/* * Copyright © 2016 Igalia S.L. * * This is part of HarfBuzz, a text shaping library. * * Permission is hereby granted, without written agreement and without * license or royalty fees, to use, copy, modify, and distribute this * software and its documentation for any purpose, provided that the * above copyright notice and the following two paragraphs appear in * all copies of this software. * * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. * * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. * * Igalia Author(s): Frédéric Wang */ #include "hb.hh" #ifndef HB_NO_MATH #include "hb-ot-math-table.hh" /** * SECTION:hb-ot-math * @title: hb-ot-math * @short_description: OpenType Math information * @include: hb-ot.h * * Functions for fetching mathematics layout data from OpenType fonts. * * HarfBuzz itself does not implement a math layout solution. The * functions and types provided can be used by client programs to access * the font data necessary for typesetting OpenType Math layout. * **/ /* * OT::MATH */ /** * hb_ot_math_has_data: * @face: #hb_face_t to test * * Tests whether a face has a `MATH` table. * * Return value: `true` if the table is found, `false` otherwise * * Since: 1.3.3 **/ hb_bool_t hb_ot_math_has_data (hb_face_t *face) { … } /** * hb_ot_math_get_constant: * @font: #hb_font_t to work upon * @constant: #hb_ot_math_constant_t the constant to retrieve * * Fetches the specified math constant. For most constants, the value returned * is an #hb_position_t. * * However, if the requested constant is #HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN, * #HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN or * #HB_OT_MATH_CONSTANT_RADICAL_DEGREE_BOTTOM_RAISE_PERCENT, then the return value is * an integer between 0 and 100 representing that percentage. * * Return value: the requested constant or zero * * Since: 1.3.3 **/ hb_position_t hb_ot_math_get_constant (hb_font_t *font, hb_ot_math_constant_t constant) { … } /** * hb_ot_math_get_glyph_italics_correction: * @font: #hb_font_t to work upon * @glyph: The glyph index from which to retrieve the value * * Fetches an italics-correction value (if one exists) for the specified * glyph index. * * Return value: the italics correction of the glyph or zero * * Since: 1.3.3 **/ hb_position_t hb_ot_math_get_glyph_italics_correction (hb_font_t *font, hb_codepoint_t glyph) { … } /** * hb_ot_math_get_glyph_top_accent_attachment: * @font: #hb_font_t to work upon * @glyph: The glyph index from which to retrieve the value * * Fetches a top-accent-attachment value (if one exists) for the specified * glyph index. * * For any glyph that does not have a top-accent-attachment value - that is, * a glyph not covered by the `MathTopAccentAttachment` table (or, when * @font has no `MathTopAccentAttachment` table or no `MATH` table, any * glyph) - the function synthesizes a value, returning the position at * one-half the glyph's advance width. * * Return value: the top accent attachment of the glyph or 0.5 * the advance * width of @glyph * * Since: 1.3.3 **/ hb_position_t hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font, hb_codepoint_t glyph) { … } /** * hb_ot_math_is_glyph_extended_shape: * @face: #hb_face_t to work upon * @glyph: The glyph index to test * * Tests whether the given glyph index is an extended shape in the face. * * Return value: `true` if the glyph is an extended shape, `false` otherwise * * Since: 1.3.3 **/ hb_bool_t hb_ot_math_is_glyph_extended_shape (hb_face_t *face, hb_codepoint_t glyph) { … } /** * hb_ot_math_get_glyph_kerning: * @font: #hb_font_t to work upon * @glyph: The glyph index from which to retrieve the value * @kern: The #hb_ot_math_kern_t from which to retrieve the value * @correction_height: the correction height to use to determine the kerning. * * Fetches the math kerning (cut-ins) value for the specified font, glyph index, and * @kern. * * If the MathKern table is found, the function examines it to find a height * value that is greater or equal to @correction_height. If such a height * value is found, corresponding kerning value from the table is returned. If * no such height value is found, the last kerning value is returned. * * Return value: requested kerning value or zero * * Since: 1.3.3 **/ hb_position_t hb_ot_math_get_glyph_kerning (hb_font_t *font, hb_codepoint_t glyph, hb_ot_math_kern_t kern, hb_position_t correction_height) { … } /** * hb_ot_math_get_glyph_kernings: * @font: #hb_font_t to work upon * @glyph: The glyph index from which to retrieve the kernings * @kern: The #hb_ot_math_kern_t from which to retrieve the kernings * @start_offset: offset of the first kern entry to retrieve * @entries_count: (inout) (optional): Input = the maximum number of kern entries to return; * Output = the actual number of kern entries returned * @kern_entries: (out caller-allocates) (array length=entries_count): array of kern entries returned * * Fetches the raw MathKern (cut-in) data for the specified font, glyph index, * and @kern. The corresponding list of kern values and correction heights is * returned as a list of #hb_ot_math_kern_entry_t structs. * * See also #hb_ot_math_get_glyph_kerning, which handles selecting the * appropriate kern value for a given correction height. * * <note>For a glyph with @n defined kern values (where @n > 0), there are only * @n−1 defined correction heights, as each correction height defines a boundary * past which the next kern value should be selected. Therefore, only the * #hb_ot_math_kern_entry_t.kern_value of the uppermost #hb_ot_math_kern_entry_t * actually comes from the font; its corresponding * #hb_ot_math_kern_entry_t.max_correction_height is always set to * <code>INT32_MAX</code>.</note> * * Return value: the total number of kern values available or zero * * Since: 3.4.0 **/ unsigned int hb_ot_math_get_glyph_kernings (hb_font_t *font, hb_codepoint_t glyph, hb_ot_math_kern_t kern, unsigned int start_offset, unsigned int *entries_count, /* IN/OUT */ hb_ot_math_kern_entry_t *kern_entries /* OUT */) { … } /** * hb_ot_math_get_glyph_variants: * @font: #hb_font_t to work upon * @glyph: The index of the glyph to stretch * @direction: The direction of the stretching (horizontal or vertical) * @start_offset: offset of the first variant to retrieve * @variants_count: (inout): Input = the maximum number of variants to return; * Output = the actual number of variants returned * @variants: (out) (array length=variants_count): array of variants returned * * Fetches the MathGlyphConstruction for the specified font, glyph index, and * direction. The corresponding list of size variants is returned as a list of * #hb_ot_math_glyph_variant_t structs. * * <note>The @direction parameter is only used to select between horizontal * or vertical directions for the construction. Even though all #hb_direction_t * values are accepted, only the result of #HB_DIRECTION_IS_HORIZONTAL is * considered.</note> * * Return value: the total number of size variants available or zero * * Since: 1.3.3 **/ unsigned int hb_ot_math_get_glyph_variants (hb_font_t *font, hb_codepoint_t glyph, hb_direction_t direction, unsigned int start_offset, unsigned int *variants_count, /* IN/OUT */ hb_ot_math_glyph_variant_t *variants /* OUT */) { … } /** * hb_ot_math_get_min_connector_overlap: * @font: #hb_font_t to work upon * @direction: direction of the stretching (horizontal or vertical) * * Fetches the MathVariants table for the specified font and returns the * minimum overlap of connecting glyphs that are required to draw a glyph * assembly in the specified direction. * * <note>The @direction parameter is only used to select between horizontal * or vertical directions for the construction. Even though all #hb_direction_t * values are accepted, only the result of #HB_DIRECTION_IS_HORIZONTAL is * considered.</note> * * Return value: requested minimum connector overlap or zero * * Since: 1.3.3 **/ hb_position_t hb_ot_math_get_min_connector_overlap (hb_font_t *font, hb_direction_t direction) { … } /** * hb_ot_math_get_glyph_assembly: * @font: #hb_font_t to work upon * @glyph: The index of the glyph to stretch * @direction: direction of the stretching (horizontal or vertical) * @start_offset: offset of the first glyph part to retrieve * @parts_count: (inout): Input = maximum number of glyph parts to return; * Output = actual number of parts returned * @parts: (out) (array length=parts_count): the glyph parts returned * @italics_correction: (out): italics correction of the glyph assembly * * Fetches the GlyphAssembly for the specified font, glyph index, and direction. * Returned are a list of #hb_ot_math_glyph_part_t glyph parts that can be * used to draw the glyph and an italics-correction value (if one is defined * in the font). * * <note>The @direction parameter is only used to select between horizontal * or vertical directions for the construction. Even though all #hb_direction_t * values are accepted, only the result of #HB_DIRECTION_IS_HORIZONTAL is * considered.</note> * * Return value: the total number of parts in the glyph assembly * * Since: 1.3.3 **/ unsigned int hb_ot_math_get_glyph_assembly (hb_font_t *font, hb_codepoint_t glyph, hb_direction_t direction, unsigned int start_offset, unsigned int *parts_count, /* IN/OUT */ hb_ot_math_glyph_part_t *parts, /* OUT */ hb_position_t *italics_correction /* OUT */) { … } #endif
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