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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_FVAR_TABLE_HH |
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28 #define HB_OT_VAR_FVAR_TABLE_HH |
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29 |
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30 #include "hb-open-type-private.hh" |
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31 |
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32 namespace OT { |
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33 |
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34 |
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35 struct InstanceRecord |
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36 { |
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37 inline bool sanitize (hb_sanitize_context_t *c, unsigned int axis_count) const |
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38 { |
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39 TRACE_SANITIZE (this); |
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40 return_trace (c->check_struct (this) && |
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41 c->check_array (coordinates, coordinates[0].static_size, axis_count)); |
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42 } |
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43 |
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44 protected: |
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45 USHORT subfamilyNameID;/* The name ID for entries in the 'name' table |
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46 * that provide subfamily names for this instance. */ |
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47 USHORT reserved; /* Reserved for future use — set to 0. */ |
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48 Fixed coordinates[VAR];/* The coordinates array for this instance. */ |
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49 //USHORT postScriptNameIDX;/*Optional. The name ID for entries in the 'name' |
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50 // * table that provide PostScript names for this |
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51 // * instance. */ |
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52 |
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53 public: |
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54 DEFINE_SIZE_ARRAY (4, coordinates); |
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55 }; |
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56 |
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57 struct AxisRecord |
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58 { |
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59 inline bool sanitize (hb_sanitize_context_t *c) const |
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60 { |
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61 TRACE_SANITIZE (this); |
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62 return_trace (c->check_struct (this)); |
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63 } |
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64 |
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65 public: |
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66 Tag axisTag; /* Tag identifying the design variation for the axis. */ |
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67 Fixed minValue; /* The minimum coordinate value for the axis. */ |
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68 Fixed defaultValue; /* The default coordinate value for the axis. */ |
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69 Fixed maxValue; /* The maximum coordinate value for the axis. */ |
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70 USHORT reserved; /* Reserved for future use — set to 0. */ |
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71 USHORT axisNameID; /* The name ID for entries in the 'name' table that |
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72 * provide a display name for this axis. */ |
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73 |
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74 public: |
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75 DEFINE_SIZE_STATIC (20); |
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76 }; |
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77 |
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78 |
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79 /* |
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80 * fvar — Font Variations Table |
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81 */ |
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82 |
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83 #define HB_OT_TAG_fvar HB_TAG('f','v','a','r') |
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84 |
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85 struct fvar |
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86 { |
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87 static const hb_tag_t tableTag = HB_OT_TAG_fvar; |
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88 |
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89 inline bool sanitize (hb_sanitize_context_t *c) const |
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90 { |
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91 TRACE_SANITIZE (this); |
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92 return_trace (version.sanitize (c) && |
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93 likely (version.major == 1) && |
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94 c->check_struct (this) && |
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95 instanceSize >= axisCount * 4 + 4 && |
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96 axisSize <= 1024 && /* Arbitrary, just to simplify overflow checks. */ |
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97 instanceSize <= 1024 && /* Arbitrary, just to simplify overflow checks. */ |
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98 c->check_range (this, things) && |
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99 c->check_range (&StructAtOffset<char> (this, things), |
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100 axisCount * axisSize + instanceCount * instanceSize)); |
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101 } |
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102 |
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103 inline unsigned int get_axis_count (void) const |
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104 { return axisCount; } |
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105 |
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106 inline bool get_axis (unsigned int index, hb_ot_var_axis_t *info) const |
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107 { |
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108 if (unlikely (index >= axisCount)) |
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109 return false; |
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110 |
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111 if (info) |
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112 { |
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113 const AxisRecord &axis = get_axes ()[index]; |
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114 info->tag = axis.axisTag; |
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115 info->name_id = axis.axisNameID; |
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116 info->default_value = axis.defaultValue / 65536.; |
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117 /* Ensure order, to simplify client math. */ |
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118 info->min_value = MIN<float> (info->default_value, axis.minValue / 65536.); |
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119 info->max_value = MAX<float> (info->default_value, axis.maxValue / 65536.); |
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120 } |
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121 |
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122 return true; |
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123 } |
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124 |
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125 inline unsigned int get_axis_infos (unsigned int start_offset, |
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126 unsigned int *axes_count /* IN/OUT */, |
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127 hb_ot_var_axis_t *axes_array /* OUT */) const |
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128 { |
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129 if (axes_count) |
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130 { |
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131 unsigned int count = axisCount; |
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132 start_offset = MIN (start_offset, count); |
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133 |
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134 count -= start_offset; |
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135 axes_array += start_offset; |
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136 |
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137 count = MIN (count, *axes_count); |
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138 *axes_count = count; |
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139 |
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140 for (unsigned int i = 0; i < count; i++) |
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141 get_axis (start_offset + i, axes_array + i); |
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142 } |
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143 return axisCount; |
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144 } |
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145 |
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146 inline bool find_axis (hb_tag_t tag, unsigned int *index, hb_ot_var_axis_t *info) const |
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147 { |
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148 const AxisRecord *axes = get_axes (); |
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149 unsigned int count = get_axis_count (); |
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150 for (unsigned int i = 0; i < count; i++) |
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151 if (axes[i].axisTag == tag) |
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152 { |
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153 if (index) |
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154 *index = i; |
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155 return get_axis (i, info); |
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156 } |
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157 if (index) |
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158 *index = HB_OT_VAR_NO_AXIS_INDEX; |
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159 return false; |
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160 } |
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161 |
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162 inline int normalize_axis_value (unsigned int axis_index, float v) const |
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163 { |
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164 hb_ot_var_axis_t axis; |
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165 if (!get_axis (axis_index, &axis)) |
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166 return 0; |
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167 |
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168 v = MAX (MIN (v, axis.max_value), axis.min_value); /* Clamp. */ |
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169 |
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170 if (v == axis.default_value) |
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171 return 0; |
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172 else if (v < axis.default_value) |
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173 v = (v - axis.default_value) / (axis.default_value - axis.min_value); |
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174 else |
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175 v = (v - axis.default_value) / (axis.max_value - axis.default_value); |
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176 return (int) (v * 16384. + (v >= 0. ? .5 : -.5)); |
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177 } |
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178 |
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179 protected: |
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180 inline const AxisRecord * get_axes (void) const |
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181 { return &StructAtOffset<AxisRecord> (this, things); } |
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182 |
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183 inline const InstanceRecord * get_instances (void) const |
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184 { return &StructAtOffset<InstanceRecord> (get_axes () + axisCount, 0); } |
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185 |
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186 protected: |
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187 FixedVersion<>version; /* Version of the fvar table |
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188 * initially set to 0x00010000u */ |
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189 Offset<> things; /* Offset in bytes from the beginning of the table |
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190 * to the start of the AxisRecord array. */ |
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191 USHORT reserved; /* This field is permanently reserved. Set to 2. */ |
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192 USHORT axisCount; /* The number of variation axes in the font (the |
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193 * number of records in the axes array). */ |
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194 USHORT axisSize; /* The size in bytes of each VariationAxisRecord — |
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195 * set to 20 (0x0014) for this version. */ |
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196 USHORT instanceCount; /* The number of named instances defined in the font |
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197 * (the number of records in the instances array). */ |
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198 USHORT instanceSize; /* The size in bytes of each InstanceRecord — set |
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199 * to either axisCount * sizeof(Fixed) + 4, or to |
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200 * axisCount * sizeof(Fixed) + 6. */ |
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201 |
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202 public: |
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203 DEFINE_SIZE_STATIC (16); |
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204 }; |
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205 |
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206 } /* namespace OT */ |
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207 |
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208 |
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209 #endif /* HB_OT_VAR_FVAR_TABLE_HH */ |