hb-ot-var-mvar-table.hh (5728B)
1 /* 2 * Copyright © 2017 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_VAR_MVAR_TABLE_HH 28 #define HB_OT_VAR_MVAR_TABLE_HH 29 30 #include "hb-ot-var-common.hh" 31 32 33 namespace OT { 34 35 36 struct VariationValueRecord 37 { 38 bool sanitize (hb_sanitize_context_t *c) const 39 { 40 TRACE_SANITIZE (this); 41 return_trace (c->check_struct (this)); 42 } 43 44 bool subset (hb_subset_context_t *c, 45 const hb_map_t& varidx_map) const 46 { 47 TRACE_SUBSET (this); 48 auto *out = c->serializer->embed (*this); 49 if (unlikely (!out)) return_trace (false); 50 51 hb_codepoint_t *new_idx; 52 return_trace (c->serializer->check_assign (out->varIdx, 53 (varidx_map.has (varIdx, &new_idx)) ? *new_idx : HB_OT_LAYOUT_NO_VARIATIONS_INDEX, 54 HB_SERIALIZE_ERROR_INT_OVERFLOW)); 55 } 56 57 public: 58 Tag valueTag; /* Four-byte tag identifying a font-wide measure. */ 59 VarIdx varIdx; /* Outer/inner index into ItemVariationStore item. */ 60 61 public: 62 DEFINE_SIZE_STATIC (8); 63 }; 64 65 66 /* 67 * MVAR -- Metrics Variations 68 * https://docs.microsoft.com/en-us/typography/opentype/spec/mvar 69 */ 70 #define HB_OT_TAG_MVAR HB_TAG('M','V','A','R') 71 72 struct MVAR 73 { 74 static constexpr hb_tag_t tableTag = HB_OT_TAG_MVAR; 75 76 bool sanitize (hb_sanitize_context_t *c) const 77 { 78 TRACE_SANITIZE (this); 79 return_trace (version.sanitize (c) && 80 hb_barrier () && 81 likely (version.major == 1) && 82 c->check_struct (this) && 83 hb_barrier () && 84 valueRecordSize >= VariationValueRecord::static_size && 85 varStore.sanitize (c, this) && 86 c->check_range (valuesZ.arrayZ, 87 valueRecordCount, 88 valueRecordSize)); 89 } 90 91 bool subset (hb_subset_context_t *c) const 92 { 93 TRACE_SUBSET (this); 94 #ifdef HB_NO_VAR 95 return_trace (false); 96 #endif 97 98 if (c->plan->all_axes_pinned) 99 return_trace (false); 100 101 MVAR *out = c->serializer->start_embed (*this); 102 if (unlikely (!c->serializer->extend_min (out))) return_trace (false); 103 out->version = version; 104 out->reserved = reserved; 105 out->valueRecordSize = valueRecordSize; 106 out->valueRecordCount = valueRecordCount; 107 108 item_variations_t item_vars; 109 const ItemVariationStore& src_var_store = this+varStore; 110 111 if (!item_vars.instantiate (src_var_store, c->plan)) 112 return_trace (false); 113 114 /* serialize varstore */ 115 if (!out->varStore.serialize_serialize (c->serializer, item_vars.has_long_word (), 116 c->plan->axis_tags, 117 item_vars.get_region_list (), 118 item_vars.get_vardata_encodings ())) 119 return_trace (false); 120 121 /* serialize value records array */ 122 unsigned value_rec_count = valueRecordCount; 123 const VariationValueRecord *record = reinterpret_cast<const VariationValueRecord*> (valuesZ.arrayZ); 124 for (unsigned i = 0; i < value_rec_count; i++) 125 { 126 if (!record->subset (c, item_vars.get_varidx_map ())) return_trace (false); 127 record++; 128 } 129 return_trace (true); 130 } 131 132 float get_var (hb_tag_t tag, 133 const int *coords, unsigned int coord_count) const 134 { 135 const VariationValueRecord *record; 136 record = (VariationValueRecord *) hb_bsearch (tag, 137 (const VariationValueRecord *) 138 (const HBUINT8 *) valuesZ, 139 valueRecordCount, valueRecordSize, 140 tag_compare); 141 if (!record) 142 return 0.; 143 144 return (this+varStore).get_delta (record->varIdx, coords, coord_count); 145 } 146 147 protected: 148 static int tag_compare (const void *pa, const void *pb) 149 { 150 const hb_tag_t *a = (const hb_tag_t *) pa; 151 const Tag *b = (const Tag *) pb; 152 return b->cmp (*a); 153 } 154 155 protected: 156 FixedVersion<>version; /* Version of the metrics variation table 157 * initially set to 0x00010000u */ 158 HBUINT16 reserved; /* Not used; set to 0. */ 159 HBUINT16 valueRecordSize;/* The size in bytes of each value record — 160 * must be greater than zero. */ 161 HBUINT16 valueRecordCount;/* The number of value records — may be zero. */ 162 Offset16To<ItemVariationStore> 163 varStore; /* Offset to item variation store table. */ 164 UnsizedArrayOf<HBUINT8> 165 valuesZ; /* Array of value records. The records must be 166 * in binary order of their valueTag field. */ 167 168 public: 169 DEFINE_SIZE_ARRAY (12, valuesZ); 170 }; 171 172 } /* namespace OT */ 173 174 175 #define HB_ADD_MVAR_VAR(tag, field) \ 176 c->serializer->check_assign (table->field, \ 177 roundf (table->field + \ 178 MVAR.get_var (tag, \ 179 c->plan->normalized_coords.arrayZ, \ 180 c->plan->normalized_coords.length)), \ 181 HB_SERIALIZE_ERROR_INT_OVERFLOW) 182 183 184 #endif /* HB_OT_VAR_MVAR_TABLE_HH */