summaryrefslogtreecommitdiff
path: root/modules/hebrew/hebrew-fc.c
blob: 12f25c5e8b6e3342047405eeba836c471a67ace7 (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
/* Pango
 * hebrew-fc.h: Hebrew shaper for FreeType-based backends
 *
 * Copyright (C) 2000, 2007 Red Hat Software
 * Authors:
 *   Owen Taylor <otaylor@redhat.com>
 *   Dov Grobgeld <dov.grobgeld@weizmann.ac.il>
 *   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 <pango/pango-ot.h>

#include "pango-engine.h"
#include "pango-utils.h"
#include "pangofc-font.h"
#include "hebrew-shaper.h"

/* No extra fields needed */
typedef PangoEngineShape      HebrewEngineFc;
typedef PangoEngineShapeClass HebrewEngineFcClass ;

#define MAX_CLUSTER_CHRS	20

static PangoEngineScriptInfo hebrew_scripts[] = {
  { PANGO_SCRIPT_HEBREW, "*" }
};

#define SCRIPT_ENGINE_NAME "HebrewScriptEngineFc"
#define RENDER_TYPE PANGO_RENDER_TYPE_FC

static PangoEngineInfo script_engines[] = {
  {
    SCRIPT_ENGINE_NAME,
    PANGO_ENGINE_TYPE_SHAPE,
    RENDER_TYPE,
    hebrew_scripts, G_N_ELEMENTS(hebrew_scripts)
  }
};

static void
get_cluster_glyphs(PangoFont      *font,
		   gunichar       cluster[],
		   gint           cluster_size,
		   gboolean       do_mirror,
		   /* output */
		   gint           glyph_num[],
		   PangoGlyph     glyph[],
		   gint           widths[],
		   PangoRectangle ink_rects[])
{
  int i;
  for (i=0; i<cluster_size; i++)
    {
      PangoRectangle logical_rect;
      gunichar wc = cluster[i];
      gunichar mirrored_ch;

      if (do_mirror)
	if (pango_get_mirror_char (wc, &mirrored_ch))
	  wc = mirrored_ch;

      if (pango_is_zero_width (wc))
	glyph_num[i] = PANGO_GLYPH_EMPTY;
      else
	{
	  glyph_num[i] = pango_fc_font_get_glyph ((PangoFcFont *)font, wc);

	  if (!glyph_num[i])
	    glyph_num[i] = PANGO_GET_UNKNOWN_GLYPH ( wc);
	}

      glyph[i] = glyph_num[i];

      pango_font_get_glyph_extents (font,
				    glyph[i], &ink_rects[i], &logical_rect);

      /* Assign the base char width to the last character in the cluster */
      if (i==0)
	{
	  widths[i] = 0;
	  widths[cluster_size-1] = logical_rect.width;
	}
      else if (i < cluster_size-1)
	widths[i] = 0;
    }
}

static void
add_glyph (PangoGlyphString *glyphs,
	   gint              cluster_start,
	   PangoGlyph        glyph,
	   gboolean          is_combining,
	   gint              width,
	   gint              x_offset,
	   gint              y_offset
	   )
{
  gint index = glyphs->num_glyphs;

  pango_glyph_string_set_size (glyphs, index + 1);

  glyphs->glyphs[index].glyph = glyph;
  glyphs->glyphs[index].attr.is_cluster_start = is_combining ? 0 : 1;

  glyphs->log_clusters[index] = cluster_start;

  glyphs->glyphs[index].geometry.x_offset = x_offset;
  glyphs->glyphs[index].geometry.y_offset = y_offset;
  glyphs->glyphs[index].geometry.width = width;
}

static void
add_cluster(PangoGlyphString *glyphs,
	    int              cluster_size,
	    int              cluster_start,
	    PangoGlyph       glyph[],
	    int              width[],
	    int              x_offset[],
	    int              y_offset[])
{
  int i;

  for (i=0; i<cluster_size; i++)
    {
      add_glyph (glyphs, cluster_start, glyph[i],
		 i == 0 ? FALSE : TRUE, width[i], x_offset[i], y_offset[i]);
    }
}

static void
fallback_shape (PangoEngineShape *engine G_GNUC_UNUSED,
		PangoFont        *font,
		const char       *text,
		gint              length,
		const PangoAnalysis *analysis,
		PangoGlyphString *glyphs)
{
  const char *p;
  const char *log_cluster;
  gunichar cluster[MAX_CLUSTER_CHRS];
  gint cluster_size;
  gint glyph_num[MAX_CLUSTER_CHRS];
  gint glyph_width[MAX_CLUSTER_CHRS], x_offset[MAX_CLUSTER_CHRS], y_offset[MAX_CLUSTER_CHRS];
  PangoRectangle ink_rects[MAX_CLUSTER_CHRS];
  PangoGlyph glyph[MAX_CLUSTER_CHRS];

  pango_glyph_string_set_size (glyphs, 0);

  p = text;
  while (p < text + length)
    {
      log_cluster = p;
      p = hebrew_shaper_get_next_cluster (p, text + length - p,
					  /* output */
					  cluster, &cluster_size);
      get_cluster_glyphs(font,
			 cluster,
			 cluster_size,
			 analysis->level % 2,
			 /* output */
			 glyph_num,
			 glyph,
			 glyph_width,
			 ink_rects);

      /* Kern the glyphs! */
      hebrew_shaper_get_cluster_kerning(cluster,
					cluster_size,
					/* Input and output */
					ink_rects,
					glyph_width,
					/* output */
					x_offset,
					y_offset);

      add_cluster(glyphs,
		  cluster_size,
		  log_cluster - text,
		  glyph,
		  glyph_width,
		  x_offset,
		  y_offset);

    }

  if (analysis->level % 2)
    hebrew_shaper_bidi_reorder(glyphs);
}

static const PangoOTFeatureMap gsub_features[] =
{
  {"ccmp", PANGO_OT_ALL_GLYPHS},
  {"locl", PANGO_OT_ALL_GLYPHS},
  {"rlig", PANGO_OT_ALL_GLYPHS},
  /* 'dlig' should be turned-on/off-able.  lets turn off for now. */
  /* {"dlig", PANGO_OT_ALL_GLYPHS}, */
};

static const PangoOTFeatureMap gpos_features[] =
{
  {"kern", PANGO_OT_ALL_GLYPHS},
  {"mark", PANGO_OT_ALL_GLYPHS},
  {"mkmk", PANGO_OT_ALL_GLYPHS}
};

static void
hebrew_engine_shape (PangoEngineShape *engine,
		     PangoFont        *font,
		     const char       *text,
		     gint              length,
		     const PangoAnalysis *analysis,
		     PangoGlyphString *glyphs)
{
  PangoFcFont *fc_font;
  FT_Face face;
  PangoOTRulesetDescription desc;
  const PangoOTRuleset *ruleset;
  PangoOTBuffer *buffer;
  guint n_gpos_features = 0;
  glong n_chars;
  const char *p;
  int cluster = 0;
  int i;

  g_return_if_fail (font != NULL);
  g_return_if_fail (text != NULL);
  g_return_if_fail (length >= 0);
  g_return_if_fail (analysis != NULL);

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

  desc.script = analysis->script;
  desc.language = analysis->language;

  desc.n_static_gsub_features = G_N_ELEMENTS (gsub_features);
  desc.static_gsub_features = gsub_features;
  desc.n_static_gpos_features = G_N_ELEMENTS (gpos_features);
  desc.static_gpos_features = gpos_features;

  /* TODO populate other_features from analysis->extra_attrs */
  desc.n_other_features = 0;
  desc.other_features = NULL;

  ruleset = pango_ot_ruleset_get_for_description (pango_ot_info_get (face), &desc);

  pango_ot_ruleset_get_feature_count (ruleset, NULL, &n_gpos_features);
  if (n_gpos_features == 0)
    {
      fallback_shape (engine, font, text, length, analysis, glyphs);
      goto out;
    }

  buffer = pango_ot_buffer_new (fc_font);
  pango_ot_buffer_set_rtl (buffer, analysis->level % 2 != 0);

  n_chars = g_utf8_strlen (text, length);

  p = text;
  for (i=0; i < n_chars; i++)
    {
      gunichar wc;
      PangoGlyph glyph;

      wc = g_utf8_get_char (p);

      if (g_unichar_type (wc) != G_UNICODE_NON_SPACING_MARK)
	cluster = p - text;

      if (pango_is_zero_width (wc))
        glyph = PANGO_GLYPH_EMPTY;
      else
        {
	  gunichar c = wc;

	  if (analysis->level % 2)
	    g_unichar_get_mirror_char (c, &c);

	  glyph = pango_fc_font_get_glyph (fc_font, c);
	}

      if (!glyph)
	glyph = PANGO_GET_UNKNOWN_GLYPH (wc);

      pango_ot_buffer_add_glyph (buffer, glyph, 0, cluster);

      p = g_utf8_next_char (p);
    }

  pango_ot_ruleset_substitute (ruleset, buffer);
  pango_ot_ruleset_position (ruleset, buffer);
  pango_ot_buffer_output (buffer, glyphs);

  pango_ot_buffer_destroy (buffer);

 out:
  pango_fc_font_unlock_face (fc_font);
}

static void
hebrew_engine_fc_class_init (PangoEngineShapeClass *class)
{
  class->script_shape = hebrew_engine_shape;
}

PANGO_ENGINE_SHAPE_DEFINE_TYPE (HebrewEngineFc, hebrew_engine_fc,
				hebrew_engine_fc_class_init, NULL)

void
PANGO_MODULE_ENTRY(init) (GTypeModule *module)
{
  hebrew_engine_fc_register_type (module);
}

void
PANGO_MODULE_ENTRY(exit) (void)
{
}

void
PANGO_MODULE_ENTRY(list) (PangoEngineInfo **engines,
			  int              *n_engines)
{
  *engines = script_engines;
  *n_engines = G_N_ELEMENTS (script_engines);
}

PangoEngine *
PANGO_MODULE_ENTRY(create) (const char *id)
{
  if (!strcmp (id, SCRIPT_ENGINE_NAME))
    return g_object_new (hebrew_engine_fc_type, NULL);
  else
    return NULL;
}