diff options
Diffstat (limited to 'src/3rdparty/harfbuzz-ng/src/hb-ot-math.cc')
| -rw-r--r-- | src/3rdparty/harfbuzz-ng/src/hb-ot-math.cc | 218 |
1 files changed, 129 insertions, 89 deletions
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-math.cc b/src/3rdparty/harfbuzz-ng/src/hb-ot-math.cc index f82a07353c..9d8c6e735a 100644 --- a/src/3rdparty/harfbuzz-ng/src/hb-ot-math.cc +++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-math.cc @@ -24,18 +24,27 @@ * Igalia Author(s): Frédéric Wang */ -#include "hb-open-type-private.hh" +#include "hb.hh" + +#ifndef HB_NO_MATH -#include "hb-ot-layout-private.hh" #include "hb-ot-math-table.hh" -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); - return *(layout->math.get ()); -} + +/** + * 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 @@ -45,31 +54,32 @@ _get_math (hb_face_t *face) * 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. + * Tests whether a face has a `MATH` table. * - * Return value: true if face has a MATH table, false otherwise + * 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 &_get_math (face) != &OT::Null(OT::MATH); + return face->table.MATH->has_data (); } /** * hb_ot_math_get_constant: - * @font: #hb_font_t from which to retrieve the value + * @font: #hb_font_t to work upon * @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. + * 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 0 + * Return value: the requested constant or zero * * Since: 1.3.3 **/ @@ -77,16 +87,18 @@ 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); + return font->face->table.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 + * @font: #hb_font_t to work upon + * @glyph: The glyph index from which to retrieve the value * - * Return value: the italics correction of the glyph or 0 + * 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 **/ @@ -94,16 +106,25 @@ 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); + 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 from which to retrieve the value - * @glyph: glyph index from which to retrieve the value + * @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 + * Return value: the top accent attachment of the glyph or 0.5 * the advance + * width of @glyph * * Since: 1.3.3 **/ @@ -111,14 +132,15 @@ 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); + return font->face->table.MATH->get_glyph_info().get_top_accent_attachment (glyph, font); } /** * hb_ot_math_is_glyph_extended_shape: - * @face: a #hb_face_t to test - * @glyph: a glyph index to test + * @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 * @@ -128,24 +150,25 @@ 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); + return face->table.MATH->get_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 + * @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. * - * 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. + * 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 or 0 + * Return value: requested kerning value or zero * * Since: 1.3.3 **/ @@ -155,26 +178,32 @@ hb_ot_math_get_glyph_kerning (hb_font_t *font, 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); + return font->face->table.MATH->get_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 + * @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: 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 + * @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 * - * 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. + * 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. * - * Return value: the total number of size variants available or 0 + * <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 **/ @@ -186,24 +215,27 @@ hb_ot_math_get_glyph_variants (hb_font_t *font, 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); + 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 from which to retrieve the value - * @direction: direction of the stretching + * @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. * - * 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. + * <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 min connector overlap or 0 + * Return value: requested minimum connector overlap or zero * * Since: 1.3.3 **/ @@ -211,25 +243,29 @@ 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); + return font->face->table.MATH->get_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 + * @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: 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 + * @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). * - * 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. + * <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 * @@ -244,10 +280,14 @@ hb_ot_math_get_glyph_assembly (hb_font_t *font, 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); + return font->face->table.MATH->get_variants().get_glyph_parts (glyph, + direction, + font, + start_offset, + parts_count, + parts, + italics_correction); } + + +#endif |