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comparison: gfx/harfbuzz/src/hb-ft.cc

gfx/harfbuzz/src/hb-ft.cc

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TOR_BUG_9701
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-1:000000000000 0:ec51109eca62
1 /*
2 * Copyright © 2009 Red Hat, Inc.
3 * Copyright © 2009 Keith Stribley
4 *
5 * This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Red Hat Author(s): Behdad Esfahbod
26 */
27
28 #include "hb-private.hh"
29
30 #include "hb-ft.h"
31
32 #include "hb-font-private.hh"
33
34 #include FT_ADVANCES_H
35 #include FT_TRUETYPE_TABLES_H
36
37
38
39 #ifndef HB_DEBUG_FT
40 #define HB_DEBUG_FT (HB_DEBUG+0)
41 #endif
42
43
44 /* TODO:
45 *
46 * In general, this file does a fine job of what it's supposed to do.
47 * There are, however, things that need more work:
48 *
49 * - We don't handle any load_flags. That definitely has API implications. :(
50 * I believe hb_ft_font_create() should take load_flags input.
51 * In particular, FT_Get_Advance() without the NO_HINTING flag seems to be
52 * buggy.
53 *
54 * - We don't handle / allow for emboldening / obliqueing.
55 *
56 * - In the future, we should add constructors to create fonts in font space?
57 *
58 * - FT_Load_Glyph() is exteremely costly. Do something about it?
59 */
60
61
62 static hb_bool_t
63 hb_ft_get_glyph (hb_font_t *font HB_UNUSED,
64 void *font_data,
65 hb_codepoint_t unicode,
66 hb_codepoint_t variation_selector,
67 hb_codepoint_t *glyph,
68 void *user_data HB_UNUSED)
69
70 {
71 FT_Face ft_face = (FT_Face) font_data;
72
73 #ifdef HAVE_FT_FACE_GETCHARVARIANTINDEX
74 if (unlikely (variation_selector)) {
75 *glyph = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector);
76 return *glyph != 0;
77 }
78 #endif
79
80 *glyph = FT_Get_Char_Index (ft_face, unicode);
81 return *glyph != 0;
82 }
83
84 static hb_position_t
85 hb_ft_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
86 void *font_data,
87 hb_codepoint_t glyph,
88 void *user_data HB_UNUSED)
89 {
90 FT_Face ft_face = (FT_Face) font_data;
91 int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
92 FT_Fixed v;
93
94 if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
95 return 0;
96
97 return (v + (1<<9)) >> 10;
98 }
99
100 static hb_position_t
101 hb_ft_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
102 void *font_data,
103 hb_codepoint_t glyph,
104 void *user_data HB_UNUSED)
105 {
106 FT_Face ft_face = (FT_Face) font_data;
107 int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING | FT_LOAD_VERTICAL_LAYOUT;
108 FT_Fixed v;
109
110 if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
111 return 0;
112
113 /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
114 * have a Y growing upward. Hence the extra negation. */
115 return (-v + (1<<9)) >> 10;
116 }
117
118 static hb_bool_t
119 hb_ft_get_glyph_h_origin (hb_font_t *font HB_UNUSED,
120 void *font_data HB_UNUSED,
121 hb_codepoint_t glyph HB_UNUSED,
122 hb_position_t *x HB_UNUSED,
123 hb_position_t *y HB_UNUSED,
124 void *user_data HB_UNUSED)
125 {
126 /* We always work in the horizontal coordinates. */
127 return true;
128 }
129
130 static hb_bool_t
131 hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
132 void *font_data,
133 hb_codepoint_t glyph,
134 hb_position_t *x,
135 hb_position_t *y,
136 void *user_data HB_UNUSED)
137 {
138 FT_Face ft_face = (FT_Face) font_data;
139 int load_flags = FT_LOAD_DEFAULT;
140
141 if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
142 return false;
143
144 /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
145 * have a Y growing upward. Hence the extra negation. */
146 *x = ft_face->glyph->metrics.horiBearingX - ft_face->glyph->metrics.vertBearingX;
147 *y = ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY);
148
149 return true;
150 }
151
152 static hb_position_t
153 hb_ft_get_glyph_h_kerning (hb_font_t *font,
154 void *font_data,
155 hb_codepoint_t left_glyph,
156 hb_codepoint_t right_glyph,
157 void *user_data HB_UNUSED)
158 {
159 FT_Face ft_face = (FT_Face) font_data;
160 FT_Vector kerningv;
161
162 FT_Kerning_Mode mode = font->x_ppem ? FT_KERNING_DEFAULT : FT_KERNING_UNFITTED;
163 if (FT_Get_Kerning (ft_face, left_glyph, right_glyph, mode, &kerningv))
164 return 0;
165
166 return kerningv.x;
167 }
168
169 static hb_position_t
170 hb_ft_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
171 void *font_data HB_UNUSED,
172 hb_codepoint_t top_glyph HB_UNUSED,
173 hb_codepoint_t bottom_glyph HB_UNUSED,
174 void *user_data HB_UNUSED)
175 {
176 /* FreeType API doesn't support vertical kerning */
177 return 0;
178 }
179
180 static hb_bool_t
181 hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,
182 void *font_data,
183 hb_codepoint_t glyph,
184 hb_glyph_extents_t *extents,
185 void *user_data HB_UNUSED)
186 {
187 FT_Face ft_face = (FT_Face) font_data;
188 int load_flags = FT_LOAD_DEFAULT;
189
190 if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
191 return false;
192
193 extents->x_bearing = ft_face->glyph->metrics.horiBearingX;
194 extents->y_bearing = ft_face->glyph->metrics.horiBearingY;
195 extents->width = ft_face->glyph->metrics.width;
196 extents->height = -ft_face->glyph->metrics.height;
197 return true;
198 }
199
200 static hb_bool_t
201 hb_ft_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
202 void *font_data,
203 hb_codepoint_t glyph,
204 unsigned int point_index,
205 hb_position_t *x,
206 hb_position_t *y,
207 void *user_data HB_UNUSED)
208 {
209 FT_Face ft_face = (FT_Face) font_data;
210 int load_flags = FT_LOAD_DEFAULT;
211
212 if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
213 return false;
214
215 if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
216 return false;
217
218 if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points))
219 return false;
220
221 *x = ft_face->glyph->outline.points[point_index].x;
222 *y = ft_face->glyph->outline.points[point_index].y;
223
224 return true;
225 }
226
227 static hb_bool_t
228 hb_ft_get_glyph_name (hb_font_t *font HB_UNUSED,
229 void *font_data,
230 hb_codepoint_t glyph,
231 char *name, unsigned int size,
232 void *user_data HB_UNUSED)
233 {
234 FT_Face ft_face = (FT_Face) font_data;
235
236 hb_bool_t ret = !FT_Get_Glyph_Name (ft_face, glyph, name, size);
237 if (ret && (size && !*name))
238 ret = false;
239
240 return ret;
241 }
242
243 static hb_bool_t
244 hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED,
245 void *font_data,
246 const char *name, int len, /* -1 means nul-terminated */
247 hb_codepoint_t *glyph,
248 void *user_data HB_UNUSED)
249 {
250 FT_Face ft_face = (FT_Face) font_data;
251
252 if (len < 0)
253 *glyph = FT_Get_Name_Index (ft_face, (FT_String *) name);
254 else {
255 /* Make a nul-terminated version. */
256 char buf[128];
257 len = MIN (len, (int) sizeof (buf) - 1);
258 strncpy (buf, name, len);
259 buf[len] = '\0';
260 *glyph = FT_Get_Name_Index (ft_face, buf);
261 }
262
263 if (*glyph == 0)
264 {
265 /* Check whether the given name was actually the name of glyph 0. */
266 char buf[128];
267 if (!FT_Get_Glyph_Name(ft_face, 0, buf, sizeof (buf)) &&
268 len < 0 ? !strcmp (buf, name) : !strncmp (buf, name, len))
269 return true;
270 }
271
272 return *glyph != 0;
273 }
274
275
276 static hb_font_funcs_t *
277 _hb_ft_get_font_funcs (void)
278 {
279 static const hb_font_funcs_t ft_ffuncs = {
280 HB_OBJECT_HEADER_STATIC,
281
282 true, /* immutable */
283
284 {
285 #define HB_FONT_FUNC_IMPLEMENT(name) hb_ft_get_##name,
286 HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
287 #undef HB_FONT_FUNC_IMPLEMENT
288 }
289 };
290
291 return const_cast<hb_font_funcs_t *> (&ft_ffuncs);
292 }
293
294
295 static hb_blob_t *
296 reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
297 {
298 FT_Face ft_face = (FT_Face) user_data;
299 FT_Byte *buffer;
300 FT_ULong length = 0;
301 FT_Error error;
302
303 /* Note: FreeType like HarfBuzz uses the NONE tag for fetching the entire blob */
304
305 error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length);
306 if (error)
307 return NULL;
308
309 buffer = (FT_Byte *) malloc (length);
310 if (buffer == NULL)
311 return NULL;
312
313 error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length);
314 if (error)
315 return NULL;
316
317 return hb_blob_create ((const char *) buffer, length,
318 HB_MEMORY_MODE_WRITABLE,
319 buffer, free);
320 }
321
322 /**
323 * hb_ft_face_create:
324 * @ft_face: (destroy destroy) (scope notified):
325 * @destroy:
326 *
327 *
328 *
329 * Return value: (transfer full):
330 * Since: 1.0
331 **/
332 hb_face_t *
333 hb_ft_face_create (FT_Face ft_face,
334 hb_destroy_func_t destroy)
335 {
336 hb_face_t *face;
337
338 if (ft_face->stream->read == NULL) {
339 hb_blob_t *blob;
340
341 blob = hb_blob_create ((const char *) ft_face->stream->base,
342 (unsigned int) ft_face->stream->size,
343 /* TODO: We assume that it's mmap()'ed, but FreeType code
344 * suggests that there are cases we reach here but font is
345 * not mmapped. For example, when mmap() fails. No idea
346 * how to deal with it better here. */
347 HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE,
348 ft_face, destroy);
349 face = hb_face_create (blob, ft_face->face_index);
350 hb_blob_destroy (blob);
351 } else {
352 face = hb_face_create_for_tables (reference_table, ft_face, destroy);
353 }
354
355 hb_face_set_index (face, ft_face->face_index);
356 hb_face_set_upem (face, ft_face->units_per_EM);
357
358 return face;
359 }
360
361 static void
362 hb_ft_face_finalize (FT_Face ft_face)
363 {
364 hb_face_destroy ((hb_face_t *) ft_face->generic.data);
365 }
366
367 /**
368 * hb_ft_face_create_cached:
369 * @ft_face:
370 *
371 *
372 *
373 * Return value: (transfer full):
374 * Since: 1.0
375 **/
376 hb_face_t *
377 hb_ft_face_create_cached (FT_Face ft_face)
378 {
379 if (unlikely (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer) hb_ft_face_finalize))
380 {
381 if (ft_face->generic.finalizer)
382 ft_face->generic.finalizer (ft_face);
383
384 ft_face->generic.data = hb_ft_face_create (ft_face, NULL);
385 ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize;
386 }
387
388 return hb_face_reference ((hb_face_t *) ft_face->generic.data);
389 }
390
391 static void
392 _do_nothing (void)
393 {
394 }
395
396
397 /**
398 * hb_ft_font_create:
399 * @ft_face: (destroy destroy) (scope notified):
400 * @destroy:
401 *
402 *
403 *
404 * Return value: (transfer full):
405 * Since: 1.0
406 **/
407 hb_font_t *
408 hb_ft_font_create (FT_Face ft_face,
409 hb_destroy_func_t destroy)
410 {
411 hb_font_t *font;
412 hb_face_t *face;
413
414 face = hb_ft_face_create (ft_face, destroy);
415 font = hb_font_create (face);
416 hb_face_destroy (face);
417 hb_font_set_funcs (font,
418 _hb_ft_get_font_funcs (),
419 ft_face, (hb_destroy_func_t) _do_nothing);
420 hb_font_set_scale (font,
421 (int) (((uint64_t) ft_face->size->metrics.x_scale * (uint64_t) ft_face->units_per_EM + (1<<15)) >> 16),
422 (int) (((uint64_t) ft_face->size->metrics.y_scale * (uint64_t) ft_face->units_per_EM + (1<<15)) >> 16));
423 hb_font_set_ppem (font,
424 ft_face->size->metrics.x_ppem,
425 ft_face->size->metrics.y_ppem);
426
427 return font;
428 }
429
430
431 /* Thread-safe, lock-free, FT_Library */
432
433 static FT_Library ft_library;
434
435 static inline
436 void free_ft_library (void)
437 {
438 FT_Done_FreeType (ft_library);
439 }
440
441 static FT_Library
442 get_ft_library (void)
443 {
444 retry:
445 FT_Library library = (FT_Library) hb_atomic_ptr_get (&ft_library);
446
447 if (unlikely (!library))
448 {
449 /* Not found; allocate one. */
450 if (FT_Init_FreeType (&library))
451 return NULL;
452
453 if (!hb_atomic_ptr_cmpexch (&ft_library, NULL, library)) {
454 FT_Done_FreeType (library);
455 goto retry;
456 }
457
458 #ifdef HAVE_ATEXIT
459 atexit (free_ft_library); /* First person registers atexit() callback. */
460 #endif
461 }
462
463 return library;
464 }
465
466 static void
467 _release_blob (FT_Face ft_face)
468 {
469 hb_blob_destroy ((hb_blob_t *) ft_face->generic.data);
470 }
471
472 void
473 hb_ft_font_set_funcs (hb_font_t *font)
474 {
475 hb_blob_t *blob = hb_face_reference_blob (font->face);
476 unsigned int blob_length;
477 const char *blob_data = hb_blob_get_data (blob, &blob_length);
478 if (unlikely (!blob_length))
479 DEBUG_MSG (FT, font, "Font face has empty blob");
480
481 FT_Face ft_face = NULL;
482 FT_Error err = FT_New_Memory_Face (get_ft_library (),
483 (const FT_Byte *) blob_data,
484 blob_length,
485 hb_face_get_index (font->face),
486 &ft_face);
487
488 if (unlikely (err)) {
489 hb_blob_destroy (blob);
490 DEBUG_MSG (FT, font, "Font face FT_New_Memory_Face() failed");
491 return;
492 }
493
494 FT_Select_Charmap (ft_face, FT_ENCODING_UNICODE);
495
496 assert (font->y_scale >= 0);
497 FT_Set_Char_Size (ft_face,
498 font->x_scale, font->y_scale,
499 0, 0);
500 #if 0
501 font->x_ppem * 72 * 64 / font->x_scale,
502 font->y_ppem * 72 * 64 / font->y_scale);
503 #endif
504
505 ft_face->generic.data = blob;
506 ft_face->generic.finalizer = (FT_Generic_Finalizer) _release_blob;
507
508 hb_font_set_funcs (font,
509 _hb_ft_get_font_funcs (),
510 ft_face,
511 (hb_destroy_func_t) FT_Done_Face);
512 }
513
514 FT_Face
515 hb_ft_font_get_face (hb_font_t *font)
516 {
517 if (font->destroy == (hb_destroy_func_t) FT_Done_Face ||
518 font->destroy == (hb_destroy_func_t) _do_nothing)
519 return (FT_Face) font->user_data;
520
521 return NULL;
522 }

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