hb-ot-shape-complex-private.hh revision 7cfee3827636f0dff7df5c8975a4fadd1b4bfbd5
1/*
2 * Copyright © 2010,2011,2012  Google, 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 * Google Author(s): Behdad Esfahbod
25 */
26
27#ifndef HB_OT_SHAPE_COMPLEX_PRIVATE_HH
28#define HB_OT_SHAPE_COMPLEX_PRIVATE_HH
29
30#include "hb-private.hh"
31
32#include "hb-ot-shape-private.hh"
33#include "hb-ot-shape-normalize-private.hh"
34
35
36
37/* buffer var allocations, used by complex shapers */
38#define complex_var_u8_0()	var2.u8[2]
39#define complex_var_u8_1()	var2.u8[3]
40
41
42enum hb_ot_shape_zero_width_marks_type_t {
43  HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
44//  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY,
45  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE,
46  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
47  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,
48
49  HB_OT_SHAPE_ZERO_WIDTH_MARKS_DEFAULT = HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE
50};
51
52
53/* Master OT shaper list */
54#define HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS \
55  HB_COMPLEX_SHAPER_IMPLEMENT (default) /* should be first */ \
56  HB_COMPLEX_SHAPER_IMPLEMENT (arabic) \
57  HB_COMPLEX_SHAPER_IMPLEMENT (hangul) \
58  HB_COMPLEX_SHAPER_IMPLEMENT (hebrew) \
59  HB_COMPLEX_SHAPER_IMPLEMENT (indic) \
60  HB_COMPLEX_SHAPER_IMPLEMENT (myanmar) \
61  HB_COMPLEX_SHAPER_IMPLEMENT (sea) \
62  HB_COMPLEX_SHAPER_IMPLEMENT (thai) \
63  HB_COMPLEX_SHAPER_IMPLEMENT (tibetan) \
64  /* ^--- Add new shapers here */
65
66
67struct hb_ot_complex_shaper_t
68{
69  char name[8];
70
71  /* collect_features()
72   * Called during shape_plan().
73   * Shapers should use plan->map to add their features and callbacks.
74   * May be NULL.
75   */
76  void (*collect_features) (hb_ot_shape_planner_t *plan);
77
78  /* override_features()
79   * Called during shape_plan().
80   * Shapers should use plan->map to override features and add callbacks after
81   * common features are added.
82   * May be NULL.
83   */
84  void (*override_features) (hb_ot_shape_planner_t *plan);
85
86
87  /* data_create()
88   * Called at the end of shape_plan().
89   * Whatever shapers return will be accessible through plan->data later.
90   * If NULL is returned, means a plan failure.
91   */
92  void *(*data_create) (const hb_ot_shape_plan_t *plan);
93
94  /* data_destroy()
95   * Called when the shape_plan is being destroyed.
96   * plan->data is passed here for destruction.
97   * If NULL is returned, means a plan failure.
98   * May be NULL.
99   */
100  void (*data_destroy) (void *data);
101
102
103  /* preprocess_text()
104   * Called during shape().
105   * Shapers can use to modify text before shaping starts.
106   * May be NULL.
107   */
108  void (*preprocess_text) (const hb_ot_shape_plan_t *plan,
109			   hb_buffer_t              *buffer,
110			   hb_font_t                *font);
111
112
113  hb_ot_shape_normalization_mode_t normalization_preference;
114
115  /* decompose()
116   * Called during shape()'s normalization.
117   * May be NULL.
118   */
119  bool (*decompose) (const hb_ot_shape_normalize_context_t *c,
120		     hb_codepoint_t  ab,
121		     hb_codepoint_t *a,
122		     hb_codepoint_t *b);
123
124  /* compose()
125   * Called during shape()'s normalization.
126   * May be NULL.
127   */
128  bool (*compose) (const hb_ot_shape_normalize_context_t *c,
129		   hb_codepoint_t  a,
130		   hb_codepoint_t  b,
131		   hb_codepoint_t *ab);
132
133  /* setup_masks()
134   * Called during shape().
135   * Shapers should use map to get feature masks and set on buffer.
136   * Shapers may NOT modify characters.
137   * May be NULL.
138   */
139  void (*setup_masks) (const hb_ot_shape_plan_t *plan,
140		       hb_buffer_t              *buffer,
141		       hb_font_t                *font);
142
143  hb_ot_shape_zero_width_marks_type_t zero_width_marks;
144
145  bool fallback_position;
146};
147
148#define HB_COMPLEX_SHAPER_IMPLEMENT(name) extern HB_INTERNAL const hb_ot_complex_shaper_t _hb_ot_complex_shaper_##name;
149HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS
150#undef HB_COMPLEX_SHAPER_IMPLEMENT
151
152
153static inline const hb_ot_complex_shaper_t *
154hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
155{
156  switch ((hb_tag_t) planner->props.script)
157  {
158    default:
159      return &_hb_ot_complex_shaper_default;
160
161
162    /* Unicode-1.1 additions */
163    case HB_SCRIPT_ARABIC:
164
165    /* Unicode-3.0 additions */
166    case HB_SCRIPT_MONGOLIAN:
167    case HB_SCRIPT_SYRIAC:
168
169    /* Unicode-5.0 additions */
170    case HB_SCRIPT_NKO:
171    case HB_SCRIPT_PHAGS_PA:
172
173    /* Unicode-6.0 additions */
174    case HB_SCRIPT_MANDAIC:
175
176    /* Unicode-7.0 additions */
177    case HB_SCRIPT_MANICHAEAN:
178    case HB_SCRIPT_PSALTER_PAHLAVI:
179
180      /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
181       * This is because we do fallback shaping for Arabic script (and not others). */
182      if (planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
183	  planner->props.script == HB_SCRIPT_ARABIC)
184	return &_hb_ot_complex_shaper_arabic;
185      else
186	return &_hb_ot_complex_shaper_default;
187
188
189    /* Unicode-1.1 additions */
190    case HB_SCRIPT_THAI:
191    case HB_SCRIPT_LAO:
192
193      return &_hb_ot_complex_shaper_thai;
194
195
196    /* Unicode-1.1 additions */
197    case HB_SCRIPT_HANGUL:
198
199      return &_hb_ot_complex_shaper_hangul;
200
201
202    /* Unicode-2.0 additions */
203    case HB_SCRIPT_TIBETAN:
204
205      return &_hb_ot_complex_shaper_tibetan;
206
207
208    /* Unicode-1.1 additions */
209    case HB_SCRIPT_HEBREW:
210
211      return &_hb_ot_complex_shaper_hebrew;
212
213
214    /* ^--- Add new shapers here */
215
216
217#if 0
218    /* Note:
219     *
220     * These disabled scripts are listed in ucd/IndicSyllabicCategory.txt, but according
221     * to Martin Hosken and Jonathan Kew do not require complex shaping.
222     *
223     * TODO We should automate figuring out which scripts do not need complex shaping
224     *
225     * TODO We currently keep data for these scripts in our indic table.  Need to fix the
226     * generator to not do that.
227     */
228
229
230    /* Simple? */
231
232    /* Unicode-3.2 additions */
233    case HB_SCRIPT_BUHID:
234    case HB_SCRIPT_HANUNOO:
235
236    /* Unicode-5.1 additions */
237    case HB_SCRIPT_SAURASHTRA:
238
239    /* Unicode-6.0 additions */
240    case HB_SCRIPT_BATAK:
241    case HB_SCRIPT_BRAHMI:
242
243
244    /* Simple */
245
246    /* Unicode-1.1 additions */
247    /* These have their own shaper now. */
248    case HB_SCRIPT_LAO:
249    case HB_SCRIPT_THAI:
250
251    /* Unicode-3.2 additions */
252    case HB_SCRIPT_TAGALOG:
253    case HB_SCRIPT_TAGBANWA:
254
255    /* Unicode-4.0 additions */
256    case HB_SCRIPT_LIMBU:
257    case HB_SCRIPT_TAI_LE:
258
259    /* Unicode-4.1 additions */
260    case HB_SCRIPT_KHAROSHTHI:
261    case HB_SCRIPT_SYLOTI_NAGRI:
262
263    /* Unicode-5.1 additions */
264    case HB_SCRIPT_KAYAH_LI:
265
266    /* Unicode-5.2 additions */
267    case HB_SCRIPT_TAI_VIET:
268
269
270#endif
271
272    /* Unicode-1.1 additions */
273    case HB_SCRIPT_BENGALI:
274    case HB_SCRIPT_DEVANAGARI:
275    case HB_SCRIPT_GUJARATI:
276    case HB_SCRIPT_GURMUKHI:
277    case HB_SCRIPT_KANNADA:
278    case HB_SCRIPT_MALAYALAM:
279    case HB_SCRIPT_ORIYA:
280    case HB_SCRIPT_TAMIL:
281    case HB_SCRIPT_TELUGU:
282
283    /* Unicode-3.0 additions */
284    case HB_SCRIPT_SINHALA:
285
286    /* Unicode-5.0 additions */
287    case HB_SCRIPT_BALINESE:
288
289    /* Unicode-5.1 additions */
290    case HB_SCRIPT_LEPCHA:
291    case HB_SCRIPT_REJANG:
292    case HB_SCRIPT_SUNDANESE:
293
294    /* Unicode-5.2 additions */
295    case HB_SCRIPT_JAVANESE:
296    case HB_SCRIPT_KAITHI:
297    case HB_SCRIPT_MEETEI_MAYEK:
298
299    /* Unicode-6.0 additions */
300
301    /* Unicode-6.1 additions */
302    case HB_SCRIPT_CHAKMA:
303    case HB_SCRIPT_SHARADA:
304    case HB_SCRIPT_TAKRI:
305
306      /* If the designer designed the font for the 'DFLT' script,
307       * use the default shaper.  Otherwise, use the Indic shaper.
308       * Note that for some simple scripts, there may not be *any*
309       * GSUB/GPOS needed, so there may be no scripts found! */
310      if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
311	return &_hb_ot_complex_shaper_default;
312      else
313	return &_hb_ot_complex_shaper_indic;
314
315    case HB_SCRIPT_KHMER:
316      /* A number of Khmer fonts in the wild don't have a 'pref' feature,
317       * and as such won't shape properly via the Indic shaper;
318       * however, they typically have 'liga' / 'clig' features that implement
319       * the necessary "reordering" by means of ligature substitutions.
320       * So we send such pref-less fonts through the generic shaper instead. */
321      if (planner->map.found_script[0] &&
322	  hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
323					      planner->map.script_index[0],
324					      planner->map.language_index[0],
325					      HB_TAG ('p','r','e','f'),
326					      NULL))
327	return &_hb_ot_complex_shaper_indic;
328      else
329	return &_hb_ot_complex_shaper_default;
330
331    case HB_SCRIPT_MYANMAR:
332      /* For Myanmar, we only want to use the Myanmar shaper if the "new" script
333       * tag is found.  For "old" script tag we want to use the default shaper. */
334      if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
335	return &_hb_ot_complex_shaper_myanmar;
336      else
337	return &_hb_ot_complex_shaper_default;
338
339    /* Unicode-4.1 additions */
340    case HB_SCRIPT_BUGINESE:
341    case HB_SCRIPT_NEW_TAI_LUE:
342
343    /* Unicode-5.1 additions */
344    case HB_SCRIPT_CHAM:
345
346    /* Unicode-5.2 additions */
347    case HB_SCRIPT_TAI_THAM:
348
349      /* If the designer designed the font for the 'DFLT' script,
350       * use the default shaper.  Otherwise, use the Indic shaper.
351       * Note that for some simple scripts, there may not be *any*
352       * GSUB/GPOS needed, so there may be no scripts found! */
353      if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
354	return &_hb_ot_complex_shaper_default;
355      else
356	return &_hb_ot_complex_shaper_sea;
357  }
358}
359
360
361#endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */
362