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-private.hh" 28 29 #include "hb-ot-layout-private.hh" 30 #include "hb-ot-math-table.hh" 31 32 static inline const OT::MATH& 33 _get_math (hb_face_t *face) 34 { 35 if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::MATH); 36 hb_ot_layout_t * layout = hb_ot_layout_from_face (face); 37 return *(layout->math.get ()); 38 } 39 40 /* 41 * OT::MATH 42 */ 43 44 /** 45 * hb_ot_math_has_data: 46 * @face: #hb_face_t to test 47 * 48 * This function allows to verify the presence of an OpenType MATH table on the 49 * face. 50 * 51 * Return value: true if face has a MATH table, false otherwise 52 * 53 * Since: 1.3.3 54 **/ 55 hb_bool_t 56 hb_ot_math_has_data (hb_face_t *face) 57 { 58 return &_get_math (face) != &OT::Null(OT::MATH); 59 } 60 61 /** 62 * hb_ot_math_get_constant: 63 * @font: #hb_font_t from which to retrieve the value 64 * @constant: #hb_ot_math_constant_t the constant to retrieve 65 * 66 * This function returns the requested math constants as a #hb_position_t. 67 * If the request constant is HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN, 68 * HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN or 69 * HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN then the return value is 70 * actually an integer between 0 and 100 representing that percentage. 71 * 72 * Return value: the requested constant or 0 73 * 74 * Since: 1.3.3 75 **/ 76 hb_position_t 77 hb_ot_math_get_constant (hb_font_t *font, 78 hb_ot_math_constant_t constant) 79 { 80 const OT::MATH &math = _get_math (font->face); 81 return math.get_constant(constant, font); 82 } 83 84 /** 85 * hb_ot_math_get_glyph_italics_correction: 86 * @font: #hb_font_t from which to retrieve the value 87 * @glyph: glyph index from which to retrieve the value 88 * 89 * Return value: the italics correction of the glyph or 0 90 * 91 * Since: 1.3.3 92 **/ 93 hb_position_t 94 hb_ot_math_get_glyph_italics_correction (hb_font_t *font, 95 hb_codepoint_t glyph) 96 { 97 const OT::MATH &math = _get_math (font->face); 98 return math.get_math_glyph_info().get_italics_correction (glyph, font); 99 } 100 101 /** 102 * hb_ot_math_get_glyph_top_accent_attachment: 103 * @font: #hb_font_t from which to retrieve the value 104 * @glyph: glyph index from which to retrieve the value 105 * 106 * Return value: the top accent attachment of the glyph or 0 107 * 108 * Since: 1.3.3 109 **/ 110 hb_position_t 111 hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font, 112 hb_codepoint_t glyph) 113 { 114 const OT::MATH &math = _get_math (font->face); 115 return math.get_math_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 const OT::MATH &math = _get_math (face); 132 return math.get_math_glyph_info().is_extended_shape (glyph); 133 } 134 135 /** 136 * hb_ot_math_get_glyph_kerning: 137 * @font: #hb_font_t from which to retrieve the value 138 * @glyph: glyph index from which to retrieve the value 139 * @kern: the #hb_ot_math_kern_t from which to retrieve the value 140 * @correction_height: the correction height to use to determine the kerning. 141 * 142 * This function tries to retrieve the MathKern table for the specified font, 143 * glyph and #hb_ot_math_kern_t. Then it browses the list of heights from the 144 * MathKern table to find one value that is greater or equal to specified 145 * correction_height. If one is found the corresponding value from the list of 146 * kerns is returned and otherwise the last kern value is returned. 147 * 148 * Return value: requested kerning or 0 149 * 150 * Since: 1.3.3 151 **/ 152 hb_position_t 153 hb_ot_math_get_glyph_kerning (hb_font_t *font, 154 hb_codepoint_t glyph, 155 hb_ot_math_kern_t kern, 156 hb_position_t correction_height) 157 { 158 const OT::MATH &math = _get_math (font->face); 159 return math.get_math_glyph_info().get_kerning (glyph, kern, correction_height, font); 160 } 161 162 /** 163 * hb_ot_math_get_glyph_variants: 164 * @font: #hb_font_t from which to retrieve the values 165 * @glyph: index of the glyph to stretch 166 * @direction: direction of the stretching 167 * @start_offset: offset of the first variant to retrieve 168 * @variants_count: maximum number of variants to retrieve after start_offset 169 * (IN) and actual number of variants retrieved (OUT) 170 * @variants: array of size at least @variants_count to store the result 171 * 172 * This function tries to retrieve the MathGlyphConstruction for the specified 173 * font, glyph and direction. Note that only the value of 174 * #HB_DIRECTION_IS_HORIZONTAL is considered. It provides the corresponding list 175 * of size variants as an array of hb_ot_math_glyph_variant_t structs. 176 * 177 * Return value: the total number of size variants available or 0 178 * 179 * Since: 1.3.3 180 **/ 181 unsigned int 182 hb_ot_math_get_glyph_variants (hb_font_t *font, 183 hb_codepoint_t glyph, 184 hb_direction_t direction, 185 unsigned int start_offset, 186 unsigned int *variants_count, /* IN/OUT */ 187 hb_ot_math_glyph_variant_t *variants /* OUT */) 188 { 189 const OT::MATH &math = _get_math (font->face); 190 return math.get_math_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 const OT::MATH &math = _get_math (font->face); 215 return math.get_math_variants().get_min_connector_overlap (direction, font); 216 } 217 218 /** 219 * hb_ot_math_get_glyph_assembly: 220 * @font: #hb_font_t from which to retrieve the values 221 * @glyph: index of the glyph to stretch 222 * @direction: direction of the stretching 223 * @start_offset: offset of the first glyph part to retrieve 224 * @parts_count: maximum number of glyph parts to retrieve after start_offset 225 * (IN) and actual number of parts retrieved (OUT) 226 * @parts: array of size at least @parts_count to store the result 227 * @italics_correction: italic correction of the glyph assembly 228 * 229 * This function tries to retrieve the GlyphAssembly for the specified font, 230 * glyph and direction. Note that only the value of #HB_DIRECTION_IS_HORIZONTAL 231 * is considered. It provides the information necessary to draw the glyph 232 * assembly as an array of #hb_ot_math_glyph_part_t. 233 * 234 * Return value: the total number of parts in the glyph assembly 235 * 236 * Since: 1.3.3 237 **/ 238 unsigned int 239 hb_ot_math_get_glyph_assembly (hb_font_t *font, 240 hb_codepoint_t glyph, 241 hb_direction_t direction, 242 unsigned int start_offset, 243 unsigned int *parts_count, /* IN/OUT */ 244 hb_ot_math_glyph_part_t *parts, /* OUT */ 245 hb_position_t *italics_correction /* OUT */) 246 { 247 const OT::MATH &math = _get_math (font->face); 248 return math.get_math_variants().get_glyph_parts (glyph, direction, font, 249 start_offset, 250 parts_count, 251 parts, 252 italics_correction); 253 } 254
