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-math-table.hh" 30 31 HB_SHAPER_DATA_ENSURE_DECLARE(ot, face) 32 33 static inline const OT::MATH& 34 _get_math (hb_face_t *face) 35 { 36 if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::MATH); 37 hb_ot_layout_t * layout = hb_ot_layout_from_face (face); 38 return *(layout->math.get ()); 39 } 40 41 /* 42 * OT::MATH 43 */ 44 45 /** 46 * hb_ot_math_has_data: 47 * @face: #hb_face_t to test 48 * 49 * This function allows to verify the presence of an OpenType MATH table on the 50 * face. 51 * 52 * Return value: true if face has a MATH table, false otherwise 53 * 54 * Since: 1.3.3 55 **/ 56 hb_bool_t 57 hb_ot_math_has_data (hb_face_t *face) 58 { 59 return &_get_math (face) != &OT::Null(OT::MATH); 60 } 61 62 /** 63 * hb_ot_math_get_constant: 64 * @font: #hb_font_t from which to retrieve the value 65 * @constant: #hb_ot_math_constant_t the constant to retrieve 66 * 67 * This function returns the requested math constants as a #hb_position_t. 68 * If the request constant is HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN, 69 * HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN or 70 * HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN then the return value is 71 * actually an integer between 0 and 100 representing that percentage. 72 * 73 * Return value: the requested constant or 0 74 * 75 * Since: 1.3.3 76 **/ 77 hb_position_t 78 hb_ot_math_get_constant (hb_font_t *font, 79 hb_ot_math_constant_t constant) 80 { 81 const OT::MATH &math = _get_math (font->face); 82 return math.get_constant(constant, font); 83 } 84 85 /** 86 * hb_ot_math_get_glyph_italics_correction: 87 * @font: #hb_font_t from which to retrieve the value 88 * @glyph: glyph index from which to retrieve the value 89 * 90 * Return value: the italics correction of the glyph or 0 91 * 92 * Since: 1.3.3 93 **/ 94 hb_position_t 95 hb_ot_math_get_glyph_italics_correction (hb_font_t *font, 96 hb_codepoint_t glyph) 97 { 98 const OT::MATH &math = _get_math (font->face); 99 return math.get_math_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 const OT::MATH &math = _get_math (font->face); 116 return math.get_math_glyph_info().get_top_accent_attachment (glyph, font); 117 } 118 119 /** 120 * hb_ot_math_is_glyph_extended_shape: 121 * @face: a #hb_face_t to test 122 * @glyph: a glyph index to test 123 * 124 * Return value: true if the glyph is an extended shape, false otherwise 125 * 126 * Since: 1.3.3 127 **/ 128 hb_bool_t 129 hb_ot_math_is_glyph_extended_shape (hb_face_t *face, 130 hb_codepoint_t glyph) 131 { 132 const OT::MATH &math = _get_math (face); 133 return math.get_math_glyph_info().is_extended_shape (glyph); 134 } 135 136 /** 137 * hb_ot_math_get_glyph_kerning: 138 * @font: #hb_font_t from which to retrieve the value 139 * @glyph: glyph index from which to retrieve the value 140 * @kern: the #hb_ot_math_kern_t from which to retrieve the value 141 * @correction_height: the correction height to use to determine the kerning. 142 * 143 * This function tries to retrieve the MathKern table for the specified font, 144 * glyph and #hb_ot_math_kern_t. Then it browses the list of heights from the 145 * MathKern table to find one value that is greater or equal to specified 146 * correction_height. If one is found the corresponding value from the list of 147 * kerns is returned and otherwise the last kern value is returned. 148 * 149 * Return value: requested kerning or 0 150 * 151 * Since: 1.3.3 152 **/ 153 hb_position_t 154 hb_ot_math_get_glyph_kerning (hb_font_t *font, 155 hb_codepoint_t glyph, 156 hb_ot_math_kern_t kern, 157 hb_position_t correction_height) 158 { 159 const OT::MATH &math = _get_math (font->face); 160 return math.get_math_glyph_info().get_kerning (glyph, kern, correction_height, 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 const OT::MATH &math = _get_math (font->face); 191 return math.get_math_variants().get_glyph_variants (glyph, direction, font, 192 start_offset, 193 variants_count, 194 variants); 195 } 196 197 /** 198 * hb_ot_math_get_min_connector_overlap: 199 * @font: #hb_font_t from which to retrieve the value 200 * @direction: direction of the stretching 201 * 202 * This function tries to retrieve the MathVariants table for the specified 203 * font and returns the minimum overlap of connecting glyphs to draw a glyph 204 * assembly in the specified direction. Note that only the value of 205 * #HB_DIRECTION_IS_HORIZONTAL is considered. 206 * 207 * Return value: requested min connector overlap or 0 208 * 209 * Since: 1.3.3 210 **/ 211 hb_position_t 212 hb_ot_math_get_min_connector_overlap (hb_font_t *font, 213 hb_direction_t direction) 214 { 215 const OT::MATH &math = _get_math (font->face); 216 return math.get_math_variants().get_min_connector_overlap (direction, font); 217 } 218 219 /** 220 * hb_ot_math_get_glyph_assembly: 221 * @font: #hb_font_t from which to retrieve the values 222 * @glyph: index of the glyph to stretch 223 * @direction: direction of the stretching 224 * @start_offset: offset of the first glyph part to retrieve 225 * @parts_count: maximum number of glyph parts to retrieve after start_offset 226 * (IN) and actual number of parts retrieved (OUT) 227 * @parts: array of size at least @parts_count to store the result 228 * @italics_correction: italic correction of the glyph assembly 229 * 230 * This function tries to retrieve the GlyphAssembly for the specified font, 231 * glyph and direction. Note that only the value of #HB_DIRECTION_IS_HORIZONTAL 232 * is considered. It provides the information necessary to draw the glyph 233 * assembly as an array of #hb_ot_math_glyph_part_t. 234 * 235 * Return value: the total number of parts in the glyph assembly 236 * 237 * Since: 1.3.3 238 **/ 239 unsigned int 240 hb_ot_math_get_glyph_assembly (hb_font_t *font, 241 hb_codepoint_t glyph, 242 hb_direction_t direction, 243 unsigned int start_offset, 244 unsigned int *parts_count, /* IN/OUT */ 245 hb_ot_math_glyph_part_t *parts, /* OUT */ 246 hb_position_t *italics_correction /* OUT */) 247 { 248 const OT::MATH &math = _get_math (font->face); 249 return math.get_math_variants().get_glyph_parts (glyph, direction, font, 250 start_offset, 251 parts_count, 252 parts, 253 italics_correction); 254 } 255
