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1 /* |
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2 * Copyright © 2017 Google, Inc. |
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3 * |
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4 * This is part of HarfBuzz, a text shaping library. |
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5 * |
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6 * Permission is hereby granted, without written agreement and without |
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7 * license or royalty fees, to use, copy, modify, and distribute this |
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8 * software and its documentation for any purpose, provided that the |
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9 * above copyright notice and the following two paragraphs appear in |
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10 * all copies of this software. |
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11 * |
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12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR |
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13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES |
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14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN |
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15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH |
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16 * DAMAGE. |
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17 * |
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18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, |
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19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
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20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS |
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21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO |
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22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. |
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23 * |
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24 * Google Author(s): Behdad Esfahbod |
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25 */ |
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26 |
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27 #ifndef HB_OT_VAR_HVAR_TABLE_HH |
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28 #define HB_OT_VAR_HVAR_TABLE_HH |
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29 |
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30 #include "hb-ot-layout-common-private.hh" |
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31 |
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32 |
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33 namespace OT { |
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34 |
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35 |
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36 struct DeltaSetIndexMap |
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37 { |
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38 inline bool sanitize (hb_sanitize_context_t *c) const |
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39 { |
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40 TRACE_SANITIZE (this); |
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41 return_trace (c->check_struct (this) && |
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42 c->check_array (mapData, get_width (), mapCount)); |
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43 } |
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44 |
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45 unsigned int map (unsigned int v) const /* Returns 16.16 outer.inner. */ |
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46 { |
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47 /* If count is zero, pass value unchanged. This takes |
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48 * care of direct mapping for advance map. */ |
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49 if (!mapCount) |
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50 return v; |
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51 |
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52 if (v >= mapCount) |
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53 v = mapCount - 1; |
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54 |
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55 unsigned int u = 0; |
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56 { /* Fetch it. */ |
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57 unsigned int w = get_width (); |
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58 const BYTE *p = mapData + w * v; |
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59 for (; w; w--) |
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60 u = (u << 8) + *p++; |
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61 } |
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62 |
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63 { /* Repack it. */ |
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64 unsigned int n = get_inner_bitcount (); |
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65 unsigned int outer = u >> n; |
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66 unsigned int inner = u & ((1 << n) - 1); |
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67 u = (outer<<16) | inner; |
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68 } |
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69 |
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70 return u; |
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71 } |
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72 |
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73 protected: |
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74 inline unsigned int get_width (void) const |
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75 { return ((format >> 4) & 3) + 1; } |
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76 |
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77 inline unsigned int get_inner_bitcount (void) const |
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78 { return (format & 0xF) + 1; } |
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79 |
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80 protected: |
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81 USHORT format; /* A packed field that describes the compressed |
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82 * representation of delta-set indices. */ |
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83 USHORT mapCount; /* The number of mapping entries. */ |
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84 BYTE mapData[VAR]; /* The delta-set index mapping data. */ |
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85 |
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86 public: |
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87 DEFINE_SIZE_ARRAY (4, mapData); |
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88 }; |
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89 |
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90 |
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91 /* |
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92 * HVAR -- The Horizontal Metrics Variations Table |
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93 * VVAR -- The Vertical Metrics Variations Table |
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94 */ |
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95 |
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96 #define HB_OT_TAG_HVAR HB_TAG('H','V','A','R') |
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97 #define HB_OT_TAG_VVAR HB_TAG('V','V','A','R') |
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98 |
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99 struct HVARVVAR |
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100 { |
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101 static const hb_tag_t HVARTag = HB_OT_TAG_HVAR; |
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102 static const hb_tag_t VVARTag = HB_OT_TAG_VVAR; |
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103 |
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104 inline bool sanitize (hb_sanitize_context_t *c) const |
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105 { |
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106 TRACE_SANITIZE (this); |
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107 return_trace (version.sanitize (c) && |
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108 likely (version.major == 1) && |
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109 varStore.sanitize (c, this) && |
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110 advMap.sanitize (c, this) && |
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111 lsbMap.sanitize (c, this) && |
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112 rsbMap.sanitize (c, this)); |
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113 } |
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114 |
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115 inline float get_advance_var (hb_codepoint_t glyph, |
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116 int *coords, unsigned int coord_count) const |
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117 { |
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118 unsigned int varidx = (this+advMap).map (glyph); |
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119 return (this+varStore).get_delta (varidx, coords, coord_count); |
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120 } |
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121 |
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122 inline bool has_sidebearing_deltas (void) const |
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123 { return lsbMap && rsbMap; } |
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124 |
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125 protected: |
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126 FixedVersion<>version; /* Version of the metrics variation table |
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127 * initially set to 0x00010000u */ |
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128 LOffsetTo<VariationStore> |
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129 varStore; /* Offset to item variation store table. */ |
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130 LOffsetTo<DeltaSetIndexMap> |
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131 advMap; /* Offset to advance var-idx mapping. */ |
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132 LOffsetTo<DeltaSetIndexMap> |
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133 lsbMap; /* Offset to lsb/tsb var-idx mapping. */ |
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134 LOffsetTo<DeltaSetIndexMap> |
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135 rsbMap; /* Offset to rsb/bsb var-idx mapping. */ |
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136 |
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137 public: |
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138 DEFINE_SIZE_STATIC (20); |
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139 }; |
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140 |
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141 struct HVAR : HVARVVAR { |
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142 static const hb_tag_t tableTag = HB_OT_TAG_HVAR; |
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143 }; |
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144 struct VVAR : HVARVVAR { |
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145 static const hb_tag_t tableTag = HB_OT_TAG_VVAR; |
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146 |
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147 inline bool sanitize (hb_sanitize_context_t *c) const |
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148 { |
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149 TRACE_SANITIZE (this); |
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150 return_trace (static_cast<const HVARVVAR *> (this)->sanitize (c) && |
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151 vorgMap.sanitize (c, this)); |
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152 } |
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153 |
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154 protected: |
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155 LOffsetTo<DeltaSetIndexMap> |
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156 vorgMap; /* Offset to vertical-origin var-idx mapping. */ |
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157 |
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158 public: |
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159 DEFINE_SIZE_STATIC (24); |
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160 }; |
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161 |
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162 } /* namespace OT */ |
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163 |
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164 |
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165 #endif /* HB_OT_VAR_HVAR_TABLE_HH */ |