aboutsummaryrefslogtreecommitdiff
path: root/freetype/src/autofit/aftypes.h
blob: 5574f0c302b3a60548a835e396e156970ac782e3 (plain)
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
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
/***************************************************************************/
/*                                                                         */
/*  aftypes.h                                                              */
/*                                                                         */
/*    Auto-fitter types (specification only).                              */
/*                                                                         */
/*  Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009 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.                                        */
/*                                                                         */
/***************************************************************************/


  /*************************************************************************
   *
   *  The auto-fitter is a complete rewrite of the old auto-hinter.
   *  Its main feature is the ability to differentiate between different
   *  scripts in order to apply language-specific rules.
   *
   *  The code has also been compartmentized into several entities that
   *  should make algorithmic experimentation easier than with the old
   *  code.
   *
   *  Finally, we get rid of the Catharon license, since this code is
   *  released under the FreeType one.
   *
   *************************************************************************/


#ifndef __AFTYPES_H__
#define __AFTYPES_H__

#include <ft2build.h>

#include FT_FREETYPE_H
#include FT_OUTLINE_H
#include FT_INTERNAL_OBJECTS_H
#include FT_INTERNAL_DEBUG_H


FT_BEGIN_HEADER

  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                    D E B U G G I N G                          *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

#define xxAF_USE_WARPER  /* only define to use warp hinting */
#define xxAF_DEBUG

#ifdef AF_DEBUG

#include FT_CONFIG_STANDARD_LIBRARY_H

#define AF_LOG( x )  do { if ( _af_debug ) printf x; } while ( 0 )

extern int    _af_debug;
extern int    _af_debug_disable_horz_hints;
extern int    _af_debug_disable_vert_hints;
extern int    _af_debug_disable_blue_hints;
extern void*  _af_debug_hints;

#else /* !AF_DEBUG */

#define AF_LOG( x )  do { } while ( 0 )        /* nothing */

#endif /* !AF_DEBUG */


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                 U T I L I T Y   S T U F F                     *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  typedef struct  AF_WidthRec_
  {
    FT_Pos  org;  /* original position/width in font units              */
    FT_Pos  cur;  /* current/scaled position/width in device sub-pixels */
    FT_Pos  fit;  /* current/fitted position/width in device sub-pixels */

  } AF_WidthRec, *AF_Width;


  FT_LOCAL( void )
  af_sort_pos( FT_UInt  count,
               FT_Pos*  table );

  FT_LOCAL( void )
  af_sort_widths( FT_UInt   count,
                  AF_Width  widths );


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                   A N G L E   T Y P E S                       *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /*
   *  The auto-fitter doesn't need a very high angular accuracy;
   *  this allows us to speed up some computations considerably with a
   *  light Cordic algorithm (see afangles.c).
   */

  typedef FT_Int  AF_Angle;


#define AF_ANGLE_PI   256
#define AF_ANGLE_2PI  ( AF_ANGLE_PI * 2 )
#define AF_ANGLE_PI2  ( AF_ANGLE_PI / 2 )
#define AF_ANGLE_PI4  ( AF_ANGLE_PI / 4 )


#if 0
  /*
   *  compute the angle of a given 2-D vector
   */
  FT_LOCAL( AF_Angle )
  af_angle_atan( FT_Pos  dx,
                 FT_Pos  dy );


  /*
   *  compute `angle2 - angle1'; the result is always within
   *  the range [-AF_ANGLE_PI .. AF_ANGLE_PI - 1]
   */
  FT_LOCAL( AF_Angle )
  af_angle_diff( AF_Angle  angle1,
                 AF_Angle  angle2 );
#endif /* 0 */


#define AF_ANGLE_DIFF( result, angle1, angle2 ) \
  FT_BEGIN_STMNT                                \
    AF_Angle  _delta = (angle2) - (angle1);     \
                                                \
                                                \
    _delta %= AF_ANGLE_2PI;                     \
    if ( _delta < 0 )                           \
      _delta += AF_ANGLE_2PI;                   \
                                                \
    if ( _delta > AF_ANGLE_PI )                 \
      _delta -= AF_ANGLE_2PI;                   \
                                                \
    result = _delta;                            \
  FT_END_STMNT


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                    O U T L I N E S                            *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /*  opaque handle to glyph-specific hints -- see `afhints.h' for more
   *  details
   */
  typedef struct AF_GlyphHintsRec_*  AF_GlyphHints;

  /*  This structure is used to model an input glyph outline to
   *  the auto-hinter.  The latter will set the `hints' field
   *  depending on the glyph's script.
   */
  typedef struct  AF_OutlineRec_
  {
    FT_Face        face;
    FT_Outline     outline;
    FT_UInt        outline_resolution;

    FT_Int         advance;
    FT_UInt        metrics_resolution;

    AF_GlyphHints  hints;

  } AF_OutlineRec;


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       S C A L E R S                           *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /*
   *  A scaler models the target pixel device that will receive the
   *  auto-hinted glyph image.
   */

  typedef enum  AF_ScalerFlags_
  {
    AF_SCALER_FLAG_NO_HORIZONTAL = 1,  /* disable horizontal hinting */
    AF_SCALER_FLAG_NO_VERTICAL   = 2,  /* disable vertical hinting   */
    AF_SCALER_FLAG_NO_ADVANCE    = 4   /* disable advance hinting    */

  } AF_ScalerFlags;


  typedef struct  AF_ScalerRec_
  {
    FT_Face         face;        /* source font face                        */
    FT_Fixed        x_scale;     /* from font units to 1/64th device pixels */
    FT_Fixed        y_scale;     /* from font units to 1/64th device pixels */
    FT_Pos          x_delta;     /* in 1/64th device pixels                 */
    FT_Pos          y_delta;     /* in 1/64th device pixels                 */
    FT_Render_Mode  render_mode; /* monochrome, anti-aliased, LCD, etc.     */
    FT_UInt32       flags;       /* additional control flags, see above     */

  } AF_ScalerRec, *AF_Scaler;


#define AF_SCALER_EQUAL_SCALES( a, b )      \
          ( (a)->x_scale == (b)->x_scale && \
            (a)->y_scale == (b)->y_scale && \
            (a)->x_delta == (b)->x_delta && \
            (a)->y_delta == (b)->y_delta )


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       S C R I P T S                           *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /*
   *  The list of know scripts.  Each different script corresponds to the
   *  following information:
   *
   *   - A set of Unicode ranges to test whether the face supports the
   *     script.
   *
   *   - A specific global analyzer that will compute global metrics
   *     specific to the script.
   *
   *   - A specific glyph analyzer that will compute segments and
   *     edges for each glyph covered by the script.
   *
   *   - A specific grid-fitting algorithm that will distort the
   *     scaled glyph outline according to the results of the glyph
   *     analyzer.
   *
   *  Note that a given analyzer and/or grid-fitting algorithm can be
   *  used by more than one script.
   */

  typedef enum  AF_Script_
  {
    AF_SCRIPT_NONE  = 0,
    AF_SCRIPT_LATIN = 1,
    AF_SCRIPT_CJK   = 2,
    AF_SCRIPT_INDIC = 3, 
#ifdef FT_OPTION_AUTOFIT2
    AF_SCRIPT_LATIN2,
#endif

    /* add new scripts here.  Don't forget to update the list in */
    /* `afglobal.c'.                                             */

    AF_SCRIPT_MAX   /* do not remove */

  } AF_Script;


  typedef struct AF_ScriptClassRec_ const*  AF_ScriptClass;

  typedef struct  AF_ScriptMetricsRec_
  {
    AF_ScriptClass  clazz;
    AF_ScalerRec    scaler;
    FT_Bool         digits_have_same_width;

  } AF_ScriptMetricsRec, *AF_ScriptMetrics;


  /*  This function parses an FT_Face to compute global metrics for
   *  a specific script.
   */
  typedef FT_Error
  (*AF_Script_InitMetricsFunc)( AF_ScriptMetrics  metrics,
                                FT_Face           face );

  typedef void
  (*AF_Script_ScaleMetricsFunc)( AF_ScriptMetrics  metrics,
                                 AF_Scaler         scaler );

  typedef void
  (*AF_Script_DoneMetricsFunc)( AF_ScriptMetrics  metrics );


  typedef FT_Error
  (*AF_Script_InitHintsFunc)( AF_GlyphHints     hints,
                              AF_ScriptMetrics  metrics );

  typedef void
  (*AF_Script_ApplyHintsFunc)( AF_GlyphHints     hints,
                               FT_Outline*       outline,
                               AF_ScriptMetrics  metrics );


  typedef struct  AF_Script_UniRangeRec_
  {
    FT_UInt32  first;
    FT_UInt32  last;

  } AF_Script_UniRangeRec;

#define AF_UNIRANGE_REC( a, b ) { (FT_UInt32)(a), (FT_UInt32)(b) }

  typedef const AF_Script_UniRangeRec  *AF_Script_UniRange;


  typedef struct  AF_ScriptClassRec_
  {
    AF_Script                   script;
    AF_Script_UniRange          script_uni_ranges; /* last must be { 0, 0 } */

    FT_Offset                   script_metrics_size;
    AF_Script_InitMetricsFunc   script_metrics_init;
    AF_Script_ScaleMetricsFunc  script_metrics_scale;
    AF_Script_DoneMetricsFunc   script_metrics_done;

    AF_Script_InitHintsFunc     script_hints_init;
    AF_Script_ApplyHintsFunc    script_hints_apply;

  } AF_ScriptClassRec;

/* Declare and define vtables for classes */
#ifndef FT_CONFIG_OPTION_PIC

#define AF_DECLARE_SCRIPT_CLASS(script_class)                                \
  FT_CALLBACK_TABLE const AF_ScriptClassRec                                  \
  script_class;

#define AF_DEFINE_SCRIPT_CLASS(script_class, script_, ranges, m_size,        \
                               m_init, m_scale, m_done, h_init, h_apply)     \
  FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec                              \
  script_class =                                                             \
  {                                                                          \
    script_,                                                                 \
    ranges,                                                                  \
                                                                             \
    m_size,                                                                  \
                                                                             \
    m_init,                                                                  \
    m_scale,                                                                 \
    m_done,                                                                  \
                                                                             \
    h_init,                                                                  \
    h_apply                                                                  \
  };

#else 

#define AF_DECLARE_SCRIPT_CLASS(script_class)                                \
  FT_LOCAL(void)                                                             \
  FT_Init_Class_##script_class(AF_ScriptClassRec* ac);

#define AF_DEFINE_SCRIPT_CLASS(script_class, script_, ranges, m_size,        \
                               m_init, m_scale, m_done, h_init, h_apply)     \
  FT_LOCAL_DEF(void)                                                         \
  FT_Init_Class_##script_class(AF_ScriptClassRec* ac)                        \
  {                                                                          \
    ac->script                = script_;                                     \
    ac->script_uni_ranges     = ranges;                                      \
                                                                             \
    ac->script_metrics_size   = m_size;                                      \
                                                                             \
    ac->script_metrics_init   = m_init;                                      \
    ac->script_metrics_scale  = m_scale;                                     \
    ac->script_metrics_done   = m_done;                                      \
                                                                             \
    ac->script_hints_init     = h_init;                                      \
    ac->script_hints_apply    = h_apply;                                     \
  }
#endif


/* */

FT_END_HEADER

#endif /* __AFTYPES_H__ */


/* END */