summaryrefslogtreecommitdiff
path: root/Build/source/libs/harfbuzz/harfbuzz-0.9.21/src/hb-ft.cc
blob: ff1e187b343bdf55f4cf5f75fe12f76c5e8a4220 (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
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
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
/*
 * Copyright © 2009  Red Hat, Inc.
 * Copyright © 2009  Keith Stribley
 *
 *  This is part of HarfBuzz, a text shaping library.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 *
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * Red Hat Author(s): Behdad Esfahbod
 */

#include "hb-private.hh"

#include "hb-ft.h"

#include "hb-font-private.hh"

#include FT_ADVANCES_H
#include FT_TRUETYPE_TABLES_H



#ifndef HB_DEBUG_FT
#define HB_DEBUG_FT (HB_DEBUG+0)
#endif


/* TODO:
 *
 * In general, this file does a fine job of what it's supposed to do.
 * There are, however, things that need more work:
 *
 *   - We don't handle any load_flags.  That definitely has API implications. :(
 *     I believe hb_ft_font_create() should take load_flags input.
 *     In particular, FT_Get_Advance() without the NO_HINTING flag seems to be
 *     buggy.
 *
 *   - We don't handle / allow for emboldening / obliqueing.
 *
 *   - In the future, we should add constructors to create fonts in font space?
 *
 *   - FT_Load_Glyph() is exteremely costly.  Do something about it?
 */


static hb_bool_t
hb_ft_get_glyph (hb_font_t *font HB_UNUSED,
		 void *font_data,
		 hb_codepoint_t unicode,
		 hb_codepoint_t variation_selector,
		 hb_codepoint_t *glyph,
		 void *user_data HB_UNUSED)

{
  FT_Face ft_face = (FT_Face) font_data;

#ifdef HAVE_FT_FACE_GETCHARVARIANTINDEX
  if (unlikely (variation_selector)) {
    *glyph = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector);
    return *glyph != 0;
  }
#endif

  *glyph = FT_Get_Char_Index (ft_face, unicode);
  return *glyph != 0;
}

static hb_position_t
hb_ft_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
			   void *font_data,
			   hb_codepoint_t glyph,
			   void *user_data HB_UNUSED)
{
  FT_Face ft_face = (FT_Face) font_data;
  int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
  FT_Fixed v;

  if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
    return 0;

  return v >> 10;
}

static hb_position_t
hb_ft_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
			   void *font_data,
			   hb_codepoint_t glyph,
			   void *user_data HB_UNUSED)
{
  FT_Face ft_face = (FT_Face) font_data;
  int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING | FT_LOAD_VERTICAL_LAYOUT;
  FT_Fixed v;

  if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
    return 0;

  /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
   * have a Y growing upward.  Hence the extra negation. */
  return -v >> 10;
}

static hb_bool_t
hb_ft_get_glyph_h_origin (hb_font_t *font HB_UNUSED,
			  void *font_data HB_UNUSED,
			  hb_codepoint_t glyph HB_UNUSED,
			  hb_position_t *x HB_UNUSED,
			  hb_position_t *y HB_UNUSED,
			  void *user_data HB_UNUSED)
{
  /* We always work in the horizontal coordinates. */
  return true;
}

static hb_bool_t
hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
			  void *font_data,
			  hb_codepoint_t glyph,
			  hb_position_t *x,
			  hb_position_t *y,
			  void *user_data HB_UNUSED)
{
  FT_Face ft_face = (FT_Face) font_data;
  int load_flags = FT_LOAD_DEFAULT;

  if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
    return false;

  /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
   * have a Y growing upward.  Hence the extra negation. */
  *x = ft_face->glyph->metrics.horiBearingX -   ft_face->glyph->metrics.vertBearingX;
  *y = ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY);

  return true;
}

static hb_position_t
hb_ft_get_glyph_h_kerning (hb_font_t *font,
			   void *font_data,
			   hb_codepoint_t left_glyph,
			   hb_codepoint_t right_glyph,
			   void *user_data HB_UNUSED)
{
  FT_Face ft_face = (FT_Face) font_data;
  FT_Vector kerningv;

  FT_Kerning_Mode mode = font->x_ppem ? FT_KERNING_DEFAULT : FT_KERNING_UNFITTED;
  if (FT_Get_Kerning (ft_face, left_glyph, right_glyph, mode, &kerningv))
    return 0;

  return kerningv.x;
}

static hb_position_t
hb_ft_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
			   void *font_data HB_UNUSED,
			   hb_codepoint_t top_glyph HB_UNUSED,
			   hb_codepoint_t bottom_glyph HB_UNUSED,
			   void *user_data HB_UNUSED)
{
  /* FreeType API doesn't support vertical kerning */
  return 0;
}

static hb_bool_t
hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,
			 void *font_data,
			 hb_codepoint_t glyph,
			 hb_glyph_extents_t *extents,
			 void *user_data HB_UNUSED)
{
  FT_Face ft_face = (FT_Face) font_data;
  int load_flags = FT_LOAD_DEFAULT;

  if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
    return false;

  extents->x_bearing = ft_face->glyph->metrics.horiBearingX;
  extents->y_bearing = ft_face->glyph->metrics.horiBearingY;
  extents->width = ft_face->glyph->metrics.width;
  extents->height = -ft_face->glyph->metrics.height;
  return true;
}

static hb_bool_t
hb_ft_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
			       void *font_data,
			       hb_codepoint_t glyph,
			       unsigned int point_index,
			       hb_position_t *x,
			       hb_position_t *y,
			       void *user_data HB_UNUSED)
{
  FT_Face ft_face = (FT_Face) font_data;
  int load_flags = FT_LOAD_DEFAULT;

  if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
      return false;

  if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
      return false;

  if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points))
      return false;

  *x = ft_face->glyph->outline.points[point_index].x;
  *y = ft_face->glyph->outline.points[point_index].y;

  return true;
}

static hb_bool_t
hb_ft_get_glyph_name (hb_font_t *font HB_UNUSED,
		      void *font_data,
		      hb_codepoint_t glyph,
		      char *name, unsigned int size,
		      void *user_data HB_UNUSED)
{
  FT_Face ft_face = (FT_Face) font_data;

  hb_bool_t ret = !FT_Get_Glyph_Name (ft_face, glyph, name, size);
  if (ret && (size && !*name))
    ret = false;

  return ret;
}

static hb_bool_t
hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED,
			   void *font_data,
			   const char *name, int len, /* -1 means nul-terminated */
			   hb_codepoint_t *glyph,
			   void *user_data HB_UNUSED)
{
  FT_Face ft_face = (FT_Face) font_data;

  if (len < 0)
    *glyph = FT_Get_Name_Index (ft_face, (FT_String *) name);
  else {
    /* Make a nul-terminated version. */
    char buf[128];
    len = MIN (len, (int) sizeof (buf) - 1);
    strncpy (buf, name, len);
    buf[len] = '\0';
    *glyph = FT_Get_Name_Index (ft_face, buf);
  }

  if (*glyph == 0)
  {
    /* Check whether the given name was actually the name of glyph 0. */
    char buf[128];
    if (!FT_Get_Glyph_Name(ft_face, 0, buf, sizeof (buf)) &&
        len < 0 ? !strcmp (buf, name) : !strncmp (buf, name, len))
      return true;
  }

  return *glyph != 0;
}


static hb_font_funcs_t *
_hb_ft_get_font_funcs (void)
{
  static const hb_font_funcs_t ft_ffuncs = {
    HB_OBJECT_HEADER_STATIC,

    true, /* immutable */

    {
#define HB_FONT_FUNC_IMPLEMENT(name) hb_ft_get_##name,
      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
#undef HB_FONT_FUNC_IMPLEMENT
    }
  };

  return const_cast<hb_font_funcs_t *> (&ft_ffuncs);
}


static hb_blob_t *
reference_table  (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
{
  FT_Face ft_face = (FT_Face) user_data;
  FT_Byte *buffer;
  FT_ULong  length = 0;
  FT_Error error;

  /* Note: FreeType like HarfBuzz uses the NONE tag for fetching the entire blob */

  error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length);
  if (error)
    return NULL;

  buffer = (FT_Byte *) malloc (length);
  if (buffer == NULL)
    return NULL;

  error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length);
  if (error)
    return NULL;

  return hb_blob_create ((const char *) buffer, length,
			 HB_MEMORY_MODE_WRITABLE,
			 buffer, free);
}

/**
 * hb_ft_face_create:
 * @ft_face: (destroy destroy) (scope notified): 
 * @destroy:
 *
 * 
 *
 * Return value: (transfer full): 
 * Since: 1.0
 **/
hb_face_t *
hb_ft_face_create (FT_Face           ft_face,
		   hb_destroy_func_t destroy)
{
  hb_face_t *face;

  if (ft_face->stream->read == NULL) {
    hb_blob_t *blob;

    blob = hb_blob_create ((const char *) ft_face->stream->base,
			   (unsigned int) ft_face->stream->size,
			   /* TODO: We assume that it's mmap()'ed, but FreeType code
			    * suggests that there are cases we reach here but font is
			    * not mmapped.  For example, when mmap() fails.  No idea
			    * how to deal with it better here. */
			   HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE,
			   ft_face, destroy);
    face = hb_face_create (blob, ft_face->face_index);
    hb_blob_destroy (blob);
  } else {
    face = hb_face_create_for_tables (reference_table, ft_face, destroy);
  }

  hb_face_set_index (face, ft_face->face_index);
  hb_face_set_upem (face, ft_face->units_per_EM);

  return face;
}

static void
hb_ft_face_finalize (FT_Face ft_face)
{
  hb_face_destroy ((hb_face_t *) ft_face->generic.data);
}

/**
 * hb_ft_face_create_cached:
 * @ft_face: 
 *
 * 
 *
 * Return value: (transfer full): 
 * Since: 1.0
 **/
hb_face_t *
hb_ft_face_create_cached (FT_Face ft_face)
{
  if (unlikely (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer) hb_ft_face_finalize))
  {
    if (ft_face->generic.finalizer)
      ft_face->generic.finalizer (ft_face);

    ft_face->generic.data = hb_ft_face_create (ft_face, NULL);
    ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize;
  }

  return hb_face_reference ((hb_face_t *) ft_face->generic.data);
}

static void
_do_nothing (void)
{
}


/**
 * hb_ft_font_create:
 * @ft_face: (destroy destroy) (scope notified): 
 * @destroy:
 *
 * 
 *
 * Return value: (transfer full): 
 * Since: 1.0
 **/
hb_font_t *
hb_ft_font_create (FT_Face           ft_face,
		   hb_destroy_func_t destroy)
{
  hb_font_t *font;
  hb_face_t *face;

  face = hb_ft_face_create (ft_face, destroy);
  font = hb_font_create (face);
  hb_face_destroy (face);
  hb_font_set_funcs (font,
		     _hb_ft_get_font_funcs (),
		     ft_face, (hb_destroy_func_t) _do_nothing);
  hb_font_set_scale (font,
		     ((uint64_t) ft_face->size->metrics.x_scale * (uint64_t) ft_face->units_per_EM) >> 16,
		     ((uint64_t) ft_face->size->metrics.y_scale * (uint64_t) ft_face->units_per_EM) >> 16);
  hb_font_set_ppem (font,
		    ft_face->size->metrics.x_ppem,
		    ft_face->size->metrics.y_ppem);

  return font;
}


/* Thread-safe, lock-free, FT_Library */

static FT_Library ft_library;

static inline
void free_ft_library (void)
{
  FT_Done_FreeType (ft_library);
}

static FT_Library
get_ft_library (void)
{
retry:
  FT_Library library = (FT_Library) hb_atomic_ptr_get (&ft_library);

  if (unlikely (!library))
  {
    /* Not found; allocate one. */
    if (FT_Init_FreeType (&library))
      return NULL;

    if (!hb_atomic_ptr_cmpexch (&ft_library, NULL, library)) {
      FT_Done_FreeType (library);
      goto retry;
    }

#ifdef HAVE_ATEXIT
    atexit (free_ft_library); /* First person registers atexit() callback. */
#endif
  }

  return library;
}

static void
_release_blob (FT_Face ft_face)
{
  hb_blob_destroy ((hb_blob_t *) ft_face->generic.data);
}

void
hb_ft_font_set_funcs (hb_font_t *font)
{
  hb_blob_t *blob = hb_face_reference_blob (font->face);
  unsigned int blob_length;
  const char *blob_data = hb_blob_get_data (blob, &blob_length);
  if (unlikely (!blob_length))
    DEBUG_MSG (FT, font, "Font face has empty blob");

  FT_Face ft_face = NULL;
  FT_Error err = FT_New_Memory_Face (get_ft_library (),
				     (const FT_Byte *) blob_data,
				     blob_length,
				     hb_face_get_index (font->face),
				     &ft_face);

  if (unlikely (err)) {
    hb_blob_destroy (blob);
    DEBUG_MSG (FT, font, "Font face FT_New_Memory_Face() failed");
    return;
  }

  FT_Select_Charmap (ft_face, FT_ENCODING_UNICODE);

  assert (font->y_scale >= 0);
  FT_Set_Char_Size (ft_face,
		    font->x_scale, font->y_scale,
		    0, 0);
#if 0
		    font->x_ppem * 72 * 64 / font->x_scale,
		    font->y_ppem * 72 * 64 / font->y_scale);
#endif

  ft_face->generic.data = blob;
  ft_face->generic.finalizer = (FT_Generic_Finalizer) _release_blob;

  hb_font_set_funcs (font,
		     _hb_ft_get_font_funcs (),
		     ft_face,
		     (hb_destroy_func_t) FT_Done_Face);
}

FT_Face
hb_ft_font_get_face (hb_font_t *font)
{
  if (font->destroy == (hb_destroy_func_t) FT_Done_Face ||
      font->destroy == (hb_destroy_func_t) _do_nothing)
    return (FT_Face) font->user_data;

  return NULL;
}