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_HVAR_TABLE_HH 28 #define HB_OT_VAR_HVAR_TABLE_HH 29 30 #include "hb-ot-layout-common.hh" 31 32 33 namespace OT { 34 35 36 struct DeltaSetIndexMap 37 { sanitizeOT::DeltaSetIndexMap38 bool sanitize (hb_sanitize_context_t *c) const 39 { 40 TRACE_SANITIZE (this); 41 return_trace (c->check_struct (this) && 42 c->check_range (mapDataZ.arrayZ, 43 mapCount, 44 get_width ())); 45 } 46 mapOT::DeltaSetIndexMap47 unsigned int map (unsigned int v) const /* Returns 16.16 outer.inner. */ 48 { 49 /* If count is zero, pass value unchanged. This takes 50 * care of direct mapping for advance map. */ 51 if (!mapCount) 52 return v; 53 54 if (v >= mapCount) 55 v = mapCount - 1; 56 57 unsigned int u = 0; 58 { /* Fetch it. */ 59 unsigned int w = get_width (); 60 const HBUINT8 *p = mapDataZ.arrayZ + w * v; 61 for (; w; w--) 62 u = (u << 8) + *p++; 63 } 64 65 { /* Repack it. */ 66 unsigned int n = get_inner_bitcount (); 67 unsigned int outer = u >> n; 68 unsigned int inner = u & ((1 << n) - 1); 69 u = (outer<<16) | inner; 70 } 71 72 return u; 73 } 74 75 protected: get_widthOT::DeltaSetIndexMap76 unsigned int get_width () const { return ((format >> 4) & 3) + 1; } 77 get_inner_bitcountOT::DeltaSetIndexMap78 unsigned int get_inner_bitcount () const { return (format & 0xF) + 1; } 79 80 protected: 81 HBUINT16 format; /* A packed field that describes the compressed 82 * representation of delta-set indices. */ 83 HBUINT16 mapCount; /* The number of mapping entries. */ 84 UnsizedArrayOf<HBUINT8> 85 mapDataZ; /* The delta-set index mapping data. */ 86 87 public: 88 DEFINE_SIZE_ARRAY (4, mapDataZ); 89 }; 90 91 92 /* 93 * HVAR -- Horizontal Metrics Variations 94 * https://docs.microsoft.com/en-us/typography/opentype/spec/hvar 95 * VVAR -- Vertical Metrics Variations 96 * https://docs.microsoft.com/en-us/typography/opentype/spec/vvar 97 */ 98 #define HB_OT_TAG_HVAR HB_TAG('H','V','A','R') 99 #define HB_OT_TAG_VVAR HB_TAG('V','V','A','R') 100 101 struct HVARVVAR 102 { 103 enum { HVARTag = HB_OT_TAG_HVAR }; 104 enum { VVARTag = HB_OT_TAG_VVAR }; 105 sanitizeOT::HVARVVAR106 bool sanitize (hb_sanitize_context_t *c) const 107 { 108 TRACE_SANITIZE (this); 109 return_trace (version.sanitize (c) && 110 likely (version.major == 1) && 111 varStore.sanitize (c, this) && 112 advMap.sanitize (c, this) && 113 lsbMap.sanitize (c, this) && 114 rsbMap.sanitize (c, this)); 115 } 116 get_advance_varOT::HVARVVAR117 float get_advance_var (hb_codepoint_t glyph, 118 const int *coords, unsigned int coord_count) const 119 { 120 unsigned int varidx = (this+advMap).map (glyph); 121 return (this+varStore).get_delta (varidx, coords, coord_count); 122 } 123 has_sidebearing_deltasOT::HVARVVAR124 bool has_sidebearing_deltas () const { return lsbMap && rsbMap; } 125 126 protected: 127 FixedVersion<>version; /* Version of the metrics variation table 128 * initially set to 0x00010000u */ 129 LOffsetTo<VariationStore> 130 varStore; /* Offset to item variation store table. */ 131 LOffsetTo<DeltaSetIndexMap> 132 advMap; /* Offset to advance var-idx mapping. */ 133 LOffsetTo<DeltaSetIndexMap> 134 lsbMap; /* Offset to lsb/tsb var-idx mapping. */ 135 LOffsetTo<DeltaSetIndexMap> 136 rsbMap; /* Offset to rsb/bsb var-idx mapping. */ 137 138 public: 139 DEFINE_SIZE_STATIC (20); 140 }; 141 142 struct HVAR : HVARVVAR { 143 enum { tableTag = HB_OT_TAG_HVAR }; 144 }; 145 struct VVAR : HVARVVAR { 146 enum { tableTag = HB_OT_TAG_VVAR }; 147 sanitizeOT::VVAR148 bool sanitize (hb_sanitize_context_t *c) const 149 { 150 TRACE_SANITIZE (this); 151 return_trace (static_cast<const HVARVVAR *> (this)->sanitize (c) && 152 vorgMap.sanitize (c, this)); 153 } 154 155 protected: 156 LOffsetTo<DeltaSetIndexMap> 157 vorgMap; /* Offset to vertical-origin var-idx mapping. */ 158 159 public: 160 DEFINE_SIZE_STATIC (24); 161 }; 162 163 } /* namespace OT */ 164 165 166 #endif /* HB_OT_VAR_HVAR_TABLE_HH */ 167