Switch to HarfBuzz on Mac and remove CoreText shaper

Source/platform/fonts/mac/FontComplexTextMac.cpp

Index: Source/platform/fonts/mac/FontComplexTextMac.cpp
diff --git a/Source/platform/fonts/mac/FontComplexTextMac.cpp b/Source/platform/fonts/mac/FontComplexTextMac.cpp
index 787412a300d720bc99334e2cc97b10478f53b544..821aeb98847eb5e8a642caf0ee7ada3acc15b685 100644
--- a/Source/platform/fonts/mac/FontComplexTextMac.cpp
+++ b/Source/platform/fonts/mac/FontComplexTextMac.cpp
@@ -30,7 +30,6 @@
 #include "platform/fonts/GlyphBuffer.h"
 #include "platform/fonts/SimpleFontData.h"
 #include "platform/fonts/harfbuzz/HarfBuzzShaper.h"
-#include "platform/fonts/mac/ComplexTextController.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/text/TextRun.h"
@@ -40,81 +39,28 @@ using namespace std;
 
 namespace WebCore {
 

[eae, 2014/03/20 18:20:30]

Do we still need this file? It doesn't look much different from
FontHarfBuzz.cpp.

-static bool preferHarfBuzz(const Font* font)
-{
-    const FontDescription& description = font->fontDescription();
-    return description.featureSettings() && description.featureSettings()->size() > 0;
-}
-
 FloatRect Font::selectionRectForComplexText(const TextRun& run, const FloatPoint& point, int h,
                                             int from, int to) const
 {
-    if (preferHarfBuzz(this)) {
-        HarfBuzzShaper shaper(this, run);
-        if (shaper.shape())
-            return shaper.selectionRect(point, h, from, to);
-    }
-    ComplexTextController controller(this, run);
-    controller.advance(from);
-    float beforeWidth = controller.runWidthSoFar();
-    controller.advance(to);
-    float afterWidth = controller.runWidthSoFar();
-
-    // Using roundf() rather than ceilf() for the right edge as a compromise to ensure correct caret positioning
-    if (run.rtl()) {
-        float totalWidth = controller.totalWidth();
-        return FloatRect(floorf(point.x() + totalWidth - afterWidth), point.y(), roundf(point.x() + totalWidth - beforeWidth) - floorf(point.x() + totalWidth - afterWidth), h);
-    }
-
-    return FloatRect(floorf(point.x() + beforeWidth), point.y(), roundf(point.x() + afterWidth) - floorf(point.x() + beforeWidth), h);
+    HarfBuzzShaper shaper(this, run);
+    return shaper.shape() ? shaper.selectionRect(point, h, from, to) : FloatRect();
 }
 
-float Font::getGlyphsAndAdvancesForComplexText(const TextRun& run, int from, int to, GlyphBuffer& glyphBuffer, ForTextEmphasisOrNot forTextEmphasis) const
+float Font::getGlyphsAndAdvancesForComplexText(const TextRun& run, int from, int to, GlyphBuffer& glyphBuffer, Font::ForTextEmphasisOrNot forTextEmphasis) const
 {
-    float initialAdvance;
-
-    ComplexTextController controller(this, run, false, 0, forTextEmphasis);
-    controller.advance(from);
-    float beforeWidth = controller.runWidthSoFar();
-    controller.advance(to, &glyphBuffer);
-
-    if (glyphBuffer.isEmpty())
-        return 0;
-
-    float afterWidth = controller.runWidthSoFar();
-
-    if (run.rtl()) {
-        initialAdvance = controller.totalWidth() + controller.finalRoundingWidth() - afterWidth;
-        glyphBuffer.reverse(0, glyphBuffer.size());
-    } else
-        initialAdvance = beforeWidth;
-
-    return initialAdvance;
+    HarfBuzzShaper shaper(this, run, forTextEmphasis == Font::ForTextEmphasis ? HarfBuzzShaper::ForTextEmphasis : HarfBuzzShaper::NotForTextEmphasis);
+    shaper.setDrawRange(from, to);
+    shaper.shape(&glyphBuffer);
+    return 0;
 }
 
 void Font::drawComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const FloatPoint& point) const
 {
-    if (preferHarfBuzz(this)) {
-        GlyphBuffer glyphBuffer;
-        HarfBuzzShaper shaper(this, runInfo.run);
-        shaper.setDrawRange(runInfo.from, runInfo.to);
-        if (shaper.shape(&glyphBuffer)) {
-            drawGlyphBuffer(context, runInfo, glyphBuffer, point);
-            return;
-        }
-    }
-    // This glyph buffer holds our glyphs + advances + font data for each glyph.
     GlyphBuffer glyphBuffer;
-
-    float startX = point.x() + getGlyphsAndAdvancesForComplexText(runInfo.run, runInfo.from, runInfo.to, glyphBuffer);
-
-    // We couldn't generate any glyphs for the run.  Give up.
-    if (glyphBuffer.isEmpty())
-        return;
-
-    // Draw the glyph buffer now at the starting point returned in startX.
-    FloatPoint startPoint(startX, point.y());
-    drawGlyphBuffer(context, runInfo, glyphBuffer, startPoint);
+    HarfBuzzShaper shaper(this, runInfo.run);
+    shaper.setDrawRange(runInfo.from, runInfo.to);
+    if (shaper.shape(&glyphBuffer))
+        drawGlyphBuffer(context, runInfo, glyphBuffer, point);
 }
 
 void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const AtomicString& mark, const FloatPoint& point) const
@@ -130,84 +76,14 @@ void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextR
 
 float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow* glyphOverflow) const

[eae, 2014/03/20 18:20:30]

We really want to use the FontHarfBuzz.cpp implementation of
floatWidthForComplexText here or we'll loose glyphOverflow support (which we
just implemented for the harfbuzz code path yesterday).

 {
-    if (preferHarfBuzz(this)) {
-        HarfBuzzShaper shaper(this, run);
-        if (shaper.shape())
-            return shaper.totalWidth();
-    }
-    ComplexTextController controller(this, run, true, fallbackFonts);
-    if (glyphOverflow) {
-        glyphOverflow->top = max<int>(glyphOverflow->top, ceilf(-controller.minGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().ascent()));
-        glyphOverflow->bottom = max<int>(glyphOverflow->bottom, ceilf(controller.maxGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().descent()));
-        glyphOverflow->left = max<int>(0, ceilf(-controller.minGlyphBoundingBoxX()));
-        glyphOverflow->right = max<int>(0, ceilf(controller.maxGlyphBoundingBoxX() - controller.totalWidth()));
-    }
-    return controller.totalWidth();
+    HarfBuzzShaper shaper(this, run);
+    return shaper.shape() ? shaper.totalWidth() : 0;
 }
 
 int Font::offsetForPositionForComplexText(const TextRun& run, float x, bool includePartialGlyphs) const
 {
-    if (preferHarfBuzz(this)) {
-        HarfBuzzShaper shaper(this, run);
-        if (shaper.shape())
-            return shaper.offsetForPosition(x);
-    }
-    ComplexTextController controller(this, run);
-    return controller.offsetForPosition(x, includePartialGlyphs);
-}
-
-const SimpleFontData* Font::fontDataForCombiningCharacterSequence(const UChar* characters, size_t length, FontDataVariant variant) const
-{
-    UChar32 baseCharacter;
-    size_t baseCharacterLength = 0;
-    U16_NEXT(characters, baseCharacterLength, length, baseCharacter);
-
-    GlyphData baseCharacterGlyphData = glyphDataForCharacter(baseCharacter, false, variant);
-
-    if (!baseCharacterGlyphData.glyph)
-        return 0;
-
-    if (length == baseCharacterLength)
-        return baseCharacterGlyphData.fontData;
-
-    bool triedBaseCharacterFontData = false;
-
-    unsigned i = 0;
-    for (const FontData* fontData = fontDataAt(0); fontData; fontData = fontDataAt(++i)) {
-        const SimpleFontData* simpleFontData = fontData->fontDataForCharacter(baseCharacter);
-        if (variant == NormalVariant) {
-            if (simpleFontData->platformData().orientation() == Vertical) {
-                if (Character::isCJKIdeographOrSymbol(baseCharacter) && !simpleFontData->hasVerticalGlyphs()) {
-                    variant = BrokenIdeographVariant;
-                    simpleFontData = simpleFontData->brokenIdeographFontData().get();
-                } else if (m_fontDescription.nonCJKGlyphOrientation() == NonCJKGlyphOrientationVerticalRight) {
-                    SimpleFontData* verticalRightFontData = simpleFontData->verticalRightOrientationFontData().get();
-                    Glyph verticalRightGlyph = verticalRightFontData->glyphForCharacter(baseCharacter);
-                    if (verticalRightGlyph == baseCharacterGlyphData.glyph)
-                        simpleFontData = verticalRightFontData;
-                } else {
-                    SimpleFontData* uprightFontData = simpleFontData->uprightOrientationFontData().get();
-                    Glyph uprightGlyph = uprightFontData->glyphForCharacter(baseCharacter);
-                    if (uprightGlyph != baseCharacterGlyphData.glyph)
-                        simpleFontData = uprightFontData;
-                }
-            }
-        } else {
-            if (const SimpleFontData* variantFontData = simpleFontData->variantFontData(m_fontDescription, variant).get())
-                simpleFontData = variantFontData;
-        }
-
-        if (simpleFontData == baseCharacterGlyphData.fontData)
-            triedBaseCharacterFontData = true;
-
-        if (simpleFontData->canRenderCombiningCharacterSequence(characters, length))
-            return simpleFontData;
-    }
-
-    if (!triedBaseCharacterFontData && baseCharacterGlyphData.fontData && baseCharacterGlyphData.fontData->canRenderCombiningCharacterSequence(characters, length))
-        return baseCharacterGlyphData.fontData;
-
-    return SimpleFontData::systemFallback();
+    HarfBuzzShaper shaper(this, run);
+    return shaper.shape() ? shaper.offsetForPosition(x) : 0;
 }
 
 } // namespace WebCore