hb-ot-map.hh (9787B)
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 unsigned int per_syllable : 1; 60 61 int cmp (const hb_tag_t tag_) const 62 { return tag_ < tag ? -1 : tag_ > tag ? 1 : 0; } 63 64 HB_INTERNAL static int cmp (const void *pa, const void *pb) 65 { 66 const feature_map_t *a = (const feature_map_t *) pa; 67 const feature_map_t *b = (const feature_map_t *) pb; 68 return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; 69 } 70 }; 71 72 struct lookup_map_t { 73 unsigned short index; 74 unsigned short auto_zwnj : 1; 75 unsigned short auto_zwj : 1; 76 unsigned short random : 1; 77 unsigned short per_syllable : 1; 78 hb_mask_t mask; 79 hb_tag_t feature_tag; 80 81 HB_INTERNAL static int cmp (const void *pa, const void *pb) 82 { 83 const lookup_map_t *a = (const lookup_map_t *) pa; 84 const lookup_map_t *b = (const lookup_map_t *) pb; 85 return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; 86 } 87 }; 88 89 /* Pause functions return true if new glyph indices might have been 90 * added to the buffer. This is used to update buffer digest. */ 91 typedef bool (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer); 92 93 struct stage_map_t { 94 unsigned int last_lookup; /* Cumulative */ 95 pause_func_t pause_func; 96 }; 97 98 void init () 99 { 100 hb_memset (this, 0, sizeof (*this)); 101 102 features.init0 (); 103 for (unsigned int table_index = 0; table_index < 2; table_index++) 104 { 105 lookups[table_index].init0 (); 106 stages[table_index].init0 (); 107 } 108 } 109 void fini () 110 { 111 features.fini (); 112 for (unsigned int table_index = 0; table_index < 2; table_index++) 113 { 114 lookups[table_index].fini (); 115 stages[table_index].fini (); 116 } 117 } 118 119 hb_mask_t get_global_mask () const { return global_mask; } 120 121 hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = nullptr) const 122 { 123 const feature_map_t *map = features.bsearch (feature_tag); 124 if (shift) *shift = map ? map->shift : 0; 125 return map ? map->mask : 0; 126 } 127 128 bool needs_fallback (hb_tag_t feature_tag) const 129 { 130 const feature_map_t *map = features.bsearch (feature_tag); 131 return map ? map->needs_fallback : false; 132 } 133 134 hb_mask_t get_1_mask (hb_tag_t feature_tag) const 135 { 136 const feature_map_t *map = features.bsearch (feature_tag); 137 return map ? map->_1_mask : 0; 138 } 139 140 unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const 141 { 142 const feature_map_t *map = features.bsearch (feature_tag); 143 return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX; 144 } 145 146 unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const 147 { 148 const feature_map_t *map = features.bsearch (feature_tag); 149 return map ? map->stage[table_index] : UINT_MAX; 150 } 151 152 hb_array_t<const hb_ot_map_t::lookup_map_t> 153 get_stage_lookups (unsigned int table_index, unsigned int stage) const 154 { 155 if (unlikely (stage > stages[table_index].length)) 156 return hb_array<const hb_ot_map_t::lookup_map_t> (nullptr, 0); 157 158 unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0; 159 unsigned int end = stage < stages[table_index].length ? stages[table_index][stage].last_lookup : lookups[table_index].length; 160 return lookups[table_index].as_array ().sub_array (start, end - start); 161 } 162 163 HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const; 164 template <typename Proxy> 165 HB_INTERNAL void apply (const Proxy &proxy, 166 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const; 167 HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const; 168 HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const; 169 HB_INTERNAL unsigned int get_feature_tags (unsigned int start_offset, 170 unsigned int *tag_count, /* IN/OUT */ 171 hb_tag_t *tags /* OUT */) const; 172 173 public: 174 hb_tag_t chosen_script[2]; 175 bool found_script[2]; 176 177 private: 178 179 hb_mask_t global_mask = 0; 180 181 hb_sorted_vector_t<feature_map_t> features; 182 hb_vector_t<lookup_map_t> lookups[2]; /* GSUB/GPOS */ 183 hb_vector_t<stage_map_t> stages[2]; /* GSUB/GPOS */ 184 }; 185 186 enum hb_ot_map_feature_flags_t 187 { 188 F_NONE = 0x0000u, 189 F_GLOBAL = 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */ 190 F_HAS_FALLBACK = 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */ 191 F_MANUAL_ZWNJ = 0x0004u, /* Don't skip over ZWNJ when matching **context**. */ 192 F_MANUAL_ZWJ = 0x0008u, /* Don't skip over ZWJ when matching **input**. */ 193 F_MANUAL_JOINERS = F_MANUAL_ZWNJ | F_MANUAL_ZWJ, 194 F_GLOBAL_MANUAL_JOINERS= F_GLOBAL | F_MANUAL_JOINERS, 195 F_GLOBAL_HAS_FALLBACK = F_GLOBAL | F_HAS_FALLBACK, 196 F_GLOBAL_SEARCH = 0x0010u, /* If feature not found in LangSys, look for it in global feature list and pick one. */ 197 F_RANDOM = 0x0020u, /* Randomly select a glyph from an AlternateSubstFormat1 subtable. */ 198 F_PER_SYLLABLE = 0x0040u /* Contain lookup application to within syllable. */ 199 }; 200 HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t); 201 202 203 struct hb_ot_map_feature_t 204 { 205 hb_tag_t tag; 206 hb_ot_map_feature_flags_t flags; 207 }; 208 209 struct hb_ot_shape_plan_key_t; 210 211 struct hb_ot_map_builder_t 212 { 213 public: 214 215 HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_, 216 const hb_segment_properties_t &props_); 217 218 HB_INTERNAL ~hb_ot_map_builder_t (); 219 220 HB_INTERNAL void add_feature (hb_tag_t tag, 221 hb_ot_map_feature_flags_t flags=F_NONE, 222 unsigned int value=1); 223 224 HB_INTERNAL bool has_feature (hb_tag_t tag); 225 226 void add_feature (const hb_ot_map_feature_t &feat) 227 { add_feature (feat.tag, feat.flags); } 228 229 void enable_feature (hb_tag_t tag, 230 hb_ot_map_feature_flags_t flags=F_NONE, 231 unsigned int value=1) 232 { add_feature (tag, F_GLOBAL | flags, value); } 233 234 void disable_feature (hb_tag_t tag) 235 { add_feature (tag, F_GLOBAL, 0); } 236 237 void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func) 238 { add_pause (0, pause_func); } 239 void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func) 240 { add_pause (1, pause_func); } 241 242 HB_INTERNAL void compile (hb_ot_map_t &m, 243 const hb_ot_shape_plan_key_t &key); 244 245 private: 246 247 HB_INTERNAL void add_lookups (hb_ot_map_t &m, 248 unsigned int table_index, 249 unsigned int feature_index, 250 unsigned int variations_index, 251 hb_mask_t mask, 252 bool auto_zwnj = true, 253 bool auto_zwj = true, 254 bool random = false, 255 bool per_syllable = false, 256 hb_tag_t feature_tag = HB_TAG(' ',' ',' ',' ')); 257 258 struct feature_info_t { 259 hb_tag_t tag; 260 unsigned int seq; /* sequence#, used for stable sorting only */ 261 unsigned int max_value; 262 hb_ot_map_feature_flags_t flags; 263 unsigned int default_value; /* for non-global features, what should the unset glyphs take */ 264 unsigned int stage[2]; /* GSUB/GPOS */ 265 266 HB_INTERNAL static int cmp (const void *pa, const void *pb) 267 { 268 const feature_info_t *a = (const feature_info_t *) pa; 269 const feature_info_t *b = (const feature_info_t *) pb; 270 return (a->tag != b->tag) ? (a->tag < b->tag ? -1 : 1) : 271 (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0); 272 } 273 }; 274 275 struct stage_info_t { 276 unsigned int index; 277 hb_ot_map_t::pause_func_t pause_func; 278 }; 279 280 HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func); 281 282 public: 283 284 hb_face_t *face; 285 hb_segment_properties_t props; 286 bool is_simple; 287 288 hb_tag_t chosen_script[2]; 289 bool found_script[2]; 290 unsigned int script_index[2], language_index[2]; 291 292 private: 293 294 unsigned int current_stage[2]; /* GSUB/GPOS */ 295 hb_vector_t<feature_info_t> feature_infos; 296 hb_vector_t<stage_info_t> stages[2]; /* GSUB/GPOS */ 297 }; 298 299 300 301 #endif /* HB_OT_MAP_HH */