1 /* 2 * Copyright 2016 Igalia S.L. 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 * 24 * Igalia Author(s): Frdric Wang 25 */ 26 27 #include "hb-open-type.hh" 28 29 #include "hb-ot-face.hh" 30 #include "hb-ot-math-table.hh" 31 32 33 /** 34 * SECTION:hb-ot-math 35 * @title: hb-ot-math 36 * @short_description: OpenType Math information 37 * @include: hb-ot.h 38 * 39 * Functions for fetching mathematics layout data from OpenType fonts. 40 **/ 41 42 43 /* 44 * OT::MATH 45 */ 46 47 /** 48 * hb_ot_math_has_data: 49 * @face: #hb_face_t to test 50 * 51 * This function allows to verify the presence of an OpenType MATH table on the 52 * face. 53 * 54 * Return value: true if face has a MATH table, false otherwise 55 * 56 * Since: 1.3.3 57 **/ 58 hb_bool_t 59 hb_ot_math_has_data (hb_face_t *face) 60 { 61 return face->table.MATH->has_data (); 62 } 63 64 /** 65 * hb_ot_math_get_constant: 66 * @font: #hb_font_t from which to retrieve the value 67 * @constant: #hb_ot_math_constant_t the constant to retrieve 68 * 69 * This function returns the requested math constants as a #hb_position_t. 70 * If the request constant is HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN, 71 * HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN or 72 * HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN then the return value is 73 * actually an integer between 0 and 100 representing that percentage. 74 * 75 * Return value: the requested constant or 0 76 * 77 * Since: 1.3.3 78 **/ 79 hb_position_t 80 hb_ot_math_get_constant (hb_font_t *font, 81 hb_ot_math_constant_t constant) 82 { 83 return font->face->table.MATH->get_constant(constant, font); 84 } 85 86 /** 87 * hb_ot_math_get_glyph_italics_correction: 88 * @font: #hb_font_t from which to retrieve the value 89 * @glyph: glyph index from which to retrieve the value 90 * 91 * Return value: the italics correction of the glyph or 0 92 * 93 * Since: 1.3.3 94 **/ 95 hb_position_t 96 hb_ot_math_get_glyph_italics_correction (hb_font_t *font, 97 hb_codepoint_t glyph) 98 { 99 return font->face->table.MATH->get_glyph_info().get_italics_correction (glyph, font); 100 } 101 102 /** 103 * hb_ot_math_get_glyph_top_accent_attachment: 104 * @font: #hb_font_t from which to retrieve the value 105 * @glyph: glyph index from which to retrieve the value 106 * 107 * Return value: the top accent attachment of the glyph or 0 108 * 109 * Since: 1.3.3 110 **/ 111 hb_position_t 112 hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font, 113 hb_codepoint_t glyph) 114 { 115 return font->face->table.MATH->get_glyph_info().get_top_accent_attachment (glyph, font); 116 } 117 118 /** 119 * hb_ot_math_is_glyph_extended_shape: 120 * @face: a #hb_face_t to test 121 * @glyph: a glyph index to test 122 * 123 * Return value: true if the glyph is an extended shape, false otherwise 124 * 125 * Since: 1.3.3 126 **/ 127 hb_bool_t 128 hb_ot_math_is_glyph_extended_shape (hb_face_t *face, 129 hb_codepoint_t glyph) 130 { 131 return face->table.MATH->get_glyph_info().is_extended_shape (glyph); 132 } 133 134 /** 135 * hb_ot_math_get_glyph_kerning: 136 * @font: #hb_font_t from which to retrieve the value 137 * @glyph: glyph index from which to retrieve the value 138 * @kern: the #hb_ot_math_kern_t from which to retrieve the value 139 * @correction_height: the correction height to use to determine the kerning. 140 * 141 * This function tries to retrieve the MathKern table for the specified font, 142 * glyph and #hb_ot_math_kern_t. Then it browses the list of heights from the 143 * MathKern table to find one value that is greater or equal to specified 144 * correction_height. If one is found the corresponding value from the list of 145 * kerns is returned and otherwise the last kern value is returned. 146 * 147 * Return value: requested kerning or 0 148 * 149 * Since: 1.3.3 150 **/ 151 hb_position_t 152 hb_ot_math_get_glyph_kerning (hb_font_t *font, 153 hb_codepoint_t glyph, 154 hb_ot_math_kern_t kern, 155 hb_position_t correction_height) 156 { 157 return font->face->table.MATH->get_glyph_info().get_kerning (glyph, 158 kern, 159 correction_height, 160 font); 161 } 162 163 /** 164 * hb_ot_math_get_glyph_variants: 165 * @font: #hb_font_t from which to retrieve the values 166 * @glyph: index of the glyph to stretch 167 * @direction: direction of the stretching 168 * @start_offset: offset of the first variant to retrieve 169 * @variants_count: maximum number of variants to retrieve after start_offset 170 * (IN) and actual number of variants retrieved (OUT) 171 * @variants: array of size at least @variants_count to store the result 172 * 173 * This function tries to retrieve the MathGlyphConstruction for the specified 174 * font, glyph and direction. Note that only the value of 175 * #HB_DIRECTION_IS_HORIZONTAL is considered. It provides the corresponding list 176 * of size variants as an array of hb_ot_math_glyph_variant_t structs. 177 * 178 * Return value: the total number of size variants available or 0 179 * 180 * Since: 1.3.3 181 **/ 182 unsigned int 183 hb_ot_math_get_glyph_variants (hb_font_t *font, 184 hb_codepoint_t glyph, 185 hb_direction_t direction, 186 unsigned int start_offset, 187 unsigned int *variants_count, /* IN/OUT */ 188 hb_ot_math_glyph_variant_t *variants /* OUT */) 189 { 190 return font->face->table.MATH->get_variants().get_glyph_variants (glyph, direction, font, 191 start_offset, 192 variants_count, 193 variants); 194 } 195 196 /** 197 * hb_ot_math_get_min_connector_overlap: 198 * @font: #hb_font_t from which to retrieve the value 199 * @direction: direction of the stretching 200 * 201 * This function tries to retrieve the MathVariants table for the specified 202 * font and returns the minimum overlap of connecting glyphs to draw a glyph 203 * assembly in the specified direction. Note that only the value of 204 * #HB_DIRECTION_IS_HORIZONTAL is considered. 205 * 206 * Return value: requested min connector overlap or 0 207 * 208 * Since: 1.3.3 209 **/ 210 hb_position_t 211 hb_ot_math_get_min_connector_overlap (hb_font_t *font, 212 hb_direction_t direction) 213 { 214 return font->face->table.MATH->get_variants().get_min_connector_overlap (direction, font); 215 } 216 217 /** 218 * hb_ot_math_get_glyph_assembly: 219 * @font: #hb_font_t from which to retrieve the values 220 * @glyph: index of the glyph to stretch 221 * @direction: direction of the stretching 222 * @start_offset: offset of the first glyph part to retrieve 223 * @parts_count: maximum number of glyph parts to retrieve after start_offset 224 * (IN) and actual number of parts retrieved (OUT) 225 * @parts: array of size at least @parts_count to store the result 226 * @italics_correction: italic correction of the glyph assembly 227 * 228 * This function tries to retrieve the GlyphAssembly for the specified font, 229 * glyph and direction. Note that only the value of #HB_DIRECTION_IS_HORIZONTAL 230 * is considered. It provides the information necessary to draw the glyph 231 * assembly as an array of #hb_ot_math_glyph_part_t. 232 * 233 * Return value: the total number of parts in the glyph assembly 234 * 235 * Since: 1.3.3 236 **/ 237 unsigned int 238 hb_ot_math_get_glyph_assembly (hb_font_t *font, 239 hb_codepoint_t glyph, 240 hb_direction_t direction, 241 unsigned int start_offset, 242 unsigned int *parts_count, /* IN/OUT */ 243 hb_ot_math_glyph_part_t *parts, /* OUT */ 244 hb_position_t *italics_correction /* OUT */) 245 { 246 return font->face->table.MATH->get_variants().get_glyph_parts (glyph, 247 direction, 248 font, 249 start_offset, 250 parts_count, 251 parts, 252 italics_correction); 253 } 254
