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_AVAR_TABLE_HH 28 #define HB_OT_VAR_AVAR_TABLE_HH 29 30 #include "hb-open-type.hh" 31 #include "hb-ot-var-common.hh" 32 33 34 /* 35 * avar -- Axis Variations 36 * https://docs.microsoft.com/en-us/typography/opentype/spec/avar 37 */ 38 39 #define HB_OT_TAG_avar HB_TAG('a','v','a','r') 40 41 42 namespace OT { 43 44 45 /* "Spec": https://github.com/be-fonts/boring-expansion-spec/issues/14 */ 46 struct avarV2Tail 47 { 48 friend struct avar; 49 sanitizeOT::avarV2Tail50 bool sanitize (hb_sanitize_context_t *c, 51 const void *base) const 52 { 53 TRACE_SANITIZE (this); 54 return_trace (varIdxMap.sanitize (c, base) && 55 varStore.sanitize (c, base)); 56 } 57 58 protected: 59 Offset32To<DeltaSetIndexMap> varIdxMap; /* Offset from the beginning of 'avar' table. */ 60 Offset32To<VariationStore> varStore; /* Offset from the beginning of 'avar' table. */ 61 62 public: 63 DEFINE_SIZE_STATIC (8); 64 }; 65 66 67 struct AxisValueMap 68 { sanitizeOT::AxisValueMap69 bool sanitize (hb_sanitize_context_t *c) const 70 { 71 TRACE_SANITIZE (this); 72 return_trace (c->check_struct (this)); 73 } 74 75 public: 76 F2DOT14 coords[2]; 77 // F2DOT14 fromCoord; /* A normalized coordinate value obtained using 78 // * default normalization. */ 79 // F2DOT14 toCoord; /* The modified, normalized coordinate value. */ 80 81 public: 82 DEFINE_SIZE_STATIC (4); 83 }; 84 85 struct SegmentMaps : Array16Of<AxisValueMap> 86 { mapOT::SegmentMaps87 int map (int value, unsigned int from_offset = 0, unsigned int to_offset = 1) const 88 { 89 #define fromCoord coords[from_offset] 90 #define toCoord coords[to_offset] 91 /* The following special-cases are not part of OpenType, which requires 92 * that at least -1, 0, and +1 must be mapped. But we include these as 93 * part of a better error recovery scheme. */ 94 if (len < 2) 95 { 96 if (!len) 97 return value; 98 else /* len == 1*/ 99 return value - arrayZ[0].fromCoord + arrayZ[0].toCoord; 100 } 101 102 if (value <= arrayZ[0].fromCoord) 103 return value - arrayZ[0].fromCoord + arrayZ[0].toCoord; 104 105 unsigned int i; 106 unsigned int count = len - 1; 107 for (i = 1; i < count && value > arrayZ[i].fromCoord; i++) 108 ; 109 110 if (value >= arrayZ[i].fromCoord) 111 return value - arrayZ[i].fromCoord + arrayZ[i].toCoord; 112 113 if (unlikely (arrayZ[i-1].fromCoord == arrayZ[i].fromCoord)) 114 return arrayZ[i-1].toCoord; 115 116 int denom = arrayZ[i].fromCoord - arrayZ[i-1].fromCoord; 117 return roundf (arrayZ[i-1].toCoord + ((float) (arrayZ[i].toCoord - arrayZ[i-1].toCoord) * 118 (value - arrayZ[i-1].fromCoord)) / denom); 119 #undef toCoord 120 #undef fromCoord 121 } 122 unmapOT::SegmentMaps123 int unmap (int value) const { return map (value, 1, 0); } 124 125 public: 126 DEFINE_SIZE_ARRAY (2, *this); 127 }; 128 129 struct avar 130 { 131 static constexpr hb_tag_t tableTag = HB_OT_TAG_avar; 132 has_dataOT::avar133 bool has_data () const { return version.to_int (); } 134 get_segment_mapsOT::avar135 const SegmentMaps* get_segment_maps () const 136 { return &firstAxisSegmentMaps; } 137 get_axis_countOT::avar138 unsigned get_axis_count () const 139 { return axisCount; } 140 sanitizeOT::avar141 bool sanitize (hb_sanitize_context_t *c) const 142 { 143 TRACE_SANITIZE (this); 144 if (!(version.sanitize (c) && 145 (version.major == 1 146 #ifndef HB_NO_AVAR2 147 || version.major == 2 148 #endif 149 ) && 150 c->check_struct (this))) 151 return_trace (false); 152 153 const SegmentMaps *map = &firstAxisSegmentMaps; 154 unsigned int count = axisCount; 155 for (unsigned int i = 0; i < count; i++) 156 { 157 if (unlikely (!map->sanitize (c))) 158 return_trace (false); 159 map = &StructAfter<SegmentMaps> (*map); 160 } 161 162 #ifndef HB_NO_AVAR2 163 if (version.major < 2) 164 return_trace (true); 165 166 const auto &v2 = * (const avarV2Tail *) map; 167 if (unlikely (!v2.sanitize (c, this))) 168 return_trace (false); 169 #endif 170 171 return_trace (true); 172 } 173 map_coordsOT::avar174 void map_coords (int *coords, unsigned int coords_length) const 175 { 176 unsigned int count = hb_min (coords_length, axisCount); 177 178 const SegmentMaps *map = &firstAxisSegmentMaps; 179 for (unsigned int i = 0; i < count; i++) 180 { 181 coords[i] = map->map (coords[i]); 182 map = &StructAfter<SegmentMaps> (*map); 183 } 184 185 #ifndef HB_NO_AVAR2 186 if (version.major < 2) 187 return; 188 189 for (; count < axisCount; count++) 190 map = &StructAfter<SegmentMaps> (*map); 191 192 const auto &v2 = * (const avarV2Tail *) map; 193 194 const auto &varidx_map = this+v2.varIdxMap; 195 const auto &var_store = this+v2.varStore; 196 auto *var_store_cache = var_store.create_cache (); 197 198 hb_vector_t<int> out; 199 out.alloc (coords_length); 200 for (unsigned i = 0; i < coords_length; i++) 201 { 202 int v = coords[i]; 203 uint32_t varidx = varidx_map.map (i); 204 float delta = var_store.get_delta (varidx, coords, coords_length, var_store_cache); 205 v += roundf (delta); 206 v = hb_clamp (v, -(1<<14), +(1<<14)); 207 out.push (v); 208 } 209 for (unsigned i = 0; i < coords_length; i++) 210 coords[i] = out[i]; 211 212 OT::VariationStore::destroy_cache (var_store_cache); 213 #endif 214 } 215 unmap_coordsOT::avar216 void unmap_coords (int *coords, unsigned int coords_length) const 217 { 218 unsigned int count = hb_min (coords_length, axisCount); 219 220 const SegmentMaps *map = &firstAxisSegmentMaps; 221 for (unsigned int i = 0; i < count; i++) 222 { 223 coords[i] = map->unmap (coords[i]); 224 map = &StructAfter<SegmentMaps> (*map); 225 } 226 } 227 228 protected: 229 FixedVersion<>version; /* Version of the avar table 230 * initially set to 0x00010000u */ 231 HBUINT16 reserved; /* This field is permanently reserved. Set to 0. */ 232 HBUINT16 axisCount; /* The number of variation axes in the font. This 233 * must be the same number as axisCount in the 234 * 'fvar' table. */ 235 SegmentMaps firstAxisSegmentMaps; 236 237 public: 238 DEFINE_SIZE_MIN (8); 239 }; 240 241 } /* namespace OT */ 242 243 244 #endif /* HB_OT_VAR_AVAR_TABLE_HH */ 245