1 /*
2 * Copyright © 2011,2014 Google, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod, Roozbeh Pournader
25 */
26
27 #include "hb-private.hh"
28
29 #include "hb-ot.h"
30
31 #include "hb-font-private.hh"
32
33 #include "hb-ot-cmap-table.hh"
34 #include "hb-ot-cbdt-table.hh"
35 #include "hb-ot-glyf-table.hh"
36 #include "hb-ot-head-table.hh"
37 #include "hb-ot-hhea-table.hh"
38 #include "hb-ot-hmtx-table.hh"
39 #include "hb-ot-kern-table.hh"
40 #include "hb-ot-os2-table.hh"
41 #include "hb-ot-post-table.hh"
42 #include "hb-ot-var-hvar-table.hh"
43
44
45 struct hb_ot_face_metrics_accelerator_t
46 {
47 unsigned int num_metrics;
48 unsigned int num_advances;
49 unsigned int default_advance;
50 unsigned short ascender;
51 unsigned short descender;
52 unsigned short line_gap;
53 bool has_font_extents;
54
55 const OT::hmtxvmtx *table;
56 hb_blob_t *blob;
57
58 const OT::HVARVVAR *var;
59 hb_blob_t *var_blob;
60
61 inline void init (hb_face_t *face,
62 hb_tag_t _hea_tag,
63 hb_tag_t _mtx_tag,
64 hb_tag_t _var_tag,
65 hb_tag_t os2_tag,
66 unsigned int default_advance = 0)
67 {
68 this->default_advance = default_advance ? default_advance : face->get_upem ();
69
70 bool got_font_extents = false;
71 if (os2_tag)
72 {
73 hb_blob_t *os2_blob = OT::Sanitizer<OT::os2>::sanitize (face->reference_table (os2_tag));
74 const OT::os2 *os2 = OT::Sanitizer<OT::os2>::lock_instance (os2_blob);
75 #define USE_TYPO_METRICS (1u<<7)
76 if (0 != (os2->fsSelection & USE_TYPO_METRICS))
77 {
78 this->ascender = os2->sTypoAscender;
79 this->descender = os2->sTypoDescender;
80 this->line_gap = os2->sTypoLineGap;
81 got_font_extents = (this->ascender | this->descender) != 0;
82 }
83 hb_blob_destroy (os2_blob);
84 }
85
86 hb_blob_t *_hea_blob = OT::Sanitizer<OT::_hea>::sanitize (face->reference_table (_hea_tag));
87 const OT::_hea *_hea = OT::Sanitizer<OT::_hea>::lock_instance (_hea_blob);
88 this->num_advances = _hea->numberOfLongMetrics;
89 if (!got_font_extents)
90 {
91 this->ascender = _hea->ascender;
92 this->descender = _hea->descender;
93 this->line_gap = _hea->lineGap;
94 got_font_extents = (this->ascender | this->descender) != 0;
95 }
96 hb_blob_destroy (_hea_blob);
97
98 this->has_font_extents = got_font_extents;
99
100 this->blob = OT::Sanitizer<OT::hmtxvmtx>::sanitize (face->reference_table (_mtx_tag));
101
102 /* Cap num_metrics() and num_advances() based on table length. */
103 unsigned int len = hb_blob_get_length (this->blob);
104 if (unlikely (this->num_advances * 4 > len))
105 this->num_advances = len / 4;
106 this->num_metrics = this->num_advances + (len - 4 * this->num_advances) / 2;
107
108 /* We MUST set num_metrics to zero if num_advances is zero.
109 * Our get_advance() depends on that. */
110 if (unlikely (!this->num_advances))
111 {
112 this->num_metrics = this->num_advances = 0;
113 hb_blob_destroy (this->blob);
114 this->blob = hb_blob_get_empty ();
115 }
116 this->table = OT::Sanitizer<OT::hmtxvmtx>::lock_instance (this->blob);
117
118 this->var_blob = OT::Sanitizer<OT::HVARVVAR>::sanitize (face->reference_table (_var_tag));
119 this->var = OT::Sanitizer<OT::HVARVVAR>::lock_instance (this->var_blob);
120 }
121
122 inline void fini (void)
123 {
124 hb_blob_destroy (this->blob);
125 hb_blob_destroy (this->var_blob);
126 }
127
128 inline unsigned int get_advance (hb_codepoint_t glyph,
129 hb_font_t *font) const
130 {
131 if (unlikely (glyph >= this->num_metrics))
132 {
133 /* If this->num_metrics is zero, it means we don't have the metrics table
134 * for this direction: return default advance. Otherwise, it means that the
135 * glyph index is out of bound: return zero. */
136 if (this->num_metrics)
137 return 0;
138 else
139 return this->default_advance;
140 }
141
142 return this->table->longMetric[MIN (glyph, (uint32_t) this->num_advances - 1)].advance
143 + this->var->get_advance_var (glyph, font->coords, font->num_coords); // TODO Optimize?!
144 }
145 };
146
147 struct hb_ot_face_glyf_accelerator_t
148 {
149 bool short_offset;
150 unsigned int num_glyphs;
151 const OT::loca *loca;
152 const OT::glyf *glyf;
153 hb_blob_t *loca_blob;
154 hb_blob_t *glyf_blob;
155 unsigned int glyf_len;
156
157 inline void init (hb_face_t *face)
158 {
159 hb_blob_t *head_blob = OT::Sanitizer<OT::head>::sanitize (face->reference_table (HB_OT_TAG_head));
160 const OT::head *head = OT::Sanitizer<OT::head>::lock_instance (head_blob);
161 if ((unsigned int) head->indexToLocFormat > 1 || head->glyphDataFormat != 0)
162 {
163 /* Unknown format. Leave num_glyphs=0, that takes care of disabling us. */
164 hb_blob_destroy (head_blob);
165 return;
166 }
167 this->short_offset = 0 == head->indexToLocFormat;
168 hb_blob_destroy (head_blob);
169
170 this->loca_blob = OT::Sanitizer<OT::loca>::sanitize (face->reference_table (HB_OT_TAG_loca));
171 this->loca = OT::Sanitizer<OT::loca>::lock_instance (this->loca_blob);
172 this->glyf_blob = OT::Sanitizer<OT::glyf>::sanitize (face->reference_table (HB_OT_TAG_glyf));
173 this->glyf = OT::Sanitizer<OT::glyf>::lock_instance (this->glyf_blob);
174
175 this->num_glyphs = MAX (1u, hb_blob_get_length (this->loca_blob) / (this->short_offset ? 2 : 4)) - 1;
176 this->glyf_len = hb_blob_get_length (this->glyf_blob);
177 }
178
179 inline void fini (void)
180 {
181 hb_blob_destroy (this->loca_blob);
182 hb_blob_destroy (this->glyf_blob);
183 }
184
185 inline bool get_extents (hb_codepoint_t glyph,
186 hb_glyph_extents_t *extents) const
187 {
188 if (unlikely (glyph >= this->num_glyphs))
189 return false;
190
191 unsigned int start_offset, end_offset;
192 if (this->short_offset)
193 {
194 start_offset = 2 * this->loca->u.shortsZ[glyph];
195 end_offset = 2 * this->loca->u.shortsZ[glyph + 1];
196 }
197 else
198 {
199 start_offset = this->loca->u.longsZ[glyph];
200 end_offset = this->loca->u.longsZ[glyph + 1];
201 }
202
203 if (start_offset > end_offset || end_offset > this->glyf_len)
204 return false;
205
206 if (end_offset - start_offset < OT::glyfGlyphHeader::static_size)
207 return true; /* Empty glyph; zero extents. */
208
209 const OT::glyfGlyphHeader &glyph_header = OT::StructAtOffset<OT::glyfGlyphHeader> (this->glyf, start_offset);
210
211 extents->x_bearing = MIN (glyph_header.xMin, glyph_header.xMax);
212 extents->y_bearing = MAX (glyph_header.yMin, glyph_header.yMax);
213 extents->width = MAX (glyph_header.xMin, glyph_header.xMax) - extents->x_bearing;
214 extents->height = MIN (glyph_header.yMin, glyph_header.yMax) - extents->y_bearing;
215
216 return true;
217 }
218 };
219
220 struct hb_ot_face_cbdt_accelerator_t
221 {
222 hb_blob_t *cblc_blob;
223 hb_blob_t *cbdt_blob;
224 const OT::CBLC *cblc;
225 const OT::CBDT *cbdt;
226
227 unsigned int cbdt_len;
228 unsigned int upem;
229
230 inline void init (hb_face_t *face)
231 {
232 upem = face->get_upem();
233
234 cblc_blob = OT::Sanitizer<OT::CBLC>::sanitize (face->reference_table (HB_OT_TAG_CBLC));
235 cbdt_blob = OT::Sanitizer<OT::CBDT>::sanitize (face->reference_table (HB_OT_TAG_CBDT));
236 cbdt_len = hb_blob_get_length (cbdt_blob);
237
238 if (hb_blob_get_length (cblc_blob) == 0) {
239 cblc = nullptr;
240 cbdt = nullptr;
241 return; /* Not a bitmap font. */
242 }
243 cblc = OT::Sanitizer<OT::CBLC>::lock_instance (cblc_blob);
244 cbdt = OT::Sanitizer<OT::CBDT>::lock_instance (cbdt_blob);
245
246 }
247
248 inline void fini (void)
249 {
250 hb_blob_destroy (this->cblc_blob);
251 hb_blob_destroy (this->cbdt_blob);
252 }
253
254 inline bool get_extents (hb_codepoint_t glyph, hb_glyph_extents_t *extents) const
255 {
256 unsigned int x_ppem = upem, y_ppem = upem; /* TODO Use font ppem if available. */
257
258 if (!cblc)
259 return false; // Not a color bitmap font.
260
261 const OT::IndexSubtableRecord *subtable_record = this->cblc->find_table(glyph, &x_ppem, &y_ppem);
262 if (!subtable_record || !x_ppem || !y_ppem)
263 return false;
264
265 if (subtable_record->get_extents (extents))
266 return true;
267
268 unsigned int image_offset = 0, image_length = 0, image_format = 0;
269 if (!subtable_record->get_image_data (glyph, &image_offset, &image_length, &image_format))
270 return false;
271
272 {
273 /* TODO Move the following into CBDT struct when adding more formats. */
274
275 if (unlikely (image_offset > cbdt_len || cbdt_len - image_offset < image_length))
276 return false;
277
278 switch (image_format)
279 {
280 case 17: {
281 if (unlikely (image_length < OT::GlyphBitmapDataFormat17::min_size))
282 return false;
283
284 const OT::GlyphBitmapDataFormat17& glyphFormat17 =
285 OT::StructAtOffset<OT::GlyphBitmapDataFormat17> (this->cbdt, image_offset);
286 glyphFormat17.glyphMetrics.get_extents (extents);
287 }
288 break;
289 default:
290 // TODO: Support other image formats.
291 return false;
292 }
293 }
294
295 /* Convert to the font units. */
296 extents->x_bearing *= upem / (float) x_ppem;
297 extents->y_bearing *= upem / (float) y_ppem;
298 extents->width *= upem / (float) x_ppem;
299 extents->height *= upem / (float) y_ppem;
300
301 return true;
302 }
303 };
304
305 struct hb_ot_face_post_accelerator_t
306 {
307 hb_blob_t *post_blob;
308 OT::post::accelerator_t accel;
309
310 inline void init (hb_face_t *face)
311 {
312 hb_blob_t *blob = this->post_blob = OT::Sanitizer<OT::post>::sanitize (face->reference_table (HB_OT_TAG_post));
313 accel.init (OT::Sanitizer<OT::post>::lock_instance (blob), hb_blob_get_length (blob));
314 }
315
316 inline void fini (void)
317 {
318 accel.fini ();
319 hb_blob_destroy (this->post_blob);
320 }
321
322 inline bool get_glyph_name (hb_codepoint_t glyph,
323 char *name, unsigned int size) const
324 {
325 return this->accel.get_glyph_name (glyph, name, size);
326 }
327
328 inline bool get_glyph_from_name (const char *name, int len,
329 hb_codepoint_t *glyph) const
330 {
331 if (unlikely (!len))
332 return false;
333
334 return this->accel.get_glyph_from_name (name, len, glyph);
335 }
336 };
337
338 struct hb_ot_face_kern_accelerator_t
339 {
340 hb_blob_t *kern_blob;
341 OT::kern::accelerator_t accel;
342
343 inline void init (hb_face_t *face)
344 {
345 hb_blob_t *blob = this->kern_blob = OT::Sanitizer<OT::kern>::sanitize (face->reference_table (HB_OT_TAG_kern));
346 accel.init (OT::Sanitizer<OT::kern>::lock_instance (blob), hb_blob_get_length (blob));
347 }
348
349 inline void fini (void)
350 {
351 accel.fini ();
352 hb_blob_destroy (this->kern_blob);
353 }
354
355 inline int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right) const
356 { return accel.get_h_kerning (left, right); }
357 };
358
359 typedef bool (*hb_cmap_get_glyph_func_t) (const void *obj,
360 hb_codepoint_t codepoint,
361 hb_codepoint_t *glyph);
362
363 template <typename Type>
364 static inline bool get_glyph_from (const void *obj,
365 hb_codepoint_t codepoint,
366 hb_codepoint_t *glyph)
367 {
368 const Type *typed_obj = (const Type *) obj;
369 return typed_obj->get_glyph (codepoint, glyph);
370 }
371
372 template <typename Type>
373 static inline bool get_glyph_from_symbol (const void *obj,
374 hb_codepoint_t codepoint,
375 hb_codepoint_t *glyph)
376 {
377 const Type *typed_obj = (const Type *) obj;
378 if (likely (typed_obj->get_glyph (codepoint, glyph)))
379 return true;
380
381 if (codepoint <= 0x00FFu)
382 {
383 /* For symbol-encoded OpenType fonts, we duplicate the
384 * U+F000..F0FF range at U+0000..U+00FF. That's what
385 * Windows seems to do, and that's hinted about at:
386 * http://www.microsoft.com/typography/otspec/recom.htm
387 * under "Non-Standard (Symbol) Fonts". */
388 return typed_obj->get_glyph (0xF000u + codepoint, glyph);
389 }
390
391 return false;
392 }
393
394 struct hb_ot_face_cmap_accelerator_t
395 {
396 hb_cmap_get_glyph_func_t get_glyph_func;
397 const void *get_glyph_data;
398 OT::CmapSubtableFormat4::accelerator_t format4_accel;
399
400 const OT::CmapSubtableFormat14 *uvs_table;
401 hb_blob_t *blob;
402
403 inline void init (hb_face_t *face)
404 {
405 this->blob = OT::Sanitizer<OT::cmap>::sanitize (face->reference_table (HB_OT_TAG_cmap));
406 const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (this->blob);
407 const OT::CmapSubtable *subtable = nullptr;
408 const OT::CmapSubtableFormat14 *subtable_uvs = nullptr;
409
410 bool symbol = false;
411 /* 32-bit subtables. */
412 if (!subtable) subtable = cmap->find_subtable (3, 10);
413 if (!subtable) subtable = cmap->find_subtable (0, 6);
414 if (!subtable) subtable = cmap->find_subtable (0, 4);
415 /* 16-bit subtables. */
416 if (!subtable) subtable = cmap->find_subtable (3, 1);
417 if (!subtable) subtable = cmap->find_subtable (0, 3);
418 if (!subtable) subtable = cmap->find_subtable (0, 2);
419 if (!subtable) subtable = cmap->find_subtable (0, 1);
420 if (!subtable) subtable = cmap->find_subtable (0, 0);
421 if (!subtable)
422 {
423 subtable = cmap->find_subtable (3, 0);
424 if (subtable) symbol = true;
425 }
426 /* Meh. */
427 if (!subtable) subtable = &OT::Null(OT::CmapSubtable);
428
429 /* UVS subtable. */
430 if (!subtable_uvs)
431 {
432 const OT::CmapSubtable *st = cmap->find_subtable (0, 5);
433 if (st && st->u.format == 14)
434 subtable_uvs = &st->u.format14;
435 }
436 /* Meh. */
437 if (!subtable_uvs) subtable_uvs = &OT::Null(OT::CmapSubtableFormat14);
438
439 this->uvs_table = subtable_uvs;
440
441 this->get_glyph_data = subtable;
442 if (unlikely (symbol))
443 this->get_glyph_func = get_glyph_from_symbol<OT::CmapSubtable>;
444 else
445 switch (subtable->u.format) {
446 /* Accelerate format 4 and format 12. */
447 default: this->get_glyph_func = get_glyph_from<OT::CmapSubtable>; break;
448 case 12: this->get_glyph_func = get_glyph_from<OT::CmapSubtableFormat12>; break;
449 case 4:
450 {
451 this->format4_accel.init (&subtable->u.format4);
452 this->get_glyph_data = &this->format4_accel;
453 this->get_glyph_func = this->format4_accel.get_glyph_func;
454 }
455 break;
456 }
457 }
458
459 inline void fini (void)
460 {
461 hb_blob_destroy (this->blob);
462 }
463
464 inline bool get_nominal_glyph (hb_codepoint_t unicode,
465 hb_codepoint_t *glyph) const
466 {
467 return this->get_glyph_func (this->get_glyph_data, unicode, glyph);
468 }
469
470 inline bool get_variation_glyph (hb_codepoint_t unicode,
471 hb_codepoint_t variation_selector,
472 hb_codepoint_t *glyph) const
473 {
474 switch (this->uvs_table->get_glyph_variant (unicode,
475 variation_selector,
476 glyph))
477 {
478 case OT::GLYPH_VARIANT_NOT_FOUND: return false;
479 case OT::GLYPH_VARIANT_FOUND: return true;
480 case OT::GLYPH_VARIANT_USE_DEFAULT: break;
481 }
482
483 return get_nominal_glyph (unicode, glyph);
484 }
485 };
486
487 struct hb_ot_font_t
488 {
489 hb_ot_face_cmap_accelerator_t cmap;
490 hb_ot_face_metrics_accelerator_t h_metrics;
491 hb_ot_face_metrics_accelerator_t v_metrics;
492 OT::hb_lazy_loader_t<hb_ot_face_glyf_accelerator_t> glyf;
493 OT::hb_lazy_loader_t<hb_ot_face_cbdt_accelerator_t> cbdt;
494 OT::hb_lazy_loader_t<hb_ot_face_post_accelerator_t> post;
495 OT::hb_lazy_loader_t<hb_ot_face_kern_accelerator_t> kern;
496 };
497
498
499 static hb_ot_font_t *
500 _hb_ot_font_create (hb_face_t *face)
501 {
502 hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t));
503
504 if (unlikely (!ot_font))
505 return nullptr;
506
507 ot_font->cmap.init (face);
508 ot_font->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, HB_OT_TAG_HVAR, HB_OT_TAG_os2);
509 ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, HB_OT_TAG_VVAR, HB_TAG_NONE,
510 ot_font->h_metrics.ascender - ot_font->h_metrics.descender); /* TODO Can we do this lazily? */
511 ot_font->glyf.init (face);
512 ot_font->cbdt.init (face);
513 ot_font->post.init (face);
514 ot_font->kern.init (face);
515
516 return ot_font;
517 }
518
519 static void
520 _hb_ot_font_destroy (void *data)
521 {
522 hb_ot_font_t *ot_font = (hb_ot_font_t *) data;
523
524 ot_font->cmap.fini ();
525 ot_font->h_metrics.fini ();
526 ot_font->v_metrics.fini ();
527 ot_font->glyf.fini ();
528 ot_font->cbdt.fini ();
529 ot_font->post.fini ();
530 ot_font->kern.fini ();
531
532 free (ot_font);
533 }
534
535
536 static hb_bool_t
537 hb_ot_get_nominal_glyph (hb_font_t *font HB_UNUSED,
538 void *font_data,
539 hb_codepoint_t unicode,
540 hb_codepoint_t *glyph,
541 void *user_data HB_UNUSED)
542
543 {
544 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
545 return ot_font->cmap.get_nominal_glyph (unicode, glyph);
546 }
547
548 static hb_bool_t
549 hb_ot_get_variation_glyph (hb_font_t *font HB_UNUSED,
550 void *font_data,
551 hb_codepoint_t unicode,
552 hb_codepoint_t variation_selector,
553 hb_codepoint_t *glyph,
554 void *user_data HB_UNUSED)
555 {
556 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
557 return ot_font->cmap.get_variation_glyph (unicode, variation_selector, glyph);
558 }
559
560 static hb_position_t
561 hb_ot_get_glyph_h_advance (hb_font_t *font,
562 void *font_data,
563 hb_codepoint_t glyph,
564 void *user_data HB_UNUSED)
565 {
566 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
567 return font->em_scale_x (ot_font->h_metrics.get_advance (glyph, font));
568 }
569
570 static hb_position_t
571 hb_ot_get_glyph_v_advance (hb_font_t *font,
572 void *font_data,
573 hb_codepoint_t glyph,
574 void *user_data HB_UNUSED)
575 {
576 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
577 return font->em_scale_y (-(int) ot_font->v_metrics.get_advance (glyph, font));
578 }
579
580 static hb_position_t
581 hb_ot_get_glyph_h_kerning (hb_font_t *font,
582 void *font_data,
583 hb_codepoint_t left_glyph,
584 hb_codepoint_t right_glyph,
585 void *user_data HB_UNUSED)
586 {
587 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
588 return font->em_scale_x (ot_font->kern->get_h_kerning (left_glyph, right_glyph));
589 }
590
591 static hb_bool_t
592 hb_ot_get_glyph_extents (hb_font_t *font HB_UNUSED,
593 void *font_data,
594 hb_codepoint_t glyph,
595 hb_glyph_extents_t *extents,
596 void *user_data HB_UNUSED)
597 {
598 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
599 bool ret = ot_font->glyf->get_extents (glyph, extents);
600 if (!ret)
601 ret = ot_font->cbdt->get_extents (glyph, extents);
602 // TODO Hook up side-bearings variations.
603 extents->x_bearing = font->em_scale_x (extents->x_bearing);
604 extents->y_bearing = font->em_scale_y (extents->y_bearing);
605 extents->width = font->em_scale_x (extents->width);
606 extents->height = font->em_scale_y (extents->height);
607 return ret;
608 }
609
610 static hb_bool_t
611 hb_ot_get_glyph_name (hb_font_t *font HB_UNUSED,
612 void *font_data,
613 hb_codepoint_t glyph,
614 char *name, unsigned int size,
615 void *user_data HB_UNUSED)
616 {
617 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
618 return ot_font->post->get_glyph_name (glyph, name, size);
619 }
620
621 static hb_bool_t
622 hb_ot_get_glyph_from_name (hb_font_t *font HB_UNUSED,
623 void *font_data,
624 const char *name, int len,
625 hb_codepoint_t *glyph,
626 void *user_data HB_UNUSED)
627 {
628 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
629 return ot_font->post->get_glyph_from_name (name, len, glyph);
630 }
631
632 static hb_bool_t
633 hb_ot_get_font_h_extents (hb_font_t *font HB_UNUSED,
634 void *font_data,
635 hb_font_extents_t *metrics,
636 void *user_data HB_UNUSED)
637 {
638 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
639 metrics->ascender = font->em_scale_y (ot_font->h_metrics.ascender);
640 metrics->descender = font->em_scale_y (ot_font->h_metrics.descender);
641 metrics->line_gap = font->em_scale_y (ot_font->h_metrics.line_gap);
642 // TODO Hook up variations.
643 return ot_font->h_metrics.has_font_extents;
644 }
645
646 static hb_bool_t
647 hb_ot_get_font_v_extents (hb_font_t *font HB_UNUSED,
648 void *font_data,
649 hb_font_extents_t *metrics,
650 void *user_data HB_UNUSED)
651 {
652 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
653 metrics->ascender = font->em_scale_x (ot_font->v_metrics.ascender);
654 metrics->descender = font->em_scale_x (ot_font->v_metrics.descender);
655 metrics->line_gap = font->em_scale_x (ot_font->v_metrics.line_gap);
656 // TODO Hook up variations.
657 return ot_font->v_metrics.has_font_extents;
658 }
659
660 static hb_font_funcs_t *static_ot_funcs = nullptr;
661
662 #ifdef HB_USE_ATEXIT
663 static
664 void free_static_ot_funcs (void)
665 {
666 hb_font_funcs_destroy (static_ot_funcs);
667 }
668 #endif
669
670 static hb_font_funcs_t *
671 _hb_ot_get_font_funcs (void)
672 {
673 retry:
674 hb_font_funcs_t *funcs = (hb_font_funcs_t *) hb_atomic_ptr_get (&static_ot_funcs);
675
676 if (unlikely (!funcs))
677 {
678 funcs = hb_font_funcs_create ();
679
680 hb_font_funcs_set_font_h_extents_func (funcs, hb_ot_get_font_h_extents, nullptr, nullptr);
681 hb_font_funcs_set_font_v_extents_func (funcs, hb_ot_get_font_v_extents, nullptr, nullptr);
682 hb_font_funcs_set_nominal_glyph_func (funcs, hb_ot_get_nominal_glyph, nullptr, nullptr);
683 hb_font_funcs_set_variation_glyph_func (funcs, hb_ot_get_variation_glyph, nullptr, nullptr);
684 hb_font_funcs_set_glyph_h_advance_func (funcs, hb_ot_get_glyph_h_advance, nullptr, nullptr);
685 hb_font_funcs_set_glyph_v_advance_func (funcs, hb_ot_get_glyph_v_advance, nullptr, nullptr);
686 //hb_font_funcs_set_glyph_h_origin_func (funcs, hb_ot_get_glyph_h_origin, nullptr, nullptr);
687 //hb_font_funcs_set_glyph_v_origin_func (funcs, hb_ot_get_glyph_v_origin, nullptr, nullptr);
688 hb_font_funcs_set_glyph_h_kerning_func (funcs, hb_ot_get_glyph_h_kerning, nullptr, nullptr);
689 //hb_font_funcs_set_glyph_v_kerning_func (funcs, hb_ot_get_glyph_v_kerning, nullptr, nullptr);
690 hb_font_funcs_set_glyph_extents_func (funcs, hb_ot_get_glyph_extents, nullptr, nullptr);
691 //hb_font_funcs_set_glyph_contour_point_func (funcs, hb_ot_get_glyph_contour_point, nullptr, nullptr); TODO
692 hb_font_funcs_set_glyph_name_func (funcs, hb_ot_get_glyph_name, nullptr, nullptr);
693 hb_font_funcs_set_glyph_from_name_func (funcs, hb_ot_get_glyph_from_name, nullptr, nullptr);
694
695 hb_font_funcs_make_immutable (funcs);
696
697 if (!hb_atomic_ptr_cmpexch (&static_ot_funcs, nullptr, funcs)) {
698 hb_font_funcs_destroy (funcs);
699 goto retry;
700 }
701
702 #ifdef HB_USE_ATEXIT
703 atexit (free_static_ot_funcs); /* First person registers atexit() callback. */
704 #endif
705 };
706
707 return funcs;
708 }
709
710
711 /**
712 * hb_ot_font_set_funcs:
713 *
714 * Since: 0.9.28
715 **/
716 void
717 hb_ot_font_set_funcs (hb_font_t *font)
718 {
719 hb_ot_font_t *ot_font = _hb_ot_font_create (font->face);
720 if (unlikely (!ot_font))
721 return;
722
723 hb_font_set_funcs (font,
724 _hb_ot_get_font_funcs (),
725 ot_font,
726 _hb_ot_font_destroy);
727 }