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1 /* |
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2 * Copyright © 2016 Igalia S.L. |
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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 * Igalia Author(s): Frédéric Wang |
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25 */ |
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26 |
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27 #include "hb-open-type.hh" |
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28 |
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29 #include "hb-ot-face.hh" |
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30 #include "hb-ot-math-table.hh" |
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31 |
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32 |
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33 /** |
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34 * SECTION:hb-ot-math |
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35 * @title: hb-ot-math |
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36 * @short_description: OpenType Math information |
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37 * @include: hb-ot.h |
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38 * |
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39 * Functions for fetching mathematics layout data from OpenType fonts. |
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40 **/ |
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41 |
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42 |
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43 /* |
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44 * OT::MATH |
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45 */ |
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46 |
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47 /** |
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48 * hb_ot_math_has_data: |
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49 * @face: #hb_face_t to test |
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50 * |
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51 * This function allows to verify the presence of an OpenType MATH table on the |
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52 * face. |
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53 * |
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54 * Return value: true if face has a MATH table, false otherwise |
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55 * |
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56 * Since: 1.3.3 |
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57 **/ |
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58 hb_bool_t |
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59 hb_ot_math_has_data (hb_face_t *face) |
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60 { |
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61 return face->table.MATH->has_data (); |
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62 } |
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63 |
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64 /** |
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65 * hb_ot_math_get_constant: |
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66 * @font: #hb_font_t from which to retrieve the value |
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67 * @constant: #hb_ot_math_constant_t the constant to retrieve |
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68 * |
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69 * This function returns the requested math constants as a #hb_position_t. |
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70 * If the request constant is HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN, |
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71 * HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN or |
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72 * HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN then the return value is |
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73 * actually an integer between 0 and 100 representing that percentage. |
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74 * |
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75 * Return value: the requested constant or 0 |
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76 * |
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77 * Since: 1.3.3 |
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78 **/ |
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79 hb_position_t |
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80 hb_ot_math_get_constant (hb_font_t *font, |
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81 hb_ot_math_constant_t constant) |
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82 { |
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83 return font->face->table.MATH->get_constant(constant, font); |
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84 } |
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85 |
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86 /** |
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87 * hb_ot_math_get_glyph_italics_correction: |
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88 * @font: #hb_font_t from which to retrieve the value |
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89 * @glyph: glyph index from which to retrieve the value |
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90 * |
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91 * Return value: the italics correction of the glyph or 0 |
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92 * |
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93 * Since: 1.3.3 |
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94 **/ |
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95 hb_position_t |
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96 hb_ot_math_get_glyph_italics_correction (hb_font_t *font, |
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97 hb_codepoint_t glyph) |
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98 { |
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99 return font->face->table.MATH->get_glyph_info().get_italics_correction (glyph, font); |
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100 } |
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101 |
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102 /** |
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103 * hb_ot_math_get_glyph_top_accent_attachment: |
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104 * @font: #hb_font_t from which to retrieve the value |
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105 * @glyph: glyph index from which to retrieve the value |
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106 * |
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107 * Return value: the top accent attachment of the glyph or 0 |
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108 * |
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109 * Since: 1.3.3 |
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110 **/ |
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111 hb_position_t |
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112 hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font, |
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113 hb_codepoint_t glyph) |
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114 { |
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115 return font->face->table.MATH->get_glyph_info().get_top_accent_attachment (glyph, font); |
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116 } |
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117 |
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118 /** |
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119 * hb_ot_math_is_glyph_extended_shape: |
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120 * @face: a #hb_face_t to test |
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121 * @glyph: a glyph index to test |
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122 * |
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123 * Return value: true if the glyph is an extended shape, false otherwise |
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124 * |
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125 * Since: 1.3.3 |
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126 **/ |
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127 hb_bool_t |
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128 hb_ot_math_is_glyph_extended_shape (hb_face_t *face, |
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129 hb_codepoint_t glyph) |
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130 { |
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131 return face->table.MATH->get_glyph_info().is_extended_shape (glyph); |
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132 } |
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133 |
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134 /** |
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135 * hb_ot_math_get_glyph_kerning: |
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136 * @font: #hb_font_t from which to retrieve the value |
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137 * @glyph: glyph index from which to retrieve the value |
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138 * @kern: the #hb_ot_math_kern_t from which to retrieve the value |
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139 * @correction_height: the correction height to use to determine the kerning. |
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140 * |
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141 * This function tries to retrieve the MathKern table for the specified font, |
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142 * glyph and #hb_ot_math_kern_t. Then it browses the list of heights from the |
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143 * MathKern table to find one value that is greater or equal to specified |
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144 * correction_height. If one is found the corresponding value from the list of |
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145 * kerns is returned and otherwise the last kern value is returned. |
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146 * |
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147 * Return value: requested kerning or 0 |
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148 * |
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149 * Since: 1.3.3 |
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150 **/ |
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151 hb_position_t |
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152 hb_ot_math_get_glyph_kerning (hb_font_t *font, |
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153 hb_codepoint_t glyph, |
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154 hb_ot_math_kern_t kern, |
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155 hb_position_t correction_height) |
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156 { |
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157 return font->face->table.MATH->get_glyph_info().get_kerning (glyph, |
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158 kern, |
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159 correction_height, |
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160 font); |
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161 } |
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162 |
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163 /** |
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164 * hb_ot_math_get_glyph_variants: |
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165 * @font: #hb_font_t from which to retrieve the values |
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166 * @glyph: index of the glyph to stretch |
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167 * @direction: direction of the stretching |
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168 * @start_offset: offset of the first variant to retrieve |
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169 * @variants_count: maximum number of variants to retrieve after start_offset |
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170 * (IN) and actual number of variants retrieved (OUT) |
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171 * @variants: array of size at least @variants_count to store the result |
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172 * |
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173 * This function tries to retrieve the MathGlyphConstruction for the specified |
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174 * font, glyph and direction. Note that only the value of |
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175 * #HB_DIRECTION_IS_HORIZONTAL is considered. It provides the corresponding list |
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176 * of size variants as an array of hb_ot_math_glyph_variant_t structs. |
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177 * |
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178 * Return value: the total number of size variants available or 0 |
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179 * |
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180 * Since: 1.3.3 |
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181 **/ |
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182 unsigned int |
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183 hb_ot_math_get_glyph_variants (hb_font_t *font, |
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184 hb_codepoint_t glyph, |
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185 hb_direction_t direction, |
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186 unsigned int start_offset, |
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187 unsigned int *variants_count, /* IN/OUT */ |
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188 hb_ot_math_glyph_variant_t *variants /* OUT */) |
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189 { |
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190 return font->face->table.MATH->get_variants().get_glyph_variants (glyph, direction, font, |
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191 start_offset, |
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192 variants_count, |
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193 variants); |
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194 } |
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195 |
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196 /** |
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197 * hb_ot_math_get_min_connector_overlap: |
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198 * @font: #hb_font_t from which to retrieve the value |
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199 * @direction: direction of the stretching |
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200 * |
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201 * This function tries to retrieve the MathVariants table for the specified |
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202 * font and returns the minimum overlap of connecting glyphs to draw a glyph |
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203 * assembly in the specified direction. Note that only the value of |
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204 * #HB_DIRECTION_IS_HORIZONTAL is considered. |
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205 * |
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206 * Return value: requested min connector overlap or 0 |
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207 * |
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208 * Since: 1.3.3 |
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209 **/ |
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210 hb_position_t |
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211 hb_ot_math_get_min_connector_overlap (hb_font_t *font, |
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212 hb_direction_t direction) |
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213 { |
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214 return font->face->table.MATH->get_variants().get_min_connector_overlap (direction, font); |
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215 } |
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216 |
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217 /** |
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218 * hb_ot_math_get_glyph_assembly: |
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219 * @font: #hb_font_t from which to retrieve the values |
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220 * @glyph: index of the glyph to stretch |
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221 * @direction: direction of the stretching |
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222 * @start_offset: offset of the first glyph part to retrieve |
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223 * @parts_count: maximum number of glyph parts to retrieve after start_offset |
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224 * (IN) and actual number of parts retrieved (OUT) |
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225 * @parts: array of size at least @parts_count to store the result |
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226 * @italics_correction: italic correction of the glyph assembly |
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227 * |
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228 * This function tries to retrieve the GlyphAssembly for the specified font, |
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229 * glyph and direction. Note that only the value of #HB_DIRECTION_IS_HORIZONTAL |
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230 * is considered. It provides the information necessary to draw the glyph |
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231 * assembly as an array of #hb_ot_math_glyph_part_t. |
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232 * |
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233 * Return value: the total number of parts in the glyph assembly |
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234 * |
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235 * Since: 1.3.3 |
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236 **/ |
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237 unsigned int |
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238 hb_ot_math_get_glyph_assembly (hb_font_t *font, |
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239 hb_codepoint_t glyph, |
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240 hb_direction_t direction, |
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241 unsigned int start_offset, |
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242 unsigned int *parts_count, /* IN/OUT */ |
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243 hb_ot_math_glyph_part_t *parts, /* OUT */ |
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244 hb_position_t *italics_correction /* OUT */) |
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245 { |
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246 return font->face->table.MATH->get_variants().get_glyph_parts (glyph, |
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247 direction, |
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248 font, |
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249 start_offset, |
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250 parts_count, |
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251 parts, |
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252 italics_correction); |
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253 } |