summaryrefslogtreecommitdiff
path: root/pango/pangofc-shape.c
blob: 2f6c7cca2926f4f265a16cc04efcd0d97881c3d6 (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
/* Pango
 * pangofc-shape.c: Basic shaper for FreeType-based backends
 *
 * Copyright (C) 2000, 2007, 2009 Red Hat Software
 * Authors:
 *   Owen Taylor <otaylor@redhat.com>
 *   Behdad Esfahbod <behdad@behdad.org>
 *
 * 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 <string.h>
#include <math.h>

#include "pangofc-private.h"
#include <hb-ft.h>
#include <hb-glib.h>

/* cache a single hb_buffer_t */
static hb_buffer_t *cached_buffer = NULL; /* MT-safe */
G_LOCK_DEFINE_STATIC (cached_buffer);

static hb_buffer_t *
create_buffer (void)
{
  hb_buffer_t *buffer;

  buffer = hb_buffer_create ();
  hb_buffer_set_unicode_funcs (buffer, hb_glib_get_unicode_funcs ());

  return buffer;
}

static hb_buffer_t *
acquire_buffer (gboolean *free_buffer)
{
  hb_buffer_t *buffer;

  if (G_LIKELY (G_TRYLOCK (cached_buffer)))
    {
      if (G_UNLIKELY (!cached_buffer))
	cached_buffer = create_buffer ();

      buffer = cached_buffer;
      *free_buffer = FALSE;
    }
  else
    {
      buffer = create_buffer ();
      *free_buffer = TRUE;
    }

  return buffer;
}

static void
release_buffer (hb_buffer_t *buffer, gboolean free_buffer)
{
  if (G_LIKELY (!free_buffer))
    {
      hb_buffer_reset (buffer);
      G_UNLOCK (cached_buffer);
    }
  else
    hb_buffer_destroy (buffer);
}

typedef struct _PangoFcHbContext {
  FT_Face ft_face;
  PangoFcFont *fc_font;
  gboolean vertical;
  double x_scale, y_scale; /* CTM scales. */
} PangoFcHbContext;

static hb_bool_t
pango_fc_hb_font_get_glyph (hb_font_t *font, void *font_data,
			    hb_codepoint_t unicode, hb_codepoint_t variation_selector,
			    hb_codepoint_t *glyph,
			    void *user_data G_GNUC_UNUSED)
{
  PangoFcHbContext *context = (PangoFcHbContext *) font_data;
  PangoFcFont *fc_font = context->fc_font;

  *glyph = pango_fc_font_get_glyph (fc_font, unicode);
  if (G_LIKELY (*glyph))
    return TRUE;

  *glyph = PANGO_GET_UNKNOWN_GLYPH (unicode);

  /* We draw our own invalid-Unicode shape, so prevent HarfBuzz
   * from using REPLACEMENT CHARACTER. */
  if (unicode > 0x10FFFF)
    return TRUE;

  return FALSE;
}

static hb_bool_t
pango_fc_hb_font_get_glyph_contour_point (hb_font_t *font, void *font_data,
					  hb_codepoint_t glyph, unsigned int point_index,
					  hb_position_t *x, hb_position_t *y,
					  void *user_data G_GNUC_UNUSED)
{
  return FALSE;
#if 0
  FT_Face ft_face = (FT_Face) font_data;
  int load_flags = FT_LOAD_DEFAULT;

  /* TODO: load_flags, embolden, etc */

  if (HB_UNLIKELY (FT_Load_Glyph (ft_face, glyph, load_flags)))
      return FALSE;

  if (HB_UNLIKELY (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
      return FALSE;

  if (HB_UNLIKELY (point_index >= (unsigned int) ft_face->glyph->outline.n_points))
      return FALSE;

  *x = ft_face->glyph->outline.points[point_index].x;
  *y = ft_face->glyph->outline.points[point_index].y;

  return TRUE;
#endif
}

static hb_position_t
pango_fc_hb_font_get_glyph_advance (hb_font_t *font, void *font_data,
				    hb_codepoint_t glyph,
				    void *user_data G_GNUC_UNUSED)
{
  PangoFcHbContext *context = (PangoFcHbContext *) font_data;
  PangoFcFont *fc_font = context->fc_font;
  PangoRectangle logical;

  pango_font_get_glyph_extents ((PangoFont *) fc_font, glyph, NULL, &logical);

  return logical.width;
}

static hb_bool_t
pango_fc_hb_font_get_glyph_extents (hb_font_t *font,  void *font_data,
				    hb_codepoint_t glyph,
				    hb_glyph_extents_t *extents,
				    void *user_data G_GNUC_UNUSED)
{
  PangoFcHbContext *context = (PangoFcHbContext *) font_data;
  PangoFcFont *fc_font = context->fc_font;
  PangoRectangle ink;

  pango_font_get_glyph_extents ((PangoFont *) fc_font, glyph, &ink, NULL);

  if (G_LIKELY (!context->vertical)) {
    extents->x_bearing  = ink.x;
    extents->y_bearing  = ink.y;
    extents->width      = ink.width;
    extents->height     = ink.height;
  } else {
    /* XXX */
    extents->x_bearing  = ink.x;
    extents->y_bearing  = ink.y;
    extents->width      = ink.height;
    extents->height     = ink.width;
  }

  return TRUE;
}

static hb_bool_t
pango_fc_hb_font_get_glyph_h_origin (hb_font_t *font, void *font_data,
				     hb_codepoint_t glyph,
				     hb_position_t *x, hb_position_t *y,
				     void *user_data G_GNUC_UNUSED)
{
  PangoFcHbContext *context = (PangoFcHbContext *) font_data;
  FT_Face ft_face = context->ft_face;
  int load_flags = FT_LOAD_DEFAULT;

  if (!context->vertical) return TRUE;

  if (FT_Load_Glyph (ft_face, glyph, load_flags))
    return FALSE;

  /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
   * have a Y growing upward.  Hence the extra negation. */
  *x = PANGO_UNITS_26_6 (ft_face->glyph->metrics.horiBearingX -   ft_face->glyph->metrics.vertBearingX);
  *y = PANGO_UNITS_26_6 (ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY));

  /* XXX */
  *x = -*x;
  *y =  *y;

  return TRUE;
}

static hb_bool_t
pango_fc_hb_font_get_glyph_v_origin (hb_font_t *font, void *font_data,
				     hb_codepoint_t glyph,
				     hb_position_t *x, hb_position_t *y,
				     void *user_data G_GNUC_UNUSED)
{
  PangoFcHbContext *context = (PangoFcHbContext *) font_data;
  FT_Face ft_face = context->ft_face;
  int load_flags = FT_LOAD_DEFAULT;

  /* pangocairo-fc configures font in vertical origin for vertical writing. */
  if (context->vertical) return TRUE;

  if (FT_Load_Glyph (ft_face, glyph, load_flags))
    return FALSE;

  /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
   * have a Y growing upward.  Hence the extra negation. */
  *x = PANGO_UNITS_26_6 (ft_face->glyph->metrics.horiBearingX -   ft_face->glyph->metrics.vertBearingX);
  *y = PANGO_UNITS_26_6 (ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY));

  /* XXX */

  return TRUE;
}


static hb_position_t
pango_fc_hb_font_get_h_kerning (hb_font_t *font, void *font_data,
				hb_codepoint_t left_glyph, hb_codepoint_t right_glyph,
				void *user_data G_GNUC_UNUSED)
{
  PangoFcHbContext *context = (PangoFcHbContext *) font_data;
  FT_Face ft_face = context->ft_face;
  FT_Vector kerning;

  if (FT_Get_Kerning (ft_face, left_glyph, right_glyph, FT_KERNING_DEFAULT, &kerning))
    return 0;

  return PANGO_UNITS_26_6 (kerning.x * context->x_scale);
}

static hb_font_funcs_t *
pango_fc_get_hb_font_funcs (void)
{
  static hb_font_funcs_t *funcs;

  if (G_UNLIKELY (!funcs)) {
    funcs = hb_font_funcs_create ();
    hb_font_funcs_set_glyph_func (funcs, pango_fc_hb_font_get_glyph, NULL, NULL);
    hb_font_funcs_set_glyph_h_advance_func (funcs, pango_fc_hb_font_get_glyph_advance, NULL, NULL);
    hb_font_funcs_set_glyph_v_advance_func (funcs, pango_fc_hb_font_get_glyph_advance, NULL, NULL);
    hb_font_funcs_set_glyph_h_origin_func (funcs, pango_fc_hb_font_get_glyph_h_origin, NULL, NULL);
    hb_font_funcs_set_glyph_v_origin_func (funcs, pango_fc_hb_font_get_glyph_v_origin, NULL, NULL);
    hb_font_funcs_set_glyph_h_kerning_func (funcs, pango_fc_hb_font_get_h_kerning, NULL, NULL);
    /* Don't need v_kerning. */
    hb_font_funcs_set_glyph_extents_func (funcs, pango_fc_hb_font_get_glyph_extents, NULL, NULL);
    hb_font_funcs_set_glyph_contour_point_func (funcs, pango_fc_hb_font_get_glyph_contour_point, NULL, NULL);
    /* Don't need glyph_name / glyph_from_name */
  }

  return funcs;
}


void
_pango_fc_shape (PangoFont           *font,
		 const char          *item_text,
		 unsigned int         item_length,
		 const PangoAnalysis *analysis,
		 PangoGlyphString    *glyphs,
		 const char          *paragraph_text,
		 unsigned int         paragraph_length)
{
  PangoFcHbContext context;
  PangoFcFont *fc_font;
  PangoFcFontKey *key;
  FT_Face ft_face;
  hb_face_t *hb_face;
  hb_font_t *hb_font;
  hb_buffer_t *hb_buffer;
  hb_direction_t hb_direction;
  gboolean free_buffer;
  hb_glyph_info_t *hb_glyph;
  hb_glyph_position_t *hb_position;
  int last_cluster;
  guint i, num_glyphs;
  unsigned int item_offset = item_text - paragraph_text;
  hb_feature_t features[32];
  unsigned int num_features = 0;
  double x_scale_inv, y_scale_inv;
  PangoGlyphInfo *infos;

  g_return_if_fail (font != NULL);
  g_return_if_fail (analysis != NULL);

  fc_font = PANGO_FC_FONT (font);
  ft_face = pango_fc_font_lock_face (fc_font);
  if (!ft_face)
    return;

  /* TODO: Cache hb_font? */

  x_scale_inv = y_scale_inv = 1.0;
  key = _pango_fc_font_get_font_key (fc_font);
  if (key)
  {
    const PangoMatrix *matrix = pango_fc_font_key_get_matrix (key);
    pango_matrix_get_font_scale_factors (matrix, &x_scale_inv, &y_scale_inv);
  }
  if (PANGO_GRAVITY_IS_IMPROPER (analysis->gravity))
  {
    x_scale_inv = -x_scale_inv;
    y_scale_inv = -y_scale_inv;
  }
  context.x_scale = 1. / x_scale_inv;
  context.y_scale = 1. / y_scale_inv;
  context.ft_face = ft_face;
  context.fc_font = fc_font;
  context.vertical = PANGO_GRAVITY_IS_VERTICAL (analysis->gravity);
  hb_face = hb_ft_face_create_cached (ft_face);
  hb_font = hb_font_create (hb_face);
  hb_font_set_funcs (hb_font,
		     pango_fc_get_hb_font_funcs (),
		     &context,
		     NULL);
  hb_font_set_scale (hb_font,
		     +(((gint64) ft_face->size->metrics.x_scale * ft_face->units_per_EM) >> 12) * context.x_scale,
		     -(((gint64) ft_face->size->metrics.y_scale * ft_face->units_per_EM) >> 12) * context.y_scale);
  hb_font_set_ppem (hb_font,
		    fc_font->is_hinted ? ft_face->size->metrics.x_ppem : 0,
		    fc_font->is_hinted ? ft_face->size->metrics.y_ppem : 0);

  hb_buffer = acquire_buffer (&free_buffer);

  hb_direction = PANGO_GRAVITY_IS_VERTICAL (analysis->gravity) ? HB_DIRECTION_TTB : HB_DIRECTION_LTR;
  if (analysis->level % 2)
    hb_direction = HB_DIRECTION_REVERSE (hb_direction);
  if (PANGO_GRAVITY_IS_IMPROPER (analysis->gravity))
    hb_direction = HB_DIRECTION_REVERSE (hb_direction);

  /* setup buffer */

  hb_buffer_set_direction (hb_buffer, hb_direction);
  hb_buffer_set_script (hb_buffer, hb_glib_script_to_script (analysis->script));
  hb_buffer_set_language (hb_buffer, hb_language_from_string (pango_language_to_string (analysis->language), -1));
  hb_buffer_set_flags (hb_buffer,
		       (item_offset == 0 ? HB_BUFFER_FLAG_BOT : 0) |
		       (item_offset + item_length == paragraph_length ? HB_BUFFER_FLAG_EOT : 0));

  hb_buffer_add_utf8 (hb_buffer, paragraph_text, paragraph_length, item_offset, item_length);

  /* Setup features from fontconfig pattern. */
  if (fc_font->font_pattern)
    {
      char *s;
      while (num_features < G_N_ELEMENTS (features) &&
	     FcResultMatch == FcPatternGetString (fc_font->font_pattern,
						  PANGO_FC_FONT_FEATURES,
						  num_features,
						  (FcChar8 **) &s))
	{
	  gboolean ret = hb_feature_from_string (s, -1, &features[num_features]);
	  features[num_features].start = 0;
	  features[num_features].end   = (unsigned int) -1;
	  if (ret)
	    num_features++;
	}
    }

  hb_shape (hb_font, hb_buffer, features, num_features);

  if (PANGO_GRAVITY_IS_IMPROPER (analysis->gravity))
    hb_buffer_reverse (hb_buffer);

  /* buffer output */
  num_glyphs = hb_buffer_get_length (hb_buffer);
  hb_glyph = hb_buffer_get_glyph_infos (hb_buffer, NULL);
  pango_glyph_string_set_size (glyphs, num_glyphs);
  infos = glyphs->glyphs;
  last_cluster = -1;
  for (i = 0; i < num_glyphs; i++)
    {
      infos[i].glyph = hb_glyph->codepoint;
      glyphs->log_clusters[i] = hb_glyph->cluster - item_offset;
      infos[i].attr.is_cluster_start = glyphs->log_clusters[i] != last_cluster;
      hb_glyph++;
      last_cluster = glyphs->log_clusters[i];
    }

  hb_position = hb_buffer_get_glyph_positions (hb_buffer, NULL);
  if (context.vertical)
    for (i = 0; i < num_glyphs; i++)
      {
        /* 90 degrees rotation counter-clockwise. */
	infos[i].geometry.width    =  hb_position->y_advance;
	infos[i].geometry.x_offset =  hb_position->y_offset;
	infos[i].geometry.y_offset = -hb_position->x_offset;
	hb_position++;
      }
  else /* horizontal */
    for (i = 0; i < num_glyphs; i++)
      {
	infos[i].geometry.width    = hb_position->x_advance;
	infos[i].geometry.x_offset = hb_position->x_offset;
	infos[i].geometry.y_offset = hb_position->y_offset;
	hb_position++;
      }

  if (fc_font->is_hinted)
  {
    if (context.x_scale == 1.0 && context.y_scale == 1.0)
      {
	for (i = 0; i < num_glyphs; i++)
	  infos[i].geometry.width = PANGO_UNITS_ROUND (infos[i].geometry.width);
      }
    else
      {
#if 0
	if (context.vertical)
	  {
	    /* XXX */
	    double tmp = x_scale;
	    x_scale = y_scale;
	    y_scale = -tmp;
	  }
#endif
#define HINT(value, scale_inv, scale) (PANGO_UNITS_ROUND ((int) ((value) * scale)) * scale_inv)
#define HINT_X(value) HINT ((value), context.x_scale, x_scale_inv)
#define HINT_Y(value) HINT ((value), context.y_scale, y_scale_inv)
	for (i = 0; i < num_glyphs; i++)
	  {
	    infos[i].geometry.width    = HINT_X (infos[i].geometry.width);
	    infos[i].geometry.x_offset = HINT_X (infos[i].geometry.x_offset);
	    infos[i].geometry.y_offset = HINT_Y (infos[i].geometry.y_offset);
	  }
#undef HINT_Y
#undef HINT_X
#undef HINT
      }
  }

  release_buffer (hb_buffer, free_buffer);
  hb_font_destroy (hb_font);
  hb_face_destroy (hb_face);
  pango_fc_font_unlock_face (fc_font);
}