summaryrefslogtreecommitdiff
path: root/system/graphics/thebes/gfxMathTable.h
diff options
context:
space:
mode:
authorMatt A. Tobin <email@mattatobin.com>2021-11-22 19:25:48 -0500
committerMatt A. Tobin <email@mattatobin.com>2021-11-22 19:25:48 -0500
commitd177d011148982c3d4640584ff88421384ada749 (patch)
tree6ff90e2275c85e6fdb854c07c3f9c271d5f2ebcb /system/graphics/thebes/gfxMathTable.h
parent96d206e2eb803f71b02ae5a8ff62730d2f053c09 (diff)
downloadaura-central-d177d011148982c3d4640584ff88421384ada749.tar.gz
Issue %3005 - Move gfx/ to system/graphics
Diffstat (limited to 'system/graphics/thebes/gfxMathTable.h')
-rw-r--r--system/graphics/thebes/gfxMathTable.h155
1 files changed, 155 insertions, 0 deletions
diff --git a/system/graphics/thebes/gfxMathTable.h b/system/graphics/thebes/gfxMathTable.h
new file mode 100644
index 000000000..bb22ff8df
--- /dev/null
+++ b/system/graphics/thebes/gfxMathTable.h
@@ -0,0 +1,155 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef GFX_MATH_TABLE_H
+#define GFX_MATH_TABLE_H
+
+#include "gfxFont.h"
+
+/**
+ * Used by |gfxFont| to represent the MATH table of an OpenType font.
+ * Each |gfxFont| owns at most one |gfxMathTable| instance.
+ */
+class gfxMathTable
+{
+public:
+ /**
+ * @param aFace The HarfBuzz face containing the math table.
+ * @param aSize The font size to pass to HarfBuzz.
+ */
+ gfxMathTable(hb_face_t *aFace, gfxFloat aSize);
+
+ /**
+ * Releases our reference to the MATH table and cleans up everything else.
+ */
+ ~gfxMathTable();
+
+ enum MathConstant {
+ // The order of the constants must match the order of the fields
+ // defined in the MATH table.
+ ScriptPercentScaleDown,
+ ScriptScriptPercentScaleDown,
+ DelimitedSubFormulaMinHeight,
+ DisplayOperatorMinHeight,
+ MathLeading,
+ AxisHeight,
+ AccentBaseHeight,
+ FlattenedAccentBaseHeight,
+ SubscriptShiftDown,
+ SubscriptTopMax,
+ SubscriptBaselineDropMin,
+ SuperscriptShiftUp,
+ SuperscriptShiftUpCramped,
+ SuperscriptBottomMin,
+ SuperscriptBaselineDropMax,
+ SubSuperscriptGapMin,
+ SuperscriptBottomMaxWithSubscript,
+ SpaceAfterScript,
+ UpperLimitGapMin,
+ UpperLimitBaselineRiseMin,
+ LowerLimitGapMin,
+ LowerLimitBaselineDropMin,
+ StackTopShiftUp,
+ StackTopDisplayStyleShiftUp,
+ StackBottomShiftDown,
+ StackBottomDisplayStyleShiftDown,
+ StackGapMin,
+ StackDisplayStyleGapMin,
+ StretchStackTopShiftUp,
+ StretchStackBottomShiftDown,
+ StretchStackGapAboveMin,
+ StretchStackGapBelowMin,
+ FractionNumeratorShiftUp,
+ FractionNumeratorDisplayStyleShiftUp,
+ FractionDenominatorShiftDown,
+ FractionDenominatorDisplayStyleShiftDown,
+ FractionNumeratorGapMin,
+ FractionNumDisplayStyleGapMin,
+ FractionRuleThickness,
+ FractionDenominatorGapMin,
+ FractionDenomDisplayStyleGapMin,
+ SkewedFractionHorizontalGap,
+ SkewedFractionVerticalGap,
+ OverbarVerticalGap,
+ OverbarRuleThickness,
+ OverbarExtraAscender,
+ UnderbarVerticalGap,
+ UnderbarRuleThickness,
+ UnderbarExtraDescender,
+ RadicalVerticalGap,
+ RadicalDisplayStyleVerticalGap,
+ RadicalRuleThickness,
+ RadicalExtraAscender,
+ RadicalKernBeforeDegree,
+ RadicalKernAfterDegree,
+ RadicalDegreeBottomRaisePercent
+ };
+
+ /**
+ * Returns the value of the specified constant from the MATH table.
+ */
+ gfxFloat Constant(MathConstant aConstant) const;
+
+ /**
+ * Returns the value of the specified constant in app units.
+ */
+ nscoord Constant(MathConstant aConstant,
+ uint32_t aAppUnitsPerDevPixel) const
+ {
+ return NSToCoordRound(Constant(aConstant) * aAppUnitsPerDevPixel);
+ }
+
+ /**
+ * If the MATH table contains an italic correction for that glyph, this
+ * function returns the corresponding value. Otherwise it returns 0.
+ */
+ gfxFloat
+ ItalicsCorrection(uint32_t aGlyphID) const;
+
+ /**
+ * @param aGlyphID glyph index of the character we want to stretch
+ * @param aVertical direction of the stretching (vertical/horizontal)
+ * @param aSize the desired size variant
+ *
+ * Returns the glyph index of the desired size variant or 0 if there is not
+ * any such size variant.
+ */
+ uint32_t VariantsSize(uint32_t aGlyphID, bool aVertical,
+ uint16_t aSize) const;
+
+ /**
+ * @param aGlyphID glyph index of the character we want to stretch
+ * @param aVertical direction of the stretching (vertical/horizontal)
+ * @param aGlyphs pre-allocated buffer of 4 elements where the glyph
+ * indexes (or 0 for absent parts) will be stored. The parts are stored in
+ * the order expected by the nsMathMLChar: Top (or Left), Middle, Bottom
+ * (or Right), Glue.
+ *
+ * Tries to fill-in aGlyphs with the relevant glyph indexes and returns
+ * whether the operation was successful. The function returns false if
+ * there is not any assembly for the character we want to stretch or if
+ * the format is not supported by the nsMathMLChar code.
+ *
+ */
+ bool VariantsParts(uint32_t aGlyphID, bool aVertical,
+ uint32_t aGlyphs[4]) const;
+
+private:
+ // size-specific font object, owned by the gfxMathTable
+ hb_font_t *mHBFont;
+
+ static const unsigned int kMaxCachedSizeCount = 10;
+ struct MathVariantCacheEntry {
+ uint32_t glyphID;
+ bool vertical;
+ uint32_t sizes[kMaxCachedSizeCount];
+ uint32_t parts[4];
+ bool arePartsValid;
+ };
+ mutable MathVariantCacheEntry mMathVariantCache;
+ void ClearCache() const;
+ void UpdateMathVariantCache(uint32_t aGlyphID, bool aVertical) const;
+};
+
+#endif