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Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-math.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-math.cc | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-math.cc b/gfx/harfbuzz/src/hb-ot-math.cc new file mode 100644 index 000000000..9ef21d299 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-math.cc @@ -0,0 +1,272 @@ +/* + * 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-open-type-private.hh" + +#include "hb-ot-layout-math-table.hh" + +HB_SHAPER_DATA_ENSURE_DECLARE(ot, face) + +static inline const OT::MATH& +_get_math (hb_face_t *face) +{ + if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::MATH); + + hb_ot_layout_t * layout = hb_ot_layout_from_face (face); + +retry: + const OT::MATH *math = (const OT::MATH *) hb_atomic_ptr_get (&layout->math); + + if (unlikely (!math)) + { + hb_blob_t *blob = OT::Sanitizer<OT::MATH>::sanitize (face->reference_table (HB_OT_TAG_MATH)); + math = OT::Sanitizer<OT::MATH>::lock_instance (blob); + if (!hb_atomic_ptr_cmpexch (&layout->math, NULL, math)) + { + hb_blob_destroy (blob); + goto retry; + } + layout->math_blob = blob; + } + + return *math; +} + +/* + * OT::MATH + */ + +/** + * hb_ot_math_has_data: + * @face: #hb_face_t to test + * + * This function allows to verify the presence of an OpenType MATH table on the + * face. If so, such a table will be loaded into memory and sanitized. You can + * then safely call other functions for math layout and shaping. + * + * Return value: #TRUE if face has a MATH table and #FALSE otherwise + * + * Since: 1.3.3 + **/ +hb_bool_t +hb_ot_math_has_data (hb_face_t *face) +{ + return &_get_math (face) != &OT::Null(OT::MATH); +} + +/** + * hb_ot_math_get_constant: + * @font: #hb_font_t from which to retrieve the value + * @constant: #hb_ot_math_constant_t the constant to retrieve + * + * This function returns the requested math constants as a #hb_position_t. + * If the request 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 + * actually an integer between 0 and 100 representing that percentage. + * + * Return value: the requested constant or 0 + * + * Since: 1.3.3 + **/ +hb_position_t +hb_ot_math_get_constant (hb_font_t *font, + hb_ot_math_constant_t constant) +{ + const OT::MATH &math = _get_math (font->face); + return math.get_constant(constant, font); +} + +/** + * hb_ot_math_get_glyph_italics_correction: + * @font: #hb_font_t from which to retrieve the value + * @glyph: glyph index from which to retrieve the value + * + * Return value: the italics correction of the glyph or 0 + * + * Since: 1.3.3 + **/ +hb_position_t +hb_ot_math_get_glyph_italics_correction (hb_font_t *font, + hb_codepoint_t glyph) +{ + const OT::MATH &math = _get_math (font->face); + return math.get_math_glyph_info().get_italics_correction (glyph, font); +} + +/** + * hb_ot_math_get_glyph_top_accent_attachment: + * @font: #hb_font_t from which to retrieve the value + * @glyph: glyph index from which to retrieve the value + * + * Return value: the top accent attachment of the glyph or 0 + * + * Since: 1.3.3 + **/ +hb_position_t +hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font, + hb_codepoint_t glyph) +{ + const OT::MATH &math = _get_math (font->face); + return math.get_math_glyph_info().get_top_accent_attachment (glyph, font); +} + +/** + * hb_ot_math_is_glyph_extended_shape: + * @font: a #hb_font_t to test + * @glyph: a glyph index to test + * + * Return value: #TRUE if the glyph is an extended shape and #FALSE otherwise + * + * Since: 1.3.3 + **/ +hb_bool_t +hb_ot_math_is_glyph_extended_shape (hb_face_t *face, + hb_codepoint_t glyph) +{ + const OT::MATH &math = _get_math (face); + return math.get_math_glyph_info().is_extended_shape (glyph); +} + +/** + * hb_ot_math_get_glyph_kerning: + * @font: #hb_font_t from which to retrieve the value + * @glyph: 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. + * + * This function tries to retrieve the MathKern table for the specified font, + * glyph and #hb_ot_math_kern_t. Then it browses the list of heights from the + * MathKern table to find one value that is greater or equal to specified + * correction_height. If one is found the corresponding value from the list of + * kerns is returned and otherwise the last kern value is returned. + * + * Return value: requested kerning or 0 + * + * 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) +{ + const OT::MATH &math = _get_math (font->face); + return math.get_math_glyph_info().get_kerning (glyph, kern, correction_height, font); +} + +/** + * hb_ot_math_get_glyph_variants: + * @font: #hb_font_t from which to retrieve the values + * @glyph: index of the glyph to stretch + * @direction: direction of the stretching + * @start_offset: offset of the first variant to retrieve + * @variants_count: maximum number of variants to retrieve after start_offset + * (IN) and actual number of variants retrieved (OUT) + * @variants: array of size at least @variants_count to store the result + * + * This function tries to retrieve the MathGlyphConstruction for the specified + * font, glyph and direction. Note that only the value of + * #HB_DIRECTION_IS_HORIZONTAL is considered. It provides the corresponding list + * of size variants as an array of hb_ot_math_glyph_variant_t structs. + * + * Return value: the total number of size variants available or 0 + * + * 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 */) +{ + const OT::MATH &math = _get_math (font->face); + return math.get_math_variants().get_glyph_variants (glyph, direction, font, + start_offset, + variants_count, + variants); +} + +/** + * hb_ot_math_get_min_connector_overlap: + * @font: #hb_font_t from which to retrieve the value + * @direction: direction of the stretching + * + * This function tries to retrieve the MathVariants table for the specified + * font and returns the minimum overlap of connecting glyphs to draw a glyph + * assembly in the specified direction. Note that only the value of + * #HB_DIRECTION_IS_HORIZONTAL is considered. + * + * Return value: requested min connector overlap or 0 + * + * Since: 1.3.3 + **/ +hb_position_t +hb_ot_math_get_min_connector_overlap (hb_font_t *font, + hb_direction_t direction) +{ + const OT::MATH &math = _get_math (font->face); + return math.get_math_variants().get_min_connector_overlap (direction, font); +} + +/** + * hb_ot_math_get_glyph_assembly: + * @font: #hb_font_t from which to retrieve the values + * @glyph: index of the glyph to stretch + * @direction: direction of the stretching + * @start_offset: offset of the first glyph part to retrieve + * @parts_count: maximum number of glyph parts to retrieve after start_offset + * (IN) and actual number of parts retrieved (OUT) + * @parts: array of size at least @parts_count to store the result + * @italics_correction: italic correction of the glyph assembly + * + * This function tries to retrieve the GlyphAssembly for the specified font, + * glyph and direction. Note that only the value of #HB_DIRECTION_IS_HORIZONTAL + * is considered. It provides the information necessary to draw the glyph + * assembly as an array of #hb_ot_math_glyph_part_t. + * + * 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 */) +{ + const OT::MATH &math = _get_math (font->face); + return math.get_math_variants().get_glyph_parts (glyph, direction, font, + start_offset, + parts_count, + parts, + italics_correction); +} |