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+/*
+ * 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
+ */
+
+#ifndef HB_OT_MATH_TABLE_HH
+#define HB_OT_MATH_TABLE_HH
+
+#include "hb-open-type.hh"
+#include "hb-ot-layout-common.hh"
+#include "hb-ot-math.h"
+
+namespace OT {
+
+
+struct MathValueRecord
+{
+ hb_position_t get_x_value (hb_font_t *font, const void *base) const
+ { return font->em_scale_x (value) + (base+deviceTable).get_x_delta (font); }
+ hb_position_t get_y_value (hb_font_t *font, const void *base) const
+ { return font->em_scale_y (value) + (base+deviceTable).get_y_delta (font); }
+
+ MathValueRecord* copy (hb_serialize_context_t *c, const void *base) const
+ {
+ TRACE_SERIALIZE (this);
+ auto *out = c->embed (this);
+ if (unlikely (!out)) return_trace (nullptr);
+ out->deviceTable.serialize_copy (c, deviceTable, base, 0, hb_serialize_context_t::Head);
+
+ return_trace (out);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c, const void *base) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) && deviceTable.sanitize (c, base));
+ }
+
+ protected:
+ HBINT16 value; /* The X or Y value in design units */
+ Offset16To<Device> deviceTable; /* Offset to the device table - from the
+ * beginning of parent table. May be NULL.
+ * Suggested format for device table is 1. */
+
+ public:
+ DEFINE_SIZE_STATIC (4);
+};
+
+struct MathConstants
+{
+ MathConstants* copy (hb_serialize_context_t *c) const
+ {
+ TRACE_SERIALIZE (this);
+ auto *out = c->start_embed (this);
+ if (unlikely (!out)) return_trace (nullptr);
+
+ HBINT16 *p = c->allocate_size<HBINT16> (HBINT16::static_size * 2);
+ if (unlikely (!p)) return_trace (nullptr);
+ hb_memcpy (p, percentScaleDown, HBINT16::static_size * 2);
+
+ HBUINT16 *m = c->allocate_size<HBUINT16> (HBUINT16::static_size * 2);
+ if (unlikely (!m)) return_trace (nullptr);
+ hb_memcpy (m, minHeight, HBUINT16::static_size * 2);
+
+ unsigned count = ARRAY_LENGTH (mathValueRecords);
+ for (unsigned i = 0; i < count; i++)
+ if (!c->copy (mathValueRecords[i], this))
+ return_trace (nullptr);
+
+ if (!c->embed (radicalDegreeBottomRaisePercent)) return_trace (nullptr);
+ return_trace (out);
+ }
+
+ bool sanitize_math_value_records (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+
+ unsigned int count = ARRAY_LENGTH (mathValueRecords);
+ for (unsigned int i = 0; i < count; i++)
+ if (!mathValueRecords[i].sanitize (c, this))
+ return_trace (false);
+
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) && sanitize_math_value_records (c));
+ }
+
+ hb_position_t get_value (hb_ot_math_constant_t constant,
+ hb_font_t *font) const
+ {
+ switch (constant) {
+
+ case HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN:
+ case HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN:
+ return percentScaleDown[constant - HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN];
+
+ case HB_OT_MATH_CONSTANT_DELIMITED_SUB_FORMULA_MIN_HEIGHT:
+ case HB_OT_MATH_CONSTANT_DISPLAY_OPERATOR_MIN_HEIGHT:
+ return font->em_scale_y (minHeight[constant - HB_OT_MATH_CONSTANT_DELIMITED_SUB_FORMULA_MIN_HEIGHT]);
+
+ case HB_OT_MATH_CONSTANT_RADICAL_KERN_AFTER_DEGREE:
+ case HB_OT_MATH_CONSTANT_RADICAL_KERN_BEFORE_DEGREE:
+ case HB_OT_MATH_CONSTANT_SKEWED_FRACTION_HORIZONTAL_GAP:
+ case HB_OT_MATH_CONSTANT_SPACE_AFTER_SCRIPT:
+ return mathValueRecords[constant - HB_OT_MATH_CONSTANT_MATH_LEADING].get_x_value (font, this);
+
+ case HB_OT_MATH_CONSTANT_ACCENT_BASE_HEIGHT:
+ case HB_OT_MATH_CONSTANT_AXIS_HEIGHT:
+ case HB_OT_MATH_CONSTANT_FLATTENED_ACCENT_BASE_HEIGHT:
+ case HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_DISPLAY_STYLE_SHIFT_DOWN:
+ case HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_GAP_MIN:
+ case HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_SHIFT_DOWN:
+ case HB_OT_MATH_CONSTANT_FRACTION_DENOM_DISPLAY_STYLE_GAP_MIN:
+ case HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_DISPLAY_STYLE_SHIFT_UP:
+ case HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_GAP_MIN:
+ case HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_SHIFT_UP:
+ case HB_OT_MATH_CONSTANT_FRACTION_NUM_DISPLAY_STYLE_GAP_MIN:
+ case HB_OT_MATH_CONSTANT_FRACTION_RULE_THICKNESS:
+ case HB_OT_MATH_CONSTANT_LOWER_LIMIT_BASELINE_DROP_MIN:
+ case HB_OT_MATH_CONSTANT_LOWER_LIMIT_GAP_MIN:
+ case HB_OT_MATH_CONSTANT_MATH_LEADING:
+ case HB_OT_MATH_CONSTANT_OVERBAR_EXTRA_ASCENDER:
+ case HB_OT_MATH_CONSTANT_OVERBAR_RULE_THICKNESS:
+ case HB_OT_MATH_CONSTANT_OVERBAR_VERTICAL_GAP:
+ case HB_OT_MATH_CONSTANT_RADICAL_DISPLAY_STYLE_VERTICAL_GAP:
+ case HB_OT_MATH_CONSTANT_RADICAL_EXTRA_ASCENDER:
+ case HB_OT_MATH_CONSTANT_RADICAL_RULE_THICKNESS:
+ case HB_OT_MATH_CONSTANT_RADICAL_VERTICAL_GAP:
+ case HB_OT_MATH_CONSTANT_SKEWED_FRACTION_VERTICAL_GAP:
+ case HB_OT_MATH_CONSTANT_STACK_BOTTOM_DISPLAY_STYLE_SHIFT_DOWN:
+ case HB_OT_MATH_CONSTANT_STACK_BOTTOM_SHIFT_DOWN:
+ case HB_OT_MATH_CONSTANT_STACK_DISPLAY_STYLE_GAP_MIN:
+ case HB_OT_MATH_CONSTANT_STACK_GAP_MIN:
+ case HB_OT_MATH_CONSTANT_STACK_TOP_DISPLAY_STYLE_SHIFT_UP:
+ case HB_OT_MATH_CONSTANT_STACK_TOP_SHIFT_UP:
+ case HB_OT_MATH_CONSTANT_STRETCH_STACK_BOTTOM_SHIFT_DOWN:
+ case HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_ABOVE_MIN:
+ case HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_BELOW_MIN:
+ case HB_OT_MATH_CONSTANT_STRETCH_STACK_TOP_SHIFT_UP:
+ case HB_OT_MATH_CONSTANT_SUBSCRIPT_BASELINE_DROP_MIN:
+ case HB_OT_MATH_CONSTANT_SUBSCRIPT_SHIFT_DOWN:
+ case HB_OT_MATH_CONSTANT_SUBSCRIPT_TOP_MAX:
+ case HB_OT_MATH_CONSTANT_SUB_SUPERSCRIPT_GAP_MIN:
+ case HB_OT_MATH_CONSTANT_SUPERSCRIPT_BASELINE_DROP_MAX:
+ case HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MAX_WITH_SUBSCRIPT:
+ case HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MIN:
+ case HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP:
+ case HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP_CRAMPED:
+ case HB_OT_MATH_CONSTANT_UNDERBAR_EXTRA_DESCENDER:
+ case HB_OT_MATH_CONSTANT_UNDERBAR_RULE_THICKNESS:
+ case HB_OT_MATH_CONSTANT_UNDERBAR_VERTICAL_GAP:
+ case HB_OT_MATH_CONSTANT_UPPER_LIMIT_BASELINE_RISE_MIN:
+ case HB_OT_MATH_CONSTANT_UPPER_LIMIT_GAP_MIN:
+ return mathValueRecords[constant - HB_OT_MATH_CONSTANT_MATH_LEADING].get_y_value (font, this);
+
+ case HB_OT_MATH_CONSTANT_RADICAL_DEGREE_BOTTOM_RAISE_PERCENT:
+ return radicalDegreeBottomRaisePercent;
+
+ default:
+ return 0;
+ }
+ }
+
+ protected:
+ HBINT16 percentScaleDown[2];
+ HBUINT16 minHeight[2];
+ MathValueRecord mathValueRecords[51];
+ HBINT16 radicalDegreeBottomRaisePercent;
+
+ public:
+ DEFINE_SIZE_STATIC (214);
+};
+
+struct MathItalicsCorrectionInfo
+{
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ const hb_set_t &glyphset = c->plan->_glyphset_mathed;
+ const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+ auto *out = c->serializer->start_embed (*this);
+ if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+
+ hb_sorted_vector_t<hb_codepoint_t> new_coverage;
+ + hb_zip (this+coverage, italicsCorrection)
+ | hb_filter (glyphset, hb_first)
+ | hb_filter (serialize_math_record_array (c->serializer, out->italicsCorrection, this), hb_second)
+ | hb_map (hb_first)
+ | hb_map (glyph_map)
+ | hb_sink (new_coverage)
+ ;
+
+ out->coverage.serialize_serialize (c->serializer, new_coverage.iter ());
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ coverage.sanitize (c, this) &&
+ italicsCorrection.sanitize (c, this));
+ }
+
+ hb_position_t get_value (hb_codepoint_t glyph,
+ hb_font_t *font) const
+ {
+ unsigned int index = (this+coverage).get_coverage (glyph);
+ return italicsCorrection[index].get_x_value (font, this);
+ }
+
+ protected:
+ Offset16To<Coverage> coverage; /* Offset to Coverage table -
+ * from the beginning of
+ * MathItalicsCorrectionInfo
+ * table. */
+ Array16Of<MathValueRecord> italicsCorrection; /* Array of MathValueRecords
+ * defining italics correction
+ * values for each
+ * covered glyph. */
+
+ public:
+ DEFINE_SIZE_ARRAY (4, italicsCorrection);
+};
+
+struct MathTopAccentAttachment
+{
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ const hb_set_t &glyphset = c->plan->_glyphset_mathed;
+ const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+ auto *out = c->serializer->start_embed (*this);
+ if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+
+ hb_sorted_vector_t<hb_codepoint_t> new_coverage;
+ + hb_zip (this+topAccentCoverage, topAccentAttachment)
+ | hb_filter (glyphset, hb_first)
+ | hb_filter (serialize_math_record_array (c->serializer, out->topAccentAttachment, this), hb_second)
+ | hb_map (hb_first)
+ | hb_map (glyph_map)
+ | hb_sink (new_coverage)
+ ;
+
+ out->topAccentCoverage.serialize_serialize (c->serializer, new_coverage.iter ());
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ topAccentCoverage.sanitize (c, this) &&
+ topAccentAttachment.sanitize (c, this));
+ }
+
+ hb_position_t get_value (hb_codepoint_t glyph,
+ hb_font_t *font) const
+ {
+ unsigned int index = (this+topAccentCoverage).get_coverage (glyph);
+ if (index == NOT_COVERED)
+ return font->get_glyph_h_advance (glyph) / 2;
+ return topAccentAttachment[index].get_x_value (font, this);
+ }
+
+ protected:
+ Offset16To<Coverage> topAccentCoverage; /* Offset to Coverage table -
+ * from the beginning of
+ * MathTopAccentAttachment
+ * table. */
+ Array16Of<MathValueRecord> topAccentAttachment; /* Array of MathValueRecords
+ * defining top accent
+ * attachment points for each
+ * covered glyph. */
+
+ public:
+ DEFINE_SIZE_ARRAY (2 + 2, topAccentAttachment);
+};
+
+struct MathKern
+{
+ MathKern* copy (hb_serialize_context_t *c) const
+ {
+ TRACE_SERIALIZE (this);
+ auto *out = c->start_embed (this);
+ if (unlikely (!out)) return_trace (nullptr);
+
+ if (unlikely (!c->embed (heightCount))) return_trace (nullptr);
+
+ unsigned count = 2 * heightCount + 1;
+ for (unsigned i = 0; i < count; i++)
+ if (!c->copy (mathValueRecordsZ.arrayZ[i], this))
+ return_trace (nullptr);
+
+ return_trace (out);
+ }
+
+ bool sanitize_math_value_records (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ unsigned int count = 2 * heightCount + 1;
+ for (unsigned int i = 0; i < count; i++)
+ if (!mathValueRecordsZ.arrayZ[i].sanitize (c, this)) return_trace (false);
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ c->check_array (mathValueRecordsZ.arrayZ, 2 * heightCount + 1) &&
+ sanitize_math_value_records (c));
+ }
+
+ hb_position_t get_value (hb_position_t correction_height, hb_font_t *font) const
+ {
+ const MathValueRecord* correctionHeight = mathValueRecordsZ.arrayZ;
+ const MathValueRecord* kernValue = mathValueRecordsZ.arrayZ + heightCount;
+ int sign = font->y_scale < 0 ? -1 : +1;
+
+ /* The description of the MathKern table is a ambiguous, but interpreting
+ * "between the two heights found at those indexes" for 0 < i < len as
+ *
+ * correctionHeight[i-1] < correction_height <= correctionHeight[i]
+ *
+ * makes the result consistent with the limit cases and we can just use the
+ * binary search algorithm of std::upper_bound:
+ */
+ unsigned int i = 0;
+ unsigned int count = heightCount;
+ while (count > 0)
+ {
+ unsigned int half = count / 2;
+ hb_position_t height = correctionHeight[i + half].get_y_value (font, this);
+ if (sign * height < sign * correction_height)
+ {
+ i += half + 1;
+ count -= half + 1;
+ } else
+ count = half;
+ }
+ return kernValue[i].get_x_value (font, this);
+ }
+
+ unsigned int get_entries (unsigned int start_offset,
+ unsigned int *entries_count, /* IN/OUT */
+ hb_ot_math_kern_entry_t *kern_entries, /* OUT */
+ hb_font_t *font) const
+ {
+ const MathValueRecord* correctionHeight = mathValueRecordsZ.arrayZ;
+ const MathValueRecord* kernValue = mathValueRecordsZ.arrayZ + heightCount;
+ const unsigned int entriesCount = heightCount + 1;
+
+ if (entries_count)
+ {
+ unsigned int start = hb_min (start_offset, entriesCount);
+ unsigned int end = hb_min (start + *entries_count, entriesCount);
+ *entries_count = end - start;
+
+ for (unsigned int i = 0; i < *entries_count; i++) {
+ unsigned int j = start + i;
+
+ hb_position_t max_height;
+ if (j == heightCount) {
+ max_height = INT32_MAX;
+ } else {
+ max_height = correctionHeight[j].get_y_value (font, this);
+ }
+
+ kern_entries[i] = {max_height, kernValue[j].get_x_value (font, this)};
+ }
+ }
+ return entriesCount;
+ }
+
+ protected:
+ HBUINT16 heightCount;
+ UnsizedArrayOf<MathValueRecord>
+ mathValueRecordsZ;
+ /* Array of correction heights at
+ * which the kern value changes.
+ * Sorted by the height value in
+ * design units (heightCount entries),
+ * Followed by:
+ * Array of kern values corresponding
+ * to heights. (heightCount+1 entries).
+ */
+
+ public:
+ DEFINE_SIZE_ARRAY (2, mathValueRecordsZ);
+};
+
+struct MathKernInfoRecord
+{
+ MathKernInfoRecord* copy (hb_serialize_context_t *c, const void *base) const
+ {
+ TRACE_SERIALIZE (this);
+ auto *out = c->embed (this);
+ if (unlikely (!out)) return_trace (nullptr);
+
+ unsigned count = ARRAY_LENGTH (mathKern);
+ for (unsigned i = 0; i < count; i++)
+ out->mathKern[i].serialize_copy (c, mathKern[i], base, 0, hb_serialize_context_t::Head);
+
+ return_trace (out);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c, const void *base) const
+ {
+ TRACE_SANITIZE (this);
+
+ unsigned int count = ARRAY_LENGTH (mathKern);
+ for (unsigned int i = 0; i < count; i++)
+ if (unlikely (!mathKern[i].sanitize (c, base)))
+ return_trace (false);
+
+ return_trace (true);
+ }
+
+ hb_position_t get_kerning (hb_ot_math_kern_t kern,
+ hb_position_t correction_height,
+ hb_font_t *font,
+ const void *base) const
+ {
+ unsigned int idx = kern;
+ if (unlikely (idx >= ARRAY_LENGTH (mathKern))) return 0;
+ return (base+mathKern[idx]).get_value (correction_height, font);
+ }
+
+ unsigned int get_kernings (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_font_t *font,
+ const void *base) const
+ {
+ unsigned int idx = kern;
+ if (unlikely (idx >= ARRAY_LENGTH (mathKern)) || !mathKern[idx]) {
+ if (entries_count) *entries_count = 0;
+ return 0;
+ }
+ return (base+mathKern[idx]).get_entries (start_offset,
+ entries_count,
+ kern_entries,
+ font);
+ }
+
+ protected:
+ /* Offset to MathKern table for each corner -
+ * from the beginning of MathKernInfo table. May be NULL. */
+ Offset16To<MathKern> mathKern[4];
+
+ public:
+ DEFINE_SIZE_STATIC (8);
+};
+
+struct MathKernInfo
+{
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ const hb_set_t &glyphset = c->plan->_glyphset_mathed;
+ const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+ auto *out = c->serializer->start_embed (*this);
+ if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+
+ hb_sorted_vector_t<hb_codepoint_t> new_coverage;
+ + hb_zip (this+mathKernCoverage, mathKernInfoRecords)
+ | hb_filter (glyphset, hb_first)
+ | hb_filter (serialize_math_record_array (c->serializer, out->mathKernInfoRecords, this), hb_second)
+ | hb_map (hb_first)
+ | hb_map (glyph_map)
+ | hb_sink (new_coverage)
+ ;
+
+ out->mathKernCoverage.serialize_serialize (c->serializer, new_coverage.iter ());
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ mathKernCoverage.sanitize (c, this) &&
+ mathKernInfoRecords.sanitize (c, this));
+ }
+
+ hb_position_t get_kerning (hb_codepoint_t glyph,
+ hb_ot_math_kern_t kern,
+ hb_position_t correction_height,
+ hb_font_t *font) const
+ {
+ unsigned int index = (this+mathKernCoverage).get_coverage (glyph);
+ return mathKernInfoRecords[index].get_kerning (kern, correction_height, font, this);
+ }
+
+ unsigned int get_kernings (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_font_t *font) const
+ {
+ unsigned int index = (this+mathKernCoverage).get_coverage (glyph);
+ return mathKernInfoRecords[index].get_kernings (kern,
+ start_offset,
+ entries_count,
+ kern_entries,
+ font,
+ this);
+ }
+
+ protected:
+ Offset16To<Coverage>
+ mathKernCoverage;
+ /* Offset to Coverage table -
+ * from the beginning of the
+ * MathKernInfo table. */
+ Array16Of<MathKernInfoRecord>
+ mathKernInfoRecords;
+ /* Array of MathKernInfoRecords,
+ * per-glyph information for
+ * mathematical positioning
+ * of subscripts and
+ * superscripts. */
+
+ public:
+ DEFINE_SIZE_ARRAY (4, mathKernInfoRecords);
+};
+
+struct MathGlyphInfo
+{
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ auto *out = c->serializer->embed (*this);
+ if (unlikely (!out)) return_trace (false);
+
+ out->mathItalicsCorrectionInfo.serialize_subset (c, mathItalicsCorrectionInfo, this);
+ out->mathTopAccentAttachment.serialize_subset (c, mathTopAccentAttachment, this);
+
+ const hb_set_t &glyphset = c->plan->_glyphset_mathed;
+ const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+ auto it =
+ + hb_iter (this+extendedShapeCoverage)
+ | hb_filter (glyphset)
+ | hb_map_retains_sorting (glyph_map)
+ ;
+
+ if (it) out->extendedShapeCoverage.serialize_serialize (c->serializer, it);
+ else out->extendedShapeCoverage = 0;
+
+ out->mathKernInfo.serialize_subset (c, mathKernInfo, this);
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ mathItalicsCorrectionInfo.sanitize (c, this) &&
+ mathTopAccentAttachment.sanitize (c, this) &&
+ extendedShapeCoverage.sanitize (c, this) &&
+ mathKernInfo.sanitize (c, this));
+ }
+
+ hb_position_t
+ get_italics_correction (hb_codepoint_t glyph, hb_font_t *font) const
+ { return (this+mathItalicsCorrectionInfo).get_value (glyph, font); }
+
+ hb_position_t
+ get_top_accent_attachment (hb_codepoint_t glyph, hb_font_t *font) const
+ { return (this+mathTopAccentAttachment).get_value (glyph, font); }
+
+ bool is_extended_shape (hb_codepoint_t glyph) const
+ { return (this+extendedShapeCoverage).get_coverage (glyph) != NOT_COVERED; }
+
+ hb_position_t get_kerning (hb_codepoint_t glyph,
+ hb_ot_math_kern_t kern,
+ hb_position_t correction_height,
+ hb_font_t *font) const
+ { return (this+mathKernInfo).get_kerning (glyph, kern, correction_height, font); }
+
+ hb_position_t get_kernings (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_font_t *font) const
+ { return (this+mathKernInfo).get_kernings (glyph,
+ kern,
+ start_offset,
+ entries_count,
+ kern_entries,
+ font); }
+
+ protected:
+ /* Offset to MathItalicsCorrectionInfo table -
+ * from the beginning of MathGlyphInfo table. */
+ Offset16To<MathItalicsCorrectionInfo> mathItalicsCorrectionInfo;
+
+ /* Offset to MathTopAccentAttachment table -
+ * from the beginning of MathGlyphInfo table. */
+ Offset16To<MathTopAccentAttachment> mathTopAccentAttachment;
+
+ /* Offset to coverage table for Extended Shape glyphs -
+ * from the beginning of MathGlyphInfo table. When the left or right glyph of
+ * a box is an extended shape variant, the (ink) box (and not the default
+ * position defined by values in MathConstants table) should be used for
+ * vertical positioning purposes. May be NULL.. */
+ Offset16To<Coverage> extendedShapeCoverage;
+
+ /* Offset to MathKernInfo table -
+ * from the beginning of MathGlyphInfo table. */
+ Offset16To<MathKernInfo> mathKernInfo;
+
+ public:
+ DEFINE_SIZE_STATIC (8);
+};
+
+struct MathGlyphVariantRecord
+{
+ friend struct MathGlyphConstruction;
+
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ auto *out = c->serializer->embed (this);
+ if (unlikely (!out)) return_trace (false);
+
+ const hb_map_t& glyph_map = *c->plan->glyph_map;
+ return_trace (c->serializer->check_assign (out->variantGlyph, glyph_map.get (variantGlyph), HB_SERIALIZE_ERROR_INT_OVERFLOW));
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this));
+ }
+
+ void closure_glyphs (hb_set_t *variant_glyphs) const
+ { variant_glyphs->add (variantGlyph); }
+
+ protected:
+ HBGlyphID16 variantGlyph; /* Glyph ID for the variant. */
+ HBUINT16 advanceMeasurement; /* Advance width/height, in design units, of the
+ * variant, in the direction of requested
+ * glyph extension. */
+
+ public:
+ DEFINE_SIZE_STATIC (4);
+};
+
+struct PartFlags : HBUINT16
+{
+ enum Flags {
+ Extender = 0x0001u, /* If set, the part can be skipped or repeated. */
+
+ Defined = 0x0001u, /* All defined flags. */
+ };
+
+ public:
+ DEFINE_SIZE_STATIC (2);
+};
+
+struct MathGlyphPartRecord
+{
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ auto *out = c->serializer->embed (this);
+ if (unlikely (!out)) return_trace (false);
+
+ const hb_map_t& glyph_map = *c->plan->glyph_map;
+ return_trace (c->serializer->check_assign (out->glyph, glyph_map.get (glyph), HB_SERIALIZE_ERROR_INT_OVERFLOW));
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this));
+ }
+
+ void extract (hb_ot_math_glyph_part_t &out,
+ int64_t mult,
+ hb_font_t *font) const
+ {
+ out.glyph = glyph;
+
+ out.start_connector_length = font->em_mult (startConnectorLength, mult);
+ out.end_connector_length = font->em_mult (endConnectorLength, mult);
+ out.full_advance = font->em_mult (fullAdvance, mult);
+
+ static_assert ((unsigned int) HB_OT_MATH_GLYPH_PART_FLAG_EXTENDER ==
+ (unsigned int) PartFlags::Extender, "");
+
+ out.flags = (hb_ot_math_glyph_part_flags_t)
+ (unsigned int)
+ (partFlags & PartFlags::Defined);
+ }
+
+ void closure_glyphs (hb_set_t *variant_glyphs) const
+ { variant_glyphs->add (glyph); }
+
+ protected:
+ HBGlyphID16 glyph; /* Glyph ID for the part. */
+ HBUINT16 startConnectorLength;
+ /* Advance width/ height of the straight bar
+ * connector material, in design units, is at
+ * the beginning of the glyph, in the
+ * direction of the extension. */
+ HBUINT16 endConnectorLength;
+ /* Advance width/ height of the straight bar
+ * connector material, in design units, is at
+ * the end of the glyph, in the direction of
+ * the extension. */
+ HBUINT16 fullAdvance; /* Full advance width/height for this part,
+ * in the direction of the extension.
+ * In design units. */
+ PartFlags partFlags; /* Part qualifiers. */
+
+ public:
+ DEFINE_SIZE_STATIC (10);
+};
+
+struct MathGlyphAssembly
+{
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ auto *out = c->serializer->start_embed (*this);
+ if (unlikely (!out)) return_trace (false);
+
+ if (!c->serializer->copy (italicsCorrection, this)) return_trace (false);
+ if (!c->serializer->copy<HBUINT16> (partRecords.len)) return_trace (false);
+
+ for (const auto& record : partRecords.iter ())
+ if (!record.subset (c)) return_trace (false);
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ italicsCorrection.sanitize (c, this) &&
+ partRecords.sanitize (c));
+ }
+
+ unsigned int get_parts (hb_direction_t direction,
+ hb_font_t *font,
+ 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
+ {
+ if (parts_count)
+ {
+ int64_t mult = font->dir_mult (direction);
+ for (auto _ : hb_zip (partRecords.as_array ().sub_array (start_offset, parts_count),
+ hb_array (parts, *parts_count)))
+ _.first.extract (_.second, mult, font);
+ }
+
+ if (italics_correction)
+ *italics_correction = italicsCorrection.get_x_value (font, this);
+
+ return partRecords.len;
+ }
+
+ void closure_glyphs (hb_set_t *variant_glyphs) const
+ {
+ for (const auto& _ : partRecords.iter ())
+ _.closure_glyphs (variant_glyphs);
+ }
+
+ protected:
+ MathValueRecord
+ italicsCorrection;
+ /* Italics correction of this
+ * MathGlyphAssembly. Should not
+ * depend on the assembly size. */
+ Array16Of<MathGlyphPartRecord>
+ partRecords; /* Array of part records, from
+ * left to right and bottom to
+ * top. */
+
+ public:
+ DEFINE_SIZE_ARRAY (6, partRecords);
+};
+
+struct MathGlyphConstruction
+{
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ auto *out = c->serializer->start_embed (*this);
+ if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+
+ out->glyphAssembly.serialize_subset (c, glyphAssembly, this);
+
+ if (!c->serializer->check_assign (out->mathGlyphVariantRecord.len, mathGlyphVariantRecord.len, HB_SERIALIZE_ERROR_INT_OVERFLOW))
+ return_trace (false);
+ for (const auto& record : mathGlyphVariantRecord.iter ())
+ if (!record.subset (c)) return_trace (false);
+
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ glyphAssembly.sanitize (c, this) &&
+ mathGlyphVariantRecord.sanitize (c));
+ }
+
+ const MathGlyphAssembly &get_assembly () const { return this+glyphAssembly; }
+
+ unsigned int get_variants (hb_direction_t direction,
+ hb_font_t *font,
+ unsigned int start_offset,
+ unsigned int *variants_count, /* IN/OUT */
+ hb_ot_math_glyph_variant_t *variants /* OUT */) const
+ {
+ if (variants_count)
+ {
+ int64_t mult = font->dir_mult (direction);
+ for (auto _ : hb_zip (mathGlyphVariantRecord.as_array ().sub_array (start_offset, variants_count),
+ hb_array (variants, *variants_count)))
+ _.second = {_.first.variantGlyph, font->em_mult (_.first.advanceMeasurement, mult)};
+ }
+ return mathGlyphVariantRecord.len;
+ }
+
+ void closure_glyphs (hb_set_t *variant_glyphs) const
+ {
+ (this+glyphAssembly).closure_glyphs (variant_glyphs);
+
+ for (const auto& _ : mathGlyphVariantRecord.iter ())
+ _.closure_glyphs (variant_glyphs);
+ }
+
+ protected:
+ /* Offset to MathGlyphAssembly table for this shape - from the beginning of
+ MathGlyphConstruction table. May be NULL. */
+ Offset16To<MathGlyphAssembly> glyphAssembly;
+
+ /* MathGlyphVariantRecords for alternative variants of the glyphs. */
+ Array16Of<MathGlyphVariantRecord> mathGlyphVariantRecord;
+
+ public:
+ DEFINE_SIZE_ARRAY (4, mathGlyphVariantRecord);
+};
+
+struct MathVariants
+{
+ void closure_glyphs (const hb_set_t *glyph_set,
+ hb_set_t *variant_glyphs) const
+ {
+ const hb_array_t<const Offset16To<MathGlyphConstruction>> glyph_construction_offsets = glyphConstruction.as_array (vertGlyphCount + horizGlyphCount);
+
+ if (vertGlyphCoverage)
+ {
+ const auto vert_offsets = glyph_construction_offsets.sub_array (0, vertGlyphCount);
+ + hb_zip (this+vertGlyphCoverage, vert_offsets)
+ | hb_filter (glyph_set, hb_first)
+ | hb_map (hb_second)
+ | hb_map (hb_add (this))
+ | hb_apply ([=] (const MathGlyphConstruction &_) { _.closure_glyphs (variant_glyphs); })
+ ;
+ }
+
+ if (horizGlyphCoverage)
+ {
+ const auto hori_offsets = glyph_construction_offsets.sub_array (vertGlyphCount, horizGlyphCount);
+ + hb_zip (this+horizGlyphCoverage, hori_offsets)
+ | hb_filter (glyph_set, hb_first)
+ | hb_map (hb_second)
+ | hb_map (hb_add (this))
+ | hb_apply ([=] (const MathGlyphConstruction &_) { _.closure_glyphs (variant_glyphs); })
+ ;
+ }
+ }
+
+ void collect_coverage_and_indices (hb_sorted_vector_t<hb_codepoint_t>& new_coverage,
+ const Offset16To<Coverage>& coverage,
+ unsigned i,
+ unsigned end_index,
+ hb_set_t& indices,
+ const hb_set_t& glyphset,
+ const hb_map_t& glyph_map) const
+ {
+ if (!coverage) return;
+
+ for (const auto _ : (this+coverage).iter ())
+ {
+ if (i >= end_index) return;
+ if (glyphset.has (_))
+ {
+ unsigned new_gid = glyph_map.get (_);
+ new_coverage.push (new_gid);
+ indices.add (i);
+ }
+ i++;
+ }
+ }
+
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ const hb_set_t &glyphset = c->plan->_glyphset_mathed;
+ const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+ auto *out = c->serializer->start_embed (*this);
+ if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+ if (!c->serializer->check_assign (out->minConnectorOverlap, minConnectorOverlap, HB_SERIALIZE_ERROR_INT_OVERFLOW))
+ return_trace (false);
+
+ hb_sorted_vector_t<hb_codepoint_t> new_vert_coverage;
+ hb_sorted_vector_t<hb_codepoint_t> new_hori_coverage;
+ hb_set_t indices;
+ collect_coverage_and_indices (new_vert_coverage, vertGlyphCoverage, 0, vertGlyphCount, indices, glyphset, glyph_map);
+ collect_coverage_and_indices (new_hori_coverage, horizGlyphCoverage, vertGlyphCount, vertGlyphCount + horizGlyphCount, indices, glyphset, glyph_map);
+
+ if (!c->serializer->check_assign (out->vertGlyphCount, new_vert_coverage.length, HB_SERIALIZE_ERROR_INT_OVERFLOW))
+ return_trace (false);
+ if (!c->serializer->check_assign (out->horizGlyphCount, new_hori_coverage.length, HB_SERIALIZE_ERROR_INT_OVERFLOW))
+ return_trace (false);
+
+ for (unsigned i : indices.iter ())
+ {
+ auto *o = c->serializer->embed (glyphConstruction[i]);
+ if (!o) return_trace (false);
+ o->serialize_subset (c, glyphConstruction[i], this);
+ }
+
+ if (new_vert_coverage)
+ out->vertGlyphCoverage.serialize_serialize (c->serializer, new_vert_coverage.iter ());
+
+ if (new_hori_coverage)
+ out->horizGlyphCoverage.serialize_serialize (c->serializer, new_hori_coverage.iter ());
+ return_trace (true);
+ }
+
+ bool sanitize_offsets (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ unsigned int count = vertGlyphCount + horizGlyphCount;
+ for (unsigned int i = 0; i < count; i++)
+ if (!glyphConstruction.arrayZ[i].sanitize (c, this)) return_trace (false);
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ vertGlyphCoverage.sanitize (c, this) &&
+ horizGlyphCoverage.sanitize (c, this) &&
+ c->check_array (glyphConstruction.arrayZ, vertGlyphCount + horizGlyphCount) &&
+ sanitize_offsets (c));
+ }
+
+ hb_position_t get_min_connector_overlap (hb_direction_t direction,
+ hb_font_t *font) const
+ { return font->em_scale_dir (minConnectorOverlap, direction); }
+
+ unsigned int get_glyph_variants (hb_codepoint_t glyph,
+ hb_direction_t direction,
+ hb_font_t *font,
+ unsigned int start_offset,
+ unsigned int *variants_count, /* IN/OUT */
+ hb_ot_math_glyph_variant_t *variants /* OUT */) const
+ { return get_glyph_construction (glyph, direction, font)
+ .get_variants (direction, font, start_offset, variants_count, variants); }
+
+ unsigned int get_glyph_parts (hb_codepoint_t glyph,
+ hb_direction_t direction,
+ hb_font_t *font,
+ 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
+ { return get_glyph_construction (glyph, direction, font)
+ .get_assembly ()
+ .get_parts (direction, font,
+ start_offset, parts_count, parts,
+ italics_correction); }
+
+ private:
+ const MathGlyphConstruction &
+ get_glyph_construction (hb_codepoint_t glyph,
+ hb_direction_t direction,
+ hb_font_t *font HB_UNUSED) const
+ {
+ bool vertical = HB_DIRECTION_IS_VERTICAL (direction);
+ unsigned int count = vertical ? vertGlyphCount : horizGlyphCount;
+ const Offset16To<Coverage> &coverage = vertical ? vertGlyphCoverage
+ : horizGlyphCoverage;
+
+ unsigned int index = (this+coverage).get_coverage (glyph);
+ if (unlikely (index >= count)) return Null (MathGlyphConstruction);
+
+ if (!vertical)
+ index += vertGlyphCount;
+
+ return this+glyphConstruction[index];
+ }
+
+ protected:
+ HBUINT16 minConnectorOverlap;
+ /* Minimum overlap of connecting
+ * glyphs during glyph construction,
+ * in design units. */
+ Offset16To<Coverage> vertGlyphCoverage;
+ /* Offset to Coverage table -
+ * from the beginning of MathVariants
+ * table. */
+ Offset16To<Coverage> horizGlyphCoverage;
+ /* Offset to Coverage table -
+ * from the beginning of MathVariants
+ * table. */
+ HBUINT16 vertGlyphCount; /* Number of glyphs for which
+ * information is provided for
+ * vertically growing variants. */
+ HBUINT16 horizGlyphCount;/* Number of glyphs for which
+ * information is provided for
+ * horizontally growing variants. */
+
+ /* Array of offsets to MathGlyphConstruction tables - from the beginning of
+ the MathVariants table, for shapes growing in vertical/horizontal
+ direction. */
+ UnsizedArrayOf<Offset16To<MathGlyphConstruction>>
+ glyphConstruction;
+
+ public:
+ DEFINE_SIZE_ARRAY (10, glyphConstruction);
+};
+
+
+/*
+ * MATH -- Mathematical typesetting
+ * https://docs.microsoft.com/en-us/typography/opentype/spec/math
+ */
+
+struct MATH
+{
+ static constexpr hb_tag_t tableTag = HB_OT_TAG_MATH;
+
+ bool has_data () const { return version.to_int (); }
+
+ void closure_glyphs (hb_set_t *glyph_set) const
+ {
+ if (mathVariants)
+ {
+ hb_set_t variant_glyphs;
+ (this+mathVariants).closure_glyphs (glyph_set, &variant_glyphs);
+ hb_set_union (glyph_set, &variant_glyphs);
+ }
+ }
+
+ bool subset (hb_subset_context_t *c) const
+ {
+ TRACE_SUBSET (this);
+ auto *out = c->serializer->embed (*this);
+ if (unlikely (!out)) return_trace (false);
+
+ out->mathConstants.serialize_copy (c->serializer, mathConstants, this, 0, hb_serialize_context_t::Head);
+ out->mathGlyphInfo.serialize_subset (c, mathGlyphInfo, this);
+ out->mathVariants.serialize_subset (c, mathVariants, this);
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (version.sanitize (c) &&
+ likely (version.major == 1) &&
+ mathConstants.sanitize (c, this) &&
+ mathGlyphInfo.sanitize (c, this) &&
+ mathVariants.sanitize (c, this));
+ }
+
+ hb_position_t get_constant (hb_ot_math_constant_t constant,
+ hb_font_t *font) const
+ { return (this+mathConstants).get_value (constant, font); }
+
+ const MathGlyphInfo &get_glyph_info () const { return this+mathGlyphInfo; }
+
+ const MathVariants &get_variants () const { return this+mathVariants; }
+
+ protected:
+ FixedVersion<>version; /* Version of the MATH table
+ * initially set to 0x00010000u */
+ Offset16To<MathConstants>
+ mathConstants; /* MathConstants table */
+ Offset16To<MathGlyphInfo>
+ mathGlyphInfo; /* MathGlyphInfo table */
+ Offset16To<MathVariants>
+ mathVariants; /* MathVariants table */
+
+ public:
+ DEFINE_SIZE_STATIC (10);
+};
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_MATH_TABLE_HH */