• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright © 2009,2010  Red Hat, Inc.
3  * Copyright © 2010,2011,2012,2013  Google, Inc.
4  *
5  *  This is part of HarfBuzz, a text shaping library.
6  *
7  * Permission is hereby granted, without written agreement and without
8  * license or royalty fees, to use, copy, modify, and distribute this
9  * software and its documentation for any purpose, provided that the
10  * above copyright notice and the following two paragraphs appear in
11  * all copies of this software.
12  *
13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17  * DAMAGE.
18  *
19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24  *
25  * Red Hat Author(s): Behdad Esfahbod
26  * Google Author(s): Behdad Esfahbod
27  */
28 
29 #ifndef HB_OT_MAP_HH
30 #define HB_OT_MAP_HH
31 
32 #include "hb-buffer.hh"
33 
34 
35 #define HB_OT_MAP_MAX_BITS 8u
36 #define HB_OT_MAP_MAX_VALUE ((1u << HB_OT_MAP_MAX_BITS) - 1u)
37 
38 struct hb_ot_shape_plan_t;
39 
40 static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
41 
42 struct hb_ot_map_t
43 {
44   friend struct hb_ot_map_builder_t;
45 
46   public:
47 
48   struct feature_map_t {
49     hb_tag_t tag; /* should be first for our bsearch to work */
50     unsigned int index[2]; /* GSUB/GPOS */
51     unsigned int stage[2]; /* GSUB/GPOS */
52     unsigned int shift;
53     hb_mask_t mask;
54     hb_mask_t _1_mask; /* mask for value=1, for quick access */
55     unsigned int needs_fallback : 1;
56     unsigned int auto_zwnj : 1;
57     unsigned int auto_zwj : 1;
58     unsigned int random : 1;
59 
cmphb_ot_map_t::feature_map_t60     int cmp (const hb_tag_t tag_) const
61     { return tag_ < tag ? -1 : tag_ > tag ? 1 : 0; }
62   };
63 
64   struct lookup_map_t {
65     unsigned short index;
66     unsigned short auto_zwnj : 1;
67     unsigned short auto_zwj : 1;
68     unsigned short random : 1;
69     hb_mask_t mask;
70 
cmphb_ot_map_t::lookup_map_t71     static int cmp (const void *pa, const void *pb)
72     {
73       const lookup_map_t *a = (const lookup_map_t *) pa;
74       const lookup_map_t *b = (const lookup_map_t *) pb;
75       return a->index < b->index ? -1 : a->index > b->index ? 1 : 0;
76     }
77   };
78 
79   typedef void (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
80 
81   struct stage_map_t {
82     unsigned int last_lookup; /* Cumulative */
83     pause_func_t pause_func;
84   };
85 
inithb_ot_map_t86   void init ()
87   {
88     memset (this, 0, sizeof (*this));
89 
90     features.init ();
91     for (unsigned int table_index = 0; table_index < 2; table_index++)
92     {
93       lookups[table_index].init ();
94       stages[table_index].init ();
95     }
96   }
finihb_ot_map_t97   void fini ()
98   {
99     features.fini ();
100     for (unsigned int table_index = 0; table_index < 2; table_index++)
101     {
102       lookups[table_index].fini ();
103       stages[table_index].fini ();
104     }
105   }
106 
get_global_maskhb_ot_map_t107   hb_mask_t get_global_mask () const { return global_mask; }
108 
get_maskhb_ot_map_t109   hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = nullptr) const
110   {
111     const feature_map_t *map = features.bsearch (feature_tag);
112     if (shift) *shift = map ? map->shift : 0;
113     return map ? map->mask : 0;
114   }
115 
needs_fallbackhb_ot_map_t116   bool needs_fallback (hb_tag_t feature_tag) const
117   {
118     const feature_map_t *map = features.bsearch (feature_tag);
119     return map ? map->needs_fallback : false;
120   }
121 
get_1_maskhb_ot_map_t122   hb_mask_t get_1_mask (hb_tag_t feature_tag) const
123   {
124     const feature_map_t *map = features.bsearch (feature_tag);
125     return map ? map->_1_mask : 0;
126   }
127 
get_feature_indexhb_ot_map_t128   unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const
129   {
130     const feature_map_t *map = features.bsearch (feature_tag);
131     return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;
132   }
133 
get_feature_stagehb_ot_map_t134   unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const
135   {
136     const feature_map_t *map = features.bsearch (feature_tag);
137     return map ? map->stage[table_index] : (unsigned int) -1;
138   }
139 
get_stage_lookupshb_ot_map_t140   void get_stage_lookups (unsigned int table_index, unsigned int stage,
141 			  const struct lookup_map_t **plookups, unsigned int *lookup_count) const
142   {
143     if (unlikely (stage == (unsigned int) -1)) {
144       *plookups = nullptr;
145       *lookup_count = 0;
146       return;
147     }
148     assert (stage <= stages[table_index].len);
149     unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
150     unsigned int end   = stage < stages[table_index].len ? stages[table_index][stage].last_lookup : lookups[table_index].len;
151     *plookups = end == start ? nullptr : &lookups[table_index][start];
152     *lookup_count = end - start;
153   }
154 
155   HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
156   template <typename Proxy>
157   HB_INTERNAL inline void apply (const Proxy &proxy,
158 				 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
159   HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
160   HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
161 
162   public:
163   hb_tag_t chosen_script[2];
164   bool found_script[2];
165 
166   private:
167 
168   hb_mask_t global_mask;
169 
170   hb_vector_t<feature_map_t, 8> features;
171   hb_vector_t<lookup_map_t, 16> lookups[2]; /* GSUB/GPOS */
172   hb_vector_t<stage_map_t, 4> stages[2]; /* GSUB/GPOS */
173 };
174 
175 enum hb_ot_map_feature_flags_t
176 {
177   F_NONE		= 0x0000u,
178   F_GLOBAL		= 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */
179   F_HAS_FALLBACK	= 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */
180   F_MANUAL_ZWNJ		= 0x0004u, /* Don't skip over ZWNJ when matching **context**. */
181   F_MANUAL_ZWJ		= 0x0008u, /* Don't skip over ZWJ when matching **input**. */
182   F_MANUAL_JOINERS	= F_MANUAL_ZWNJ | F_MANUAL_ZWJ,
183   F_GLOBAL_MANUAL_JOINERS= F_GLOBAL | F_MANUAL_JOINERS,
184   F_GLOBAL_HAS_FALLBACK = F_GLOBAL | F_HAS_FALLBACK,
185   F_GLOBAL_SEARCH	= 0x0010u, /* If feature not found in LangSys, look for it in global feature list and pick one. */
186   F_RANDOM		= 0x0020u  /* Randomly select a glyph from an AlternateSubstFormat1 subtable. */
187 };
188 HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);
189 
190 
191 struct hb_ot_map_feature_t
192 {
193   hb_tag_t tag;
194   hb_ot_map_feature_flags_t flags;
195 };
196 
197 struct hb_ot_shape_plan_key_t;
198 
199 struct hb_ot_map_builder_t
200 {
201   public:
202 
203   HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
204 				   const hb_segment_properties_t *props_);
205 
206   HB_INTERNAL ~hb_ot_map_builder_t ();
207 
208   HB_INTERNAL void add_feature (hb_tag_t tag,
209 				hb_ot_map_feature_flags_t flags=F_NONE,
210 				unsigned int value=1);
211 
add_featurehb_ot_map_builder_t212   void add_feature (const hb_ot_map_feature_t &feat)
213   { add_feature (feat.tag, feat.flags); }
214 
enable_featurehb_ot_map_builder_t215   void enable_feature (hb_tag_t tag,
216 			      hb_ot_map_feature_flags_t flags=F_NONE,
217 			      unsigned int value=1)
218   { add_feature (tag, F_GLOBAL | flags, value); }
219 
disable_featurehb_ot_map_builder_t220   void disable_feature (hb_tag_t tag)
221   { add_feature (tag, F_GLOBAL, 0); }
222 
add_gsub_pausehb_ot_map_builder_t223   void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
224   { add_pause (0, pause_func); }
add_gpos_pausehb_ot_map_builder_t225   void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
226   { add_pause (1, pause_func); }
227 
228   HB_INTERNAL void compile (hb_ot_map_t                  &m,
229 			    const hb_ot_shape_plan_key_t &key);
230 
231   private:
232 
233   HB_INTERNAL void add_lookups (hb_ot_map_t  &m,
234 				unsigned int  table_index,
235 				unsigned int  feature_index,
236 				unsigned int  variations_index,
237 				hb_mask_t     mask,
238 				bool          auto_zwnj = true,
239 				bool          auto_zwj = true,
240 				bool          random = false);
241 
242   struct feature_info_t {
243     hb_tag_t tag;
244     unsigned int seq; /* sequence#, used for stable sorting only */
245     unsigned int max_value;
246     hb_ot_map_feature_flags_t flags;
247     unsigned int default_value; /* for non-global features, what should the unset glyphs take */
248     unsigned int stage[2]; /* GSUB/GPOS */
249 
cmphb_ot_map_builder_t::feature_info_t250     static int cmp (const void *pa, const void *pb)
251     {
252       const feature_info_t *a = (const feature_info_t *) pa;
253       const feature_info_t *b = (const feature_info_t *) pb;
254       return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) :
255 	     (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0);
256     }
257   };
258 
259   struct stage_info_t {
260     unsigned int index;
261     hb_ot_map_t::pause_func_t pause_func;
262   };
263 
264   HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
265 
266   public:
267 
268   hb_face_t *face;
269   hb_segment_properties_t props;
270 
271   hb_tag_t chosen_script[2];
272   bool found_script[2];
273   unsigned int script_index[2], language_index[2];
274 
275   private:
276 
277   unsigned int current_stage[2]; /* GSUB/GPOS */
278   hb_vector_t<feature_info_t, 32> feature_infos;
279   hb_vector_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */
280 };
281 
282 
283 
284 #endif /* HB_OT_MAP_HH */
285