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1 /* |
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2 * Copyright © 2018 Ebrahim Byagowi |
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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 |
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25 #ifndef HB_AAT_LAYOUT_FEAT_TABLE_HH |
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26 #define HB_AAT_LAYOUT_FEAT_TABLE_HH |
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27 |
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28 #include "hb-aat-layout-common.hh" |
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29 |
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30 /* |
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31 * feat -- Feature Name |
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32 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6feat.html |
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33 */ |
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34 #define HB_AAT_TAG_feat HB_TAG('f','e','a','t') |
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35 |
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36 |
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37 namespace AAT { |
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38 |
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39 |
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40 struct SettingName |
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41 { |
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42 friend struct FeatureName; |
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43 |
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44 int cmp (hb_aat_layout_feature_selector_t key) const |
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45 { return (int) key - (int) setting; } |
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46 |
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47 hb_aat_layout_feature_selector_t get_selector () const |
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48 { return (hb_aat_layout_feature_selector_t) (unsigned) setting; } |
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49 |
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50 void get_info (hb_aat_layout_feature_selector_info_t *s, |
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51 hb_aat_layout_feature_selector_t default_selector) const |
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52 { |
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53 s->name_id = nameIndex; |
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54 |
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55 s->enable = (hb_aat_layout_feature_selector_t) (unsigned int) setting; |
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56 s->disable = default_selector == HB_AAT_LAYOUT_FEATURE_SELECTOR_INVALID ? |
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57 (hb_aat_layout_feature_selector_t) (s->enable + 1) : |
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58 default_selector; |
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59 |
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60 s->reserved = 0; |
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61 } |
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62 |
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63 bool sanitize (hb_sanitize_context_t *c) const |
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64 { |
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65 TRACE_SANITIZE (this); |
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66 return_trace (likely (c->check_struct (this))); |
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67 } |
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68 |
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69 protected: |
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70 HBUINT16 setting; /* The setting. */ |
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71 NameID nameIndex; /* The name table index for the setting's name. */ |
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72 public: |
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73 DEFINE_SIZE_STATIC (4); |
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74 }; |
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75 DECLARE_NULL_NAMESPACE_BYTES (AAT, SettingName); |
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76 |
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77 struct feat; |
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78 |
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79 struct FeatureName |
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80 { |
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81 int cmp (hb_aat_layout_feature_type_t key) const |
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82 { return (int) key - (int) feature; } |
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83 |
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84 enum { |
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85 Exclusive = 0x8000, /* If set, the feature settings are mutually exclusive. */ |
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86 NotDefault = 0x4000, /* If clear, then the setting with an index of 0 in |
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87 * the setting name array for this feature should |
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88 * be taken as the default for the feature |
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89 * (if one is required). If set, then bits 0-15 of this |
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90 * featureFlags field contain the index of the setting |
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91 * which is to be taken as the default. */ |
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92 IndexMask = 0x00FF /* If bits 30 and 31 are set, then these sixteen bits |
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93 * indicate the index of the setting in the setting name |
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94 * array for this feature which should be taken |
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95 * as the default. */ |
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96 }; |
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97 |
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98 unsigned int get_selector_infos (unsigned int start_offset, |
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99 unsigned int *selectors_count, /* IN/OUT. May be NULL. */ |
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100 hb_aat_layout_feature_selector_info_t *selectors, /* OUT. May be NULL. */ |
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101 unsigned int *pdefault_index, /* OUT. May be NULL. */ |
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102 const void *base) const |
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103 { |
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104 hb_array_t< const SettingName> settings_table = (base+settingTableZ).as_array (nSettings); |
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105 |
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106 static_assert (Index::NOT_FOUND_INDEX == HB_AAT_LAYOUT_NO_SELECTOR_INDEX, ""); |
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107 |
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108 hb_aat_layout_feature_selector_t default_selector = HB_AAT_LAYOUT_FEATURE_SELECTOR_INVALID; |
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109 unsigned int default_index = Index::NOT_FOUND_INDEX; |
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110 if (featureFlags & Exclusive) |
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111 { |
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112 default_index = (featureFlags & NotDefault) ? featureFlags & IndexMask : 0; |
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113 default_selector = settings_table[default_index].get_selector (); |
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114 } |
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115 if (pdefault_index) |
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116 *pdefault_index = default_index; |
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117 |
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118 if (selectors_count) |
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119 { |
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120 hb_array_t<const SettingName> arr = settings_table.sub_array (start_offset, selectors_count); |
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121 for (unsigned int i = 0; i < arr.length; i++) |
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122 settings_table[start_offset + i].get_info (&selectors[i], default_selector); |
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123 } |
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124 return settings_table.length; |
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125 } |
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126 |
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127 hb_aat_layout_feature_type_t get_feature_type () const |
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128 { return (hb_aat_layout_feature_type_t) (unsigned int) feature; } |
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129 |
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130 hb_ot_name_id_t get_feature_name_id () const { return nameIndex; } |
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131 |
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132 bool sanitize (hb_sanitize_context_t *c, const void *base) const |
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133 { |
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134 TRACE_SANITIZE (this); |
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135 return_trace (likely (c->check_struct (this) && |
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136 (base+settingTableZ).sanitize (c, nSettings))); |
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137 } |
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138 |
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139 protected: |
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140 HBUINT16 feature; /* Feature type. */ |
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141 HBUINT16 nSettings; /* The number of records in the setting name array. */ |
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142 LOffsetTo<UnsizedArrayOf<SettingName>, false> |
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143 settingTableZ; /* Offset in bytes from the beginning of this table to |
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144 * this feature's setting name array. The actual type of |
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145 * record this offset refers to will depend on the |
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146 * exclusivity value, as described below. */ |
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147 HBUINT16 featureFlags; /* Single-bit flags associated with the feature type. */ |
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148 HBINT16 nameIndex; /* The name table index for the feature's name. |
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149 * This index has values greater than 255 and |
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150 * less than 32768. */ |
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151 public: |
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152 DEFINE_SIZE_STATIC (12); |
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153 }; |
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154 |
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155 struct feat |
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156 { |
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157 static constexpr hb_tag_t tableTag = HB_AAT_TAG_feat; |
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158 |
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159 bool has_data () const { return version.to_int (); } |
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160 |
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161 unsigned int get_feature_types (unsigned int start_offset, |
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162 unsigned int *count, |
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163 hb_aat_layout_feature_type_t *features) const |
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164 { |
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165 unsigned int feature_count = featureNameCount; |
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166 if (count && *count) |
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167 { |
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168 unsigned int len = MIN (feature_count - start_offset, *count); |
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169 for (unsigned int i = 0; i < len; i++) |
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170 features[i] = namesZ[i + start_offset].get_feature_type (); |
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171 *count = len; |
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172 } |
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173 return featureNameCount; |
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174 } |
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175 |
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176 const FeatureName& get_feature (hb_aat_layout_feature_type_t feature_type) const |
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177 { |
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178 return namesZ.bsearch (featureNameCount, feature_type); |
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179 } |
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180 |
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181 hb_ot_name_id_t get_feature_name_id (hb_aat_layout_feature_type_t feature) const |
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182 { return get_feature (feature).get_feature_name_id (); } |
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183 |
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184 unsigned int get_selector_infos (hb_aat_layout_feature_type_t feature_type, |
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185 unsigned int start_offset, |
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186 unsigned int *selectors_count, /* IN/OUT. May be NULL. */ |
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187 hb_aat_layout_feature_selector_info_t *selectors, /* OUT. May be NULL. */ |
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188 unsigned int *default_index /* OUT. May be NULL. */) const |
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189 { |
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190 return get_feature (feature_type).get_selector_infos (start_offset, selectors_count, selectors, |
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191 default_index, this); |
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192 } |
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193 |
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194 bool sanitize (hb_sanitize_context_t *c) const |
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195 { |
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196 TRACE_SANITIZE (this); |
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197 return_trace (likely (c->check_struct (this) && |
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198 version.major == 1 && |
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199 namesZ.sanitize (c, featureNameCount, this))); |
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200 } |
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201 |
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202 protected: |
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203 FixedVersion<>version; /* Version number of the feature name table |
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204 * (0x00010000 for the current version). */ |
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205 HBUINT16 featureNameCount; |
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206 /* The number of entries in the feature name array. */ |
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207 HBUINT16 reserved1; /* Reserved (set to zero). */ |
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208 HBUINT32 reserved2; /* Reserved (set to zero). */ |
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209 SortedUnsizedArrayOf<FeatureName> |
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210 namesZ; /* The feature name array. */ |
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211 public: |
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212 DEFINE_SIZE_STATIC (24); |
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213 }; |
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214 |
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215 } /* namespace AAT */ |
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216 |
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217 #endif /* HB_AAT_LAYOUT_FEAT_TABLE_HH */ |