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