3rdparty/include/freetype/ftadvanc.h


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187

/***************************************************************************/
/*                                                                         */
/*  ftadvanc.h                                                             */
/*                                                                         */
/*    Quick computation of advance widths (specification only).            */
/*                                                                         */
/*  Copyright 2008-2018 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 FTADVANC_H_
#define FTADVANC_H_


#include <ft2build.h>
#include FT_FREETYPE_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:
   *   quick_advance
   *
   * @title:
   *   Quick retrieval of advance values
   *
   * @abstract:
   *   Retrieve horizontal and vertical advance values without processing
   *   glyph outlines, if possible.
   *
   * @description:
   *   This section contains functions to quickly extract advance values
   *   without handling glyph outlines, if possible.
   *
   * @order:
   *   FT_Get_Advance
   *   FT_Get_Advances
   *
   */


  /*************************************************************************/
  /*                                                                       */
  /* <Const>                                                               */
  /*    FT_ADVANCE_FLAG_FAST_ONLY                                          */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A bit-flag to be OR-ed with the `flags' parameter of the           */
  /*    @FT_Get_Advance and @FT_Get_Advances functions.                    */
  /*                                                                       */
  /*    If set, it indicates that you want these functions to fail if the  */
  /*    corresponding hinting mode or font driver doesn't allow for very   */
  /*    quick advance computation.                                         */
  /*                                                                       */
  /*    Typically, glyphs that are either unscaled, unhinted, bitmapped,   */
  /*    or light-hinted can have their advance width computed very         */
  /*    quickly.                                                           */
  /*                                                                       */
  /*    Normal and bytecode hinted modes that require loading, scaling,    */
  /*    and hinting of the glyph outline, are extremely slow by            */
  /*    comparison.                                                        */
  /*                                                                       */
#define FT_ADVANCE_FLAG_FAST_ONLY  0x20000000L


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FT_Get_Advance                                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Retrieve the advance value of a given glyph outline in an          */
  /*    @FT_Face.                                                          */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face       :: The source @FT_Face handle.                          */
  /*                                                                       */
  /*    gindex     :: The glyph index.                                     */
  /*                                                                       */
  /*    load_flags :: A set of bit flags similar to those used when        */
  /*                  calling @FT_Load_Glyph, used to determine what kind  */
  /*                  of advances you need.                                */
  /* <Output>                                                              */
  /*    padvance :: The advance value.  If scaling is performed (based on  */
  /*                the value of `load_flags'), the advance value is in    */
  /*                16.16 format.  Otherwise, it is in font units.         */
  /*                                                                       */
  /*                If @FT_LOAD_VERTICAL_LAYOUT is set, this is the        */
  /*                vertical advance corresponding to a vertical layout.   */
  /*                Otherwise, it is the horizontal advance in a           */
  /*                horizontal layout.                                     */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and   */
  /*    if the corresponding font backend doesn't have a quick way to      */
  /*    retrieve the advances.                                             */
  /*                                                                       */
  /*    A scaled advance is returned in 16.16 format but isn't transformed */
  /*    by the affine transformation specified by @FT_Set_Transform.       */
  /*                                                                       */
  FT_EXPORT( FT_Error )
  FT_Get_Advance( FT_Face    face,
                  FT_UInt    gindex,
                  FT_Int32   load_flags,
                  FT_Fixed  *padvance );


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FT_Get_Advances                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Retrieve the advance values of several glyph outlines in an        */
  /*    @FT_Face.                                                          */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face        :: The source @FT_Face handle.                         */
  /*                                                                       */
  /*    start       :: The first glyph index.                              */
  /*                                                                       */
  /*    count       :: The number of advance values you want to retrieve.  */
  /*                                                                       */
  /*    load_flags  :: A set of bit flags similar to those used when       */
  /*                   calling @FT_Load_Glyph.                             */
  /*                                                                       */
  /* <Output>                                                              */
  /*    padvance :: The advance values.  This array, to be provided by the */
  /*                caller, must contain at least `count' elements.        */
  /*                                                                       */
  /*                If scaling is performed (based on the value of         */
  /*                `load_flags'), the advance values are in 16.16 format. */
  /*                Otherwise, they are in font units.                     */
  /*                                                                       */
  /*                If @FT_LOAD_VERTICAL_LAYOUT is set, these are the      */
  /*                vertical advances corresponding to a vertical layout.  */
  /*                Otherwise, they are the horizontal advances in a       */
  /*                horizontal layout.                                     */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and   */
  /*    if the corresponding font backend doesn't have a quick way to      */
  /*    retrieve the advances.                                             */
  /*                                                                       */
  /*    Scaled advances are returned in 16.16 format but aren't            */
  /*    transformed by the affine transformation specified by              */
  /*    @FT_Set_Transform.                                                 */
  /*                                                                       */
  FT_EXPORT( FT_Error )
  FT_Get_Advances( FT_Face    face,
                   FT_UInt    start,
                   FT_UInt    count,
                   FT_Int32   load_flags,
                   FT_Fixed  *padvances );

  /* */


FT_END_HEADER

#endif /* FTADVANC_H_ */


/* END */