| /* |
| * 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) |
| { |
| return face->table.MATH->has_data (); |
| } |
| |
| /** |
| * 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_SCRIPT_PERCENT_SCALE_DOWN, 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) |
| { |
| return font->face->table.MATH->get_constant(constant, font); |
| } |
| |
| /** |
| * 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) |
| { |
| return font->face->table.MATH->get_glyph_info().get_italics_correction (glyph, font); |
| } |
| |
| /** |
| * 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) |
| { |
| return font->face->table.MATH->get_glyph_info().get_top_accent_attachment (glyph, font); |
| } |
| |
| /** |
| * 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) |
| { |
| return face->table.MATH->get_glyph_info().is_extended_shape (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) |
| { |
| return font->face->table.MATH->get_glyph_info().get_kerning (glyph, |
| kern, |
| correction_height, |
| font); |
| } |
| |
| /** |
| * 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 */) |
| { |
| return font->face->table.MATH->get_glyph_info().get_kernings (glyph, |
| kern, |
| start_offset, |
| entries_count, |
| kern_entries, |
| font); |
| } |
| |
| /** |
| * 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 */) |
| { |
| return font->face->table.MATH->get_variants().get_glyph_variants (glyph, direction, font, |
| start_offset, |
| variants_count, |
| variants); |
| } |
| |
| /** |
| * 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) |
| { |
| return font->face->table.MATH->get_variants().get_min_connector_overlap (direction, font); |
| } |
| |
| /** |
| * 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 */) |
| { |
| return font->face->table.MATH->get_variants().get_glyph_parts (glyph, |
| direction, |
| font, |
| start_offset, |
| parts_count, |
| parts, |
| italics_correction); |
| } |
| |
| |
| #endif |