/
+
+  /*
+  palette (PLTE and tRNS)
+
+  Dynamically allocated with the colors of the palette, including alpha.
+  This field may not be allocated directly, use lodepng_color_mode_init first,
+  then lodepng_palette_add per color to correctly initialize it (to ensure size
+  of exactly 1024 bytes).
+
+  The alpha channels must be set as well, set them to 255 for opaque images.
+
+  When decoding, by default you can ignore this palette, since LodePNG already
+  fills the palette colors in the pixels of the raw RGBA output.
+
+  The palette is only supported for color type 3.
+  */
+  unsigned char* palette; /*palette in RGBARGBA... order. Must be either 0, or when allocated must have 1024 bytes*/
+  size_t palettesize; /*palette size in number of colors (amount of used bytes is 4 * palettesize)*/
+
+  /*
+  transparent color key (tRNS)
+
+  This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit.
+  For grayscale PNGs, r, g and b will all 3 be set to the same.
+
+  When decoding, by default you can ignore this information, since LodePNG sets
+  pixels with this key to transparent already in the raw RGBA output.
+
+  The color key is only supported for color types 0 and 2.
+  */
+  unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/
+  unsigned key_r;       /*red/grayscale component of color key*/
+  unsigned key_g;       /*green component of color key*/
+  unsigned key_b;       /*blue component of color key*/
+} LodePNGColorMode;
+
+/*init, cleanup and copy functions to use with this struct*/
+void lodepng_color_mode_init(LodePNGColorMode* info);
+void lodepng_color_mode_cleanup(LodePNGColorMode* info);
+/*return value is error code (0 means no error)*/
+unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source);
+/* Makes a temporary LodePNGColorMode that does not need cleanup (no palette) */
+LodePNGColorMode lodepng_color_mode_make(LodePNGColorType colortype, unsigned bitdepth);
+
+void lodepng_palette_clear(LodePNGColorMode* info);
+/*add 1 color to the palette*/
+unsigned lodepng_palette_add(LodePNGColorMode* info,
+                             unsigned char r, unsigned char g, unsigned char b, unsigned char a);
+
+/*get the total amount of bits per pixel, based on colortype and bitdepth in the struct*/
+unsigned lodepng_get_bpp(const LodePNGColorMode* info);
+/*get the amount of color channels used, based on colortype in the struct.
+If a palette is used, it counts as 1 channel.*/
+unsigned lodepng_get_channels(const LodePNGColorMode* info);
+/*is it a grayscale type? (only colortype 0 or 4)*/
+unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info);
+/*has it got an alpha channel? (only colortype 2 or 6)*/
+unsigned lodepng_is_alpha_type(const LodePNGColorMode* info);
+/*has it got a palette? (only colortype 3)*/
+unsigned lodepng_is_palette_type(const LodePNGColorMode* info);
+/*only returns true if there is a palette and there is a value in the palette with alpha < 255.
+Loops through the palette to check this.*/
+unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info);
+/*
+Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image.
+Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels).
+Returns false if the image can only have opaque pixels.
+In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values,
+or if "key_defined" is true.
+*/
+unsigned lodepng_can_have_alpha(const LodePNGColorMode* info);
+/*Returns the byte size of a raw image buffer with given width, height and color mode*/
+size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color);
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*The information of a Time chunk in PNG.*/
+typedef struct LodePNGTime {
+  unsigned year;    /*2 bytes used (0-65535)*/
+  unsigned month;   /*1-12*/
+  unsigned day;     /*1-31*/
+  unsigned hour;    /*0-23*/
+  unsigned minute;  /*0-59*/
+  unsigned second;  /*0-60 (to allow for leap seconds)*/
+} LodePNGTime;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+/*Information about the PNG image, except pixels, width and height.*/
+typedef struct LodePNGInfo {
+  /*header (IHDR), palette (PLTE) and transparency (tRNS) chunks*/
+  unsigned compression_method;/*compression method of the original file. Always 0.*/
+  unsigned filter_method;     /*filter method of the original file*/
+  unsigned interlace_method;  /*interlace method of the original file: 0=none, 1=Adam7*/
+  LodePNGColorMode color;     /*color type and bits, palette and transparency of the PNG file*/
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  /*
+  Suggested background color chunk (bKGD)
+
+  This uses the same color mode and bit depth as the PNG (except no alpha channel),
+  with values truncated to the bit depth in the unsigned integer.
+
+  For grayscale and palette PNGs, the value is stored in background_r. The values
+  in background_g and background_b are then unused.
+
+  So when decoding, you may get these in a different color mode than the one you requested
+  for the raw pixels.
+
+  When encoding with auto_convert, you must use the color model defined in info_png.color for
+  these values. The encoder normally ignores info_png.color when auto_convert is on, but will
+  use it to interpret these values (and convert copies of them to its chosen color model).
+
+  When encoding, avoid setting this to an expensive color, such as a non-gray value
+  when the image is gray, or the compression will be worse since it will be forced to
+  write the PNG with a more expensive color mode (when auto_convert is on).
+
+  The decoder does not use this background color to edit the color of pixels. This is a
+  completely optional metadata feature.
+  */
+  unsigned background_defined; /*is a suggested background color given?*/
+  unsigned background_r;       /*red/gray/palette component of suggested background color*/
+  unsigned background_g;       /*green component of suggested background color*/
+  unsigned background_b;       /*blue component of suggested background color*/
+
+  /*
+  non-international text chunks (tEXt and zTXt)
+
+  The char** arrays each contain num strings. The actual messages are in
+  text_strings, while text_keys are keywords that give a short description what
+  the actual text represents, e.g. Title, Author, Description, or anything else.
+
+  All the string fields below including keys, names and language tags are null terminated.
+  The PNG specification uses null characters for the keys, names and tags, and forbids null
+  characters to appear in the main text which is why we can use null termination everywhere here.
+
+  A keyword is minimum 1 character and maximum 79 characters long. It's
+  discouraged to use a single line length longer than 79 characters for texts.
+
+  Don't allocate these text buffers yourself. Use the init/cleanup functions
+  correctly and use lodepng_add_text and lodepng_clear_text.
+  */
+  size_t text_num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/
+  char** text_keys; /*the keyword of a text chunk (e.g. "Comment")*/
+  char** text_strings; /*the actual text*/
+
+  /*
+  international text chunks (iTXt)
+  Similar to the non-international text chunks, but with additional strings
+  "langtags" and "transkeys".
+  */
+  size_t itext_num; /*the amount of international texts in this PNG*/
+  char** itext_keys; /*the English keyword of the text chunk (e.g. "Comment")*/
+  char** itext_langtags; /*language tag for this text's language, ISO/IEC 646 string, e.g. ISO 639 language tag*/
+  char** itext_transkeys; /*keyword translated to the international language - UTF-8 string*/
+  char** itext_strings; /*the actual international text - UTF-8 string*/
+
+  /*time chunk (tIME)*/
+  unsigned time_defined; /*set to 1 to make the encoder generate a tIME chunk*/
+  LodePNGTime time;
+
+  /*phys chunk (pHYs)*/
+  unsigned phys_defined; /*if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one*/
+  unsigned phys_x; /*pixels per unit in x direction*/
+  unsigned phys_y; /*pixels per unit in y direction*/
+  unsigned phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/
+
+  /*
+  Color profile related chunks: gAMA, cHRM, sRGB, iCPP
+
+  LodePNG does not apply any color conversions on pixels in the encoder or decoder and does not interpret these color
+  profile values. It merely passes on the information. If you wish to use color profiles and convert colors, please
+  use these values with a color management library.
+
+  See the PNG, ICC and sRGB specifications for more information about the meaning of these values.
+  */
+
+  /* gAMA chunk: optional, overridden by sRGB or iCCP if those are present. */
+  unsigned gama_defined; /* Whether a gAMA chunk is present (0 = not present, 1 = present). */
+  unsigned gama_gamma;   /* Gamma exponent times 100000 */
+
+  /* cHRM chunk: optional, overridden by sRGB or iCCP if those are present. */
+  unsigned chrm_defined; /* Whether a cHRM chunk is present (0 = not present, 1 = present). */
+  unsigned chrm_white_x; /* White Point x times 100000 */
+  unsigned chrm_white_y; /* White Point y times 100000 */
+  unsigned chrm_red_x;   /* Red x times 100000 */
+  unsigned chrm_red_y;   /* Red y times 100000 */
+  unsigned chrm_green_x; /* Green x times 100000 */
+  unsigned chrm_green_y; /* Green y times 100000 */
+  unsigned chrm_blue_x;  /* Blue x times 100000 */
+  unsigned chrm_blue_y;  /* Blue y times 100000 */
+
+  /*
+  sRGB chunk: optional. May not appear at the same time as iCCP.
+  If gAMA is also present gAMA must contain value 45455.
+  If cHRM is also present cHRM must contain respectively 31270,32900,64000,33000,30000,60000,15000,6000.
+  */
+  unsigned srgb_defined; /* Whether an sRGB chunk is present (0 = not present, 1 = present). */
+  unsigned srgb_intent;  /* Rendering intent: 0=perceptual, 1=rel. colorimetric, 2=saturation, 3=abs. colorimetric */
+
+  /*
+  iCCP chunk: optional. May not appear at the same time as sRGB.
+
+  LodePNG does not parse or use the ICC profile (except its color space header field for an edge case), a
+  separate library to handle the ICC data (not included in LodePNG) format is needed to use it for color
+  management and conversions.
+
+  For encoding, if iCCP is present, gAMA and cHRM are recommended to be added as well with values that match the ICC
+  profile as closely as possible, if you wish to do this you should provide the correct values for gAMA and cHRM and
+  enable their '_defined' flags since LodePNG will not automatically compute them from the ICC profile.
+
+  For encoding, the ICC profile is required by the PNG specification to be an "RGB" profile for non-gray
+  PNG color types and a "GRAY" profile for gray PNG color types. If you disable auto_convert, you must ensure
+  the ICC profile type matches your requested color type, else the encoder gives an error. If auto_convert is
+  enabled (the default), and the ICC profile is not a good match for the pixel data, this will result in an encoder
+  error if the pixel data has non-gray pixels for a GRAY profile, or a silent less-optimal compression of the pixel
+  data if the pixels could be encoded as grayscale but the ICC profile is RGB.
+
+  To avoid this do not set an ICC profile in the image unless there is a good reason for it, and when doing so
+  make sure you compute it carefully to avoid the above problems.
+  */
+  unsigned iccp_defined;      /* Whether an iCCP chunk is present (0 = not present, 1 = present). */
+  char* iccp_name;            /* Null terminated string with profile name, 1-79 bytes */
+  /*
+  The ICC profile in iccp_profile_size bytes.
+  Don't allocate this buffer yourself. Use the init/cleanup functions
+  correctly and use lodepng_set_icc and lodepng_clear_icc.
+  */
+  unsigned char* iccp_profile;
+  unsigned iccp_profile_size; /* The size of iccp_profile in bytes */
+
+  /* End of color profile related chunks */
+
+
+  /*
+  unknown chunks: chunks not known by LodePNG, passed on byte for byte.
+
+  There are 3 buffers, one for each position in the PNG where unknown chunks can appear.
+  Each buffer contains all unknown chunks for that position consecutively.
+  The 3 positions are:
+  0: between IHDR and PLTE, 1: between PLTE and IDAT, 2: between IDAT and IEND.
+
+  For encoding, do not store critical chunks or known chunks that are enabled with a "_defined" flag
+  above in here, since the encoder will blindly follow this and could then encode an invalid PNG file
+  (such as one with two IHDR chunks or the disallowed combination of sRGB with iCCP). But do use
+  this if you wish to store an ancillary chunk that is not supported by LodePNG (such as sPLT or hIST),
+  or any non-standard PNG chunk.
+
+  Do not allocate or traverse this data yourself. Use the chunk traversing functions declared
+  later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct.
+  */
+  unsigned char* unknown_chunks_data[3];
+  size_t unknown_chunks_size[3]; /*size in bytes of the unknown chunks, given for protection*/
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+} LodePNGInfo;
+
+/*init, cleanup and copy functions to use with this struct*/
+void lodepng_info_init(LodePNGInfo* info);
+void lodepng_info_cleanup(LodePNGInfo* info);
+/*return value is error code (0 means no error)*/
+unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source);
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /*push back both texts at once*/
+void lodepng_clear_text(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/
+
+unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
+                           const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/
+void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/
+
+/*replaces if exists*/
+unsigned lodepng_set_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size);
+void lodepng_clear_icc(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+/*
+Converts raw buffer from one color type to another color type, based on
+LodePNGColorMode structs to describe the input and output color type.
+See the reference manual at the end of this header file to see which color conversions are supported.
+return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported)
+The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel
+of the output color type (lodepng_get_bpp).
+For < 8 bpp images, there should not be padding bits at the end of scanlines.
+For 16-bit per channel colors, uses big endian format like PNG does.
+Return value is LodePNG error code
+*/
+unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
+                         const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
+                         unsigned w, unsigned h);
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*
+Settings for the decoder. This contains settings for the PNG and the Zlib
+decoder, but not the Info settings from the Info structs.
+*/
+typedef struct LodePNGDecoderSettings {
+  LodePNGDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/
+
+  /* Check LodePNGDecompressSettings for more ignorable errors such as ignore_adler32 */
+  unsigned ignore_crc; /*ignore CRC checksums*/
+  unsigned ignore_critical; /*ignore unknown critical chunks*/
+  unsigned ignore_end; /*ignore issues at end of file if possible (missing IEND chunk, too large chunk, ...)*/
+  /* TODO: make a system involving warnings with levels and a strict mode instead. Other potentially recoverable
+     errors: srgb rendering intent value, size of content of ancillary chunks, more than 79 characters for some
+     strings, placement/combination rules for ancillary chunks, crc of unknown chunks, allowed characters
+     in string keys, etc... */
+
+  unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  unsigned read_text_chunks; /*if false but remember_unknown_chunks is true, they're stored in the unknown chunks*/
+  /*store all bytes from unknown chunks in the LodePNGInfo (off by default, useful for a png editor)*/
+  unsigned remember_unknown_chunks;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+} LodePNGDecoderSettings;
+
+void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings);
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*automatically use color type with less bits per pixel if losslessly possible. Default: AUTO*/
+typedef enum LodePNGFilterStrategy {
+  /*every filter at zero*/
+  LFS_ZERO = 0,
+  /*every filter at 1, 2, 3 or 4 (paeth), unlike LFS_ZERO not a good choice, but for testing*/
+  LFS_ONE = 1,
+  LFS_TWO = 2,
+  LFS_THREE = 3,
+  LFS_FOUR = 4,
+  /*Use filter that gives minimum sum, as described in the official PNG filter heuristic.*/
+  LFS_MINSUM,
+  /*Use the filter type that gives smallest Shannon entropy for this scanline. Depending
+  on the image, this is better or worse than minsum.*/
+  LFS_ENTROPY,
+  /*
+  Brute-force-search PNG filters by compressing each filter for each scanline.
+  Experimental, very slow, and only rarely gives better compression than MINSUM.
+  */
+  LFS_BRUTE_FORCE,
+  /*use predefined_filters buffer: you specify the filter type for each scanline*/
+  LFS_PREDEFINED
+} LodePNGFilterStrategy;
+
+/*Gives characteristics about the integer RGBA colors of the image (count, alpha channel usage, bit depth, ...),
+which helps decide which color model to use for encoding.
+Used internally by default if "auto_convert" is enabled. Public because it's useful for custom algorithms.*/
+typedef struct LodePNGColorStats {
+  unsigned colored; /*not grayscale*/
+  unsigned key; /*image is not opaque and color key is possible instead of full alpha*/
+  unsigned short key_r; /*key values, always as 16-bit, in 8-bit case the byte is duplicated, e.g. 65535 means 255*/
+  unsigned short key_g;
+  unsigned short key_b;
+  unsigned alpha; /*image is not opaque and alpha channel or alpha palette required*/
+  unsigned numcolors; /*amount of colors, up to 257. Not valid if bits == 16 or allow_palette is disabled.*/
+  unsigned char palette[1024]; /*Remembers up to the first 256 RGBA colors, in no particular order, only valid when numcolors is valid*/
+  unsigned bits; /*bits per channel (not for palette). 1,2 or 4 for grayscale only. 16 if 16-bit per channel required.*/
+  size_t numpixels;
+
+  /*user settings for computing/using the stats*/
+  unsigned allow_palette; /*default 1. if 0, disallow choosing palette colortype in auto_choose_color, and don't count numcolors*/
+  unsigned allow_greyscale; /*default 1. if 0, choose RGB or RGBA even if the image only has gray colors*/
+} LodePNGColorStats;
+
+void lodepng_color_stats_init(LodePNGColorStats* stats);
+
+/*Get a LodePNGColorStats of the image. The stats must already have been inited.
+Returns error code (e.g. alloc fail) or 0 if ok.*/
+unsigned lodepng_compute_color_stats(LodePNGColorStats* stats,
+                                     const unsigned char* image, unsigned w, unsigned h,
+                                     const LodePNGColorMode* mode_in);
+
+/*Settings for the encoder.*/
+typedef struct LodePNGEncoderSettings {
+  LodePNGCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/
+
+  unsigned auto_convert; /*automatically choose output PNG color type. Default: true*/
+
+  /*If true, follows the official PNG heuristic: if the PNG uses a palette or lower than
+  8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to
+  completely follow the official PNG heuristic, filter_palette_zero must be true and
+  filter_strategy must be LFS_MINSUM*/
+  unsigned filter_palette_zero;
+  /*Which filter strategy to use when not using zeroes due to filter_palette_zero.
+  Set filter_palette_zero to 0 to ensure always using your chosen strategy. Default: LFS_MINSUM*/
+  LodePNGFilterStrategy filter_strategy;
+  /*used if filter_strategy is LFS_PREDEFINED. In that case, this must point to a buffer with
+  the same length as the amount of scanlines in the image, and each value must <= 5. You
+  have to cleanup this buffer, LodePNG will never free it. Don't forget that filter_palette_zero
+  must be set to 0 to ensure this is also used on palette or low bitdepth images.*/
+  const unsigned char* predefined_filters;
+
+  /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette).
+  If colortype is 3, PLTE is _always_ created.*/
+  unsigned force_palette;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  /*add LodePNG identifier and version as a text chunk, for debugging*/
+  unsigned add_id;
+  /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/
+  unsigned text_compression;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+} LodePNGEncoderSettings;
+
+void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+
+#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
+/*The settings, state and information for extended encoding and decoding.*/
+typedef struct LodePNGState {
+#ifdef LODEPNG_COMPILE_DECODER
+  LodePNGDecoderSettings decoder; /*the decoding settings*/
+#endif /*LODEPNG_COMPILE_DECODER*/
+#ifdef LODEPNG_COMPILE_ENCODER
+  LodePNGEncoderSettings encoder; /*the encoding settings*/
+#endif /*LODEPNG_COMPILE_ENCODER*/
+  LodePNGColorMode info_raw; /*specifies the format in which you would like to get the raw pixel buffer*/
+  LodePNGInfo info_png; /*info of the PNG image obtained after decoding*/
+  unsigned error;
+} LodePNGState;
+
+/*init, cleanup and copy functions to use with this struct*/
+void lodepng_state_init(LodePNGState* state);
+void lodepng_state_cleanup(LodePNGState* state);
+void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source);
+#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*
+Same as lodepng_decode_memory, but uses a LodePNGState to allow custom settings and
+getting much more information about the PNG image and color mode.
+*/
+unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
+                        LodePNGState* state,
+                        const unsigned char* in, size_t insize);
+
+/*
+Read the PNG header, but not the actual data. This returns only the information
+that is in the IHDR chunk of the PNG, such as width, height and color type. The
+information is placed in the info_png field of the LodePNGState.
+*/
+unsigned lodepng_inspect(unsigned* w, unsigned* h,
+                         LodePNGState* state,
+                         const unsigned char* in, size_t insize);
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+/*
+Reads one metadata chunk (other than IHDR) of the PNG file and outputs what it
+read in the state. Returns error code on failure.
+Use lodepng_inspect first with a new state, then e.g. lodepng_chunk_find_const
+to find the desired chunk type, and if non null use lodepng_inspect_chunk (with
+chunk_pointer - start_of_file as pos).
+Supports most metadata chunks from the PNG standard (gAMA, bKGD, tEXt, ...).
+Ignores unsupported, unknown, non-metadata or IHDR chunks (without error).
+Requirements: &in[pos] must point to start of a chunk, must use regular
+lodepng_inspect first since format of most other chunks depends on IHDR, and if
+there is a PLTE chunk, that one must be inspected before tRNS or bKGD.
+*/
+unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos,
+                               const unsigned char* in, size_t insize);
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/
+unsigned lodepng_encode(unsigned char** out, size_t* outsize,
+                        const unsigned char* image, unsigned w, unsigned h,
+                        LodePNGState* state);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+/*
+The lodepng_chunk functions are normally not needed, except to traverse the
+unknown chunks stored in the LodePNGInfo struct, or add new ones to it.
+It also allows traversing the chunks of an encoded PNG file yourself.
+
+The chunk pointer always points to the beginning of the chunk itself, that is
+the first byte of the 4 length bytes.
+
+In the PNG file format, chunks have the following format:
+-4 bytes length: length of the data of the chunk in bytes (chunk itself is 12 bytes longer)
+-4 bytes chunk type (ASCII a-z,A-Z only, see below)
+-length bytes of data (may be 0 bytes if length was 0)
+-4 bytes of CRC, computed on chunk name + data
+
+The first chunk starts at the 8th byte of the PNG file, the entire rest of the file
+exists out of concatenated chunks with the above format.
+
+PNG standard chunk ASCII naming conventions:
+-First byte: uppercase = critical, lowercase = ancillary
+-Second byte: uppercase = public, lowercase = private
+-Third byte: must be uppercase
+-Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy
+*/
+
+/*
+Gets the length of the data of the chunk. Total chunk length has 12 bytes more.
+There must be at least 4 bytes to read from. If the result value is too large,
+it may be corrupt data.
+*/
+unsigned lodepng_chunk_length(const unsigned char* chunk);
+
+/*puts the 4-byte type in null terminated string*/
+void lodepng_chunk_type(char type[5], const unsigned char* chunk);
+
+/*check if the type is the given type*/
+unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type);
+
+/*0: it's one of the critical chunk types, 1: it's an ancillary chunk (see PNG standard)*/
+unsigned char lodepng_chunk_ancillary(const unsigned char* chunk);
+
+/*0: public, 1: private (see PNG standard)*/
+unsigned char lodepng_chunk_private(const unsigned char* chunk);
+
+/*0: the chunk is unsafe to copy, 1: the chunk is safe to copy (see PNG standard)*/
+unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk);
+
+/*get pointer to the data of the chunk, where the input points to the header of the chunk*/
+unsigned char* lodepng_chunk_data(unsigned char* chunk);
+const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk);
+
+/*returns 0 if the crc is correct, 1 if it's incorrect (0 for OK as usual!)*/
+unsigned lodepng_chunk_check_crc(const unsigned char* chunk);
+
+/*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/
+void lodepng_chunk_generate_crc(unsigned char* chunk);
+
+/*
+Iterate to next chunks, allows iterating through all chunks of the PNG file.
+Input must be at the beginning of a chunk (result of a previous lodepng_chunk_next call,
+or the 8th byte of a PNG file which always has the first chunk), or alternatively may
+point to the first byte of the PNG file (which is not a chunk but the magic header, the
+function will then skip over it and return the first real chunk).
+Will output pointer to the start of the next chunk, or at or beyond end of the file if there
+is no more chunk after this or possibly if the chunk is corrupt.
+Start this process at the 8th byte of the PNG file.
+In a non-corrupt PNG file, the last chunk should have name "IEND".
+*/
+unsigned char* lodepng_chunk_next(unsigned char* chunk, unsigned char* end);
+const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk, const unsigned char* end);
+
+/*Finds the first chunk with the given type in the range [chunk, end), or returns NULL if not found.*/
+unsigned char* lodepng_chunk_find(unsigned char* chunk, unsigned char* end, const char type[5]);
+const unsigned char* lodepng_chunk_find_const(const unsigned char* chunk, const unsigned char* end, const char type[5]);
+
+/*
+Appends chunk to the data in out. The given chunk should already have its chunk header.
+The out variable and outsize are updated to reflect the new reallocated buffer.
+Returns error code (0 if it went ok)
+*/
+unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk);
+
+/*
+Appends new chunk to out. The chunk to append is given by giving its length, type
+and data separately. The type is a 4-letter string.
+The out variable and outsize are updated to reflect the new reallocated buffer.
+Returne error code (0 if it went ok)
+*/
+unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize, unsigned length,
+                              const char* type, const unsigned char* data);
+
+
+/*Calculate CRC32 of buffer*/
+unsigned lodepng_crc32(const unsigned char* buf, size_t len);
+#endif /*LODEPNG_COMPILE_PNG*/
+
+
+#ifdef LODEPNG_COMPILE_ZLIB
+/*
+This zlib part can be used independently to zlib compress and decompress a
+buffer. It cannot be used to create gzip files however, and it only supports the
+part of zlib that is required for PNG, it does not support dictionaries.
+*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*Inflate a buffer. Inflate is the decompression step of deflate. Out buffer must be freed after use.*/
+unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
+                         const unsigned char* in, size_t insize,
+                         const LodePNGDecompressSettings* settings);
+
+/*
+Decompresses Zlib data. Reallocates the out buffer and appends the data. The
+data must be according to the zlib specification.
+Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
+buffer and *outsize its size in bytes. out must be freed by user after usage.
+*/
+unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize,
+                                 const unsigned char* in, size_t insize,
+                                 const LodePNGDecompressSettings* settings);
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*
+Compresses data with Zlib. Reallocates the out buffer and appends the data.
+Zlib adds a small header and trailer around the deflate data.
+The data is output in the format of the zlib specification.
+Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
+buffer and *outsize its size in bytes. out must be freed by user after usage.
+*/
+unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize,
+                               const unsigned char* in, size_t insize,
+                               const LodePNGCompressSettings* settings);
+
+/*
+Find length-limited Huffman code for given frequencies. This function is in the
+public interface only for tests, it's used internally by lodepng_deflate.
+*/
+unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
+                                      size_t numcodes, unsigned maxbitlen);
+
+/*Compress a buffer with deflate. See RFC 1951. Out buffer must be freed after use.*/
+unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
+                         const unsigned char* in, size_t insize,
+                         const LodePNGCompressSettings* settings);
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+#ifdef LODEPNG_COMPILE_DISK
+/*
+Load a file from disk into buffer. The function allocates the out buffer, and
+after usage you should free it.
+out: output parameter, contains pointer to loaded buffer.
+outsize: output parameter, size of the allocated out buffer
+filename: the path to the file to load
+return value: error code (0 means ok)
+*/
+unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename);
+
+/*
+Save a file from buffer to disk. Warning, if it exists, this function overwrites
+the file without warning!
+buffer: the buffer to write
+buffersize: size of the buffer to write
+filename: the path to the file to save to
+return value: error code (0 means ok)
+*/
+unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename);
+#endif /*LODEPNG_COMPILE_DISK*/
+
+#ifdef LODEPNG_COMPILE_CPP
+/* The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers. */
+namespace lodepng {
+#ifdef LODEPNG_COMPILE_PNG
+class State : public LodePNGState {
+  public:
+    State();
+    State(const State& other);
+    ~State();
+    State& operator=(const State& other);
+};
+
+#ifdef LODEPNG_COMPILE_DECODER
+/* Same as other lodepng::decode, but using a State for more settings and information. */
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                State& state,
+                const unsigned char* in, size_t insize);
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                State& state,
+                const std::vector<unsigned char>& in);
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/* Same as other lodepng::encode, but using a State for more settings and information. */
+unsigned encode(std::vector<unsigned char>& out,
+                const unsigned char* in, unsigned w, unsigned h,
+                State& state);
+unsigned encode(std::vector<unsigned char>& out,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                State& state);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_DISK
+/*
+Load a file from disk into an std::vector.
+return value: error code (0 means ok)
+*/
+unsigned load_file(std::vector<unsigned char>& buffer, const std::string& filename);
+
+/*
+Save the binary data in an std::vector to a file on disk. The file is overwritten
+without warning.
+*/
+unsigned save_file(const std::vector<unsigned char>& buffer, const std::string& filename);
+#endif /* LODEPNG_COMPILE_DISK */
+#endif /* LODEPNG_COMPILE_PNG */
+
+#ifdef LODEPNG_COMPILE_ZLIB
+#ifdef LODEPNG_COMPILE_DECODER
+/* Zlib-decompress an unsigned char buffer */
+unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
+                    const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
+
+/* Zlib-decompress an std::vector */
+unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+                    const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
+#endif /* LODEPNG_COMPILE_DECODER */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/* Zlib-compress an unsigned char buffer */
+unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
+                  const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
+
+/* Zlib-compress an std::vector */
+unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+                  const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
+#endif /* LODEPNG_COMPILE_ENCODER */
+#endif /* LODEPNG_COMPILE_ZLIB */
+} /* namespace lodepng */
+#endif /*LODEPNG_COMPILE_CPP*/
+
+/*
+TODO:
+[.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often
+[.] check compatibility with various compilers  - done but needs to be redone for every newer version
+[X] converting color to 16-bit per channel types
+[X] support color profile chunk types (but never let them touch RGB values by default)
+[ ] support all public PNG chunk types (almost done except sBIT, sPLT and hIST)
+[ ] make sure encoder generates no chunks with size > (2^31)-1
+[ ] partial decoding (stream processing)
+[X] let the "isFullyOpaque" function check color keys and transparent palettes too
+[X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl"
+[ ] allow treating some errors like warnings, when image is recoverable (e.g. 69, 57, 58)
+[ ] make warnings like: oob palette, checksum fail, data after iend, wrong/unknown crit chunk, no null terminator in text, ...
+[ ] error messages with line numbers (and version)
+[ ] errors in state instead of as return code?
+[ ] new errors/warnings like suspiciously big decompressed ztxt or iccp chunk
+[ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes
+[ ] allow user to provide custom color conversion functions, e.g. for premultiplied alpha, padding bits or not, ...
+[ ] allow user to give data (void*) to custom allocator
+[X] provide alternatives for C library functions not present on some platforms (memcpy, ...)
+*/
+
+#endif /*LODEPNG_H inclusion guard*/
+
+/*
+LodePNG Documentation
+---------------------
+
+0. table of contents
+--------------------
+
+  1. about
+   1.1. supported features
+   1.2. features not supported
+  2. C and C++ version
+  3. security
+  4. decoding
+  5. encoding
+  6. color conversions
+    6.1. PNG color types
+    6.2. color conversions
+    6.3. padding bits
+    6.4. A note about 16-bits per channel and endianness
+  7. error values
+  8. chunks and PNG editing
+  9. compiler support
+  10. examples
+   10.1. decoder C++ example
+   10.2. decoder C example
+  11. state settings reference
+  12. changes
+  13. contact information
+
+
+1. about
+--------
+
+PNG is a file format to store raster images losslessly with good compression,
+supporting different color types and alpha channel.
+
+LodePNG is a PNG codec according to the Portable Network Graphics (PNG)
+Specification (Second Edition) - W3C Recommendation 10 November 2003.
+
+The specifications used are:
+
+*) Portable Network Graphics (PNG) Specification (Second Edition):
+     http://www.w3.org/TR/2003/REC-PNG-20031110
+*) RFC 1950 ZLIB Compressed Data Format version 3.3:
+     http://www.gzip.org/zlib/rfc-zlib.html
+*) RFC 1951 DEFLATE Compressed Data Format Specification ver 1.3:
+     http://www.gzip.org/zlib/rfc-deflate.html
+
+The most recent version of LodePNG can currently be found at
+http://lodev.org/lodepng/
+
+LodePNG works both in C (ISO C90) and C++, with a C++ wrapper that adds
+extra functionality.
+
+LodePNG exists out of two files:
+-lodepng.h: the header file for both C and C++
+-lodepng.c(pp): give it the name lodepng.c or lodepng.cpp (or .cc) depending on your usage
+
+If you want to start using LodePNG right away without reading this doc, get the
+examples from the LodePNG website to see how to use it in code, or check the
+smaller examples in chapter 13 here.
+
+LodePNG is simple but only supports the basic requirements. To achieve
+simplicity, the following design choices were made: There are no dependencies
+on any external library. There are functions to decode and encode a PNG with
+a single function call, and extended versions of these functions taking a
+LodePNGState struct allowing to specify or get more information. By default
+the colors of the raw image are always RGB or RGBA, no matter what color type
+the PNG file uses. To read and write files, there are simple functions to
+convert the files to/from buffers in memory.
+
+This all makes LodePNG suitable for loading textures in games, demos and small
+programs, ... It's less suitable for full fledged image editors, loading PNGs
+over network (it requires all the image data to be available before decoding can
+begin), life-critical systems, ...
+
+1.1. supported features
+-----------------------
+
+The following features are supported by the decoder:
+
+*) decoding of PNGs with any color type, bit depth and interlace mode, to a 24- or 32-bit color raw image,
+   or the same color type as the PNG
+*) encoding of PNGs, from any raw image to 24- or 32-bit color, or the same color type as the raw image
+*) Adam7 interlace and deinterlace for any color type
+*) loading the image from harddisk or decoding it from a buffer from other sources than harddisk
+*) support for alpha channels, including RGBA color model, translucent palettes and color keying
+*) zlib decompression (inflate)
+*) zlib compression (deflate)
+*) CRC32 and ADLER32 checksums
+*) colorimetric color profile conversions: currently experimentally available in lodepng_util.cpp only,
+   plus alternatively ability to pass on chroma/gamma/ICC profile information to other color management system.
+*) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks.
+*) the following chunks are supported by both encoder and decoder:
+    IHDR: header information
+    PLTE: color palette
+    IDAT: pixel data
+    IEND: the final chunk
+    tRNS: transparency for palettized images
+    tEXt: textual information
+    zTXt: compressed textual information
+    iTXt: international textual information
+    bKGD: suggested background color
+    pHYs: physical dimensions
+    tIME: modification time
+    cHRM: RGB chromaticities
+    gAMA: RGB gamma correction
+    iCCP: ICC color profile
+    sRGB: rendering intent
+
+1.2. features not supported
+---------------------------
+
+The following features are _not_ supported:
+
+*) some features needed to make a conformant PNG-Editor might be still missing.
+*) partial loading/stream processing. All data must be available and is processed in one call.
+*) The following public chunks are not (yet) supported but treated as unknown chunks by LodePNG:
+    sBIT
+    hIST
+    sPLT
+
+
+2. C and C++ version
+--------------------
+
+The C version uses buffers allocated with alloc that you need to free()
+yourself. You need to use init and cleanup functions for each struct whenever
+using a struct from the C version to avoid exploits and memory leaks.
+
+The C++ version has extra functions with std::vectors in the interface and the
+lodepng::State class which is a LodePNGState with constructor and destructor.
+
+These files work without modification for both C and C++ compilers because all
+the additional C++ code is in "#ifdef __cplusplus" blocks that make C-compilers
+ignore it, and the C code is made to compile both with strict ISO C90 and C++.
+
+To use the C++ version, you need to rename the source file to lodepng.cpp
+(instead of lodepng.c), and compile it with a C++ compiler.
+
+To use the C version, you need to rename the source file to lodepng.c (instead
+of lodepng.cpp), and compile it with a C compiler.
+
+
+3. Security
+-----------
+
+Even if carefully designed, it's always possible that LodePNG contains possible
+exploits. If you discover one, please let me know, and it will be fixed.
+
+When using LodePNG, care has to be taken with the C version of LodePNG, as well
+as the C-style structs when working with C++. The following conventions are used
+for all C-style structs:
+
+-if a struct has a corresponding init function, always call the init function when making a new one
+-if a struct has a corresponding cleanup function, call it before the struct disappears to avoid memory leaks
+-if a struct has a corresponding copy function, use the copy function instead of "=".
+ The destination must also be inited already.
+
+
+4. Decoding
+-----------
+
+Decoding converts a PNG compressed image to a raw pixel buffer.
+
+Most documentation on using the decoder is at its declarations in the header
+above. For C, simple decoding can be done with functions such as
+lodepng_decode32, and more advanced decoding can be done with the struct
+LodePNGState and lodepng_decode. For C++, all decoding can be done with the
+various lodepng::decode functions, and lodepng::State can be used for advanced
+features.
+
+When using the LodePNGState, it uses the following fields for decoding:
+*) LodePNGInfo info_png: it stores extra information about the PNG (the input) in here
+*) LodePNGColorMode info_raw: here you can say what color mode of the raw image (the output) you want to get
+*) LodePNGDecoderSettings decoder: you can specify a few extra settings for the decoder to use
+
+LodePNGInfo info_png
+--------------------
+
+After decoding, this contains extra information of the PNG image, except the actual
+pixels, width and height because these are already gotten directly from the decoder
+functions.
+
+It contains for example the original color type of the PNG image, text comments,
+suggested background color, etc... More details about the LodePNGInfo struct are
+at its declaration documentation.
+
+LodePNGColorMode info_raw
+-------------------------
+
+When decoding, here you can specify which color type you want
+the resulting raw image to be. If this is different from the colortype of the
+PNG, then the decoder will automatically convert the result. This conversion
+always works, except if you want it to convert a color PNG to grayscale or to
+a palette with missing colors.
+
+By default, 32-bit color is used for the result.
+
+LodePNGDecoderSettings decoder
+------------------------------
+
+The settings can be used to ignore the errors created by invalid CRC and Adler32
+chunks, and to disable the decoding of tEXt chunks.
+
+There's also a setting color_convert, true by default. If false, no conversion
+is done, the resulting data will be as it was in the PNG (after decompression)
+and you'll have to puzzle the colors of the pixels together yourself using the
+color type information in the LodePNGInfo.
+
+
+5. Encoding
+-----------
+
+Encoding converts a raw pixel buffer to a PNG compressed image.
+
+Most documentation on using the encoder is at its declarations in the header
+above. For C, simple encoding can be done with functions such as
+lodepng_encode32, and more advanced decoding can be done with the struct
+LodePNGState and lodepng_encode. For C++, all encoding can be done with the
+various lodepng::encode functions, and lodepng::State can be used for advanced
+features.
+
+Like the decoder, the encoder can also give errors. However it gives less errors
+since the encoder input is trusted, the decoder input (a PNG image that could
+be forged by anyone) is not trusted.
+
+When using the LodePNGState, it uses the following fields for encoding:
+*) LodePNGInfo info_png: here you specify how you want the PNG (the output) to be.
+*) LodePNGColorMode info_raw: here you say what color type of the raw image (the input) has
+*) LodePNGEncoderSettings encoder: you can specify a few settings for the encoder to use
+
+LodePNGInfo info_png
+--------------------
+
+When encoding, you use this the opposite way as when decoding: for encoding,
+you fill in the values you want the PNG to have before encoding. By default it's
+not needed to specify a color type for the PNG since it's automatically chosen,
+but it's possible to choose it yourself given the right settings.
+
+The encoder will not always exactly match the LodePNGInfo struct you give,
+it tries as close as possible. Some things are ignored by the encoder. The
+encoder uses, for example, the following settings from it when applicable:
+colortype and bitdepth, text chunks, time chunk, the color key, the palette, the
+background color, the interlace method, unknown chunks, ...
+
+When encoding to a PNG with colortype 3, the encoder will generate a PLTE chunk.
+If the palette contains any colors for which the alpha channel is not 255 (so
+there are translucent colors in the palette), it'll add a tRNS chunk.
+
+LodePNGColorMode info_raw
+-------------------------
+
+You specify the color type of the raw image that you give to the input here,
+including a possible transparent color key and palette you happen to be using in
+your raw image data.
+
+By default, 32-bit color is assumed, meaning your input has to be in RGBA
+format with 4 bytes (unsigned chars) per pixel.
+
+LodePNGEncoderSettings encoder
+------------------------------
+
+The following settings are supported (some are in sub-structs):
+*) auto_convert: when this option is enabled, the encoder will
+automatically choose the smallest possible color mode (including color key) that
+can encode the colors of all pixels without information loss.
+*) btype: the block type for LZ77. 0 = uncompressed, 1 = fixed huffman tree,
+   2 = dynamic huffman tree (best compression). Should be 2 for proper
+   compression.
+*) use_lz77: whether or not to use LZ77 for compressed block types. Should be
+   true for proper compression.
+*) windowsize: the window size used by the LZ77 encoder (1 - 32768). Has value
+   2048 by default, but can be set to 32768 for better, but slow, compression.
+*) force_palette: if colortype is 2 or 6, you can make the encoder write a PLTE
+   chunk if force_palette is true. This can used as suggested palette to convert
+   to by viewers that don't support more than 256 colors (if those still exist)
+*) add_id: add text chunk "Encoder: LodePNG <version>" to the image.
+*) text_compression: default 1. If 1, it'll store texts as zTXt instead of tEXt chunks.
+  zTXt chunks use zlib compression on the text. This gives a smaller result on
+  large texts but a larger result on small texts (such as a single program name).
+  It's all tEXt or all zTXt though, there's no separate setting per text yet.
+
+
+6. color conversions
+--------------------
+
+An important thing to note about LodePNG, is that the color type of the PNG, and
+the color type of the raw image, are completely independent. By default, when
+you decode a PNG, you get the result as a raw image in the color type you want,
+no matter whether the PNG was encoded with a palette, grayscale or RGBA color.
+And if you encode an image, by default LodePNG will automatically choose the PNG
+color type that gives good compression based on the values of colors and amount
+of colors in the image. It can be configured to let you control it instead as
+well, though.
+
+To be able to do this, LodePNG does conversions from one color mode to another.
+It can convert from almost any color type to any other color type, except the
+following conversions: RGB to grayscale is not supported, and converting to a
+palette when the palette doesn't have a required color is not supported. This is
+not supported on purpose: this is information loss which requires a color
+reduction algorithm that is beyond the scope of a PNG encoder (yes, RGB to gray
+is easy, but there are multiple ways if you want to give some channels more
+weight).
+
+By default, when decoding, you get the raw image in 32-bit RGBA or 24-bit RGB
+color, no matter what color type the PNG has. And by default when encoding,
+LodePNG automatically picks the best color model for the output PNG, and expects
+the input image to be 32-bit RGBA or 24-bit RGB. So, unless you want to control
+the color format of the images yourself, you can skip this chapter.
+
+6.1. PNG color types
+--------------------
+
+A PNG image can have many color types, ranging from 1-bit color to 64-bit color,
+as well as palettized color modes. After the zlib decompression and unfiltering
+in the PNG image is done, the raw pixel data will have that color type and thus
+a certain amount of bits per pixel. If you want the output raw image after
+decoding to have another color type, a conversion is done by LodePNG.
+
+The PNG specification gives the following color types:
+
+0: grayscale, bit depths 1, 2, 4, 8, 16
+2: RGB, bit depths 8 and 16
+3: palette, bit depths 1, 2, 4 and 8
+4: grayscale with alpha, bit depths 8 and 16
+6: RGBA, bit depths 8 and 16
+
+Bit depth is the amount of bits per pixel per color channel. So the total amount
+of bits per pixel is: amount of channels * bitdepth.
+
+6.2. color conversions
+----------------------
+
+As explained in the sections about the encoder and decoder, you can specify
+color types and bit depths in info_png and info_raw to change the default
+behaviour.
+
+If, when decoding, you want the raw image to be something else than the default,
+you need to set the color type and bit depth you want in the LodePNGColorMode,
+or the parameters colortype and bitdepth of the simple decoding function.
+
+If, when encoding, you use another color type than the default in the raw input
+image, you need to specify its color type and bit depth in the LodePNGColorMode
+of the raw image, or use the parameters colortype and bitdepth of the simple
+encoding function.
+
+If, when encoding, you don't want LodePNG to choose the output PNG color type
+but control it yourself, you need to set auto_convert in the encoder settings
+to false, and specify the color type you want in the LodePNGInfo of the
+encoder (including palette: it can generate a palette if auto_convert is true,
+otherwise not).
+
+If the input and output color type differ (whether user chosen or auto chosen),
+LodePNG will do a color conversion, which follows the rules below, and may
+sometimes result in an error.
+
+To avoid some confusion:
+-the decoder converts from PNG to raw image
+-the encoder converts from raw image to PNG
+-the colortype and bitdepth in LodePNGColorMode info_raw, are those of the raw image
+-the colortype and bitdepth in the color field of LodePNGInfo info_png, are those of the PNG
+-when encoding, the color type in LodePNGInfo is ignored if auto_convert
+ is enabled, it is automatically generated instead
+-when decoding, the color type in LodePNGInfo is set by the decoder to that of the original
+ PNG image, but it can be ignored since the raw image has the color type you requested instead
+-if the color type of the LodePNGColorMode and PNG image aren't the same, a conversion
+ between the color types is done if the color types are supported. If it is not
+ supported, an error is returned. If the types are the same, no conversion is done.
+-even though some conversions aren't supported, LodePNG supports loading PNGs from any
+ colortype and saving PNGs to any colortype, sometimes it just requires preparing
+ the raw image correctly before encoding.
+-both encoder and decoder use the same color converter.
+
+The function lodepng_convert does the color conversion. It is available in the
+interface but normally isn't needed since the encoder and decoder already call
+it.
+
+Non supported color conversions:
+-color to grayscale when non-gray pixels are present: no error is thrown, but
+the result will look ugly because only the red channel is taken (it assumes all
+three channels are the same in this case so ignores green and blue). The reason
+no error is given is to allow converting from three-channel grayscale images to
+one-channel even if there are numerical imprecisions.
+-anything to palette when the palette does not have an exact match for a from-color
+in it: in this case an error is thrown
+
+Supported color conversions:
+-anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA
+-any gray or gray+alpha, to gray or gray+alpha
+-anything to a palette, as long as the palette has the requested colors in it
+-removing alpha channel
+-higher to smaller bitdepth, and vice versa
+
+If you want no color conversion to be done (e.g. for speed or control):
+-In the encoder, you can make it save a PNG with any color type by giving the
+raw color mode and LodePNGInfo the same color mode, and setting auto_convert to
+false.
+-In the decoder, you can make it store the pixel data in the same color type
+as the PNG has, by setting the color_convert setting to false. Settings in
+info_raw are then ignored.
+
+6.3. padding bits
+-----------------
+
+In the PNG file format, if a less than 8-bit per pixel color type is used and the scanlines
+have a bit amount that isn't a multiple of 8, then padding bits are used so that each
+scanline starts at a fresh byte. But that is NOT true for the LodePNG raw input and output.
+The raw input image you give to the encoder, and the raw output image you get from the decoder
+will NOT have these padding bits, e.g. in the case of a 1-bit image with a width
+of 7 pixels, the first pixel of the second scanline will the 8th bit of the first byte,
+not the first bit of a new byte.
+
+6.4. A note about 16-bits per channel and endianness
+----------------------------------------------------
+
+LodePNG uses unsigned char arrays for 16-bit per channel colors too, just like
+for any other color format. The 16-bit values are stored in big endian (most
+significant byte first) in these arrays. This is the opposite order of the
+little endian used by x86 CPU's.
+
+LodePNG always uses big endian because the PNG file format does so internally.
+Conversions to other formats than PNG uses internally are not supported by
+LodePNG on purpose, there are myriads of formats, including endianness of 16-bit
+colors, the order in which you store R, G, B and A, and so on. Supporting and
+converting to/from all that is outside the scope of LodePNG.
+
+This may mean that, depending on your use case, you may want to convert the big
+endian output of LodePNG to little endian with a for loop. This is certainly not
+always needed, many applications and libraries support big endian 16-bit colors
+anyway, but it means you cannot simply cast the unsigned char* buffer to an
+unsigned short* buffer on x86 CPUs.
+
+
+7. error values
+---------------
+
+All functions in LodePNG that return an error code, return 0 if everything went
+OK, or a non-zero code if there was an error.
+
+The meaning of the LodePNG error values can be retrieved with the function
+lodepng_error_text: given the numerical error code, it returns a description
+of the error in English as a string.
+
+Check the implementation of lodepng_error_text to see the meaning of each code.
+
+
+8. chunks and PNG editing
+-------------------------
+
+If you want to add extra chunks to a PNG you encode, or use LodePNG for a PNG
+editor that should follow the rules about handling of unknown chunks, or if your
+program is able to read other types of chunks than the ones handled by LodePNG,
+then that's possible with the chunk functions of LodePNG.
+
+A PNG chunk has the following layout:
+
+4 bytes length
+4 bytes type name
+length bytes data
+4 bytes CRC
+
+8.1. iterating through chunks
+-----------------------------
+
+If you have a buffer containing the PNG image data, then the first chunk (the
+IHDR chunk) starts at byte number 8 of that buffer. The first 8 bytes are the
+signature of the PNG and are not part of a chunk. But if you start at byte 8
+then you have a chunk, and can check the following things of it.
+
+NOTE: none of these functions check for memory buffer boundaries. To avoid
+exploits, always make sure the buffer contains all the data of the chunks.
+When using lodepng_chunk_next, make sure the returned value is within the
+allocated memory.
+
+unsigned lodepng_chunk_length(const unsigned char* chunk):
+
+Get the length of the chunk's data. The total chunk length is this length + 12.
+
+void lodepng_chunk_type(char type[5], const unsigned char* chunk):
+unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type):
+
+Get the type of the chunk or compare if it's a certain type
+
+unsigned char lodepng_chunk_critical(const unsigned char* chunk):
+unsigned char lodepng_chunk_private(const unsigned char* chunk):
+unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk):
+
+Check if the chunk is critical in the PNG standard (only IHDR, PLTE, IDAT and IEND are).
+Check if the chunk is private (public chunks are part of the standard, private ones not).
+Check if the chunk is safe to copy. If it's not, then, when modifying data in a critical
+chunk, unsafe to copy chunks of the old image may NOT be saved in the new one if your
+program doesn't handle that type of unknown chunk.
+
+unsigned char* lodepng_chunk_data(unsigned char* chunk):
+const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk):
+
+Get a pointer to the start of the data of the chunk.
+
+unsigned lodepng_chunk_check_crc(const unsigned char* chunk):
+void lodepng_chunk_generate_crc(unsigned char* chunk):
+
+Check if the crc is correct or generate a correct one.
+
+unsigned char* lodepng_chunk_next(unsigned char* chunk):
+const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk):
+
+Iterate to the next chunk. This works if you have a buffer with consecutive chunks. Note that these
+functions do no boundary checking of the allocated data whatsoever, so make sure there is enough
+data available in the buffer to be able to go to the next chunk.
+
+unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk):
+unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize, unsigned length,
+                              const char* type, const unsigned char* data):
+
+These functions are used to create new chunks that are appended to the data in *out that has
+length *outsize. The append function appends an existing chunk to the new data. The create
+function creates a new chunk with the given parameters and appends it. Type is the 4-letter
+name of the chunk.
+
+8.2. chunks in info_png
+-----------------------
+
+The LodePNGInfo struct contains fields with the unknown chunk in it. It has 3
+buffers (each with size) to contain 3 types of unknown chunks:
+the ones that come before the PLTE chunk, the ones that come between the PLTE
+and the IDAT chunks, and the ones that come after the IDAT chunks.
+It's necessary to make the distinction between these 3 cases because the PNG
+standard forces to keep the ordering of unknown chunks compared to the critical
+chunks, but does not force any other ordering rules.
+
+info_png.unknown_chunks_data[0] is the chunks before PLTE
+info_png.unknown_chunks_data[1] is the chunks after PLTE, before IDAT
+info_png.unknown_chunks_data[2] is the chunks after IDAT
+
+The chunks in these 3 buffers can be iterated through and read by using the same
+way described in the previous subchapter.
+
+When using the decoder to decode a PNG, you can make it store all unknown chunks
+if you set the option settings.remember_unknown_chunks to 1. By default, this
+option is off (0).
+
+The encoder will always encode unknown chunks that are stored in the info_png.
+If you need it to add a particular chunk that isn't known by LodePNG, you can
+use lodepng_chunk_append or lodepng_chunk_create to the chunk data in
+info_png.unknown_chunks_data[x].
+
+Chunks that are known by LodePNG should not be added in that way. E.g. to make
+LodePNG add a bKGD chunk, set background_defined to true and add the correct
+parameters there instead.
+
+
+9. compiler support
+-------------------
+
+No libraries other than the current standard C library are needed to compile
+LodePNG. For the C++ version, only the standard C++ library is needed on top.
+Add the files lodepng.c(pp) and lodepng.h to your project, include
+lodepng.h where needed, and your program can read/write PNG files.
+
+It is compatible with C90 and up, and C++03 and up.
+
+If performance is important, use optimization when compiling! For both the
+encoder and decoder, this makes a large difference.
+
+Make sure that LodePNG is compiled with the same compiler of the same version
+and with the same settings as the rest of the program, or the interfaces with
+std::vectors and std::strings in C++ can be incompatible.
+
+CHAR_BITS must be 8 or higher, because LodePNG uses unsigned chars for octets.
+
+*) gcc and g++
+
+LodePNG is developed in gcc so this compiler is natively supported. It gives no
+warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++
+version 4.7.1 on Linux, 32-bit and 64-bit.
+
+*) Clang
+
+Fully supported and warning-free.
+
+*) Mingw
+
+The Mingw compiler (a port of gcc for Windows) should be fully supported by
+LodePNG.
+
+*) Visual Studio and Visual C++ Express Edition
+
+LodePNG should be warning-free with warning level W4. Two warnings were disabled
+with pragmas though: warning 4244 about implicit conversions, and warning 4996
+where it wants to use a non-standard function fopen_s instead of the standard C
+fopen.
+
+Visual Studio may want "stdafx.h" files to be included in each source file and
+give an error "unexpected end of file while looking for precompiled header".
+This is not standard C++ and will not be added to the stock LodePNG. You can
+disable it for lodepng.cpp only by right clicking it, Properties, C/C++,
+Precompiled Headers, and set it to Not Using Precompiled Headers there.
+
+NOTE: Modern versions of VS should be fully supported, but old versions, e.g.
+VS6, are not guaranteed to work.
+
+*) Compilers on Macintosh
+
+LodePNG has been reported to work both with gcc and LLVM for Macintosh, both for
+C and C++.
+
+*) Other Compilers
+
+If you encounter problems on any compilers, feel free to let me know and I may
+try to fix it if the compiler is modern and standards compliant.
+
+
+10. examples
+------------
+
+This decoder example shows the most basic usage of LodePNG. More complex
+examples can be found on the LodePNG website.
+
+10.1. decoder C++ example
+-------------------------
+
+#include "lodepng.h"
+#include <iostream>
+
+int main(int argc, char *argv[]) {
+  const char* filename = argc > 1 ? argv[1] : "test.png";
+
+  //load and decode
+  std::vector<unsigned char> image;
+  unsigned width, height;
+  unsigned error = lodepng::decode(image, width, height, filename);
+
+  //if there's an error, display it
+  if(error) std::cout << "decoder error " << error << ": " << lodepng_error_text(error) << std::endl;
+
+  //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...
+}
+
+10.2. decoder C example
+-----------------------
+
+#include "lodepng.h"
+
+int main(int argc, char *argv[]) {
+  unsigned error;
+  unsigned char* image;
+  size_t width, height;
+  const char* filename = argc > 1 ? argv[1] : "test.png";
+
+  error = lodepng_decode32_file(&image, &width, &height, filename);
+
+  if(error) printf("decoder error %u: %s\n", error, lodepng_error_text(error));
+
+  / * use image here * /
+
+  free(image);
+  return 0;
+}
+
+11. state settings reference
+----------------------------
+
+A quick reference of some settings to set on the LodePNGState
+
+For decoding:
+
+state.decoder.zlibsettings.ignore_adler32: ignore ADLER32 checksums
+state.decoder.zlibsettings.custom_...: use custom inflate function
+state.decoder.ignore_crc: ignore CRC checksums
+state.decoder.ignore_critical: ignore unknown critical chunks
+state.decoder.ignore_end: ignore missing IEND chunk. May fail if this corruption causes other errors
+state.decoder.color_convert: convert internal PNG color to chosen one
+state.decoder.read_text_chunks: whether to read in text metadata chunks
+state.decoder.remember_unknown_chunks: whether to read in unknown chunks
+state.info_raw.colortype: desired color type for decoded image
+state.info_raw.bitdepth: desired bit depth for decoded image
+state.info_raw....: more color settings, see struct LodePNGColorMode
+state.info_png....: no settings for decoder but ouput, see struct LodePNGInfo
+
+For encoding:
+
+state.encoder.zlibsettings.btype: disable compression by setting it to 0
+state.encoder.zlibsettings.use_lz77: use LZ77 in compression
+state.encoder.zlibsettings.windowsize: tweak LZ77 windowsize
+state.encoder.zlibsettings.minmatch: tweak min LZ77 length to match
+state.encoder.zlibsettings.nicematch: tweak LZ77 match where to stop searching
+state.encoder.zlibsettings.lazymatching: try one more LZ77 matching
+state.encoder.zlibsettings.custom_...: use custom deflate function
+state.encoder.auto_convert: choose optimal PNG color type, if 0 uses info_png
+state.encoder.filter_palette_zero: PNG filter strategy for palette
+state.encoder.filter_strategy: PNG filter strategy to encode with
+state.encoder.force_palette: add palette even if not encoding to one
+state.encoder.add_id: add LodePNG identifier and version as a text chunk
+state.encoder.text_compression: use compressed text chunks for metadata
+state.info_raw.colortype: color type of raw input image you provide
+state.info_raw.bitdepth: bit depth of raw input image you provide
+state.info_raw: more color settings, see struct LodePNGColorMode
+state.info_png.color.colortype: desired color type if auto_convert is false
+state.info_png.color.bitdepth: desired bit depth if auto_convert is false
+state.info_png.color....: more color settings, see struct LodePNGColorMode
+state.info_png....: more PNG related settings, see struct LodePNGInfo
+
+
+12. changes
+-----------
+
+The version number of LodePNG is the date of the change given in the format
+yyyymmdd.
+
+Some changes aren't backwards compatible. Those are indicated with a (!)
+symbol.
+
+Not all changes are listed here, the commit history in github lists more:
+https://github.com/lvandeve/lodepng
+
+*) 06 mar 2020: simplified some of the dynamic memory allocations.
+*) 12 jan 2020: (!) added 'end' argument to lodepng_chunk_next to allow correct
+   overflow checks.
+*) 14 aug 2019: around 25% faster decoding thanks to huffman lookup tables.
+*) 15 jun 2019: (!) auto_choose_color API changed (for bugfix: don't use palette
+   if gray ICC profile) and non-ICC LodePNGColorProfile renamed to
+   LodePNGColorStats.
+*) 30 dec 2018: code style changes only: removed newlines before opening braces.
+*) 10 sep 2018: added way to inspect metadata chunks without full decoding.
+*) 19 aug 2018: (!) fixed color mode bKGD is encoded with and made it use
+   palette index in case of palette.
+*) 10 aug 2018: (!) added support for gAMA, cHRM, sRGB and iCCP chunks. This
+   change is backwards compatible unless you relied on unknown_chunks for those.
+*) 11 jun 2018: less restrictive check for pixel size integer overflow
+*) 14 jan 2018: allow optionally ignoring a few more recoverable errors
+*) 17 sep 2017: fix memory leak for some encoder input error cases
+*) 27 nov 2016: grey+alpha auto color model detection bugfix
+*) 18 apr 2016: Changed qsort to custom stable sort (for platforms w/o qsort).
+*) 09 apr 2016: Fixed colorkey usage detection, and better file loading (within
+   the limits of pure C90).
+*) 08 dec 2015: Made load_file function return error if file can't be opened.
+*) 24 okt 2015: Bugfix with decoding to palette output.
+*) 18 apr 2015: Boundary PM instead of just package-merge for faster encoding.
+*) 24 aug 2014: Moved to github
+*) 23 aug 2014: Reduced needless memory usage of decoder.
+*) 28 jun 2014: Removed fix_png setting, always support palette OOB for
+    simplicity. Made ColorProfile public.
+*) 09 jun 2014: Faster encoder by fixing hash bug and more zeros optimization.
+*) 22 dec 2013: Power of two windowsize required for optimization.
+*) 15 apr 2013: Fixed bug with LAC_ALPHA and color key.
+*) 25 mar 2013: Added an optional feature to ignore some PNG errors (fix_png).
+*) 11 mar 2013: (!) Bugfix with custom free. Changed from "my" to "lodepng_"
+    prefix for the custom allocators and made it possible with a new #define to
+    use custom ones in your project without needing to change lodepng's code.
+*) 28 jan 2013: Bugfix with color key.
+*) 27 okt 2012: Tweaks in text chunk keyword length error handling.
+*) 8 okt 2012: (!) Added new filter strategy (entropy) and new auto color mode.
+    (no palette). Better deflate tree encoding. New compression tweak settings.
+    Faster color conversions while decoding. Some internal cleanups.
+*) 23 sep 2012: Reduced warnings in Visual Studio a little bit.
+*) 1 sep 2012: (!) Removed #define's for giving custom (de)compression functions
+    and made it work with function pointers instead.
+*) 23 jun 2012: Added more filter strategies. Made it easier to use custom alloc
+    and free functions and toggle #defines from compiler flags. Small fixes.
+*) 6 may 2012: (!) Made plugging in custom zlib/deflate functions more flexible.
+*) 22 apr 2012: (!) Made interface more consistent, renaming a lot. Removed
+    redundant C++ codec classes. Reduced amount of structs. Everything changed,
+    but it is cleaner now imho and functionality remains the same. Also fixed
+    several bugs and shrunk the implementation code. Made new samples.
+*) 6 nov 2011: (!) By default, the encoder now automatically chooses the best
+    PNG color model and bit depth, based on the amount and type of colors of the
+    raw image. For this, autoLeaveOutAlphaChannel replaced by auto_choose_color.
+*) 9 okt 2011: simpler hash chain implementation for the encoder.
+*) 8 sep 2011: lz77 encoder lazy matching instead of greedy matching.
+*) 23 aug 2011: tweaked the zlib compression parameters after benchmarking.
+    A bug with the PNG filtertype heuristic was fixed, so that it chooses much
+    better ones (it's quite significant). A setting to do an experimental, slow,
+    brute force search for PNG filter types is added.
+*) 17 aug 2011: (!) changed some C zlib related function names.
+*) 16 aug 2011: made the code less wide (max 120 characters per line).
+*) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors.
+*) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled.
+*) 11 dec 2010: encoding is made faster, based on suggestion by Peter Eastman
+    to optimize long sequences of zeros.
+*) 13 nov 2010: added LodePNG_InfoColor_hasPaletteAlpha and
+    LodePNG_InfoColor_canHaveAlpha functions for convenience.
+*) 7 nov 2010: added LodePNG_error_text function to get error code description.
+*) 30 okt 2010: made decoding slightly faster
+*) 26 okt 2010: (!) changed some C function and struct names (more consistent).
+     Reorganized the documentation and the declaration order in the header.
+*) 08 aug 2010: only changed some comments and external samples.
+*) 05 jul 2010: fixed bug thanks to warnings in the new gcc version.
+*) 14 mar 2010: fixed bug where too much memory was allocated for char buffers.
+*) 02 sep 2008: fixed bug where it could create empty tree that linux apps could
+    read by ignoring the problem but windows apps couldn't.
+*) 06 jun 2008: added more error checks for out of memory cases.
+*) 26 apr 2008: added a few more checks here and there to ensure more safety.
+*) 06 mar 2008: crash with encoding of strings fixed
+*) 02 feb 2008: support for international text chunks added (iTXt)
+*) 23 jan 2008: small cleanups, and #defines to divide code in sections
+*) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor.
+*) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder.
+*) 17 jan 2008: ability to encode and decode compressed zTXt chunks added
+    Also various fixes, such as in the deflate and the padding bits code.
+*) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved
+    filtering code of encoder.
+*) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A
+    C++ wrapper around this provides an interface almost identical to before.
+    Having LodePNG be pure ISO C90 makes it more portable. The C and C++ code
+    are together in these files but it works both for C and C++ compilers.
+*) 29 dec 2007: (!) changed most integer types to unsigned int + other tweaks
+*) 30 aug 2007: bug fixed which makes this Borland C++ compatible
+*) 09 aug 2007: some VS2005 warnings removed again
+*) 21 jul 2007: deflate code placed in new namespace separate from zlib code
+*) 08 jun 2007: fixed bug with 2- and 4-bit color, and small interlaced images
+*) 04 jun 2007: improved support for Visual Studio 2005: crash with accessing
+    invalid std::vector element [0] fixed, and level 3 and 4 warnings removed
+*) 02 jun 2007: made the encoder add a tag with version by default
+*) 27 may 2007: zlib and png code separated (but still in the same file),
+    simple encoder/decoder functions added for more simple usage cases
+*) 19 may 2007: minor fixes, some code cleaning, new error added (error 69),
+    moved some examples from here to lodepng_examples.cpp
+*) 12 may 2007: palette decoding bug fixed
+*) 24 apr 2007: changed the license from BSD to the zlib license
+*) 11 mar 2007: very simple addition: ability to encode bKGD chunks.
+*) 04 mar 2007: (!) tEXt chunk related fixes, and support for encoding
+    palettized PNG images. Plus little interface change with palette and texts.
+*) 03 mar 2007: Made it encode dynamic Huffman shorter with repeat codes.
+    Fixed a bug where the end code of a block had length 0 in the Huffman tree.
+*) 26 feb 2007: Huffman compression with dynamic trees (BTYPE 2) now implemented
+    and supported by the encoder, resulting in smaller PNGs at the output.
+*) 27 jan 2007: Made the Adler-32 test faster so that a timewaste is gone.
+*) 24 jan 2007: gave encoder an error interface. Added color conversion from any
+    greyscale type to 8-bit greyscale with or without alpha.
+*) 21 jan 2007: (!) Totally changed the interface. It allows more color types
+    to convert to and is more uniform. See the manual for how it works now.
+*) 07 jan 2007: Some cleanup & fixes, and a few changes over the last days:
+    encode/decode custom tEXt chunks, separate classes for zlib & deflate, and
+    at last made the decoder give errors for incorrect Adler32 or Crc.
+*) 01 jan 2007: Fixed bug with encoding PNGs with less than 8 bits per channel.
+*) 29 dec 2006: Added support for encoding images without alpha channel, and
+    cleaned out code as well as making certain parts faster.
+*) 28 dec 2006: Added "Settings" to the encoder.
+*) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now.
+    Removed some code duplication in the decoder. Fixed little bug in an example.
+*) 09 dec 2006: (!) Placed output parameters of public functions as first parameter.
+    Fixed a bug of the decoder with 16-bit per color.
+*) 15 okt 2006: Changed documentation structure
+*) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the
+    given image buffer, however for now it's not compressed.
+*) 08 sep 2006: (!) Changed to interface with a Decoder class
+*) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different
+    way. Renamed decodePNG to decodePNGGeneric.
+*) 29 jul 2006: (!) Changed the interface: image info is now returned as a
+    struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy.
+*) 28 jul 2006: Cleaned the code and added new error checks.
+    Corrected terminology "deflate" into "inflate".
+*) 23 jun 2006: Added SDL example in the documentation in the header, this
+    example allows easy debugging by displaying the PNG and its transparency.
+*) 22 jun 2006: (!) Changed way to obtain error value. Added
+    loadFile function for convenience. Made decodePNG32 faster.
+*) 21 jun 2006: (!) Changed type of info vector to unsigned.
+    Changed position of palette in info vector. Fixed an important bug that
+    happened on PNGs with an uncompressed block.
+*) 16 jun 2006: Internally changed unsigned into unsigned where
+    needed, and performed some optimizations.
+*) 07 jun 2006: (!) Renamed functions to decodePNG and placed them
+    in LodePNG namespace. Changed the order of the parameters. Rewrote the
+    documentation in the header. Renamed files to lodepng.cpp and lodepng.h
+*) 22 apr 2006: Optimized and improved some code
+*) 07 sep 2005: (!) Changed to std::vector interface
+*) 12 aug 2005: Initial release (C++, decoder only)
+
+
+13. contact information
+-----------------------
+
+Feel free to contact me with suggestions, problems, comments, ... concerning
+LodePNG. If you encounter a PNG image that doesn't work properly with this
+decoder, feel free to send it and I'll use it to find and fix the problem.
+
+My email address is (puzzle the account and domain together with an @ symbol):
+Domain: gmail dot com.
+Account: lode dot vandevenne.
+
+
+Copyright (c) 2005-2020 Lode Vandevenne
+*/
diff --git a/graphics/scancodes.h b/graphics/scancodes.h
new file mode 100644
index 0000000..f06c192
--- /dev/null
+++ b/graphics/scancodes.h
@@ -0,0 +1,282 @@
+#pragma once
+
+// Scan codes of keyboard keys. The values are directly copied from the SDL scancode.h header file.
+namespace graphics
+{
+	/** The available scancode IDs for the keyboard keys. 
+	
+		For the detailed list of IDs, please see the corresponding header file [scancodes.h](@ref scancodes.h)
+	    
+	*/
+	typedef enum
+	{
+		SCANCODE_UNKNOWN = 0,
+		SCANCODE_A = 4,
+		SCANCODE_B = 5,
+		SCANCODE_C = 6,
+		SCANCODE_D = 7,
+		SCANCODE_E = 8,
+		SCANCODE_F = 9,
+		SCANCODE_G = 10,
+		SCANCODE_H = 11,
+		SCANCODE_I = 12,
+		SCANCODE_J = 13,
+		SCANCODE_K = 14,
+		SCANCODE_L = 15,
+		SCANCODE_M = 16,
+		SCANCODE_N = 17,
+		SCANCODE_O = 18,
+		SCANCODE_P = 19,
+		SCANCODE_Q = 20,
+		SCANCODE_R = 21,
+		SCANCODE_S = 22,
+		SCANCODE_T = 23,
+		SCANCODE_U = 24,
+		SCANCODE_V = 25,
+		SCANCODE_W = 26,
+		SCANCODE_X = 27,
+		SCANCODE_Y = 28,
+		SCANCODE_Z = 29,
+
+		SCANCODE_1 = 30,
+		SCANCODE_2 = 31,
+		SCANCODE_3 = 32,
+		SCANCODE_4 = 33,
+		SCANCODE_5 = 34,
+		SCANCODE_6 = 35,
+		SCANCODE_7 = 36,
+		SCANCODE_8 = 37,
+		SCANCODE_9 = 38,
+		SCANCODE_0 = 39,
+
+		SCANCODE_RETURN = 40,
+		SCANCODE_ESCAPE = 41,
+		SCANCODE_BACKSPACE = 42,
+		SCANCODE_TAB = 43,
+		SCANCODE_SPACE = 44,
+
+		SCANCODE_MINUS = 45,
+		SCANCODE_EQUALS = 46,
+		SCANCODE_LEFTBRACKET = 47,
+		SCANCODE_RIGHTBRACKET = 48,
+		SCANCODE_BACKSLASH = 49,
+		SCANCODE_NONUSHASH = 50,
+		SCANCODE_SEMICOLON = 51,
+		SCANCODE_APOSTROPHE = 52,
+		SCANCODE_GRAVE = 53,
+		SCANCODE_COMMA = 54,
+		SCANCODE_PERIOD = 55,
+		SCANCODE_SLASH = 56,
+
+		SCANCODE_CAPSLOCK = 57,
+
+		SCANCODE_F1 = 58,
+		SCANCODE_F2 = 59,
+		SCANCODE_F3 = 60,
+		SCANCODE_F4 = 61,
+		SCANCODE_F5 = 62,
+		SCANCODE_F6 = 63,
+		SCANCODE_F7 = 64,
+		SCANCODE_F8 = 65,
+		SCANCODE_F9 = 66,
+		SCANCODE_F10 = 67,
+		SCANCODE_F11 = 68,
+		SCANCODE_F12 = 69,
+
+		SCANCODE_PRINTSCREEN = 70,
+		SCANCODE_SCROLLLOCK = 71,
+		SCANCODE_PAUSE = 72,
+		SCANCODE_INSERT = 73,
+		SCANCODE_HOME = 74,
+		SCANCODE_PAGEUP = 75,
+		SCANCODE_DELETE = 76,
+		SCANCODE_END = 77,
+		SCANCODE_PAGEDOWN = 78,
+		SCANCODE_RIGHT = 79,
+		SCANCODE_LEFT = 80,
+		SCANCODE_DOWN = 81,
+		SCANCODE_UP = 82,
+
+		SCANCODE_NUMLOCKCLEAR = 83,
+
+		SCANCODE_KP_DIVIDE = 84,
+		SCANCODE_KP_MULTIPLY = 85,
+		SCANCODE_KP_MINUS = 86,
+		SCANCODE_KP_PLUS = 87,
+		SCANCODE_KP_ENTER = 88,
+		SCANCODE_KP_1 = 89,
+		SCANCODE_KP_2 = 90,
+		SCANCODE_KP_3 = 91,
+		SCANCODE_KP_4 = 92,
+		SCANCODE_KP_5 = 93,
+		SCANCODE_KP_6 = 94,
+		SCANCODE_KP_7 = 95,
+		SCANCODE_KP_8 = 96,
+		SCANCODE_KP_9 = 97,
+		SCANCODE_KP_0 = 98,
+		SCANCODE_KP_PERIOD = 99,
+
+		SCANCODE_NONUSBACKSLASH = 100,
+
+		SCANCODE_APPLICATION = 101,
+		SCANCODE_POWER = 102,
+		SCANCODE_KP_EQUALS = 103,
+		SCANCODE_F13 = 104,
+		SCANCODE_F14 = 105,
+		SCANCODE_F15 = 106,
+		SCANCODE_F16 = 107,
+		SCANCODE_F17 = 108,
+		SCANCODE_F18 = 109,
+		SCANCODE_F19 = 110,
+		SCANCODE_F20 = 111,
+		SCANCODE_F21 = 112,
+		SCANCODE_F22 = 113,
+		SCANCODE_F23 = 114,
+		SCANCODE_F24 = 115,
+		SCANCODE_EXECUTE = 116,
+		SCANCODE_HELP = 117,
+		SCANCODE_MENU = 118,
+		SCANCODE_SELECT = 119,
+		SCANCODE_STOP = 120,
+		SCANCODE_AGAIN = 121,
+		SCANCODE_UNDO = 122,
+		SCANCODE_CUT = 123,
+		SCANCODE_COPY = 124,
+		SCANCODE_PASTE = 125,
+		SCANCODE_FIND = 126,
+		SCANCODE_MUTE = 127,
+		SCANCODE_VOLUMEUP = 128,
+		SCANCODE_VOLUMEDOWN = 129,
+
+		SCANCODE_KP_COMMA = 133,
+		SCANCODE_KP_EQUALSAS400 = 134,
+
+		SCANCODE_INTERNATIONAL1 = 135,
+
+		SCANCODE_INTERNATIONAL2 = 136,
+		SCANCODE_INTERNATIONAL3 = 137,
+		SCANCODE_INTERNATIONAL4 = 138,
+		SCANCODE_INTERNATIONAL5 = 139,
+		SCANCODE_INTERNATIONAL6 = 140,
+		SCANCODE_INTERNATIONAL7 = 141,
+		SCANCODE_INTERNATIONAL8 = 142,
+		SCANCODE_INTERNATIONAL9 = 143,
+		SCANCODE_LANG1 = 144,
+		SCANCODE_LANG2 = 145,
+		SCANCODE_LANG3 = 146,
+		SCANCODE_LANG4 = 147,
+		SCANCODE_LANG5 = 148,
+		SCANCODE_LANG6 = 149,
+		SCANCODE_LANG7 = 150,
+		SCANCODE_LANG8 = 151,
+		SCANCODE_LANG9 = 152,
+
+		SCANCODE_ALTERASE = 153,
+		SCANCODE_SYSREQ = 154,
+		SCANCODE_CANCEL = 155,
+		SCANCODE_CLEAR = 156,
+		SCANCODE_PRIOR = 157,
+		SCANCODE_RETURN2 = 158,
+		SCANCODE_SEPARATOR = 159,
+		SCANCODE_OUT = 160,
+		SCANCODE_OPER = 161,
+		SCANCODE_CLEARAGAIN = 162,
+		SCANCODE_CRSEL = 163,
+		SCANCODE_EXSEL = 164,
+
+		SCANCODE_KP_00 = 176,
+		SCANCODE_KP_000 = 177,
+		SCANCODE_THOUSANDSSEPARATOR = 178,
+		SCANCODE_DECIMALSEPARATOR = 179,
+		SCANCODE_CURRENCYUNIT = 180,
+		SCANCODE_CURRENCYSUBUNIT = 181,
+		SCANCODE_KP_LEFTPAREN = 182,
+		SCANCODE_KP_RIGHTPAREN = 183,
+		SCANCODE_KP_LEFTBRACE = 184,
+		SCANCODE_KP_RIGHTBRACE = 185,
+		SCANCODE_KP_TAB = 186,
+		SCANCODE_KP_BACKSPACE = 187,
+		SCANCODE_KP_A = 188,
+		SCANCODE_KP_B = 189,
+		SCANCODE_KP_C = 190,
+		SCANCODE_KP_D = 191,
+		SCANCODE_KP_E = 192,
+		SCANCODE_KP_F = 193,
+		SCANCODE_KP_XOR = 194,
+		SCANCODE_KP_POWER = 195,
+		SCANCODE_KP_PERCENT = 196,
+		SCANCODE_KP_LESS = 197,
+		SCANCODE_KP_GREATER = 198,
+		SCANCODE_KP_AMPERSAND = 199,
+		SCANCODE_KP_DBLAMPERSAND = 200,
+		SCANCODE_KP_VERTICALBAR = 201,
+		SCANCODE_KP_DBLVERTICALBAR = 202,
+		SCANCODE_KP_COLON = 203,
+		SCANCODE_KP_HASH = 204,
+		SCANCODE_KP_SPACE = 205,
+		SCANCODE_KP_AT = 206,
+		SCANCODE_KP_EXCLAM = 207,
+		SCANCODE_KP_MEMSTORE = 208,
+		SCANCODE_KP_MEMRECALL = 209,
+		SCANCODE_KP_MEMCLEAR = 210,
+		SCANCODE_KP_MEMADD = 211,
+		SCANCODE_KP_MEMSUBTRACT = 212,
+		SCANCODE_KP_MEMMULTIPLY = 213,
+		SCANCODE_KP_MEMDIVIDE = 214,
+		SCANCODE_KP_PLUSMINUS = 215,
+		SCANCODE_KP_CLEAR = 216,
+		SCANCODE_KP_CLEARENTRY = 217,
+		SCANCODE_KP_BINARY = 218,
+		SCANCODE_KP_OCTAL = 219,
+		SCANCODE_KP_DECIMAL = 220,
+		SCANCODE_KP_HEXADECIMAL = 221,
+
+		SCANCODE_LCTRL = 224,
+		SCANCODE_LSHIFT = 225,
+		SCANCODE_LALT = 226,
+		SCANCODE_LGUI = 227,
+		SCANCODE_RCTRL = 228,
+		SCANCODE_RSHIFT = 229,
+		SCANCODE_RALT = 230,
+		SCANCODE_RGUI = 231,
+
+		SCANCODE_MODE = 257,
+
+		SCANCODE_AUDIONEXT = 258,
+		SCANCODE_AUDIOPREV = 259,
+		SCANCODE_AUDIOSTOP = 260,
+		SCANCODE_AUDIOPLAY = 261,
+		SCANCODE_AUDIOMUTE = 262,
+		SCANCODE_MEDIASELECT = 263,
+		SCANCODE_WWW = 264,
+		SCANCODE_MAIL = 265,
+		SCANCODE_CALCULATOR = 266,
+		SCANCODE_COMPUTER = 267,
+		SCANCODE_AC_SEARCH = 268,
+		SCANCODE_AC_HOME = 269,
+		SCANCODE_AC_BACK = 270,
+		SCANCODE_AC_FORWARD = 271,
+		SCANCODE_AC_STOP = 272,
+		SCANCODE_AC_REFRESH = 273,
+		SCANCODE_AC_BOOKMARKS = 274,
+
+		SCANCODE_BRIGHTNESSDOWN = 275,
+		SCANCODE_BRIGHTNESSUP = 276,
+		SCANCODE_DISPLAYSWITCH = 277,
+
+		SCANCODE_KBDILLUMTOGGLE = 278,
+		SCANCODE_KBDILLUMDOWN = 279,
+		SCANCODE_KBDILLUMUP = 280,
+		SCANCODE_EJECT = 281,
+		SCANCODE_SLEEP = 282,
+
+		SCANCODE_APP1 = 283,
+		SCANCODE_APP2 = 284,
+
+		SCANCODE_AUDIOREWIND = 285,
+		SCANCODE_AUDIOFASTFORWARD = 286,
+
+		NUM_SCANCODES = 512
+
+	} scancode_t;
+}
\ No newline at end of file
diff --git a/graphics/shader.cpp b/graphics/shader.cpp
new file mode 100644
index 0000000..8e1598f
--- /dev/null
+++ b/graphics/shader.cpp
@@ -0,0 +1,246 @@
+#include "shader.h"
+#include <GL/glew.h>
+#include <iostream>
+#include <glm/gtc/type_ptr.hpp>
+
+const char* __DefaultVertexShader = R"glsl(
+	#version 120
+    in vec3 position;
+	void main()
+    {
+        gl_Position = vec4(position, 1.0);
+    }
+)glsl";
+
+
+const char* __DefaultFragmentShader = R"glsl(
+	#version 120
+    out vec4 fragcolor;
+    void main()
+    {
+        fragcolor = vec4(0.0,1.0,0.0,1.0);
+    }
+)glsl";
+
+void Shader::printLog(unsigned int object)
+{
+	GLint log_length = 0;
+	if (glIsShader(object))
+		glGetShaderiv(object, GL_INFO_LOG_LENGTH, &log_length);
+	else if (glIsProgram(object))
+		glGetProgramiv(object, GL_INFO_LOG_LENGTH, &log_length);
+	else
+	{
+		printf("printlog: Not a shader or a program\n");
+		return;
+	}
+	if (log_length == 0)
+		return;
+
+	char* log = new char[log_length];
+
+	if (glIsShader(object))
+		glGetShaderInfoLog(object, log_length, NULL, log);
+	else if (glIsProgram(object))
+		glGetProgramInfoLog(object, log_length, NULL, log);
+
+	printf("%s", log);
+	delete[] log;
+}
+Shader::Shader(const char * vertex, const char * fragment)
+{
+
+	if (!vertex || !fragment)
+		return;
+
+	vshader = glCreateShader(GL_VERTEX_SHADER);
+	glShaderSource(vshader, 1, &vertex, NULL);
+
+	fshader = glCreateShader(GL_FRAGMENT_SHADER);
+	glShaderSource(fshader, 1, &fragment, NULL);
+
+	GLint status;
+
+	glCompileShader(vshader);
+	glGetShaderiv(vshader, GL_COMPILE_STATUS, &status);
+	if (!status)
+	{
+		printLog(vshader);
+		return;
+	}
+	glCompileShader(fshader);
+	glGetShaderiv(fshader, GL_COMPILE_STATUS, &status);
+	if (!status)
+	{
+		printLog(fshader);
+		return;
+	}
+
+	program = glCreateProgram();
+	glAttachShader(program, vshader);
+	glAttachShader(program, fshader);
+	glLinkProgram(program);
+	assert(glGetError() == GL_NO_ERROR);
+//	GLint status;
+
+	glGetProgramiv(program, GL_LINK_STATUS, &status);
+
+	if (!status)
+	{
+		printLog(program);
+		return;
+	}
+
+	glValidateProgram(program);
+
+	glGetProgramiv(program, GL_VALIDATE_STATUS, &status);
+	if (!status)
+	{
+		printLog(program);
+		return;
+	}
+
+}
+
+Uniform & Shader::operator[](const char * name)
+{
+	
+	auto iter = uniforms.find(name);
+	if (iter == uniforms.end())
+	{
+		Uniform uni = glGetUniformLocation(program, name);
+		
+		uniforms[name] = uni;
+		return uniforms[name];
+	}
+	else
+	{
+		return iter->second;
+	}	
+	
+}
+
+bool Shader::use(bool use)
+{
+	if (!ready)
+		return false;
+
+	if (use)
+		glUseProgram(program);
+	else
+		glUseProgram(0);
+
+	return true;
+}
+
+std::string Shader::loadShaderText(char * file)
+{
+	return std::string();
+}
+
+bool Shader::init()
+{
+	
+	
+	ready = true;
+	return true;
+}
+
+void Shader::setFragmentLocation(char * name, unsigned int location)
+{
+	glBindFragDataLocation(program, location, name);
+}
+
+unsigned int Shader::getAttributeLocation(const char * attrib)
+{
+	return glGetAttribLocation(program, attrib);
+}
+
+Shader::~Shader()
+{
+	glDetachShader(program, vshader);
+	glDeleteShader(vshader);
+	glDetachShader(program, fshader);
+	glDeleteShader(fshader);
+	
+}
+
+Uniform::Uniform(const Uniform & right)
+{
+	id = right.id;
+}
+
+Uniform & Uniform::operator=(const Uniform & right)
+{
+	id = right.id;
+	return *this;
+}
+
+Uniform & Uniform::operator=(int i)
+{
+	glUniform1i(this->id, i);
+	return *this;
+}
+
+Uniform & Uniform::operator=(float f)
+{
+	glUniform1f(this->id, f);
+	return *this;
+}
+
+Uniform & Uniform::operator=(unsigned int i)
+{
+	glUniform1ui(this->id, i);
+	return *this;
+}
+
+Uniform & Uniform::operator=(glm::vec3 v)
+{
+	glUniform3f(this->id, v.x, v.y, v.z);
+	int err = glGetError();
+	assert(err == GL_NO_ERROR);
+
+	return *this;
+}
+
+Uniform & Uniform::operator=(glm::vec4 v)
+{
+	glUniform4f(this->id, v.x, v.y, v.z, v.w);
+	return *this;
+}
+
+Uniform & Uniform::operator=(glm::vec2 v)
+{
+	glUniform2fv(this->id, 1, &(v[0]));
+	return *this;
+}
+
+Uniform & Uniform::operator=(glm::ivec3 v)
+{
+	glUniform3iv(this->id, 1, &(v[0]));
+	return *this;
+}
+
+Uniform & Uniform::operator=(glm::ivec2 v)
+{
+	glUniform2iv(this->id, 1, &(v[0]));
+	return *this;
+}
+
+Uniform & Uniform::operator=(glm::ivec4 v)
+{
+	glUniform4iv(this->id, 1, &(v[0]));
+	return *this;
+}
+
+Uniform & Uniform::operator=(glm::mat4 m)
+{
+	glUniformMatrix4fv(this->id, 1, false, &(m[0][0]));
+	return *this;
+}
+
+Uniform & Uniform::operator=(glm::mat3 m)
+{
+	glUniformMatrix3fv(this->id, 1, false, &(m[0][0]));
+	return *this;
+}
diff --git a/graphics/shader.h b/graphics/shader.h
new file mode 100644
index 0000000..4774d64
--- /dev/null
+++ b/graphics/shader.h
@@ -0,0 +1,57 @@
+#pragma once
+
+#include <map>
+#include <string>
+#include "glm/glm.hpp"
+
+#define ASSERT_GL {assert (glGetError()==GL_NO_ERROR);}
+
+class Uniform
+{
+protected:
+	int id;
+public:
+	operator int() { return id; }
+	Uniform(int i) : id(i) {}
+	Uniform() : id(-1) {}
+	Uniform(const Uniform & right);
+	Uniform & operator = (const Uniform & right);
+	Uniform & operator = (int);
+	Uniform & operator = (float);
+	Uniform & operator = (unsigned int);
+	Uniform & operator = (glm::vec3);
+	Uniform & operator = (glm::vec4);
+	Uniform & operator = (glm::vec2);
+	Uniform & operator = (glm::ivec3);
+	Uniform & operator = (glm::ivec2);
+	Uniform & operator = (glm::ivec4);
+	Uniform & operator = (glm::mat4);
+	Uniform & operator = (glm::mat3);
+};
+
+
+
+
+class Shader
+{
+	std::map<const char *, Uniform> uniforms;
+	bool ready = false;
+	
+	
+	unsigned int vshader, fshader;
+
+protected:
+	void printLog(unsigned int obj);
+
+public:
+	unsigned int program;
+	explicit operator bool () const { return ready; }
+	Shader(const char * vertex = nullptr, const char * fragment = nullptr);
+	Uniform & operator [] (const char * name);
+	bool use(bool use = true);
+	std::string loadShaderText(char * file);
+	bool init();
+	void setFragmentLocation(char * name, unsigned int location);
+	unsigned int getAttributeLocation(const char * attrib);
+	~Shader();
+};
diff --git a/graphics/texture.cpp b/graphics/texture.cpp
new file mode 100644
index 0000000..5539f6d
--- /dev/null
+++ b/graphics/texture.cpp
@@ -0,0 +1,83 @@
+#include "texture.h"
+#include "lodepng.h"
+#include <vector>
+#include <cmath>
+
+void graphics::Texture::makePowerOfTwo()
+{
+	// Texture size must be power of two for the primitive OpenGL version this is written for. Find next power of two.
+	int u2 = 1; while (u2 < m_width) u2 *= 2;
+	int v2 = 1; while (v2 < m_height) v2 *= 2;
+	if (u2 == m_width && v2 == m_height)
+		return;
+
+	// Make power of two version of the image.
+	std::vector<unsigned char> image2(u2 * v2 * 4);
+	for (int i = 0; i < v2; i++)
+		for (int j = 0; j < u2; j++)
+		{
+			float x = (m_width-1) * j / (float)u2;
+			float y = (m_height-1) * i / (float)v2;
+			int x_L = (int)floorf(x);
+			int x_U = (int)ceilf(x);
+			int y_L = (int)floorf(y);
+			int y_U = (int)ceilf(y);
+			float sx = x - x_L;
+			float sy = y - y_L;
+
+			for (int c = 0; c < 4; c++)
+			{
+				float valx1 = (1.0f - sx) * m_buffer[4 * (y_L*m_width + x_L) + c] + sx * m_buffer[4 * (y_L*m_width + x_U) + c];
+				float valx2 = (1.0f - sx) * m_buffer[4 * (y_U*m_width + x_L) + c] + sx * m_buffer[4 * (y_U*m_width + x_U) + c];
+				float valy = (1.0f - sy) * valx1 + sy * valx2;
+				image2[4 * (i*u2 + j) + c] = (unsigned char)roundf(valy);
+			}
+		}
+
+	m_buffer = std::move(image2);
+	m_width = u2;
+	m_height = v2;
+}
+
+bool graphics::Texture::load(const std::string & file)
+{
+	unsigned int error = lodepng::decode(m_buffer, m_width, m_height, file.c_str());
+	return !error;
+}
+
+void graphics::Texture::buildGLTexture()
+{
+	glEnable(GL_TEXTURE_2D);
+	glGenTextures(1, &m_id);
+	glBindTexture(GL_TEXTURE_2D, m_id);
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST); 
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexImage2D(GL_TEXTURE_2D, 0, 4, m_width, m_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, &m_buffer[0]);
+	glGenerateMipmap(GL_TEXTURE_2D);
+	glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+graphics::Texture::Texture(const std::string & filename)
+{
+	m_filename = filename;
+	if (!load(filename))
+		return;
+	makePowerOfTwo();
+	buildGLTexture();
+}
+
+GLuint graphics::TextureManager::getTexture(std::string file)
+{
+	auto iter = textures.find(file);
+	if (iter != textures.end())
+	{
+		return iter->second.getID();
+	}
+	else
+	{
+		textures.insert(std::make_pair(file, Texture(file)));
+	}
+	return GLuint();
+}
diff --git a/graphics/texture.h b/graphics/texture.h
new file mode 100644
index 0000000..c0d16e3
--- /dev/null
+++ b/graphics/texture.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <GL/glew.h>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace graphics
+{
+	class Texture
+	{
+	private:
+		GLuint m_id = 0;
+		std::string	m_filename;
+		unsigned int m_width, m_height;
+		unsigned int m_channels;
+		std::vector<unsigned char> m_buffer;
+		bool m_ready = false;
+		void makePowerOfTwo();
+		bool load(const std::string & file);
+		void buildGLTexture();
+	public:
+		Texture(const std::string & filename);
+		GLuint getID() { return m_id; }
+		int getWidth() { return m_width; }
+		int getHeight() { return m_height; }
+		
+	};
+
+	class TextureManager
+	{
+	private:
+		std::unordered_map<std::string, Texture> textures;
+	public:
+		GLuint getTexture(std::string file);
+	};
+}