diff options
author | Nikolas <nikolas@boutalas.com> | 2024-10-27 12:52:55 +0200 |
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committer | Nikolas <nikolas@boutalas.com> | 2024-10-27 12:52:55 +0200 |
commit | 43394c8a8908442982e3a7e25975c31b3c952923 (patch) | |
tree | 2facd563e29f48fe3b0653ac5c113998940b4d5e /3rdparty/include/freetype/ftincrem.h |
Diffstat (limited to '3rdparty/include/freetype/ftincrem.h')
-rw-r--r-- | 3rdparty/include/freetype/ftincrem.h | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/3rdparty/include/freetype/ftincrem.h b/3rdparty/include/freetype/ftincrem.h new file mode 100644 index 0000000..44619f9 --- /dev/null +++ b/3rdparty/include/freetype/ftincrem.h @@ -0,0 +1,343 @@ +/***************************************************************************/ +/* */ +/* ftincrem.h */ +/* */ +/* FreeType incremental loading (specification). */ +/* */ +/* Copyright 2002-2018 by */ +/* David Turner, Robert Wilhelm, and Werner Lemberg. */ +/* */ +/* This file is part of the FreeType project, and may only be used, */ +/* modified, and distributed under the terms of the FreeType project */ +/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ +/* this file you indicate that you have read the license and */ +/* understand and accept it fully. */ +/* */ +/***************************************************************************/ + + +#ifndef FTINCREM_H_ +#define FTINCREM_H_ + +#include <ft2build.h> +#include FT_FREETYPE_H +#include FT_PARAMETER_TAGS_H + +#ifdef FREETYPE_H +#error "freetype.h of FreeType 1 has been loaded!" +#error "Please fix the directory search order for header files" +#error "so that freetype.h of FreeType 2 is found first." +#endif + + +FT_BEGIN_HEADER + + /*************************************************************************** + * + * @section: + * incremental + * + * @title: + * Incremental Loading + * + * @abstract: + * Custom Glyph Loading. + * + * @description: + * This section contains various functions used to perform so-called + * `incremental' glyph loading. This is a mode where all glyphs loaded + * from a given @FT_Face are provided by the client application. + * + * Apart from that, all other tables are loaded normally from the font + * file. This mode is useful when FreeType is used within another + * engine, e.g., a PostScript Imaging Processor. + * + * To enable this mode, you must use @FT_Open_Face, passing an + * @FT_Parameter with the @FT_PARAM_TAG_INCREMENTAL tag and an + * @FT_Incremental_Interface value. See the comments for + * @FT_Incremental_InterfaceRec for an example. + * + */ + + + /*************************************************************************** + * + * @type: + * FT_Incremental + * + * @description: + * An opaque type describing a user-provided object used to implement + * `incremental' glyph loading within FreeType. This is used to support + * embedded fonts in certain environments (e.g., PostScript interpreters), + * where the glyph data isn't in the font file, or must be overridden by + * different values. + * + * @note: + * It is up to client applications to create and implement @FT_Incremental + * objects, as long as they provide implementations for the methods + * @FT_Incremental_GetGlyphDataFunc, @FT_Incremental_FreeGlyphDataFunc + * and @FT_Incremental_GetGlyphMetricsFunc. + * + * See the description of @FT_Incremental_InterfaceRec to understand how + * to use incremental objects with FreeType. + * + */ + typedef struct FT_IncrementalRec_* FT_Incremental; + + + /*************************************************************************** + * + * @struct: + * FT_Incremental_MetricsRec + * + * @description: + * A small structure used to contain the basic glyph metrics returned + * by the @FT_Incremental_GetGlyphMetricsFunc method. + * + * @fields: + * bearing_x :: + * Left bearing, in font units. + * + * bearing_y :: + * Top bearing, in font units. + * + * advance :: + * Horizontal component of glyph advance, in font units. + * + * advance_v :: + * Vertical component of glyph advance, in font units. + * + * @note: + * These correspond to horizontal or vertical metrics depending on the + * value of the `vertical' argument to the function + * @FT_Incremental_GetGlyphMetricsFunc. + * + */ + typedef struct FT_Incremental_MetricsRec_ + { + FT_Long bearing_x; + FT_Long bearing_y; + FT_Long advance; + FT_Long advance_v; /* since 2.3.12 */ + + } FT_Incremental_MetricsRec; + + + /*************************************************************************** + * + * @struct: + * FT_Incremental_Metrics + * + * @description: + * A handle to an @FT_Incremental_MetricsRec structure. + * + */ + typedef struct FT_Incremental_MetricsRec_* FT_Incremental_Metrics; + + + /*************************************************************************** + * + * @type: + * FT_Incremental_GetGlyphDataFunc + * + * @description: + * A function called by FreeType to access a given glyph's data bytes + * during @FT_Load_Glyph or @FT_Load_Char if incremental loading is + * enabled. + * + * Note that the format of the glyph's data bytes depends on the font + * file format. For TrueType, it must correspond to the raw bytes within + * the `glyf' table. For PostScript formats, it must correspond to the + * *unencrypted* charstring bytes, without any `lenIV' header. It is + * undefined for any other format. + * + * @input: + * incremental :: + * Handle to an opaque @FT_Incremental handle provided by the client + * application. + * + * glyph_index :: + * Index of relevant glyph. + * + * @output: + * adata :: + * A structure describing the returned glyph data bytes (which will be + * accessed as a read-only byte block). + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * If this function returns successfully the method + * @FT_Incremental_FreeGlyphDataFunc will be called later to release + * the data bytes. + * + * Nested calls to @FT_Incremental_GetGlyphDataFunc can happen for + * compound glyphs. + * + */ + typedef FT_Error + (*FT_Incremental_GetGlyphDataFunc)( FT_Incremental incremental, + FT_UInt glyph_index, + FT_Data* adata ); + + + /*************************************************************************** + * + * @type: + * FT_Incremental_FreeGlyphDataFunc + * + * @description: + * A function used to release the glyph data bytes returned by a + * successful call to @FT_Incremental_GetGlyphDataFunc. + * + * @input: + * incremental :: + * A handle to an opaque @FT_Incremental handle provided by the client + * application. + * + * data :: + * A structure describing the glyph data bytes (which will be accessed + * as a read-only byte block). + * + */ + typedef void + (*FT_Incremental_FreeGlyphDataFunc)( FT_Incremental incremental, + FT_Data* data ); + + + /*************************************************************************** + * + * @type: + * FT_Incremental_GetGlyphMetricsFunc + * + * @description: + * A function used to retrieve the basic metrics of a given glyph index + * before accessing its data. This is necessary because, in certain + * formats like TrueType, the metrics are stored in a different place from + * the glyph images proper. + * + * @input: + * incremental :: + * A handle to an opaque @FT_Incremental handle provided by the client + * application. + * + * glyph_index :: + * Index of relevant glyph. + * + * vertical :: + * If true, return vertical metrics. + * + * ametrics :: + * This parameter is used for both input and output. + * The original glyph metrics, if any, in font units. If metrics are + * not available all the values must be set to zero. + * + * @output: + * ametrics :: + * The replacement glyph metrics in font units. + * + */ + typedef FT_Error + (*FT_Incremental_GetGlyphMetricsFunc) + ( FT_Incremental incremental, + FT_UInt glyph_index, + FT_Bool vertical, + FT_Incremental_MetricsRec *ametrics ); + + + /************************************************************************** + * + * @struct: + * FT_Incremental_FuncsRec + * + * @description: + * A table of functions for accessing fonts that load data + * incrementally. Used in @FT_Incremental_InterfaceRec. + * + * @fields: + * get_glyph_data :: + * The function to get glyph data. Must not be null. + * + * free_glyph_data :: + * The function to release glyph data. Must not be null. + * + * get_glyph_metrics :: + * The function to get glyph metrics. May be null if the font does + * not provide overriding glyph metrics. + * + */ + typedef struct FT_Incremental_FuncsRec_ + { + FT_Incremental_GetGlyphDataFunc get_glyph_data; + FT_Incremental_FreeGlyphDataFunc free_glyph_data; + FT_Incremental_GetGlyphMetricsFunc get_glyph_metrics; + + } FT_Incremental_FuncsRec; + + + /*************************************************************************** + * + * @struct: + * FT_Incremental_InterfaceRec + * + * @description: + * A structure to be used with @FT_Open_Face to indicate that the user + * wants to support incremental glyph loading. You should use it with + * @FT_PARAM_TAG_INCREMENTAL as in the following example: + * + * { + * FT_Incremental_InterfaceRec inc_int; + * FT_Parameter parameter; + * FT_Open_Args open_args; + * + * + * // set up incremental descriptor + * inc_int.funcs = my_funcs; + * inc_int.object = my_object; + * + * // set up optional parameter + * parameter.tag = FT_PARAM_TAG_INCREMENTAL; + * parameter.data = &inc_int; + * + * // set up FT_Open_Args structure + * open_args.flags = FT_OPEN_PATHNAME | FT_OPEN_PARAMS; + * open_args.pathname = my_font_pathname; + * open_args.num_params = 1; + * open_args.params = ¶meter; // we use one optional argument + * + * // open the font + * error = FT_Open_Face( library, &open_args, index, &face ); + * ... + * } + * + */ + typedef struct FT_Incremental_InterfaceRec_ + { + const FT_Incremental_FuncsRec* funcs; + FT_Incremental object; + + } FT_Incremental_InterfaceRec; + + + /*************************************************************************** + * + * @type: + * FT_Incremental_Interface + * + * @description: + * A pointer to an @FT_Incremental_InterfaceRec structure. + * + */ + typedef FT_Incremental_InterfaceRec* FT_Incremental_Interface; + + + /* */ + + +FT_END_HEADER + +#endif /* FTINCREM_H_ */ + + +/* END */ |