summaryrefslogtreecommitdiff
path: root/pango/pangocairo-fcfont.c
blob: 65b9e038b6126512eb2071e6048d0fbcf4ba8279 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
/* Pango
 * pangocairofc-font.c: Cairo font handling, fontconfig backend
 *
 * Copyright (C) 2000-2005 Red Hat Software
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <config.h>

#include <math.h>
#include <stdlib.h>

#include <cairo-ft.h>

#include "pango-fontmap.h"
#include "pangocairo-private.h"
#include "pangocairo-fc.h"
#include "pangofc-private.h"
#include "pango-impl-utils.h"

#define PANGO_TYPE_CAIRO_FC_FONT           (pango_cairo_fc_font_get_type ())
#define PANGO_CAIRO_FC_FONT(object)        (G_TYPE_CHECK_INSTANCE_CAST ((object), PANGO_TYPE_CAIRO_FC_FONT, PangoCairoFcFont))
#define PANGO_CAIRO_FC_FONT_CLASS(klass)   (G_TYPE_CHECK_CLASS_CAST ((klass), PANGO_TYPE_CAIRO_FC_FONT, PangoCairoFcFontClass))
#define PANGO_CAIRO_IS_FONT_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), PANGO_TYPE_CAIRO_FC_FONT))
#define PANGO_CAIRO_FC_FONT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), PANGO_TYPE_CAIRO_FC_FONT, PangoCairoFcFontClass))

typedef struct _PangoCairoFcFont      PangoCairoFcFont;
typedef struct _PangoCairoFcFontClass PangoCairoFcFontClass;

typedef struct _GlyphExtentsCacheEntry    GlyphExtentsCacheEntry;

#define GLYPH_CACHE_NUM_ENTRIES 256 /* should be power of two */
#define GLYPH_CACHE_MASK (GLYPH_CACHE_NUM_ENTRIES - 1)

/* An entry in the fixed-size cache for the glyph -> ink_rect mapping.
 * The cache is indexed by the lower N bits of the glyph (see
 * GLYPH_CACHE_NUM_ENTRIES).  For scripts with few glyphs,
 * this should provide pretty much instant lookups.
 */
struct _GlyphExtentsCacheEntry
{
  PangoGlyph     glyph;
  int            width;
  PangoRectangle ink_rect;
};

struct _PangoCairoFcFont
{
  PangoFcFont font;

  cairo_font_face_t *font_face;
  cairo_scaled_font_t *scaled_font;
  cairo_matrix_t font_matrix;
  cairo_matrix_t ctm;
  cairo_font_options_t *options;
  PangoGravity gravity;

  PangoRectangle font_extents;
  GlyphExtentsCacheEntry    *glyph_extents_cache;
};

struct _PangoCairoFcFontClass
{
  PangoFcFontClass  parent_class;
};

GType pango_cairo_fc_font_get_type (void);

static cairo_font_face_t *pango_cairo_fc_font_get_font_face (PangoCairoFont *font);

/*******************************
 *       Utility functions     *
 *******************************/

static cairo_font_face_t *
pango_cairo_fc_font_get_font_face (PangoCairoFont *font)
{
  PangoCairoFcFont *cffont = (PangoCairoFcFont *) (font);
  PangoFcFont *fcfont = (PangoFcFont *) (cffont);

  if (!cffont->font_face)
    {
      cffont->font_face = cairo_ft_font_face_create_for_pattern (fcfont->font_pattern);

      /* Unable to create FT2 cairo scaled font.
       * This means out of memory or a cairo/fontconfig/FreeType bug,
       */
      if (!cffont->font_face)
	return NULL;
    }

  return cffont->font_face;
}

static cairo_scaled_font_t *
pango_cairo_fc_font_get_scaled_font (PangoCairoFont *font)
{
  PangoCairoFcFont *cffont = (PangoCairoFcFont *)font;

  if (!cffont->scaled_font)
    {
      cairo_font_face_t *font_face;

      font_face = pango_cairo_fc_font_get_font_face (font);

      if (!font_face)
	return NULL;

      cffont->scaled_font = cairo_scaled_font_create (font_face,
						      &cffont->font_matrix,
						      &cffont->ctm,
						      cffont->options);

      /* Unable to create FT2 cairo scaled font.
       * This means out of memory or a cairo/fontconfig/FreeType bug,
       * or a missing font...
       */
      if (!cffont->scaled_font)
	return NULL;
    }

  return cffont->scaled_font;
}

/********************************
 *    Method implementations    *
 ********************************/

static gboolean
pango_cairo_fc_font_install (PangoCairoFont *font,
			     cairo_t        *cr)
{
  PangoCairoFcFont *cffont = (PangoCairoFcFont *) (font);

  cairo_set_font_face (cr,
		       pango_cairo_fc_font_get_font_face (font));
  cairo_set_font_matrix (cr, &cffont->font_matrix);
  cairo_set_font_options (cr, cffont->options);

  return TRUE;
}

static void
cairo_font_iface_init (PangoCairoFontIface *iface)
{
  iface->install = pango_cairo_fc_font_install;
  iface->get_font_face = pango_cairo_fc_font_get_font_face;
  iface->get_scaled_font = pango_cairo_fc_font_get_scaled_font;
}

G_DEFINE_TYPE_WITH_CODE (PangoCairoFcFont, pango_cairo_fc_font, PANGO_TYPE_FC_FONT,
    { G_IMPLEMENT_INTERFACE (PANGO_TYPE_CAIRO_FONT, cairo_font_iface_init) })

static void
pango_cairo_fc_font_finalize (GObject *object)
{
  PangoCairoFcFont *cffont = (PangoCairoFcFont *) (object);

  if (cffont->font_face)
    cairo_font_face_destroy (cffont->font_face);
  if (cffont->scaled_font)
    cairo_scaled_font_destroy (cffont->scaled_font);
  if (cffont->options)
    cairo_font_options_destroy (cffont->options);


  if (cffont->glyph_extents_cache)
    {
      g_free (cffont->glyph_extents_cache);
    }

  G_OBJECT_CLASS (pango_cairo_fc_font_parent_class)->finalize (object);
}

/* This function is cut-and-pasted from pangocairo-fcfont.c - it might be
 * better to add a virtual fcfont->create_context (font).
 */
static PangoFontMetrics *
pango_cairo_fc_font_get_metrics (PangoFont     *font,
				 PangoLanguage *language)
{
  PangoFcFont *fcfont = (PangoFcFont *) (font);
  PangoCairoFcFont *cffont = (PangoCairoFcFont *) (font);
  PangoFcMetricsInfo *info = NULL; /* Quiet gcc */
  GSList *tmp_list;

  const char *sample_str = pango_language_get_sample_string (language);

  tmp_list = fcfont->metrics_by_lang;
  while (tmp_list)
    {
      info = tmp_list->data;

      if (info->sample_str == sample_str)    /* We _don't_ need strcmp */
	break;

      tmp_list = tmp_list->next;
    }

  if (!tmp_list)
    {
      PangoContext *context;
      int height, shift;

      if (!fcfont->fontmap)
	return pango_font_metrics_new ();

      info = g_slice_new0 (PangoFcMetricsInfo);

      fcfont->metrics_by_lang = g_slist_prepend (fcfont->metrics_by_lang, info);

      info->sample_str = sample_str;

      context = pango_fc_font_map_create_context (PANGO_FC_FONT_MAP (fcfont->fontmap));
      pango_context_set_language (context, language);
      pango_cairo_context_set_font_options (context, cffont->options);

      info->metrics = pango_fc_font_create_metrics_for_context (fcfont, context);
      /* We may actually reuse ascent/descent we got from cairo here.  that's
       * in cffont->font_extents.
       */
      height = info->metrics->ascent + info->metrics->descent;
      switch (cffont->gravity)
	{
	  default:
	  case PANGO_GRAVITY_AUTO:
	  case PANGO_GRAVITY_SOUTH:
	    break;
	  case PANGO_GRAVITY_NORTH:
	    info->metrics->ascent = info->metrics->descent;
	    break;
	  case PANGO_GRAVITY_EAST:
	  case PANGO_GRAVITY_WEST:
	    info->metrics->ascent = height / 2;
	}
      shift = (height - info->metrics->ascent) - info->metrics->descent;
      if (fcfont->is_hinted)
	shift &= ~(PANGO_SCALE - 1);
      info->metrics->descent += shift;
      info->metrics->underline_position -= shift;
      info->metrics->strikethrough_position -= shift;
      info->metrics->ascent = height - info->metrics->descent;

      g_object_unref (context);
    }

  return pango_font_metrics_ref (info->metrics);
}

static FT_Face
pango_cairo_fc_font_lock_face (PangoFcFont *font)
{
  PangoCairoFont *cfont = (PangoCairoFont *)font;
  cairo_scaled_font_t *scaled_font = pango_cairo_fc_font_get_scaled_font (cfont);
  if (G_UNLIKELY (!scaled_font))
    return NULL;

  return cairo_ft_scaled_font_lock_face (scaled_font);
}

static void
pango_cairo_fc_font_unlock_face (PangoFcFont *font)
{
  PangoCairoFont *cfont = (PangoCairoFont *)font;
  cairo_scaled_font_t *scaled_font = pango_cairo_fc_font_get_scaled_font (cfont);
  if (G_UNLIKELY (!scaled_font))
    return;

  cairo_ft_scaled_font_unlock_face (scaled_font);
}

static void
pango_cairo_fc_font_glyph_extents_cache_init (PangoCairoFcFont *cffont)
{
  PangoCairoFont *cfont = (PangoCairoFont *)cffont;
  cairo_scaled_font_t *scaled_font = pango_cairo_fc_font_get_scaled_font (cfont);
  cairo_font_extents_t font_extents;

  cairo_scaled_font_extents (scaled_font, &font_extents);

  cffont->font_extents.x = 0;
  cffont->font_extents.width = 0;
  cffont->font_extents.height = pango_units_from_double (font_extents.ascent + font_extents.descent);
  switch (cffont->gravity)
    {
      default:
      case PANGO_GRAVITY_AUTO:
      case PANGO_GRAVITY_SOUTH:
	cffont->font_extents.y = - pango_units_from_double (font_extents.ascent);
	break;
      case PANGO_GRAVITY_NORTH:
	cffont->font_extents.y = - pango_units_from_double (font_extents.descent);
	break;
      case PANGO_GRAVITY_EAST:
      case PANGO_GRAVITY_WEST:
	cffont->font_extents.y = - pango_units_from_double ((font_extents.ascent + font_extents.descent) * 0.5);
    }

  cffont->glyph_extents_cache = g_new0 (GlyphExtentsCacheEntry, GLYPH_CACHE_NUM_ENTRIES);
  /* Make sure all cache entries are invalid initially */
  cffont->glyph_extents_cache[0].glyph = 1; /* glyph 1 cannot happen in bucket 0 */
}

/* Fills in the glyph extents cache entry
 */
static void
compute_glyph_extents (PangoCairoFcFont       *cffont,
		       PangoGlyph              glyph,
		       GlyphExtentsCacheEntry *entry)
{
  cairo_text_extents_t extents;
  cairo_glyph_t cairo_glyph;

  cairo_glyph.index = glyph;
  cairo_glyph.x = 0;
  cairo_glyph.y = 0;

  cairo_scaled_font_glyph_extents (cffont->scaled_font,
				   &cairo_glyph, 1, &extents);

  entry->glyph = glyph;
  entry->width = pango_units_from_double (extents.x_advance);
  entry->ink_rect.x = pango_units_from_double (extents.x_bearing);
  entry->ink_rect.y = pango_units_from_double (extents.y_bearing);
  entry->ink_rect.width = pango_units_from_double (extents.width);
  entry->ink_rect.height = pango_units_from_double (extents.height);
}

static GlyphExtentsCacheEntry *
pango_cairo_fc_font_get_glyph_extents_cache_entry (PangoCairoFcFont       *cffont,
						   PangoGlyph              glyph)
{
  GlyphExtentsCacheEntry *entry;
  guint idx;

  idx = glyph & GLYPH_CACHE_MASK;
  entry = cffont->glyph_extents_cache + idx;

  if (entry->glyph != glyph)
    {
      compute_glyph_extents (cffont, glyph, entry);
    }

  return entry;
}

static void
pango_cairo_fc_font_get_glyph_extents (PangoFont      *font,
				       PangoGlyph      glyph,
				       PangoRectangle *ink_rect,
				       PangoRectangle *logical_rect)
{
  PangoCairoFcFont *cffont = (PangoCairoFcFont *)font;
  GlyphExtentsCacheEntry *entry;

  if (!pango_cairo_fc_font_get_scaled_font ((PangoCairoFont *)cffont))
    {
      /* Get generic unknown-glyph extents. */
      pango_font_get_glyph_extents (NULL, glyph, ink_rect, logical_rect);
      return;
    }

  /* We need to initialize the cache here, since we use cffont->font_extents
   */
  if (cffont->glyph_extents_cache == NULL)
    pango_cairo_fc_font_glyph_extents_cache_init (cffont);

  if (glyph == PANGO_GLYPH_EMPTY)
    {
      if (ink_rect)
	ink_rect->x = ink_rect->y = ink_rect->width = ink_rect->height = 0;
      if (logical_rect)
	*logical_rect = cffont->font_extents;
      return;
    }
  else if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
    {
      _pango_cairo_get_glyph_extents_missing((PangoCairoFont *)font, glyph, ink_rect, logical_rect);
      return;
    }

  entry = pango_cairo_fc_font_get_glyph_extents_cache_entry (cffont, glyph);

  if (ink_rect)
    *ink_rect = entry->ink_rect;
  if (logical_rect)
    {
      *logical_rect = cffont->font_extents;
      logical_rect->width = entry->width;
    }
}

static void
pango_cairo_fc_font_shutdown (PangoFcFont *fcfont)
{
  PangoCairoFcFont *cffont = (PangoCairoFcFont *) (fcfont);
  if (cffont->scaled_font)
    {
      cairo_scaled_font_destroy (cffont->scaled_font);
      cffont->scaled_font = NULL;
    }
  if (cffont->font_face)
    {
      cairo_font_face_destroy (cffont->font_face);
      cffont->font_face = NULL;
    }
}

static void
pango_cairo_fc_font_class_init (PangoCairoFcFontClass *class)
{
  GObjectClass *object_class = G_OBJECT_CLASS (class);
  PangoFontClass *font_class = PANGO_FONT_CLASS (class);
  PangoFcFontClass *fc_font_class = PANGO_FC_FONT_CLASS (class);

  object_class->finalize = pango_cairo_fc_font_finalize;

  font_class->get_glyph_extents = pango_cairo_fc_font_get_glyph_extents;
  font_class->get_metrics = pango_cairo_fc_font_get_metrics;

  fc_font_class->lock_face = pango_cairo_fc_font_lock_face;
  fc_font_class->unlock_face = pango_cairo_fc_font_unlock_face;
  fc_font_class->shutdown = pango_cairo_fc_font_shutdown;
}

static void
pango_cairo_fc_font_init (PangoCairoFcFont *cffont)
{
}

/********************
 *    Private API   *
 ********************/

static double
get_font_size (PangoCairoFcFontMap        *cffontmap,
	       PangoContext               *context,
	       const PangoFontDescription *desc,
	       FcPattern                  *pattern,
	       const PangoMatrix          *matrix)
{
  double size;

 /* The reason why we read FC_PIXEL_SIZE here rather than just
  * using the specified size is to support operations like clamping
  * a font to a minimal readable size in fonts.conf. This is pretty weird,
  * since it could mean that changing the Cairo CTM doesn't change the
  * font size, but it's just a more radical version of the non-linear
  * font scaling we already have due to hinting and due to bitmap
  * fonts being only available at a few sizes.
  *
  * If honoring FC_PIXEL_SIZE gets in the way of more useful features
  * it should be removed since it only matters in the unusual case
  * of people doing exotic stuff in fonts.conf.
  */

  if (FcPatternGetDouble (pattern, FC_PIXEL_SIZE, 0, &size) == FcResultMatch)
    return size * PANGO_SCALE / pango_matrix_get_font_scale_factor (matrix);

  /* Just in case FC_PIXEL_SIZE got unset between pango_fc_make_pattern()
   * and here.
   */
  if (pango_font_description_get_size_is_absolute (desc))
    return pango_font_description_get_size (desc);
  else
    {
      double dpi = pango_cairo_context_get_resolution (context);

      if (dpi <= 0)
	dpi = cffontmap->dpi;

      return dpi * pango_font_description_get_size (desc) / 72.;
    }
}

PangoFcFont *
_pango_cairo_fc_font_new (PangoCairoFcFontMap        *cffontmap,
			  PangoContext               *context,
			  const PangoFontDescription *desc,
			  FcPattern	             *pattern)
{
  PangoCairoFcFont *cffont;
  const PangoMatrix *pango_ctm;
  FcMatrix *fc_matrix;
  double size;

  g_return_val_if_fail (PANGO_IS_CAIRO_FC_FONT_MAP (cffontmap), NULL);
  g_return_val_if_fail (pattern != NULL, NULL);

  cffont = g_object_new (PANGO_TYPE_CAIRO_FC_FONT,
			 "pattern", pattern,
			 NULL);

  cffont->gravity = pango_font_description_get_gravity (desc);

  if  (FcPatternGetMatrix (pattern,
			   FC_MATRIX, 0, &fc_matrix) == FcResultMatch)
    {
      cairo_matrix_init (&cffont->font_matrix,
			 fc_matrix->xx,
			 - fc_matrix->yx,
			 - fc_matrix->xy,
			 fc_matrix->yy,
			 0., 0.);
    }
  else
    cairo_matrix_init_identity (&cffont->font_matrix);

  cairo_matrix_rotate(&cffont->font_matrix,
		      pango_gravity_to_rotation (cffont->gravity));

  pango_ctm = pango_context_get_matrix (context);

  size = get_font_size (cffontmap, context, desc, pattern, pango_ctm);

  cairo_matrix_scale (&cffont->font_matrix,
		      size / PANGO_SCALE, size / PANGO_SCALE);

  if (pango_ctm)
    cairo_matrix_init (&cffont->ctm,
		       pango_ctm->xx,
		       pango_ctm->yx,
		       pango_ctm->xy,
		       pango_ctm->yy,
		       0., 0.);
  else
    cairo_matrix_init_identity (&cffont->ctm);


  cffont->options = cairo_font_options_copy (_pango_cairo_context_get_merged_font_options (context));

  /* fcfont's is_hinted controls metric hinting
   */
  ((PangoFcFont *)(cffont))->is_hinted =
    (cairo_font_options_get_hint_metrics(cffont->options) != CAIRO_HINT_METRICS_OFF);

  return (PangoFcFont *) (cffont);
}