Add m-esr52 at 52.6.0

1 files changed, 155 insertions, 0 deletions

diff --git a/gfx/thebes/gfxMathTable.h b/gfx/thebes/gfxMathTable.h
new file mode 100644
index 000000000..bb22ff8df
--- /dev/null
+++ b/gfx/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