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
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
|
/***************************************************************************/
/* */
/* aftypes.h */
/* */
/* Auto-fitter types (specification only). */
/* */
/* Copyright 2003-2009, 2011-2013 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
* writing systems in order to apply script-specific rules.
*
* The code has also been compartmentized into several entities that
* should make algorithmic experimentation easier than with the old
* code.
*
*************************************************************************/
#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
#include "afblue.h"
FT_BEGIN_HEADER
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** D E B U G G I N G *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
#ifdef FT_DEBUG_AUTOFIT
#include FT_CONFIG_STANDARD_LIBRARY_H
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;
#endif /* FT_DEBUG_AUTOFIT */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** 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_and_quantize_widths( FT_UInt* count,
AF_Width widths,
FT_Pos threshold );
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** 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
/* opaque handle to glyph-specific hints -- see `afhints.h' for more
* details
*/
typedef struct AF_GlyphHintsRec_* AF_GlyphHints;
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** 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 M E T R I C S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* This is the main structure which combines writing systems and script */
/* data (for a given face object, see below). */
typedef struct AF_WritingSystemClassRec_ const* AF_WritingSystemClass;
typedef struct AF_ScriptClassRec_ const* AF_ScriptClass;
typedef struct AF_FaceGlobalsRec_* AF_FaceGlobals;
typedef struct AF_ScriptMetricsRec_
{
AF_ScriptClass script_class;
AF_ScalerRec scaler;
FT_Bool digits_have_same_width;
AF_FaceGlobals globals; /* to access properties */
} 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 );
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** W R I T I N G S Y S T E M S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*
* In FreeType, a writing system consists of multiple scripts which can
* be handled similarly *in a typographical way*; the relationship is not
* based on history. For example, both the Greek and the unrelated
* Armenian scripts share the same features like ascender, descender,
* x-height, etc. Essentially, a writing system is covered by a
* submodule of the auto-fitter; it contains
*
* - a specific global analyzer which computes global metrics specific to
* the script (based on script-specific characters to identify ascender
* height, x-height, etc.),
*
* - a specific glyph analyzer that computes segments and edges for each
* glyph covered by the script,
*
* - a specific grid-fitting algorithm that distorts the scaled glyph
* outline according to the results of the glyph analyzer.
*/
#define __AFWRTSYS_H__ /* don't load header files */
#undef WRITING_SYSTEM
#define WRITING_SYSTEM( ws, WS ) \
AF_WRITING_SYSTEM_ ## WS,
/* The list of known writing systems. */
typedef enum AF_WritingSystem_
{
#include "afwrtsys.h"
AF_WRITING_SYSTEM_MAX /* do not remove */
} AF_WritingSystem;
#undef __AFWRTSYS_H__
typedef struct AF_WritingSystemClassRec_
{
AF_WritingSystem writing_system;
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_WritingSystemClassRec;
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** S C R I P T S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*
* Each script is associated with a set of Unicode ranges which gets used
* to test whether the font face supports the script. It also references
* the writing system it belongs to.
*
* We use four-letter script tags from the OpenType specification.
*/
#undef SCRIPT
#define SCRIPT( s, S, d ) \
AF_SCRIPT_ ## S,
/* The list of known scripts. */
typedef enum AF_Script_
{
#include "afscript.h"
AF_SCRIPT_MAX /* do not remove */
} AF_Script;
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_Blue_Stringset blue_stringset;
AF_WritingSystem writing_system;
AF_Script_UniRange script_uni_ranges; /* last must be { 0, 0 } */
FT_UInt32 standard_char; /* for default width and height */
} AF_ScriptClassRec;
/* Declare and define vtables for classes */
#ifndef FT_CONFIG_OPTION_PIC
#define AF_DECLARE_WRITING_SYSTEM_CLASS( writing_system_class ) \
FT_CALLBACK_TABLE const AF_WritingSystemClassRec \
writing_system_class;
#define AF_DEFINE_WRITING_SYSTEM_CLASS( \
writing_system_class, \
system, \
m_size, \
m_init, \
m_scale, \
m_done, \
h_init, \
h_apply ) \
FT_CALLBACK_TABLE_DEF \
const AF_WritingSystemClassRec writing_system_class = \
{ \
system, \
\
m_size, \
\
m_init, \
m_scale, \
m_done, \
\
h_init, \
h_apply \
};
#define AF_DECLARE_SCRIPT_CLASS( script_class ) \
FT_CALLBACK_TABLE const AF_ScriptClassRec \
script_class;
#define AF_DEFINE_SCRIPT_CLASS( \
script_class, \
script_, \
blue_stringset_, \
writing_system_, \
ranges, \
std_char ) \
FT_CALLBACK_TABLE_DEF \
const AF_ScriptClassRec script_class = \
{ \
script_, \
blue_stringset_, \
writing_system_, \
ranges, \
std_char \
};
#else /* FT_CONFIG_OPTION_PIC */
#define AF_DECLARE_WRITING_SYSTEM_CLASS( writing_system_class ) \
FT_LOCAL( void ) \
FT_Init_Class_ ## writing_system_class( AF_WritingSystemClassRec* ac );
#define AF_DEFINE_WRITING_SYSTEM_CLASS( \
writing_system_class, \
system, \
m_size, \
m_init, \
m_scale, \
m_done, \
h_init, \
h_apply ) \
FT_LOCAL_DEF( void ) \
FT_Init_Class_ ## writing_system_class( AF_WritingSystemClassRec* ac ) \
{ \
ac->writing_system = system; \
\
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; \
}
#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_, \
blue_string_set_, \
writing_system_, \
ranges, \
std_char ) \
FT_LOCAL_DEF( void ) \
FT_Init_Class_ ## script_class( AF_ScriptClassRec* ac ) \
{ \
ac->script = script_; \
ac->blue_stringset = blue_stringset_; \
ac->writing_system = writing_system_; \
ac->script_uni_ranges = ranges; \
ac->standard_char = std_char; \
}
#endif /* FT_CONFIG_OPTION_PIC */
/* */
FT_END_HEADER
#endif /* __AFTYPES_H__ */
/* END */
|