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1 /* |
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2 * Copyright © 2011,2012,2013 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 #include "hb-ot-shape-complex-indic-private.hh" |
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28 |
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29 /* buffer var allocations */ |
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30 #define sea_category() complex_var_u8_0() /* indic_category_t */ |
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31 #define sea_position() complex_var_u8_1() /* indic_position_t */ |
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32 |
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33 |
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34 /* |
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35 * South-East Asian shaper. |
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36 * Loosely based on the Myanmar spec / shaper. |
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37 * There is no OpenType spec for this. |
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38 */ |
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39 |
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40 static const hb_tag_t |
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41 basic_features[] = |
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42 { |
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43 /* |
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44 * Basic features. |
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45 * These features are applied in order, one at a time, after initial_reordering. |
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46 */ |
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47 HB_TAG('p','r','e','f'), |
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48 HB_TAG('a','b','v','f'), |
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49 HB_TAG('b','l','w','f'), |
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50 HB_TAG('p','s','t','f'), |
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51 }; |
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52 static const hb_tag_t |
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53 other_features[] = |
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54 { |
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55 /* |
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56 * Other features. |
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57 * These features are applied all at once, after final_reordering. |
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58 */ |
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59 HB_TAG('p','r','e','s'), |
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60 HB_TAG('a','b','v','s'), |
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61 HB_TAG('b','l','w','s'), |
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62 HB_TAG('p','s','t','s'), |
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63 /* Positioning features, though we don't care about the types. */ |
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64 HB_TAG('d','i','s','t'), |
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65 }; |
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66 |
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67 static void |
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68 setup_syllables (const hb_ot_shape_plan_t *plan, |
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69 hb_font_t *font, |
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70 hb_buffer_t *buffer); |
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71 static void |
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72 initial_reordering (const hb_ot_shape_plan_t *plan, |
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73 hb_font_t *font, |
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74 hb_buffer_t *buffer); |
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75 static void |
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76 final_reordering (const hb_ot_shape_plan_t *plan, |
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77 hb_font_t *font, |
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78 hb_buffer_t *buffer); |
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79 |
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80 static void |
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81 collect_features_sea (hb_ot_shape_planner_t *plan) |
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82 { |
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83 hb_ot_map_builder_t *map = &plan->map; |
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84 |
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85 /* Do this before any lookups have been applied. */ |
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86 map->add_gsub_pause (setup_syllables); |
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87 |
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88 map->add_global_bool_feature (HB_TAG('l','o','c','l')); |
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89 /* The Indic specs do not require ccmp, but we apply it here since if |
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90 * there is a use of it, it's typically at the beginning. */ |
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91 map->add_global_bool_feature (HB_TAG('c','c','m','p')); |
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92 |
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93 map->add_gsub_pause (initial_reordering); |
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94 for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++) |
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95 { |
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96 map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ); |
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97 map->add_gsub_pause (NULL); |
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98 } |
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99 map->add_gsub_pause (final_reordering); |
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100 for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++) |
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101 map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ); |
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102 } |
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103 |
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104 static void |
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105 override_features_sea (hb_ot_shape_planner_t *plan) |
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106 { |
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107 plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL); |
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108 } |
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109 |
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110 |
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111 enum syllable_type_t { |
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112 consonant_syllable, |
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113 broken_cluster, |
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114 non_sea_cluster, |
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115 }; |
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116 |
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117 #include "hb-ot-shape-complex-sea-machine.hh" |
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118 |
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119 |
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120 /* Note: This enum is duplicated in the -machine.rl source file. |
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121 * Not sure how to avoid duplication. */ |
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122 enum sea_category_t { |
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123 // OT_C = 1, |
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124 OT_GB = 12, /* Generic Base XXX DOTTED CIRCLE only for now */ |
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125 // OT_H = 4, /* Halant */ |
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126 OT_IV = 2, /* Independent Vowel */ |
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127 OT_MR = 22, /* Medial Ra */ |
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128 // OT_CM = 17, /* Consonant Medial */ |
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129 OT_VAbv = 26, |
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130 OT_VBlw = 27, |
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131 OT_VPre = 28, |
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132 OT_VPst = 29, |
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133 OT_T = 3, /* Tone Marks */ |
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134 // OT_A = 10, /* Anusvara */ |
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135 }; |
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136 |
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137 static inline void |
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138 set_sea_properties (hb_glyph_info_t &info) |
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139 { |
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140 hb_codepoint_t u = info.codepoint; |
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141 unsigned int type = hb_indic_get_categories (u); |
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142 indic_category_t cat = (indic_category_t) (type & 0x7F); |
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143 indic_position_t pos = (indic_position_t) (type >> 8); |
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144 |
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145 /* Medial Ra */ |
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146 if (u == 0x1A55 || u == 0xAA34) |
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147 cat = (indic_category_t) OT_MR; |
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148 |
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149 if (cat == OT_M) |
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150 { |
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151 switch ((int) pos) |
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152 { |
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153 case POS_PRE_C: cat = (indic_category_t) OT_VPre; break; |
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154 case POS_ABOVE_C: cat = (indic_category_t) OT_VAbv; break; |
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155 case POS_BELOW_C: cat = (indic_category_t) OT_VBlw; break; |
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156 case POS_POST_C: cat = (indic_category_t) OT_VPst; break; |
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157 } |
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158 } |
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159 |
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160 info.sea_category() = (sea_category_t) cat; |
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161 info.sea_position() = pos; |
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162 } |
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163 |
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164 |
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165 static void |
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166 setup_masks_sea (const hb_ot_shape_plan_t *plan HB_UNUSED, |
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167 hb_buffer_t *buffer, |
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168 hb_font_t *font HB_UNUSED) |
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169 { |
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170 HB_BUFFER_ALLOCATE_VAR (buffer, sea_category); |
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171 HB_BUFFER_ALLOCATE_VAR (buffer, sea_position); |
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172 |
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173 /* We cannot setup masks here. We save information about characters |
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174 * and setup masks later on in a pause-callback. */ |
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175 |
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176 unsigned int count = buffer->len; |
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177 for (unsigned int i = 0; i < count; i++) |
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178 set_sea_properties (buffer->info[i]); |
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179 } |
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180 |
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181 static void |
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182 setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED, |
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183 hb_font_t *font HB_UNUSED, |
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184 hb_buffer_t *buffer) |
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185 { |
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186 find_syllables (buffer); |
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187 } |
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188 |
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189 static int |
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190 compare_sea_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb) |
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191 { |
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192 int a = pa->sea_position(); |
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193 int b = pb->sea_position(); |
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194 |
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195 return a < b ? -1 : a == b ? 0 : +1; |
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196 } |
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197 |
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198 |
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199 static void |
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200 initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan, |
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201 hb_face_t *face, |
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202 hb_buffer_t *buffer, |
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203 unsigned int start, unsigned int end) |
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204 { |
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205 hb_glyph_info_t *info = buffer->info; |
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206 unsigned int base = start; |
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207 |
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208 /* Reorder! */ |
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209 unsigned int i = start; |
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210 for (; i < base; i++) |
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211 info[i].sea_position() = POS_PRE_C; |
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212 if (i < end) |
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213 { |
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214 info[i].sea_position() = POS_BASE_C; |
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215 i++; |
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216 } |
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217 for (; i < end; i++) |
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218 { |
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219 if (info[i].sea_category() == OT_MR) /* Pre-base reordering */ |
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220 { |
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221 info[i].sea_position() = POS_PRE_C; |
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222 continue; |
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223 } |
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224 if (info[i].sea_category() == OT_VPre) /* Left matra */ |
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225 { |
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226 info[i].sea_position() = POS_PRE_M; |
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227 continue; |
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228 } |
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229 |
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230 info[i].sea_position() = POS_AFTER_MAIN; |
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231 } |
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232 |
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233 buffer->merge_clusters (start, end); |
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234 /* Sit tight, rock 'n roll! */ |
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235 hb_bubble_sort (info + start, end - start, compare_sea_order); |
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236 } |
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237 |
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238 static void |
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239 initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan, |
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240 hb_face_t *face, |
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241 hb_buffer_t *buffer, |
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242 unsigned int start, unsigned int end) |
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243 { |
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244 /* We already inserted dotted-circles, so just call the consonant_syllable. */ |
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245 initial_reordering_consonant_syllable (plan, face, buffer, start, end); |
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246 } |
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247 |
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248 static void |
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249 initial_reordering_non_sea_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED, |
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250 hb_face_t *face HB_UNUSED, |
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251 hb_buffer_t *buffer HB_UNUSED, |
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252 unsigned int start HB_UNUSED, unsigned int end HB_UNUSED) |
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253 { |
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254 /* Nothing to do right now. If we ever switch to using the output |
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255 * buffer in the reordering process, we'd need to next_glyph() here. */ |
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256 } |
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257 |
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258 |
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259 static void |
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260 initial_reordering_syllable (const hb_ot_shape_plan_t *plan, |
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261 hb_face_t *face, |
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262 hb_buffer_t *buffer, |
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263 unsigned int start, unsigned int end) |
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264 { |
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265 syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F); |
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266 switch (syllable_type) { |
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267 case consonant_syllable: initial_reordering_consonant_syllable (plan, face, buffer, start, end); return; |
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268 case broken_cluster: initial_reordering_broken_cluster (plan, face, buffer, start, end); return; |
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269 case non_sea_cluster: initial_reordering_non_sea_cluster (plan, face, buffer, start, end); return; |
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270 } |
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271 } |
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272 |
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273 static inline void |
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274 insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED, |
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275 hb_font_t *font, |
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276 hb_buffer_t *buffer) |
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277 { |
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278 /* Note: This loop is extra overhead, but should not be measurable. */ |
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279 bool has_broken_syllables = false; |
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280 unsigned int count = buffer->len; |
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281 for (unsigned int i = 0; i < count; i++) |
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282 if ((buffer->info[i].syllable() & 0x0F) == broken_cluster) { |
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283 has_broken_syllables = true; |
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284 break; |
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285 } |
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286 if (likely (!has_broken_syllables)) |
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287 return; |
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288 |
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289 |
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290 hb_codepoint_t dottedcircle_glyph; |
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291 if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph)) |
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292 return; |
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293 |
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294 hb_glyph_info_t dottedcircle = {0}; |
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295 dottedcircle.codepoint = 0x25CC; |
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296 set_sea_properties (dottedcircle); |
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297 dottedcircle.codepoint = dottedcircle_glyph; |
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298 |
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299 buffer->clear_output (); |
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300 |
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301 buffer->idx = 0; |
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302 unsigned int last_syllable = 0; |
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303 while (buffer->idx < buffer->len) |
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304 { |
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305 unsigned int syllable = buffer->cur().syllable(); |
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306 syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F); |
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307 if (unlikely (last_syllable != syllable && syllable_type == broken_cluster)) |
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308 { |
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309 last_syllable = syllable; |
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310 |
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311 hb_glyph_info_t info = dottedcircle; |
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312 info.cluster = buffer->cur().cluster; |
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313 info.mask = buffer->cur().mask; |
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314 info.syllable() = buffer->cur().syllable(); |
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315 |
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316 buffer->output_info (info); |
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317 } |
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318 else |
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319 buffer->next_glyph (); |
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320 } |
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321 |
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322 buffer->swap_buffers (); |
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323 } |
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324 |
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325 static void |
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326 initial_reordering (const hb_ot_shape_plan_t *plan, |
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327 hb_font_t *font, |
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328 hb_buffer_t *buffer) |
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329 { |
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330 insert_dotted_circles (plan, font, buffer); |
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331 |
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332 hb_glyph_info_t *info = buffer->info; |
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333 unsigned int count = buffer->len; |
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334 if (unlikely (!count)) return; |
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335 unsigned int last = 0; |
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336 unsigned int last_syllable = info[0].syllable(); |
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337 for (unsigned int i = 1; i < count; i++) |
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338 if (last_syllable != info[i].syllable()) { |
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339 initial_reordering_syllable (plan, font->face, buffer, last, i); |
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340 last = i; |
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341 last_syllable = info[last].syllable(); |
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342 } |
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343 initial_reordering_syllable (plan, font->face, buffer, last, count); |
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344 } |
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345 |
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346 static void |
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347 final_reordering (const hb_ot_shape_plan_t *plan, |
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348 hb_font_t *font HB_UNUSED, |
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349 hb_buffer_t *buffer) |
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350 { |
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351 hb_glyph_info_t *info = buffer->info; |
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352 unsigned int count = buffer->len; |
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353 |
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354 /* Zero syllables now... */ |
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355 for (unsigned int i = 0; i < count; i++) |
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356 info[i].syllable() = 0; |
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357 |
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358 HB_BUFFER_DEALLOCATE_VAR (buffer, sea_category); |
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359 HB_BUFFER_DEALLOCATE_VAR (buffer, sea_position); |
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360 } |
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361 |
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362 |
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363 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_sea = |
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364 { |
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365 "sea", |
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366 collect_features_sea, |
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367 override_features_sea, |
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368 NULL, /* data_create */ |
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369 NULL, /* data_destroy */ |
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370 NULL, /* preprocess_text */ |
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371 HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, |
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372 NULL, /* decompose */ |
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373 NULL, /* compose */ |
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374 setup_masks_sea, |
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375 HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, |
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376 false, /* fallback_position */ |
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377 }; |