hb-font.cc revision 1d720192b193f48b44be0385eda3c2c5d5cd28ad 
1/*
2 * Copyright (C) 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.h"
28
29#include "hb-font-private.h"
30#include "hb-open-file-private.hh"
31#include "hb-blob.h"
32
33#include "hb-ot-layout-private.h"
34
35#include <string.h>
36
37
38/*
39 * hb_font_funcs_t
40 */
41
42static hb_codepoint_t
43hb_font_get_glyph_nil (hb_font_t *font HB_GNUC_UNUSED,
44		       hb_face_t *face HB_GNUC_UNUSED,
45		       const void *user_data HB_GNUC_UNUSED,
46		       hb_codepoint_t unicode HB_GNUC_UNUSED,
47		       hb_codepoint_t variation_selector HB_GNUC_UNUSED)
48{ return 0; }
49
50static hb_bool_t
51hb_font_get_contour_point_nil (hb_font_t *font HB_GNUC_UNUSED,
52			       hb_face_t *face HB_GNUC_UNUSED,
53			       const void *user_data HB_GNUC_UNUSED,
54			       unsigned int point_index HB_GNUC_UNUSED,
55			       hb_codepoint_t glyph HB_GNUC_UNUSED,
56			       hb_position_t *x HB_GNUC_UNUSED,
57			       hb_position_t *y HB_GNUC_UNUSED)
58{ return false; }
59
60static void
61hb_font_get_glyph_metrics_nil (hb_font_t *font HB_GNUC_UNUSED,
62			       hb_face_t *face HB_GNUC_UNUSED,
63			       const void *user_data HB_GNUC_UNUSED,
64			       hb_codepoint_t glyph HB_GNUC_UNUSED,
65			       hb_glyph_metrics_t *metrics)
66{ memset (metrics, 0, sizeof (*metrics)); }
67
68static hb_position_t
69hb_font_get_kerning_nil (hb_font_t *font HB_GNUC_UNUSED,
70			 hb_face_t *face HB_GNUC_UNUSED,
71			 const void *user_data HB_GNUC_UNUSED,
72			 hb_codepoint_t first_glyph HB_GNUC_UNUSED,
73			 hb_codepoint_t second_glyph HB_GNUC_UNUSED)
74{ return 0; }
75
76hb_font_funcs_t _hb_font_funcs_nil = {
77  HB_REFERENCE_COUNT_INVALID, /* ref_count */
78
79  TRUE,  /* immutable */
80
81  hb_font_get_glyph_nil,
82  hb_font_get_contour_point_nil,
83  hb_font_get_glyph_metrics_nil,
84  hb_font_get_kerning_nil
85};
86
87hb_font_funcs_t *
88hb_font_funcs_create (void)
89{
90  hb_font_funcs_t *ffuncs;
91
92  if (!HB_OBJECT_DO_CREATE (hb_font_funcs_t, ffuncs))
93    return &_hb_font_funcs_nil;
94
95  return ffuncs;
96}
97
98hb_font_funcs_t *
99hb_font_funcs_reference (hb_font_funcs_t *ffuncs)
100{
101  HB_OBJECT_DO_REFERENCE (ffuncs);
102}
103
104unsigned int
105hb_font_funcs_get_reference_count (hb_font_funcs_t *ffuncs)
106{
107  HB_OBJECT_DO_GET_REFERENCE_COUNT (ffuncs);
108}
109
110void
111hb_font_funcs_destroy (hb_font_funcs_t *ffuncs)
112{
113  HB_OBJECT_DO_DESTROY (ffuncs);
114
115  free (ffuncs);
116}
117
118hb_font_funcs_t *
119hb_font_funcs_copy (hb_font_funcs_t *other_ffuncs)
120{
121  hb_font_funcs_t *ffuncs;
122
123  if (!HB_OBJECT_DO_CREATE (hb_font_funcs_t, ffuncs))
124    return &_hb_font_funcs_nil;
125
126  *ffuncs = *other_ffuncs;
127
128  /* re-init refcount */
129  HB_OBJECT_DO_INIT (ffuncs);
130  ffuncs->immutable = FALSE;
131
132  return ffuncs;
133}
134
135void
136hb_font_funcs_make_immutable (hb_font_funcs_t *ffuncs)
137{
138  if (HB_OBJECT_IS_INERT (ffuncs))
139    return;
140
141  ffuncs->immutable = TRUE;
142}
143
144
145void
146hb_font_funcs_set_glyph_func (hb_font_funcs_t *ffuncs,
147			      hb_font_get_glyph_func_t glyph_func)
148{
149  if (ffuncs->immutable)
150    return;
151
152  ffuncs->get_glyph = glyph_func ? glyph_func : hb_font_get_glyph_nil;
153}
154
155void
156hb_font_funcs_set_contour_point_func (hb_font_funcs_t *ffuncs,
157				      hb_font_get_contour_point_func_t contour_point_func)
158{
159  if (ffuncs->immutable)
160    return;
161
162  ffuncs->get_contour_point = contour_point_func ? contour_point_func : hb_font_get_contour_point_nil;
163}
164
165void
166hb_font_funcs_set_glyph_metrics_func (hb_font_funcs_t *ffuncs,
167				      hb_font_get_glyph_metrics_func_t glyph_metrics_func)
168{
169  if (ffuncs->immutable)
170    return;
171
172  ffuncs->get_glyph_metrics = glyph_metrics_func ? glyph_metrics_func : hb_font_get_glyph_metrics_nil;
173}
174
175void
176hb_font_funcs_set_kerning_func (hb_font_funcs_t *ffuncs,
177				hb_font_get_kerning_func_t kerning_func)
178{
179  if (ffuncs->immutable)
180    return;
181
182  ffuncs->get_kerning = kerning_func ? kerning_func : hb_font_get_kerning_nil;
183}
184
185
186hb_codepoint_t
187hb_font_get_glyph (hb_font_t *font, hb_face_t *face,
188		   hb_codepoint_t unicode, hb_codepoint_t variation_selector)
189{
190  return font->klass->get_glyph (font, face, font->user_data,
191				 unicode, variation_selector);
192}
193
194hb_bool_t
195hb_font_get_contour_point (hb_font_t *font, hb_face_t *face,
196			   unsigned int point_index,
197			   hb_codepoint_t glyph, hb_position_t *x, hb_position_t *y)
198{
199  return font->klass->get_contour_point (font, face, font->user_data,
200					 point_index,
201					 glyph, x, y);
202}
203
204void
205hb_font_get_glyph_metrics (hb_font_t *font, hb_face_t *face,
206			   hb_codepoint_t glyph, hb_glyph_metrics_t *metrics)
207{
208  /* TODO Zero metrics here? */
209  return font->klass->get_glyph_metrics (font, face, font->user_data,
210					 glyph, metrics);
211}
212
213hb_position_t
214hb_font_get_kerning (hb_font_t *font, hb_face_t *face,
215		     hb_codepoint_t first_glyph, hb_codepoint_t second_glyph)
216{
217  return font->klass->get_kerning (font, face, font->user_data,
218				   first_glyph, second_glyph);
219}
220
221/*
222 * hb_face_t
223 */
224
225static hb_blob_t *
226_hb_face_get_table_from_blob (hb_tag_t tag, void *user_data)
227{
228  hb_face_t *face = (hb_face_t *) user_data;
229
230  const OpenTypeFontFile &ot_file = Sanitizer<OpenTypeFontFile>::lock_instance (face->blob);
231  const OpenTypeFontFace &ot_face = ot_file.get_face (face->index);
232
233  const OpenTypeTable &table = ot_face.get_table_by_tag (tag);
234
235  hb_blob_t *blob = hb_blob_create_sub_blob (face->blob, table.offset, table.length);
236
237  hb_blob_unlock (face->blob);
238
239  return blob;
240}
241
242static hb_face_t _hb_face_nil = {
243  HB_REFERENCE_COUNT_INVALID, /* ref_count */
244
245  NULL, /* blob */
246  0, /* index */
247
248  NULL, /* get_table */
249  NULL, /* destroy */
250  NULL, /* user_data */
251
252  {} /* ot_layout */
253};
254
255hb_face_t *
256hb_face_create_for_tables (hb_get_table_func_t  get_table,
257			   hb_destroy_func_t    destroy,
258			   void                *user_data)
259{
260  hb_face_t *face;
261
262  if (!HB_OBJECT_DO_CREATE (hb_face_t, face)) {
263    if (destroy)
264      destroy (user_data);
265    return &_hb_face_nil;
266  }
267
268  face->get_table = get_table;
269  face->destroy = destroy;
270  face->user_data = user_data;
271
272  _hb_ot_layout_init (face);
273
274  return face;
275}
276
277hb_face_t *
278hb_face_create_for_data (hb_blob_t    *blob,
279			 unsigned int  index)
280{
281  hb_face_t *face;
282
283  if (!HB_OBJECT_DO_CREATE (hb_face_t, face))
284    return &_hb_face_nil;
285
286  face->blob = Sanitizer<OpenTypeFontFile>::sanitize (hb_blob_reference (blob));
287  face->index = index;
288  face->get_table = _hb_face_get_table_from_blob;
289  face->user_data = face;
290
291  _hb_ot_layout_init (face);
292
293  return face;
294}
295
296hb_face_t *
297hb_face_reference (hb_face_t *face)
298{
299  HB_OBJECT_DO_REFERENCE (face);
300}
301
302unsigned int
303hb_face_get_reference_count (hb_face_t *face)
304{
305  HB_OBJECT_DO_GET_REFERENCE_COUNT (face);
306}
307
308void
309hb_face_destroy (hb_face_t *face)
310{
311  HB_OBJECT_DO_DESTROY (face);
312
313  _hb_ot_layout_fini (face);
314
315  hb_blob_destroy (face->blob);
316
317  if (face->destroy)
318    face->destroy (face->user_data);
319
320  free (face);
321}
322
323hb_blob_t *
324hb_face_get_table (hb_face_t *face,
325		   hb_tag_t   tag)
326{
327  if (HB_UNLIKELY (!face || !face->get_table))
328    return hb_blob_create_empty ();
329
330  return face->get_table (tag, face->user_data);
331}
332
333
334/*
335 * hb_font_t
336 */
337
338static hb_font_t _hb_font_nil = {
339  HB_REFERENCE_COUNT_INVALID, /* ref_count */
340
341  0, /* x_scale */
342  0, /* y_scale */
343
344  0, /* x_ppem */
345  0, /* y_ppem */
346
347  NULL, /* klass */
348  NULL, /* destroy */
349  NULL  /* user_data */
350};
351
352hb_font_t *
353hb_font_create (void)
354{
355  hb_font_t *font;
356
357  if (!HB_OBJECT_DO_CREATE (hb_font_t, font))
358    return &_hb_font_nil;
359
360  font->klass = &_hb_font_funcs_nil;
361
362  return font;
363}
364
365hb_font_t *
366hb_font_reference (hb_font_t *font)
367{
368  HB_OBJECT_DO_REFERENCE (font);
369}
370
371unsigned int
372hb_font_get_reference_count (hb_font_t *font)
373{
374  HB_OBJECT_DO_GET_REFERENCE_COUNT (font);
375}
376
377void
378hb_font_destroy (hb_font_t *font)
379{
380  HB_OBJECT_DO_DESTROY (font);
381
382  hb_font_funcs_destroy (font->klass);
383  if (font->destroy)
384    font->destroy (font->user_data);
385
386  free (font);
387}
388
389void
390hb_font_set_funcs (hb_font_t         *font,
391		   hb_font_funcs_t   *klass,
392		   hb_destroy_func_t  destroy,
393		   void              *user_data)
394{
395  if (HB_OBJECT_IS_INERT (font))
396    return;
397
398  if (font->destroy)
399    font->destroy (font->user_data);
400
401  if (!klass)
402    klass = &_hb_font_funcs_nil;
403
404  hb_font_funcs_reference (klass);
405  hb_font_funcs_destroy (font->klass);
406  font->klass = klass;
407  font->destroy = destroy;
408  font->user_data = user_data;
409}
410
411void
412hb_font_set_scale (hb_font_t *font,
413		   hb_16dot16_t x_scale,
414		   hb_16dot16_t y_scale)
415{
416  if (HB_OBJECT_IS_INERT (font))
417    return;
418
419  font->x_scale = x_scale;
420  font->y_scale = y_scale;
421}
422
423void
424hb_font_set_ppem (hb_font_t *font,
425		  unsigned int x_ppem,
426		  unsigned int y_ppem)
427{
428  if (HB_OBJECT_IS_INERT (font))
429    return;
430
431  font->x_ppem = x_ppem;
432  font->y_ppem = y_ppem;
433}
434
435