Track the region where text is painted.

Source/core/platform/graphics/mac/FontComplexTextMac.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 74 matching lines @@
 
     if (run.rtl()) {
         initialAdvance = controller.totalWidth() + controller.finalRoundingWidth() - afterWidth;
         glyphBuffer.reverse(0, glyphBuffer.size());
     } else
         initialAdvance = beforeWidth;
 
     return initialAdvance;
 }
 
-void Font::drawComplexText(GraphicsContext* context, const TextRun& run, const FloatPoint& point, int from, int to) const
+void Font::drawComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const FloatPoint& point) const
 {
     if (preferHarfBuzz(this)) {
         GlyphBuffer glyphBuffer;
-        HarfBuzzShaper shaper(this, run);
-        shaper.setDrawRange(from, to);
+        HarfBuzzShaper shaper(this, runInfo.run);
+        shaper.setDrawRange(runInfo.from, runInfo.to);
         if (shaper.shape(&glyphBuffer)) {
-            drawGlyphBuffer(context, run, glyphBuffer, point);
+            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(run, from, to, 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, run, glyphBuffer, startPoint);
+    drawGlyphBuffer(context, runInfo, glyphBuffer, startPoint);
 }
 
-void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRun& run, const AtomicString& mark, const FloatPoint& point, int from, int to) const
+void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const AtomicString& mark, const FloatPoint& point) const
 {
     GlyphBuffer glyphBuffer;
-    float initialAdvance = getGlyphsAndAdvancesForComplexText(run, from, to, glyphBuffer, ForTextEmphasis);
+    float initialAdvance = getGlyphsAndAdvancesForComplexText(runInfo.run, runInfo.from, runInfo.to, glyphBuffer, ForTextEmphasis);
 
     if (glyphBuffer.isEmpty())
         return;
 
-    drawEmphasisMarks(context, run, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
+    drawEmphasisMarks(context, runInfo, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
 }
 
 float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
 {
     if (preferHarfBuzz(this)) {
         HarfBuzzShaper shaper(this, run);
         if (shaper.shape())
             return shaper.totalWidth();
     }
     ComplexTextController controller(this, run, true, fallbackFonts);
@@ skipping 65 matching lines @@
             return simpleFontData;
     }
 
     if (!triedBaseCharacterFontData && baseCharacterGlyphData.fontData && baseCharacterGlyphData.fontData->canRenderCombiningCharacterSequence(characters, length))
         return baseCharacterGlyphData.fontData;
 
     return SimpleFontData::systemFallback();
 }
 
 } // namespace WebCore