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-private.hh" 31 32 33 namespace OT { 34 35 36 struct DeltaSetIndexMap 37 { 38 inline bool sanitize (hb_sanitize_context_t *c) const 39 { 40 TRACE_SANITIZE (this); 41 return_trace (c->check_struct (this) && 42 c->check_array (mapData, get_width (), mapCount)); 43 } 44 45 unsigned int map (unsigned int v) const /* Returns 16.16 outer.inner. */ 46 { 47 /* If count is zero, pass value unchanged. This takes 48 * care of direct mapping for advance map. */ 49 if (!mapCount) 50 return v; 51 52 if (v >= mapCount) 53 v = mapCount - 1; 54 55 unsigned int u = 0; 56 { /* Fetch it. */ 57 unsigned int w = get_width (); 58 const UINT8 *p = mapData + w * v; 59 for (; w; w--) 60 u = (u << 8) + *p++; 61 } 62 63 { /* Repack it. */ 64 unsigned int n = get_inner_bitcount (); 65 unsigned int outer = u >> n; 66 unsigned int inner = u & ((1 << n) - 1); 67 u = (outer<<16) | inner; 68 } 69 70 return u; 71 } 72 73 protected: 74 inline unsigned int get_width (void) const 75 { return ((format >> 4) & 3) + 1; } 76 77 inline unsigned int get_inner_bitcount (void) const 78 { return (format & 0xF) + 1; } 79 80 protected: 81 UINT16 format; /* A packed field that describes the compressed 82 * representation of delta-set indices. */ 83 UINT16 mapCount; /* The number of mapping entries. */ 84 UINT8 mapData[VAR]; /* The delta-set index mapping data. */ 85 86 public: 87 DEFINE_SIZE_ARRAY (4, mapData); 88 }; 89 90 91 /* 92 * HVAR -- The Horizontal Metrics Variations Table 93 * VVAR -- The Vertical Metrics Variations Table 94 */ 95 96 #define HB_OT_TAG_HVAR HB_TAG('H','V','A','R') 97 #define HB_OT_TAG_VVAR HB_TAG('V','V','A','R') 98 99 struct HVARVVAR 100 { 101 static const hb_tag_t HVARTag = HB_OT_TAG_HVAR; 102 static const hb_tag_t VVARTag = HB_OT_TAG_VVAR; 103 104 inline bool sanitize (hb_sanitize_context_t *c) const 105 { 106 TRACE_SANITIZE (this); 107 return_trace (version.sanitize (c) && 108 likely (version.major == 1) && 109 varStore.sanitize (c, this) && 110 advMap.sanitize (c, this) && 111 lsbMap.sanitize (c, this) && 112 rsbMap.sanitize (c, this)); 113 } 114 115 inline float get_advance_var (hb_codepoint_t glyph, 116 int *coords, unsigned int coord_count) const 117 { 118 unsigned int varidx = (this+advMap).map (glyph); 119 return (this+varStore).get_delta (varidx, coords, coord_count); 120 } 121 122 inline bool has_sidebearing_deltas (void) const 123 { return lsbMap && rsbMap; } 124 125 protected: 126 FixedVersion<>version; /* Version of the metrics variation table 127 * initially set to 0x00010000u */ 128 LOffsetTo<VariationStore> 129 varStore; /* Offset to item variation store table. */ 130 LOffsetTo<DeltaSetIndexMap> 131 advMap; /* Offset to advance var-idx mapping. */ 132 LOffsetTo<DeltaSetIndexMap> 133 lsbMap; /* Offset to lsb/tsb var-idx mapping. */ 134 LOffsetTo<DeltaSetIndexMap> 135 rsbMap; /* Offset to rsb/bsb var-idx mapping. */ 136 137 public: 138 DEFINE_SIZE_STATIC (20); 139 }; 140 141 struct HVAR : HVARVVAR { 142 static const hb_tag_t tableTag = HB_OT_TAG_HVAR; 143 }; 144 struct VVAR : HVARVVAR { 145 static const hb_tag_t tableTag = HB_OT_TAG_VVAR; 146 147 inline bool sanitize (hb_sanitize_context_t *c) const 148 { 149 TRACE_SANITIZE (this); 150 return_trace (static_cast<const HVARVVAR *> (this)->sanitize (c) && 151 vorgMap.sanitize (c, this)); 152 } 153 154 protected: 155 LOffsetTo<DeltaSetIndexMap> 156 vorgMap; /* Offset to vertical-origin var-idx mapping. */ 157 158 public: 159 DEFINE_SIZE_STATIC (24); 160 }; 161 162 } /* namespace OT */ 163 164 165 #endif /* HB_OT_VAR_HVAR_TABLE_HH */ 166
