2 * Copyright © 2011,2014 Google, Inc.
4 * This is part of HarfBuzz, a text shaping library.
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.
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
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.
24 * Google Author(s): Behdad Esfahbod, Roozbeh Pournader
27 #include "hb-private.hh"
31 #include "hb-font-private.hh"
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-os2-table.hh"
40 #include "hb-ot-var-hvar-table.hh"
41 //#include "hb-ot-post-table.hh"
44 struct hb_ot_face_metrics_accelerator_t
46 unsigned int num_metrics;
47 unsigned int num_advances;
48 unsigned int default_advance;
49 unsigned short ascender;
50 unsigned short descender;
51 unsigned short line_gap;
52 bool has_font_extents;
54 const OT::hmtxvmtx *table;
57 const OT::HVARVVAR *var;
60 inline void init (hb_face_t *face,
65 unsigned int default_advance = 0)
67 this->default_advance = default_advance ? default_advance : face->get_upem ();
69 bool got_font_extents = false;
72 hb_blob_t *os2_blob = OT::Sanitizer<OT::os2>::sanitize (face->reference_table (os2_tag));
73 const OT::os2 *os2 = OT::Sanitizer<OT::os2>::lock_instance (os2_blob);
74 #define USE_TYPO_METRICS (1u<<7)
75 if (0 != (os2->fsSelection & USE_TYPO_METRICS))
77 this->ascender = os2->sTypoAscender;
78 this->descender = os2->sTypoDescender;
79 this->line_gap = os2->sTypoLineGap;
80 got_font_extents = (this->ascender | this->descender) != 0;
82 hb_blob_destroy (os2_blob);
85 hb_blob_t *_hea_blob = OT::Sanitizer<OT::_hea>::sanitize (face->reference_table (_hea_tag));
86 const OT::_hea *_hea = OT::Sanitizer<OT::_hea>::lock_instance (_hea_blob);
87 this->num_advances = _hea->numberOfLongMetrics;
88 if (!got_font_extents)
90 this->ascender = _hea->ascender;
91 this->descender = _hea->descender;
92 this->line_gap = _hea->lineGap;
93 got_font_extents = (this->ascender | this->descender) != 0;
95 hb_blob_destroy (_hea_blob);
97 this->has_font_extents = got_font_extents;
99 this->blob = OT::Sanitizer<OT::hmtxvmtx>::sanitize (face->reference_table (_mtx_tag));
101 /* Cap num_metrics() and num_advances() based on table length. */
102 unsigned int len = hb_blob_get_length (this->blob);
103 if (unlikely (this->num_advances * 4 > len))
104 this->num_advances = len / 4;
105 this->num_metrics = this->num_advances + (len - 4 * this->num_advances) / 2;
107 /* We MUST set num_metrics to zero if num_advances is zero.
108 * Our get_advance() depends on that. */
109 if (unlikely (!this->num_advances))
111 this->num_metrics = this->num_advances = 0;
112 hb_blob_destroy (this->blob);
113 this->blob = hb_blob_get_empty ();
115 this->table = OT::Sanitizer<OT::hmtxvmtx>::lock_instance (this->blob);
117 this->var_blob = OT::Sanitizer<OT::HVARVVAR>::sanitize (face->reference_table (_var_tag));
118 this->var = OT::Sanitizer<OT::HVARVVAR>::lock_instance (this->var_blob);
121 inline void fini (void)
123 hb_blob_destroy (this->blob);
124 hb_blob_destroy (this->var_blob);
127 inline unsigned int get_advance (hb_codepoint_t glyph,
128 hb_font_t *font) const
130 if (unlikely (glyph >= this->num_metrics))
132 /* If this->num_metrics is zero, it means we don't have the metrics table
133 * for this direction: return default advance. Otherwise, it means that the
134 * glyph index is out of bound: return zero. */
135 if (this->num_metrics)
138 return this->default_advance;
141 return this->table->longMetric[MIN (glyph, this->num_advances - 1)].advance
142 + this->var->get_advance_var (glyph, font->coords, font->num_coords); // TODO Optimize?!
146 struct hb_ot_face_glyf_accelerator_t
149 unsigned int num_glyphs;
150 const OT::loca *loca;
151 const OT::glyf *glyf;
152 hb_blob_t *loca_blob;
153 hb_blob_t *glyf_blob;
154 unsigned int glyf_len;
156 inline void init (hb_face_t *face)
158 hb_blob_t *head_blob = OT::Sanitizer<OT::head>::sanitize (face->reference_table (HB_OT_TAG_head));
159 const OT::head *head = OT::Sanitizer<OT::head>::lock_instance (head_blob);
160 if ((unsigned int) head->indexToLocFormat > 1 || head->glyphDataFormat != 0)
162 /* Unknown format. Leave num_glyphs=0, that takes care of disabling us. */
163 hb_blob_destroy (head_blob);
166 this->short_offset = 0 == head->indexToLocFormat;
167 hb_blob_destroy (head_blob);
169 this->loca_blob = OT::Sanitizer<OT::loca>::sanitize (face->reference_table (HB_OT_TAG_loca));
170 this->loca = OT::Sanitizer<OT::loca>::lock_instance (this->loca_blob);
171 this->glyf_blob = OT::Sanitizer<OT::glyf>::sanitize (face->reference_table (HB_OT_TAG_glyf));
172 this->glyf = OT::Sanitizer<OT::glyf>::lock_instance (this->glyf_blob);
174 this->num_glyphs = MAX (1u, hb_blob_get_length (this->loca_blob) / (this->short_offset ? 2 : 4)) - 1;
175 this->glyf_len = hb_blob_get_length (this->glyf_blob);
178 inline void fini (void)
180 hb_blob_destroy (this->loca_blob);
181 hb_blob_destroy (this->glyf_blob);
184 inline bool get_extents (hb_codepoint_t glyph,
185 hb_glyph_extents_t *extents) const
187 if (unlikely (glyph >= this->num_glyphs))
190 unsigned int start_offset, end_offset;
191 if (this->short_offset)
193 start_offset = 2 * this->loca->u.shortsZ[glyph];
194 end_offset = 2 * this->loca->u.shortsZ[glyph + 1];
198 start_offset = this->loca->u.longsZ[glyph];
199 end_offset = this->loca->u.longsZ[glyph + 1];
202 if (start_offset > end_offset || end_offset > this->glyf_len)
205 if (end_offset - start_offset < OT::glyfGlyphHeader::static_size)
206 return true; /* Empty glyph; zero extents. */
208 const OT::glyfGlyphHeader &glyph_header = OT::StructAtOffset<OT::glyfGlyphHeader> (this->glyf, start_offset);
210 extents->x_bearing = MIN (glyph_header.xMin, glyph_header.xMax);
211 extents->y_bearing = MAX (glyph_header.yMin, glyph_header.yMax);
212 extents->width = MAX (glyph_header.xMin, glyph_header.xMax) - extents->x_bearing;
213 extents->height = MIN (glyph_header.yMin, glyph_header.yMax) - extents->y_bearing;
219 struct hb_ot_face_cbdt_accelerator_t
221 hb_blob_t *cblc_blob;
222 hb_blob_t *cbdt_blob;
223 const OT::CBLC *cblc;
224 const OT::CBDT *cbdt;
226 unsigned int cbdt_len;
229 inline void init (hb_face_t *face)
231 upem = face->get_upem();
233 cblc_blob = OT::Sanitizer<OT::CBLC>::sanitize (face->reference_table (HB_OT_TAG_CBLC));
234 cbdt_blob = OT::Sanitizer<OT::CBDT>::sanitize (face->reference_table (HB_OT_TAG_CBDT));
235 cbdt_len = hb_blob_get_length (cbdt_blob);
237 if (hb_blob_get_length (cblc_blob) == 0) {
240 return; /* Not a bitmap font. */
242 cblc = OT::Sanitizer<OT::CBLC>::lock_instance (cblc_blob);
243 cbdt = OT::Sanitizer<OT::CBDT>::lock_instance (cbdt_blob);
247 inline void fini (void)
249 hb_blob_destroy (this->cblc_blob);
250 hb_blob_destroy (this->cbdt_blob);
253 inline bool get_extents (hb_codepoint_t glyph, hb_glyph_extents_t *extents) const
255 unsigned int x_ppem = upem, y_ppem = upem; /* TODO Use font ppem if available. */
258 return false; // Not a color bitmap font.
260 const OT::IndexSubtableRecord *subtable_record = this->cblc->find_table(glyph, &x_ppem, &y_ppem);
261 if (subtable_record == NULL)
264 if (subtable_record->get_extents (extents))
267 unsigned int image_offset = 0, image_length = 0, image_format = 0;
268 if (!subtable_record->get_image_data (glyph, &image_offset, &image_length, &image_format))
272 /* TODO Move the following into CBDT struct when adding more formats. */
274 if (unlikely (image_offset > cbdt_len || cbdt_len - image_offset < image_length))
277 switch (image_format)
280 if (unlikely (image_length < OT::GlyphBitmapDataFormat17::min_size))
283 const OT::GlyphBitmapDataFormat17& glyphFormat17 =
284 OT::StructAtOffset<OT::GlyphBitmapDataFormat17> (this->cbdt, image_offset);
285 glyphFormat17.glyphMetrics.get_extents (extents);
289 // TODO: Support other image formats.
294 /* Convert to the font units. */
295 extents->x_bearing *= upem / (float) x_ppem;
296 extents->y_bearing *= upem / (float) y_ppem;
297 extents->width *= upem / (float) x_ppem;
298 extents->height *= upem / (float) y_ppem;
304 typedef bool (*hb_cmap_get_glyph_func_t) (const void *obj,
305 hb_codepoint_t codepoint,
306 hb_codepoint_t *glyph);
308 template <typename Type>
309 static inline bool get_glyph_from (const void *obj,
310 hb_codepoint_t codepoint,
311 hb_codepoint_t *glyph)
313 const Type *typed_obj = (const Type *) obj;
314 return typed_obj->get_glyph (codepoint, glyph);
317 template <typename Type>
318 static inline bool get_glyph_from_symbol (const void *obj,
319 hb_codepoint_t codepoint,
320 hb_codepoint_t *glyph)
322 const Type *typed_obj = (const Type *) obj;
323 if (likely (typed_obj->get_glyph (codepoint, glyph)))
326 if (codepoint <= 0x00FFu)
328 /* For symbol-encoded OpenType fonts, we duplicate the
329 * U+F000..F0FF range at U+0000..U+00FF. That's what
330 * Windows seems to do, and that's hinted about at:
331 * http://www.microsoft.com/typography/otspec/recom.htm
332 * under "Non-Standard (Symbol) Fonts". */
333 return typed_obj->get_glyph (0xF000u + codepoint, glyph);
339 struct hb_ot_face_cmap_accelerator_t
341 hb_cmap_get_glyph_func_t get_glyph_func;
342 const void *get_glyph_data;
343 OT::CmapSubtableFormat4::accelerator_t format4_accel;
345 const OT::CmapSubtableFormat14 *uvs_table;
348 inline void init (hb_face_t *face)
350 this->blob = OT::Sanitizer<OT::cmap>::sanitize (face->reference_table (HB_OT_TAG_cmap));
351 const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (this->blob);
352 const OT::CmapSubtable *subtable = NULL;
353 const OT::CmapSubtableFormat14 *subtable_uvs = NULL;
356 /* 32-bit subtables. */
357 if (!subtable) subtable = cmap->find_subtable (3, 10);
358 if (!subtable) subtable = cmap->find_subtable (0, 6);
359 if (!subtable) subtable = cmap->find_subtable (0, 4);
360 /* 16-bit subtables. */
361 if (!subtable) subtable = cmap->find_subtable (3, 1);
362 if (!subtable) subtable = cmap->find_subtable (0, 3);
363 if (!subtable) subtable = cmap->find_subtable (0, 2);
364 if (!subtable) subtable = cmap->find_subtable (0, 1);
365 if (!subtable) subtable = cmap->find_subtable (0, 0);
368 subtable = cmap->find_subtable (3, 0);
369 if (subtable) symbol = true;
372 if (!subtable) subtable = &OT::Null(OT::CmapSubtable);
377 const OT::CmapSubtable *st = cmap->find_subtable (0, 5);
378 if (st && st->u.format == 14)
379 subtable_uvs = &st->u.format14;
382 if (!subtable_uvs) subtable_uvs = &OT::Null(OT::CmapSubtableFormat14);
384 this->uvs_table = subtable_uvs;
386 this->get_glyph_data = subtable;
387 if (unlikely (symbol))
388 this->get_glyph_func = get_glyph_from_symbol<OT::CmapSubtable>;
390 switch (subtable->u.format) {
391 /* Accelerate format 4 and format 12. */
392 default: this->get_glyph_func = get_glyph_from<OT::CmapSubtable>; break;
393 case 12: this->get_glyph_func = get_glyph_from<OT::CmapSubtableFormat12>; break;
396 this->format4_accel.init (&subtable->u.format4);
397 this->get_glyph_data = &this->format4_accel;
398 this->get_glyph_func = this->format4_accel.get_glyph_func;
404 inline void fini (void)
406 hb_blob_destroy (this->blob);
409 inline bool get_nominal_glyph (hb_codepoint_t unicode,
410 hb_codepoint_t *glyph) const
412 return this->get_glyph_func (this->get_glyph_data, unicode, glyph);
415 inline bool get_variation_glyph (hb_codepoint_t unicode,
416 hb_codepoint_t variation_selector,
417 hb_codepoint_t *glyph) const
419 switch (this->uvs_table->get_glyph_variant (unicode,
423 case OT::GLYPH_VARIANT_NOT_FOUND: return false;
424 case OT::GLYPH_VARIANT_FOUND: return true;
425 case OT::GLYPH_VARIANT_USE_DEFAULT: break;
428 return get_nominal_glyph (unicode, glyph);
434 hb_ot_face_cmap_accelerator_t cmap;
435 hb_ot_face_metrics_accelerator_t h_metrics;
436 hb_ot_face_metrics_accelerator_t v_metrics;
437 OT::hb_lazy_loader_t<hb_ot_face_glyf_accelerator_t> glyf;
438 OT::hb_lazy_loader_t<hb_ot_face_cbdt_accelerator_t> cbdt;
442 static hb_ot_font_t *
443 _hb_ot_font_create (hb_face_t *face)
445 hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t));
447 if (unlikely (!ot_font))
450 ot_font->cmap.init (face);
451 ot_font->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, HB_OT_TAG_HVAR, HB_OT_TAG_os2);
452 ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, HB_OT_TAG_VVAR, HB_TAG_NONE,
453 ot_font->h_metrics.ascender - ot_font->h_metrics.descender); /* TODO Can we do this lazily? */
454 ot_font->glyf.init (face);
455 ot_font->cbdt.init (face);
461 _hb_ot_font_destroy (hb_ot_font_t *ot_font)
463 ot_font->cmap.fini ();
464 ot_font->h_metrics.fini ();
465 ot_font->v_metrics.fini ();
466 ot_font->glyf.fini ();
467 ot_font->cbdt.fini ();
474 hb_ot_get_nominal_glyph (hb_font_t *font HB_UNUSED,
476 hb_codepoint_t unicode,
477 hb_codepoint_t *glyph,
478 void *user_data HB_UNUSED)
481 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
482 return ot_font->cmap.get_nominal_glyph (unicode, glyph);
486 hb_ot_get_variation_glyph (hb_font_t *font HB_UNUSED,
488 hb_codepoint_t unicode,
489 hb_codepoint_t variation_selector,
490 hb_codepoint_t *glyph,
491 void *user_data HB_UNUSED)
493 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
494 return ot_font->cmap.get_variation_glyph (unicode, variation_selector, glyph);
498 hb_ot_get_glyph_h_advance (hb_font_t *font,
500 hb_codepoint_t glyph,
501 void *user_data HB_UNUSED)
503 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
504 return font->em_scale_x (ot_font->h_metrics.get_advance (glyph, font));
508 hb_ot_get_glyph_v_advance (hb_font_t *font,
510 hb_codepoint_t glyph,
511 void *user_data HB_UNUSED)
513 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
514 return font->em_scale_y (-(int) ot_font->v_metrics.get_advance (glyph, font));
518 hb_ot_get_glyph_extents (hb_font_t *font HB_UNUSED,
520 hb_codepoint_t glyph,
521 hb_glyph_extents_t *extents,
522 void *user_data HB_UNUSED)
524 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
525 bool ret = ot_font->glyf->get_extents (glyph, extents);
527 ret = ot_font->cbdt->get_extents (glyph, extents);
528 // TODO Hook up side-bearings variations.
529 extents->x_bearing = font->em_scale_x (extents->x_bearing);
530 extents->y_bearing = font->em_scale_y (extents->y_bearing);
531 extents->width = font->em_scale_x (extents->width);
532 extents->height = font->em_scale_y (extents->height);
537 hb_ot_get_font_h_extents (hb_font_t *font HB_UNUSED,
539 hb_font_extents_t *metrics,
540 void *user_data HB_UNUSED)
542 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
543 metrics->ascender = font->em_scale_y (ot_font->h_metrics.ascender);
544 metrics->descender = font->em_scale_y (ot_font->h_metrics.descender);
545 metrics->line_gap = font->em_scale_y (ot_font->h_metrics.line_gap);
546 // TODO Hook up variations.
547 return ot_font->h_metrics.has_font_extents;
551 hb_ot_get_font_v_extents (hb_font_t *font HB_UNUSED,
553 hb_font_extents_t *metrics,
554 void *user_data HB_UNUSED)
556 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
557 metrics->ascender = font->em_scale_x (ot_font->v_metrics.ascender);
558 metrics->descender = font->em_scale_x (ot_font->v_metrics.descender);
559 metrics->line_gap = font->em_scale_x (ot_font->v_metrics.line_gap);
560 // TODO Hook up variations.
561 return ot_font->v_metrics.has_font_extents;
564 static hb_font_funcs_t *static_ot_funcs = NULL;
568 void free_static_ot_funcs (void)
570 hb_font_funcs_destroy (static_ot_funcs);
574 static hb_font_funcs_t *
575 _hb_ot_get_font_funcs (void)
578 hb_font_funcs_t *funcs = (hb_font_funcs_t *) hb_atomic_ptr_get (&static_ot_funcs);
580 if (unlikely (!funcs))
582 funcs = hb_font_funcs_create ();
584 hb_font_funcs_set_font_h_extents_func (funcs, hb_ot_get_font_h_extents, NULL, NULL);
585 hb_font_funcs_set_font_v_extents_func (funcs, hb_ot_get_font_v_extents, NULL, NULL);
586 hb_font_funcs_set_nominal_glyph_func (funcs, hb_ot_get_nominal_glyph, NULL, NULL);
587 hb_font_funcs_set_variation_glyph_func (funcs, hb_ot_get_variation_glyph, NULL, NULL);
588 hb_font_funcs_set_glyph_h_advance_func (funcs, hb_ot_get_glyph_h_advance, NULL, NULL);
589 hb_font_funcs_set_glyph_v_advance_func (funcs, hb_ot_get_glyph_v_advance, NULL, NULL);
590 //hb_font_funcs_set_glyph_h_origin_func (funcs, hb_ot_get_glyph_h_origin, NULL, NULL);
591 //hb_font_funcs_set_glyph_v_origin_func (funcs, hb_ot_get_glyph_v_origin, NULL, NULL);
592 //hb_font_funcs_set_glyph_h_kerning_func (funcs, hb_ot_get_glyph_h_kerning, NULL, NULL); TODO
593 //hb_font_funcs_set_glyph_v_kerning_func (funcs, hb_ot_get_glyph_v_kerning, NULL, NULL);
594 hb_font_funcs_set_glyph_extents_func (funcs, hb_ot_get_glyph_extents, NULL, NULL);
595 //hb_font_funcs_set_glyph_contour_point_func (funcs, hb_ot_get_glyph_contour_point, NULL, NULL); TODO
596 //hb_font_funcs_set_glyph_name_func (funcs, hb_ot_get_glyph_name, NULL, NULL); TODO
597 //hb_font_funcs_set_glyph_from_name_func (funcs, hb_ot_get_glyph_from_name, NULL, NULL); TODO
599 hb_font_funcs_make_immutable (funcs);
601 if (!hb_atomic_ptr_cmpexch (&static_ot_funcs, NULL, funcs)) {
602 hb_font_funcs_destroy (funcs);
607 atexit (free_static_ot_funcs); /* First person registers atexit() callback. */
616 * hb_ot_font_set_funcs:
621 hb_ot_font_set_funcs (hb_font_t *font)
623 hb_ot_font_t *ot_font = _hb_ot_font_create (font->face);
624 if (unlikely (!ot_font))
627 hb_font_set_funcs (font,
628 _hb_ot_get_font_funcs (),
630 (hb_destroy_func_t) _hb_ot_font_destroy);