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 cmphb_ot_map_t::feature_map_t61 int cmp (const hb_tag_t tag_) const 62 { return tag_ < tag ? -1 : tag_ > tag ? 1 : 0; } 63 }; 64 65 struct lookup_map_t { 66 unsigned short index; 67 unsigned short auto_zwnj : 1; 68 unsigned short auto_zwj : 1; 69 unsigned short random : 1; 70 unsigned short per_syllable : 1; 71 hb_mask_t mask; 72 hb_tag_t feature_tag; 73 cmphb_ot_map_t::lookup_map_t74 HB_INTERNAL static int cmp (const void *pa, const void *pb) 75 { 76 const lookup_map_t *a = (const lookup_map_t *) pa; 77 const lookup_map_t *b = (const lookup_map_t *) pb; 78 return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; 79 } 80 }; 81 82 /* Pause functions return true if new glyph indices might have been 83 * added to the buffer. This is used to update buffer digest. */ 84 typedef bool (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer); 85 86 struct stage_map_t { 87 unsigned int last_lookup; /* Cumulative */ 88 pause_func_t pause_func; 89 }; 90 inithb_ot_map_t91 void init () 92 { 93 hb_memset (this, 0, sizeof (*this)); 94 95 features.init0 (); 96 for (unsigned int table_index = 0; table_index < 2; table_index++) 97 { 98 lookups[table_index].init0 (); 99 stages[table_index].init0 (); 100 } 101 } finihb_ot_map_t102 void fini () 103 { 104 features.fini (); 105 for (unsigned int table_index = 0; table_index < 2; table_index++) 106 { 107 lookups[table_index].fini (); 108 stages[table_index].fini (); 109 } 110 } 111 get_global_maskhb_ot_map_t112 hb_mask_t get_global_mask () const { return global_mask; } 113 get_maskhb_ot_map_t114 hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = nullptr) const 115 { 116 const feature_map_t *map = features.bsearch (feature_tag); 117 if (shift) *shift = map ? map->shift : 0; 118 return map ? map->mask : 0; 119 } 120 needs_fallbackhb_ot_map_t121 bool needs_fallback (hb_tag_t feature_tag) const 122 { 123 const feature_map_t *map = features.bsearch (feature_tag); 124 return map ? map->needs_fallback : false; 125 } 126 get_1_maskhb_ot_map_t127 hb_mask_t get_1_mask (hb_tag_t feature_tag) const 128 { 129 const feature_map_t *map = features.bsearch (feature_tag); 130 return map ? map->_1_mask : 0; 131 } 132 get_feature_indexhb_ot_map_t133 unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const 134 { 135 const feature_map_t *map = features.bsearch (feature_tag); 136 return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX; 137 } 138 get_feature_stagehb_ot_map_t139 unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const 140 { 141 const feature_map_t *map = features.bsearch (feature_tag); 142 return map ? map->stage[table_index] : UINT_MAX; 143 } 144 145 hb_array_t<const hb_ot_map_t::lookup_map_t> get_stage_lookupshb_ot_map_t146 get_stage_lookups (unsigned int table_index, unsigned int stage) const 147 { 148 if (unlikely (stage > stages[table_index].length)) 149 return hb_array<const hb_ot_map_t::lookup_map_t> (nullptr, 0); 150 151 unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0; 152 unsigned int end = stage < stages[table_index].length ? stages[table_index][stage].last_lookup : lookups[table_index].length; 153 return lookups[table_index].as_array ().sub_array (start, end - start); 154 } 155 156 HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const; 157 template <typename Proxy> 158 HB_INTERNAL void apply (const Proxy &proxy, 159 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const; 160 HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const; 161 HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const; 162 163 public: 164 hb_tag_t chosen_script[2]; 165 bool found_script[2]; 166 167 private: 168 169 hb_mask_t global_mask = 0; 170 171 hb_sorted_vector_t<feature_map_t> features; 172 hb_vector_t<lookup_map_t> lookups[2]; /* GSUB/GPOS */ 173 hb_vector_t<stage_map_t> stages[2]; /* GSUB/GPOS */ 174 }; 175 176 enum hb_ot_map_feature_flags_t 177 { 178 F_NONE = 0x0000u, 179 F_GLOBAL = 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */ 180 F_HAS_FALLBACK = 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */ 181 F_MANUAL_ZWNJ = 0x0004u, /* Don't skip over ZWNJ when matching **context**. */ 182 F_MANUAL_ZWJ = 0x0008u, /* Don't skip over ZWJ when matching **input**. */ 183 F_MANUAL_JOINERS = F_MANUAL_ZWNJ | F_MANUAL_ZWJ, 184 F_GLOBAL_MANUAL_JOINERS= F_GLOBAL | F_MANUAL_JOINERS, 185 F_GLOBAL_HAS_FALLBACK = F_GLOBAL | F_HAS_FALLBACK, 186 F_GLOBAL_SEARCH = 0x0010u, /* If feature not found in LangSys, look for it in global feature list and pick one. */ 187 F_RANDOM = 0x0020u, /* Randomly select a glyph from an AlternateSubstFormat1 subtable. */ 188 F_PER_SYLLABLE = 0x0040u /* Contain lookup application to within syllable. */ 189 }; 190 HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t); 191 192 193 struct hb_ot_map_feature_t 194 { 195 hb_tag_t tag; 196 hb_ot_map_feature_flags_t flags; 197 }; 198 199 struct hb_ot_shape_plan_key_t; 200 201 struct hb_ot_map_builder_t 202 { 203 public: 204 205 HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_, 206 const hb_segment_properties_t &props_); 207 208 HB_INTERNAL ~hb_ot_map_builder_t (); 209 210 HB_INTERNAL void add_feature (hb_tag_t tag, 211 hb_ot_map_feature_flags_t flags=F_NONE, 212 unsigned int value=1); 213 214 HB_INTERNAL bool has_feature (hb_tag_t tag); 215 add_featurehb_ot_map_builder_t216 void add_feature (const hb_ot_map_feature_t &feat) 217 { add_feature (feat.tag, feat.flags); } 218 enable_featurehb_ot_map_builder_t219 void enable_feature (hb_tag_t tag, 220 hb_ot_map_feature_flags_t flags=F_NONE, 221 unsigned int value=1) 222 { add_feature (tag, F_GLOBAL | flags, value); } 223 disable_featurehb_ot_map_builder_t224 void disable_feature (hb_tag_t tag) 225 { add_feature (tag, F_GLOBAL, 0); } 226 add_gsub_pausehb_ot_map_builder_t227 void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func) 228 { add_pause (0, pause_func); } add_gpos_pausehb_ot_map_builder_t229 void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func) 230 { add_pause (1, pause_func); } 231 232 HB_INTERNAL void compile (hb_ot_map_t &m, 233 const hb_ot_shape_plan_key_t &key); 234 235 private: 236 237 HB_INTERNAL void add_lookups (hb_ot_map_t &m, 238 unsigned int table_index, 239 unsigned int feature_index, 240 unsigned int variations_index, 241 hb_mask_t mask, 242 bool auto_zwnj = true, 243 bool auto_zwj = true, 244 bool random = false, 245 bool per_syllable = false, 246 hb_tag_t feature_tag = HB_TAG(' ',' ',' ',' ')); 247 248 struct feature_info_t { 249 hb_tag_t tag; 250 unsigned int seq; /* sequence#, used for stable sorting only */ 251 unsigned int max_value; 252 hb_ot_map_feature_flags_t flags; 253 unsigned int default_value; /* for non-global features, what should the unset glyphs take */ 254 unsigned int stage[2]; /* GSUB/GPOS */ 255 cmphb_ot_map_builder_t::feature_info_t256 HB_INTERNAL static int cmp (const void *pa, const void *pb) 257 { 258 const feature_info_t *a = (const feature_info_t *) pa; 259 const feature_info_t *b = (const feature_info_t *) pb; 260 return (a->tag != b->tag) ? (a->tag < b->tag ? -1 : 1) : 261 (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0); 262 } 263 }; 264 265 struct stage_info_t { 266 unsigned int index; 267 hb_ot_map_t::pause_func_t pause_func; 268 }; 269 270 HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func); 271 272 public: 273 274 hb_face_t *face; 275 hb_segment_properties_t props; 276 277 hb_tag_t chosen_script[2]; 278 bool found_script[2]; 279 unsigned int script_index[2], language_index[2]; 280 281 private: 282 283 unsigned int current_stage[2]; /* GSUB/GPOS */ 284 hb_vector_t<feature_info_t> feature_infos; 285 hb_vector_t<stage_info_t> stages[2]; /* GSUB/GPOS */ 286 }; 287 288 289 290 #endif /* HB_OT_MAP_HH */ 291