hb-ot-map.cc revision 49baa1f69efb0e3c62e45bd59dd88459a84bf390
1/* 2 * Copyright (C) 2009,2010 Red Hat, Inc. 3 * Copyright (C) 2010 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#include "hb-ot-map-private.hh" 30 31#include "hb-ot-shape-private.hh" 32 33HB_BEGIN_DECLS 34 35 36void 37hb_ot_map_t::add_lookups (hb_face_t *face, 38 unsigned int table_index, 39 unsigned int feature_index, 40 hb_mask_t mask) 41{ 42 unsigned int i = MAX_LOOKUPS - lookup_count[table_index]; 43 lookup_map_t *lookups = lookup_maps[table_index] + lookup_count[table_index]; 44 45 unsigned int *lookup_indices = (unsigned int *) lookups; 46 47 hb_ot_layout_feature_get_lookup_indexes (face, 48 table_tags[table_index], 49 feature_index, 50 0, &i, 51 lookup_indices); 52 53 lookup_count[table_index] += i; 54 55 while (i--) { 56 lookups[i].mask = mask; 57 lookups[i].index = lookup_indices[i]; 58 } 59} 60 61 62void 63hb_ot_map_t::compile (hb_face_t *face, 64 const hb_segment_properties_t *props) 65{ 66 global_mask = 0; 67 lookup_count[0] = lookup_count[1] = 0; 68 69 if (!feature_count) 70 return; 71 72 73 /* Fetch script/language indices for GSUB/GPOS. We need these later to skip 74 * features not available in either table and not waste precious bits for them. */ 75 76 const hb_tag_t *script_tags; 77 hb_tag_t language_tag; 78 79 script_tags = hb_ot_tags_from_script (props->script); 80 language_tag = hb_ot_tag_from_language (props->language); 81 82 unsigned int script_index[2], language_index[2]; 83 for (unsigned int table_index = 0; table_index < 2; table_index++) { 84 hb_tag_t table_tag = table_tags[table_index]; 85 hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index]); 86 hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]); 87 } 88 89 90 /* Sort features and merge duplicates */ 91 qsort (feature_infos, feature_count, sizeof (feature_infos[0]), (hb_compare_func_t) feature_info_t::cmp); 92 unsigned int j = 0; 93 for (unsigned int i = 1; i < feature_count; i++) 94 if (feature_infos[i].tag != feature_infos[j].tag) 95 feature_infos[++j] = feature_infos[i]; 96 else { 97 if (feature_infos[i].global) 98 feature_infos[j] = feature_infos[i]; 99 else { 100 feature_infos[j].global = false; 101 feature_infos[j].value = MAX (feature_infos[j].value, feature_infos[i].value); 102 } 103 } 104 feature_count = j + 1; 105 106 107 /* Allocate bits now */ 108 unsigned int next_bit = 1; 109 j = 0; 110 for (unsigned int i = 0; i < feature_count; i++) { 111 const feature_info_t *info = &feature_infos[i]; 112 113 unsigned int bits_needed; 114 115 if (info->global && info->value == 1) 116 /* Uses the global bit */ 117 bits_needed = 0; 118 else 119 bits_needed = _hb_bit_storage (info->value); 120 121 if (!info->value || next_bit + bits_needed > 8 * sizeof (hb_mask_t)) 122 continue; /* Feature disabled, or not enough bits. */ 123 124 125 bool found = false; 126 unsigned int feature_index[2]; 127 for (unsigned int table_index = 0; table_index < 2; table_index++) 128 found |= hb_ot_layout_language_find_feature (face, 129 table_tags[table_index], 130 script_index[table_index], 131 language_index[table_index], 132 info->tag, 133 &feature_index[table_index]); 134 if (!found) 135 continue; 136 137 138 feature_map_t *map = &feature_maps[j++]; 139 140 map->tag = info->tag; 141 map->index[0] = feature_index[0]; 142 map->index[1] = feature_index[1]; 143 if (info->global && info->value == 1) { 144 /* Uses the global bit */ 145 map->shift = 0; 146 map->mask = 1; 147 } else { 148 map->shift = next_bit; 149 map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit); 150 next_bit += bits_needed; 151 if (info->global) 152 global_mask |= map->mask; 153 } 154 155 } 156 feature_count = j; 157 158 159 for (unsigned int table_index = 0; table_index < 2; table_index++) { 160 hb_tag_t table_tag = table_tags[table_index]; 161 162 /* Collect lookup indices for features */ 163 164 unsigned int required_feature_index; 165 if (hb_ot_layout_language_get_required_feature_index (face, 166 table_tag, 167 script_index[table_index], 168 language_index[table_index], 169 &required_feature_index)) 170 add_lookups (face, table_index, required_feature_index, 1); 171 172 for (unsigned i = 0; i < feature_count; i++) 173 add_lookups (face, table_index, feature_maps[i].index[table_index], feature_maps[i].mask); 174 175 /* Sort lookups and merge duplicates */ 176 qsort (lookup_maps[table_index], lookup_count[table_index], sizeof (lookup_maps[table_index][0]), (hb_compare_func_t) lookup_map_t::cmp); 177 if (lookup_count[table_index]) 178 { 179 unsigned int j = 0; 180 for (unsigned int i = 1; i < lookup_count[table_index]; i++) 181 if (lookup_maps[table_index][i].index != lookup_maps[table_index][j].index) 182 lookup_maps[table_index][++j] = lookup_maps[table_index][i]; 183 else 184 lookup_maps[table_index][j].mask |= lookup_maps[table_index][i].mask; 185 j++; 186 lookup_count[table_index] = j; 187 } 188 } 189} 190 191 192HB_END_DECLS 193