hb-font.cc revision f06ab8a4262c759b4723614fd28f55ee77aa8466 
1/*
2 * Copyright © 2009  Red Hat, 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 * Red Hat Author(s): Behdad Esfahbod
25 */
26
27#include "hb-private.hh"
28
29#include "hb-ot-layout-private.hh"
30
31#include "hb-font-private.hh"
32#include "hb-blob.h"
33#include "hb-open-file-private.hh"
34#include "hb-ot-head-table.hh"
35
36#include "hb-cache-private.hh"
37
38#include <string.h>
39
40
41
42/*
43 * hb_font_funcs_t
44 */
45
46static hb_bool_t
47hb_font_get_glyph_nil (hb_font_t *font,
48		       void *font_data HB_UNUSED,
49		       hb_codepoint_t unicode,
50		       hb_codepoint_t variation_selector,
51		       hb_codepoint_t *glyph,
52		       void *user_data HB_UNUSED)
53{
54  if (font->parent)
55    return hb_font_get_glyph (font->parent, unicode, variation_selector, glyph);
56
57  *glyph = 0;
58  return FALSE;
59}
60
61static hb_position_t
62hb_font_get_glyph_h_advance_nil (hb_font_t *font,
63				 void *font_data HB_UNUSED,
64				 hb_codepoint_t glyph,
65				 void *user_data HB_UNUSED)
66{
67  if (font->parent)
68    return font->parent_scale_x_distance (hb_font_get_glyph_h_advance (font->parent, glyph));
69
70  return font->x_scale;
71}
72
73static hb_position_t
74hb_font_get_glyph_v_advance_nil (hb_font_t *font,
75				 void *font_data HB_UNUSED,
76				 hb_codepoint_t glyph,
77				 void *user_data HB_UNUSED)
78{
79  if (font->parent)
80    return font->parent_scale_y_distance (hb_font_get_glyph_v_advance (font->parent, glyph));
81
82  return font->y_scale;
83}
84
85static hb_bool_t
86hb_font_get_glyph_h_origin_nil (hb_font_t *font,
87				void *font_data HB_UNUSED,
88				hb_codepoint_t glyph,
89				hb_position_t *x,
90				hb_position_t *y,
91				void *user_data HB_UNUSED)
92{
93  if (font->parent) {
94    hb_bool_t ret = hb_font_get_glyph_h_origin (font->parent, glyph, x, y);
95    if (ret)
96      font->parent_scale_position (x, y);
97    return ret;
98  }
99
100  *x = *y = 0;
101  return FALSE;
102}
103
104static hb_bool_t
105hb_font_get_glyph_v_origin_nil (hb_font_t *font,
106				void *font_data HB_UNUSED,
107				hb_codepoint_t glyph,
108				hb_position_t *x,
109				hb_position_t *y,
110				void *user_data HB_UNUSED)
111{
112  if (font->parent) {
113    hb_bool_t ret = hb_font_get_glyph_v_origin (font->parent, glyph, x, y);
114    if (ret)
115      font->parent_scale_position (x, y);
116    return ret;
117  }
118
119  *x = *y = 0;
120  return FALSE;
121}
122
123static hb_position_t
124hb_font_get_glyph_h_kerning_nil (hb_font_t *font,
125				 void *font_data HB_UNUSED,
126				 hb_codepoint_t left_glyph,
127				 hb_codepoint_t right_glyph,
128				 void *user_data HB_UNUSED)
129{
130  if (font->parent)
131    return font->parent_scale_x_distance (hb_font_get_glyph_h_kerning (font->parent, left_glyph, right_glyph));
132
133  return 0;
134}
135
136static hb_position_t
137hb_font_get_glyph_v_kerning_nil (hb_font_t *font,
138				 void *font_data HB_UNUSED,
139				 hb_codepoint_t top_glyph,
140				 hb_codepoint_t bottom_glyph,
141				 void *user_data HB_UNUSED)
142{
143  if (font->parent)
144    return font->parent_scale_y_distance (hb_font_get_glyph_v_kerning (font->parent, top_glyph, bottom_glyph));
145
146  return 0;
147}
148
149static hb_bool_t
150hb_font_get_glyph_extents_nil (hb_font_t *font,
151			       void *font_data HB_UNUSED,
152			       hb_codepoint_t glyph,
153			       hb_glyph_extents_t *extents,
154			       void *user_data HB_UNUSED)
155{
156  if (font->parent) {
157    hb_bool_t ret = hb_font_get_glyph_extents (font->parent,
158					       glyph,
159					       extents);
160    if (ret) {
161      font->parent_scale_position (&extents->x_bearing, &extents->y_bearing);
162      font->parent_scale_distance (&extents->width, &extents->height);
163    }
164    return ret;
165  }
166
167  memset (extents, 0, sizeof (*extents));
168  return FALSE;
169}
170
171static hb_bool_t
172hb_font_get_glyph_contour_point_nil (hb_font_t *font,
173				     void *font_data HB_UNUSED,
174				     hb_codepoint_t glyph,
175				     unsigned int point_index,
176				     hb_position_t *x,
177				     hb_position_t *y,
178				     void *user_data HB_UNUSED)
179{
180  if (font->parent) {
181    hb_bool_t ret = hb_font_get_glyph_contour_point (font->parent, glyph, point_index, x, y);
182    if (ret)
183      font->parent_scale_position (x, y);
184    return ret;
185  }
186
187  *x = *y = 0;
188  return FALSE;
189}
190
191static hb_bool_t
192hb_font_get_glyph_name_nil (hb_font_t *font,
193			    void *font_data HB_UNUSED,
194			    hb_codepoint_t glyph,
195			    char *name, unsigned int size,
196			    void *user_data HB_UNUSED)
197{
198  if (font->parent)
199    return hb_font_get_glyph_name (font->parent, glyph, name, size);
200
201  snprintf (name, size, "gid%u", glyph);
202  return FALSE;
203}
204
205static hb_bool_t
206hb_font_get_glyph_from_name_nil (hb_font_t *font,
207				 void *font_data HB_UNUSED,
208				 const char *name, int len, /* -1 means nul-terminated */
209				 hb_codepoint_t *glyph,
210				 void *user_data HB_UNUSED)
211{
212  if (font->parent)
213    return hb_font_get_glyph_from_name (font->parent, name, len, glyph);
214
215  *glyph = 0;
216  return FALSE;
217}
218
219
220static const hb_font_funcs_t _hb_font_funcs_nil = {
221  HB_OBJECT_HEADER_STATIC,
222
223  TRUE, /* immutable */
224
225  {
226#define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_nil,
227    HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
228#undef HB_FONT_FUNC_IMPLEMENT
229  }
230};
231
232
233hb_font_funcs_t *
234hb_font_funcs_create (void)
235{
236  hb_font_funcs_t *ffuncs;
237
238  if (!(ffuncs = hb_object_create<hb_font_funcs_t> ()))
239    return hb_font_funcs_get_empty ();
240
241  ffuncs->get = _hb_font_funcs_nil.get;
242
243  return ffuncs;
244}
245
246hb_font_funcs_t *
247hb_font_funcs_get_empty (void)
248{
249  return const_cast<hb_font_funcs_t *> (&_hb_font_funcs_nil);
250}
251
252hb_font_funcs_t *
253hb_font_funcs_reference (hb_font_funcs_t *ffuncs)
254{
255  return hb_object_reference (ffuncs);
256}
257
258void
259hb_font_funcs_destroy (hb_font_funcs_t *ffuncs)
260{
261  if (!hb_object_destroy (ffuncs)) return;
262
263#define HB_FONT_FUNC_IMPLEMENT(name) if (ffuncs->destroy.name) \
264  ffuncs->destroy.name (ffuncs->user_data.name);
265  HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
266#undef HB_FONT_FUNC_IMPLEMENT
267
268  free (ffuncs);
269}
270
271hb_bool_t
272hb_font_funcs_set_user_data (hb_font_funcs_t    *ffuncs,
273			     hb_user_data_key_t *key,
274			     void *              data,
275			     hb_destroy_func_t   destroy,
276			     hb_bool_t           replace)
277{
278  return hb_object_set_user_data (ffuncs, key, data, destroy, replace);
279}
280
281void *
282hb_font_funcs_get_user_data (hb_font_funcs_t    *ffuncs,
283			     hb_user_data_key_t *key)
284{
285  return hb_object_get_user_data (ffuncs, key);
286}
287
288
289void
290hb_font_funcs_make_immutable (hb_font_funcs_t *ffuncs)
291{
292  if (hb_object_is_inert (ffuncs))
293    return;
294
295  ffuncs->immutable = TRUE;
296}
297
298hb_bool_t
299hb_font_funcs_is_immutable (hb_font_funcs_t *ffuncs)
300{
301  return ffuncs->immutable;
302}
303
304
305#define HB_FONT_FUNC_IMPLEMENT(name) \
306                                                                         \
307void                                                                     \
308hb_font_funcs_set_##name##_func (hb_font_funcs_t             *ffuncs,    \
309                                 hb_font_get_##name##_func_t  func,      \
310                                 void                        *user_data, \
311                                 hb_destroy_func_t            destroy)   \
312{                                                                        \
313  if (ffuncs->immutable) {                                               \
314    if (destroy)                                                         \
315      destroy (user_data);                                               \
316    return;                                                              \
317  }                                                                      \
318                                                                         \
319  if (ffuncs->destroy.name)                                              \
320    ffuncs->destroy.name (ffuncs->user_data.name);                       \
321                                                                         \
322  if (func) {                                                            \
323    ffuncs->get.name = func;                                             \
324    ffuncs->user_data.name = user_data;                                  \
325    ffuncs->destroy.name = destroy;                                      \
326  } else {                                                               \
327    ffuncs->get.name = hb_font_get_##name##_nil;                         \
328    ffuncs->user_data.name = NULL;                                       \
329    ffuncs->destroy.name = NULL;                                         \
330  }                                                                      \
331}
332
333HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
334#undef HB_FONT_FUNC_IMPLEMENT
335
336
337hb_bool_t
338hb_font_get_glyph (hb_font_t *font,
339		   hb_codepoint_t unicode, hb_codepoint_t variation_selector,
340		   hb_codepoint_t *glyph)
341{
342  *glyph = 0;
343  return font->klass->get.glyph (font, font->user_data,
344				 unicode, variation_selector, glyph,
345				 font->klass->user_data.glyph);
346}
347
348hb_position_t
349hb_font_get_glyph_h_advance (hb_font_t *font,
350			     hb_codepoint_t glyph)
351{
352  return font->klass->get.glyph_h_advance (font, font->user_data,
353					   glyph,
354					   font->klass->user_data.glyph_h_advance);
355}
356
357hb_position_t
358hb_font_get_glyph_v_advance (hb_font_t *font,
359			     hb_codepoint_t glyph)
360{
361  return font->klass->get.glyph_v_advance (font, font->user_data,
362					   glyph,
363					   font->klass->user_data.glyph_v_advance);
364}
365
366hb_bool_t
367hb_font_get_glyph_h_origin (hb_font_t *font,
368			    hb_codepoint_t glyph,
369			    hb_position_t *x, hb_position_t *y)
370{
371  *x = *y = 0;
372  return font->klass->get.glyph_h_origin (font, font->user_data,
373					   glyph, x, y,
374					   font->klass->user_data.glyph_h_origin);
375}
376
377hb_bool_t
378hb_font_get_glyph_v_origin (hb_font_t *font,
379			    hb_codepoint_t glyph,
380			    hb_position_t *x, hb_position_t *y)
381{
382  *x = *y = 0;
383  return font->klass->get.glyph_v_origin (font, font->user_data,
384					   glyph, x, y,
385					   font->klass->user_data.glyph_v_origin);
386}
387
388hb_position_t
389hb_font_get_glyph_h_kerning (hb_font_t *font,
390			     hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)
391{
392  return font->klass->get.glyph_h_kerning (font, font->user_data,
393					   left_glyph, right_glyph,
394					   font->klass->user_data.glyph_h_kerning);
395}
396
397hb_position_t
398hb_font_get_glyph_v_kerning (hb_font_t *font,
399			     hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)
400{
401  return font->klass->get.glyph_v_kerning (font, font->user_data,
402				     left_glyph, right_glyph,
403				     font->klass->user_data.glyph_v_kerning);
404}
405
406hb_bool_t
407hb_font_get_glyph_extents (hb_font_t *font,
408			   hb_codepoint_t glyph,
409			   hb_glyph_extents_t *extents)
410{
411  memset (extents, 0, sizeof (*extents));
412  return font->klass->get.glyph_extents (font, font->user_data,
413					 glyph,
414					 extents,
415					 font->klass->user_data.glyph_extents);
416}
417
418hb_bool_t
419hb_font_get_glyph_contour_point (hb_font_t *font,
420				 hb_codepoint_t glyph, unsigned int point_index,
421				 hb_position_t *x, hb_position_t *y)
422{
423  *x = *y = 0;
424  return font->klass->get.glyph_contour_point (font, font->user_data,
425					       glyph, point_index,
426					       x, y,
427					       font->klass->user_data.glyph_contour_point);
428}
429
430hb_bool_t
431hb_font_get_glyph_name (hb_font_t *font,
432			hb_codepoint_t glyph,
433			char *name, unsigned int size)
434{
435  return font->klass->get.glyph_name (font, font->user_data,
436				      glyph,
437				      name, size,
438				      font->klass->user_data.glyph_name);
439}
440
441hb_bool_t
442hb_font_get_glyph_from_name (hb_font_t *font,
443			     const char *name, int len, /* -1 means nul-terminated */
444			     hb_codepoint_t *glyph)
445{
446  return font->klass->get.glyph_from_name (font, font->user_data,
447					   name, len,
448					   glyph,
449					   font->klass->user_data.glyph_from_name);
450}
451
452
453/* A bit higher-level, and with fallback */
454
455void
456hb_font_get_glyph_advance_for_direction (hb_font_t *font,
457					 hb_codepoint_t glyph,
458					 hb_direction_t direction,
459					 hb_position_t *x, hb_position_t *y)
460{
461  if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
462    *x = hb_font_get_glyph_h_advance (font, glyph);
463    *y = 0;
464  } else {
465    *x = 0;
466    *y = hb_font_get_glyph_v_advance (font, glyph);
467  }
468}
469
470static void
471guess_v_origin_minus_h_origin (hb_font_t *font,
472			       hb_codepoint_t glyph,
473			       hb_position_t *x, hb_position_t *y)
474{
475  *x = hb_font_get_glyph_h_advance (font, glyph) / 2;
476
477  /* TODO use font_metics.ascent */
478  *y = font->y_scale;
479}
480
481
482void
483hb_font_get_glyph_origin_for_direction (hb_font_t *font,
484					hb_codepoint_t glyph,
485					hb_direction_t direction,
486					hb_position_t *x, hb_position_t *y)
487{
488  if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
489    hb_bool_t ret = hb_font_get_glyph_h_origin (font, glyph, x, y);
490    if (!ret && (ret = hb_font_get_glyph_v_origin (font, glyph, x, y))) {
491      hb_position_t dx, dy;
492      guess_v_origin_minus_h_origin (font, glyph, &dx, &dy);
493      *x -= dx; *y -= dy;
494    }
495  } else {
496    hb_bool_t ret = hb_font_get_glyph_v_origin (font, glyph, x, y);
497    if (!ret && (ret = hb_font_get_glyph_h_origin (font, glyph, x, y))) {
498      hb_position_t dx, dy;
499      guess_v_origin_minus_h_origin (font, glyph, &dx, &dy);
500      *x += dx; *y += dy;
501    }
502  }
503}
504
505void
506hb_font_add_glyph_origin_for_direction (hb_font_t *font,
507					hb_codepoint_t glyph,
508					hb_direction_t direction,
509					hb_position_t *x, hb_position_t *y)
510{
511  hb_position_t origin_x, origin_y;
512
513  hb_font_get_glyph_origin_for_direction (font, glyph, direction, &origin_x, &origin_y);
514
515  *x += origin_x;
516  *y += origin_y;
517}
518
519void
520hb_font_subtract_glyph_origin_for_direction (hb_font_t *font,
521					     hb_codepoint_t glyph,
522					     hb_direction_t direction,
523					     hb_position_t *x, hb_position_t *y)
524{
525  hb_position_t origin_x, origin_y;
526
527  hb_font_get_glyph_origin_for_direction (font, glyph, direction, &origin_x, &origin_y);
528
529  *x -= origin_x;
530  *y -= origin_y;
531}
532
533void
534hb_font_get_glyph_kerning_for_direction (hb_font_t *font,
535					 hb_codepoint_t first_glyph, hb_codepoint_t second_glyph,
536					 hb_direction_t direction,
537					 hb_position_t *x, hb_position_t *y)
538{
539  if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
540    *x = hb_font_get_glyph_h_kerning (font, first_glyph, second_glyph);
541    *y = 0;
542  } else {
543    *x = 0;
544    *y = hb_font_get_glyph_v_kerning (font, first_glyph, second_glyph);
545  }
546}
547
548hb_bool_t
549hb_font_get_glyph_extents_for_origin (hb_font_t *font,
550				      hb_codepoint_t glyph,
551				      hb_direction_t direction,
552				      hb_glyph_extents_t *extents)
553{
554  hb_bool_t ret = hb_font_get_glyph_extents (font, glyph, extents);
555
556  if (ret)
557    hb_font_subtract_glyph_origin_for_direction (font, glyph, direction, &extents->x_bearing, &extents->y_bearing);
558
559  return ret;
560}
561
562hb_bool_t
563hb_font_get_glyph_contour_point_for_origin (hb_font_t *font,
564					    hb_codepoint_t glyph, unsigned int point_index,
565					    hb_direction_t direction,
566					    hb_position_t *x, hb_position_t *y)
567{
568  hb_bool_t ret = hb_font_get_glyph_contour_point (font, glyph, point_index, x, y);
569
570  if (ret)
571    hb_font_subtract_glyph_origin_for_direction (font, glyph, direction, x, y);
572
573  return ret;
574}
575
576
577/*
578 * hb_face_t
579 */
580
581static const hb_face_t _hb_face_nil = {
582  HB_OBJECT_HEADER_STATIC,
583
584  TRUE, /* immutable */
585
586  NULL, /* reference_table */
587  NULL, /* user_data */
588  NULL, /* destroy */
589
590  NULL, /* ot_layout */
591
592  0,    /* index */
593  1000  /* upem */
594};
595
596
597hb_face_t *
598hb_face_create_for_tables (hb_reference_table_func_t  reference_table,
599			   void                      *user_data,
600			   hb_destroy_func_t          destroy)
601{
602  hb_face_t *face;
603
604  if (!reference_table || !(face = hb_object_create<hb_face_t> ())) {
605    if (destroy)
606      destroy (user_data);
607    return hb_face_get_empty ();
608  }
609
610  face->reference_table = reference_table;
611  face->user_data = user_data;
612  face->destroy = destroy;
613
614  face->ot_layout = _hb_ot_layout_create (face);
615
616  face->upem = 0;
617
618  return face;
619}
620
621
622typedef struct _hb_face_for_data_closure_t {
623  hb_blob_t *blob;
624  unsigned int  index;
625} hb_face_for_data_closure_t;
626
627static hb_face_for_data_closure_t *
628_hb_face_for_data_closure_create (hb_blob_t *blob, unsigned int index)
629{
630  hb_face_for_data_closure_t *closure;
631
632  closure = (hb_face_for_data_closure_t *) malloc (sizeof (hb_face_for_data_closure_t));
633  if (unlikely (!closure))
634    return NULL;
635
636  closure->blob = blob;
637  closure->index = index;
638
639  return closure;
640}
641
642static void
643_hb_face_for_data_closure_destroy (hb_face_for_data_closure_t *closure)
644{
645  hb_blob_destroy (closure->blob);
646  free (closure);
647}
648
649static hb_blob_t *
650_hb_face_for_data_reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
651{
652  hb_face_for_data_closure_t *data = (hb_face_for_data_closure_t *) user_data;
653
654  if (tag == HB_TAG_NONE)
655    return hb_blob_reference (data->blob);
656
657  const OpenTypeFontFile &ot_file = *Sanitizer<OpenTypeFontFile>::lock_instance (data->blob);
658  const OpenTypeFontFace &ot_face = ot_file.get_face (data->index);
659
660  const OpenTypeTable &table = ot_face.get_table_by_tag (tag);
661
662  hb_blob_t *blob = hb_blob_create_sub_blob (data->blob, table.offset, table.length);
663
664  return blob;
665}
666
667hb_face_t *
668hb_face_create (hb_blob_t    *blob,
669		unsigned int  index)
670{
671  hb_face_t *face;
672
673  if (unlikely (!blob || !hb_blob_get_length (blob)))
674    return hb_face_get_empty ();
675
676  hb_face_for_data_closure_t *closure = _hb_face_for_data_closure_create (Sanitizer<OpenTypeFontFile>::sanitize (hb_blob_reference (blob)), index);
677
678  if (unlikely (!closure))
679    return hb_face_get_empty ();
680
681  face = hb_face_create_for_tables (_hb_face_for_data_reference_table,
682				    closure,
683				    (hb_destroy_func_t) _hb_face_for_data_closure_destroy);
684
685  hb_face_set_index (face, index);
686
687  return face;
688}
689
690hb_face_t *
691hb_face_get_empty (void)
692{
693  return const_cast<hb_face_t *> (&_hb_face_nil);
694}
695
696
697hb_face_t *
698hb_face_reference (hb_face_t *face)
699{
700  return hb_object_reference (face);
701}
702
703void
704hb_face_destroy (hb_face_t *face)
705{
706  if (!hb_object_destroy (face)) return;
707
708  _hb_ot_layout_destroy (face->ot_layout);
709
710  if (face->destroy)
711    face->destroy (face->user_data);
712
713  free (face);
714}
715
716hb_bool_t
717hb_face_set_user_data (hb_face_t          *face,
718		       hb_user_data_key_t *key,
719		       void *              data,
720		       hb_destroy_func_t   destroy,
721		       hb_bool_t           replace)
722{
723  return hb_object_set_user_data (face, key, data, destroy, replace);
724}
725
726void *
727hb_face_get_user_data (hb_face_t          *face,
728		       hb_user_data_key_t *key)
729{
730  return hb_object_get_user_data (face, key);
731}
732
733void
734hb_face_make_immutable (hb_face_t *face)
735{
736  if (hb_object_is_inert (face))
737    return;
738
739  face->immutable = true;
740}
741
742hb_bool_t
743hb_face_is_immutable (hb_face_t *face)
744{
745  return face->immutable;
746}
747
748
749hb_blob_t *
750hb_face_reference_table (hb_face_t *face,
751			 hb_tag_t   tag)
752{
753  hb_blob_t *blob;
754
755  if (unlikely (!face || !face->reference_table))
756    return hb_blob_get_empty ();
757
758  blob = face->reference_table (face, tag, face->user_data);
759  if (unlikely (!blob))
760    return hb_blob_get_empty ();
761
762  return blob;
763}
764
765hb_blob_t *
766hb_face_reference_blob (hb_face_t *face)
767{
768  return hb_face_reference_table (face, HB_TAG_NONE);
769}
770
771void
772hb_face_set_index (hb_face_t    *face,
773		   unsigned int  index)
774{
775  if (hb_object_is_inert (face))
776    return;
777
778  face->index = index;
779}
780
781unsigned int
782hb_face_get_index (hb_face_t    *face)
783{
784  return face->index;
785}
786
787void
788hb_face_set_upem (hb_face_t    *face,
789		  unsigned int  upem)
790{
791  if (hb_object_is_inert (face))
792    return;
793
794  face->upem = upem;
795}
796
797unsigned int
798hb_face_get_upem (hb_face_t *face)
799{
800  if (unlikely (!face->upem)) {
801    hb_blob_t *head_blob = Sanitizer<head>::sanitize (hb_face_reference_table (face, HB_OT_TAG_head));
802    const head *head_table = Sanitizer<head>::lock_instance (head_blob);
803    face->upem = head_table->get_upem ();
804    hb_blob_destroy (head_blob);
805  }
806  return face->upem;
807}
808
809
810/*
811 * hb_font_t
812 */
813
814hb_font_t *
815hb_font_create (hb_face_t *face)
816{
817  hb_font_t *font;
818
819  if (unlikely (!face))
820    face = hb_face_get_empty ();
821  if (unlikely (hb_object_is_inert (face)))
822    return hb_font_get_empty ();
823  if (!(font = hb_object_create<hb_font_t> ()))
824    return hb_font_get_empty ();
825
826  hb_face_make_immutable (face);
827  font->face = hb_face_reference (face);
828  font->klass = hb_font_funcs_get_empty ();
829
830  return font;
831}
832
833hb_font_t *
834hb_font_create_sub_font (hb_font_t *parent)
835{
836  if (unlikely (!parent))
837    return hb_font_get_empty ();
838
839  hb_font_t *font = hb_font_create (parent->face);
840
841  if (unlikely (hb_object_is_inert (font)))
842    return font;
843
844  hb_font_make_immutable (parent);
845  font->parent = hb_font_reference (parent);
846
847  font->x_scale = parent->x_scale;
848  font->y_scale = parent->y_scale;
849  font->x_ppem = parent->x_ppem;
850  font->y_ppem = parent->y_ppem;
851
852  return font;
853}
854
855hb_font_t *
856hb_font_get_empty (void)
857{
858  static const hb_font_t _hb_font_nil = {
859    HB_OBJECT_HEADER_STATIC,
860
861    TRUE, /* immutable */
862
863    NULL, /* parent */
864    const_cast<hb_face_t *> (&_hb_face_nil),
865
866    0, /* x_scale */
867    0, /* y_scale */
868
869    0, /* x_ppem */
870    0, /* y_ppem */
871
872    const_cast<hb_font_funcs_t *> (&_hb_font_funcs_nil), /* klass */
873    NULL, /* user_data */
874    NULL  /* destroy */
875  };
876
877  return const_cast<hb_font_t *> (&_hb_font_nil);
878}
879
880hb_font_t *
881hb_font_reference (hb_font_t *font)
882{
883  return hb_object_reference (font);
884}
885
886void
887hb_font_destroy (hb_font_t *font)
888{
889  if (!hb_object_destroy (font)) return;
890
891  hb_font_destroy (font->parent);
892  hb_face_destroy (font->face);
893  hb_font_funcs_destroy (font->klass);
894  if (font->destroy)
895    font->destroy (font->user_data);
896
897  free (font);
898}
899
900hb_bool_t
901hb_font_set_user_data (hb_font_t          *font,
902		       hb_user_data_key_t *key,
903		       void *              data,
904		       hb_destroy_func_t   destroy,
905		       hb_bool_t           replace)
906{
907  return hb_object_set_user_data (font, key, data, destroy, replace);
908}
909
910void *
911hb_font_get_user_data (hb_font_t          *font,
912		       hb_user_data_key_t *key)
913{
914  return hb_object_get_user_data (font, key);
915}
916
917void
918hb_font_make_immutable (hb_font_t *font)
919{
920  if (hb_object_is_inert (font))
921    return;
922
923  font->immutable = true;
924}
925
926hb_bool_t
927hb_font_is_immutable (hb_font_t *font)
928{
929  return font->immutable;
930}
931
932hb_font_t *
933hb_font_get_parent (hb_font_t *font)
934{
935  return font->parent;
936}
937
938hb_face_t *
939hb_font_get_face (hb_font_t *font)
940{
941  return font->face;
942}
943
944
945void
946hb_font_set_funcs (hb_font_t         *font,
947		   hb_font_funcs_t   *klass,
948		   void              *user_data,
949		   hb_destroy_func_t  destroy)
950{
951  if (font->immutable) {
952    if (destroy)
953      destroy (user_data);
954    return;
955  }
956
957  if (font->destroy)
958    font->destroy (font->user_data);
959
960  if (!klass)
961    klass = hb_font_funcs_get_empty ();
962
963  hb_font_funcs_reference (klass);
964  hb_font_funcs_destroy (font->klass);
965  font->klass = klass;
966  font->user_data = user_data;
967  font->destroy = destroy;
968}
969
970void
971hb_font_set_funcs_data (hb_font_t         *font,
972		        void              *user_data,
973		        hb_destroy_func_t  destroy)
974{
975  /* Destroy user_data? */
976  if (font->immutable) {
977    if (destroy)
978      destroy (user_data);
979    return;
980  }
981
982  if (font->destroy)
983    font->destroy (font->user_data);
984
985  font->user_data = user_data;
986  font->destroy = destroy;
987}
988
989
990void
991hb_font_set_scale (hb_font_t *font,
992		   int x_scale,
993		   int y_scale)
994{
995  if (font->immutable)
996    return;
997
998  font->x_scale = x_scale;
999  font->y_scale = y_scale;
1000}
1001
1002void
1003hb_font_get_scale (hb_font_t *font,
1004		   int *x_scale,
1005		   int *y_scale)
1006{
1007  if (x_scale) *x_scale = font->x_scale;
1008  if (y_scale) *y_scale = font->y_scale;
1009}
1010
1011void
1012hb_font_set_ppem (hb_font_t *font,
1013		  unsigned int x_ppem,
1014		  unsigned int y_ppem)
1015{
1016  if (font->immutable)
1017    return;
1018
1019  font->x_ppem = x_ppem;
1020  font->y_ppem = y_ppem;
1021}
1022
1023void
1024hb_font_get_ppem (hb_font_t *font,
1025		  unsigned int *x_ppem,
1026		  unsigned int *y_ppem)
1027{
1028  if (x_ppem) *x_ppem = font->x_ppem;
1029  if (y_ppem) *y_ppem = font->y_ppem;
1030}
1031
1032
1033