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   /* disable_otl()
150    * Called during shape().
151    * If set and returns true, GDEF/GSUB/GPOS of the font are ignored
152    * and fallback operations used.
153    * May be NULL.
154    */
155   bool (*disable_otl) (const hb_ot_shape_plan_t *plan);
156 
157   hb_ot_shape_zero_width_marks_type_t zero_width_marks;
158 
159   bool fallback_position;
160 };
161 
162 #define HB_COMPLEX_SHAPER_IMPLEMENT(name) extern HB_INTERNAL const hb_ot_complex_shaper_t _hb_ot_complex_shaper_##name;
163 HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS
164 #undef HB_COMPLEX_SHAPER_IMPLEMENT
165 
166 
167 static inline const hb_ot_complex_shaper_t *
hb_ot_shape_complex_categorize(const hb_ot_shape_planner_t * planner)168 hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
169 {
170   switch ((hb_tag_t) planner->props.script)
171   {
172     default:
173       return &_hb_ot_complex_shaper_default;
174 
175 
176     /* Unicode-1.1 additions */
177     case HB_SCRIPT_ARABIC:
178 
179     /* Unicode-3.0 additions */
180     case HB_SCRIPT_MONGOLIAN:
181     case HB_SCRIPT_SYRIAC:
182 
183     /* Unicode-5.0 additions */
184     case HB_SCRIPT_NKO:
185     case HB_SCRIPT_PHAGS_PA:
186 
187     /* Unicode-6.0 additions */
188     case HB_SCRIPT_MANDAIC:
189 
190     /* Unicode-7.0 additions */
191     case HB_SCRIPT_MANICHAEAN:
192     case HB_SCRIPT_PSALTER_PAHLAVI:
193 
194       /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
195        * This is because we do fallback shaping for Arabic script (and not others).
196        * But note that Arabic shaping is applicable only to horizontal layout; for
197        * vertical text, just use the generic shaper instead. */
198       if ((planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
199 	   planner->props.script == HB_SCRIPT_ARABIC) &&
200 	  HB_DIRECTION_IS_HORIZONTAL(planner->props.direction))
201 	return &_hb_ot_complex_shaper_arabic;
202       else
203 	return &_hb_ot_complex_shaper_default;
204 
205 
206     /* Unicode-1.1 additions */
207     case HB_SCRIPT_THAI:
208     case HB_SCRIPT_LAO:
209 
210       return &_hb_ot_complex_shaper_thai;
211 
212 
213     /* Unicode-1.1 additions */
214     case HB_SCRIPT_HANGUL:
215 
216       return &_hb_ot_complex_shaper_hangul;
217 
218 
219     /* Unicode-2.0 additions */
220     case HB_SCRIPT_TIBETAN:
221 
222       return &_hb_ot_complex_shaper_tibetan;
223 
224 
225     /* Unicode-1.1 additions */
226     case HB_SCRIPT_HEBREW:
227 
228       return &_hb_ot_complex_shaper_hebrew;
229 
230 
231     /* ^--- Add new shapers here */
232 
233 #if 0
234     /* Unicode-4.1 additions */
235     case HB_SCRIPT_NEW_TAI_LUE:
236 #endif
237 
238     /* Unicode-1.1 additions */
239     case HB_SCRIPT_BENGALI:
240     case HB_SCRIPT_DEVANAGARI:
241     case HB_SCRIPT_GUJARATI:
242     case HB_SCRIPT_GURMUKHI:
243     case HB_SCRIPT_KANNADA:
244     case HB_SCRIPT_MALAYALAM:
245     case HB_SCRIPT_ORIYA:
246     case HB_SCRIPT_TAMIL:
247     case HB_SCRIPT_TELUGU:
248 
249     /* Unicode-3.0 additions */
250     case HB_SCRIPT_SINHALA:
251 
252       /* If the designer designed the font for the 'DFLT' script,
253        * use the default shaper.  Otherwise, use the specific shaper.
254        * Note that for some simple scripts, there may not be *any*
255        * GSUB/GPOS needed, so there may be no scripts found! */
256       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
257 	return &_hb_ot_complex_shaper_default;
258       else
259 	return &_hb_ot_complex_shaper_indic;
260 
261     case HB_SCRIPT_KHMER:
262       /* A number of Khmer fonts in the wild don't have a 'pref' feature,
263        * and as such won't shape properly via the Indic shaper;
264        * however, they typically have 'liga' / 'clig' features that implement
265        * the necessary "reordering" by means of ligature substitutions.
266        * So we send such pref-less fonts through the generic shaper instead. */
267       if (planner->map.found_script[0] &&
268 	  hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
269 					      planner->map.script_index[0],
270 					      planner->map.language_index[0],
271 					      HB_TAG ('p','r','e','f'),
272 					      NULL))
273 	return &_hb_ot_complex_shaper_indic;
274       else
275 	return &_hb_ot_complex_shaper_default;
276 
277     case HB_SCRIPT_MYANMAR:
278       if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
279 	return &_hb_ot_complex_shaper_myanmar;
280       else if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','r'))
281 	return &_hb_ot_complex_shaper_myanmar_old;
282       else
283 	return &_hb_ot_complex_shaper_default;
284 
285 
286     /* Unicode-2.0 additions */
287     //case HB_SCRIPT_TIBETAN:
288 
289     /* Unicode-3.0 additions */
290     //case HB_SCRIPT_MONGOLIAN:
291     //case HB_SCRIPT_SINHALA:
292 
293     /* Unicode-3.2 additions */
294     case HB_SCRIPT_BUHID:
295     case HB_SCRIPT_HANUNOO:
296     case HB_SCRIPT_TAGALOG:
297     case HB_SCRIPT_TAGBANWA:
298 
299     /* Unicode-4.0 additions */
300     case HB_SCRIPT_LIMBU:
301     case HB_SCRIPT_TAI_LE:
302 
303     /* Unicode-4.1 additions */
304     case HB_SCRIPT_BUGINESE:
305     case HB_SCRIPT_KHAROSHTHI:
306     case HB_SCRIPT_SYLOTI_NAGRI:
307     case HB_SCRIPT_TIFINAGH:
308 
309     /* Unicode-5.0 additions */
310     case HB_SCRIPT_BALINESE:
311     //case HB_SCRIPT_NKO:
312     //case HB_SCRIPT_PHAGS_PA:
313 
314     /* Unicode-5.1 additions */
315     case HB_SCRIPT_CHAM:
316     case HB_SCRIPT_KAYAH_LI:
317     case HB_SCRIPT_LEPCHA:
318     case HB_SCRIPT_REJANG:
319     case HB_SCRIPT_SAURASHTRA:
320     case HB_SCRIPT_SUNDANESE:
321 
322     /* Unicode-5.2 additions */
323     case HB_SCRIPT_EGYPTIAN_HIEROGLYPHS:
324     case HB_SCRIPT_JAVANESE:
325     case HB_SCRIPT_KAITHI:
326     case HB_SCRIPT_MEETEI_MAYEK:
327     case HB_SCRIPT_TAI_THAM:
328     case HB_SCRIPT_TAI_VIET:
329 
330     /* Unicode-6.0 additions */
331     case HB_SCRIPT_BATAK:
332     case HB_SCRIPT_BRAHMI:
333     //case HB_SCRIPT_MANDAIC:
334 
335     /* Unicode-6.1 additions */
336     case HB_SCRIPT_CHAKMA:
337     case HB_SCRIPT_SHARADA:
338     case HB_SCRIPT_TAKRI:
339 
340     /* Unicode-7.0 additions */
341     case HB_SCRIPT_DUPLOYAN:
342     case HB_SCRIPT_GRANTHA:
343     case HB_SCRIPT_KHOJKI:
344     case HB_SCRIPT_KHUDAWADI:
345     case HB_SCRIPT_MAHAJANI:
346     //case HB_SCRIPT_MANICHAEAN:
347     case HB_SCRIPT_MODI:
348     case HB_SCRIPT_PAHAWH_HMONG:
349     //case HB_SCRIPT_PSALTER_PAHLAVI:
350     case HB_SCRIPT_SIDDHAM:
351     case HB_SCRIPT_TIRHUTA:
352 
353     /* Unicode-8.0 additions */
354     case HB_SCRIPT_AHOM:
355     //case HB_SCRIPT_MULTANI:
356 
357     /* Unicode-9.0 additions */
358     case HB_SCRIPT_BHAIKSUKI:
359     case HB_SCRIPT_MARCHEN:
360     case HB_SCRIPT_NEWA:
361 
362       /* If the designer designed the font for the 'DFLT' script,
363        * use the default shaper.  Otherwise, use the specific shaper.
364        * Note that for some simple scripts, there may not be *any*
365        * GSUB/GPOS needed, so there may be no scripts found! */
366       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
367 	return &_hb_ot_complex_shaper_default;
368       else
369 	return &_hb_ot_complex_shaper_use;
370   }
371 }
372 
373 
374 #endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */
375