Separate advance from offset in GlypBuffer

Source/platform/fonts/Font.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2010, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 209 matching lines @@
     if (codePathToUse != ComplexPath)
         return buildTextBlobForSimpleText(runInfo, textOrigin, couldUseLCDRenderedText);
 
     return nullptr;
 }
 
 PassTextBlobPtr Font::buildTextBlobForSimpleText(const TextRunPaintInfo& runInfo, const FloatPoint& textOrigin, bool couldUseLCDRenderedText) const
 {
     GlyphBuffer glyphBuffer;
     float initialAdvance = getGlyphsAndAdvancesForSimpleText(runInfo, glyphBuffer);
-    ASSERT(!glyphBuffer.hasVerticalAdvances());
 
     if (glyphBuffer.isEmpty())
         return nullptr;
 
     FloatRect blobBounds = runInfo.bounds;
     blobBounds.moveBy(-textOrigin);
 
     float ignoredWidth;
     return buildTextBlob(glyphBuffer, initialAdvance, blobBounds, ignoredWidth, couldUseLCDRenderedText);
 }
@@ skipping 441 matching lines @@
     }
 
     return initialAdvance;
 }
 
 float Font::drawSimpleText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const FloatPoint& point) const
 {
     // This glyph buffer holds our glyphs+advances+font data for each glyph.
     GlyphBuffer glyphBuffer;
     float initialAdvance = getGlyphsAndAdvancesForSimpleText(runInfo, glyphBuffer);
-    ASSERT(!glyphBuffer.hasVerticalAdvances());
 
     if (glyphBuffer.isEmpty())
         return 0;
 
     TextBlobPtr textBlob;
     float advance = 0;
     if (RuntimeEnabledFeatures::textBlobEnabled()) {
         // Using text blob causes a small difference in how gradients and
         // patterns are rendered.
         // FIXME: Fix this, most likely in Skia.
@@ skipping 22 matching lines @@
         return;
 
     drawEmphasisMarks(context, runInfo, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
 }
 
 float Font::drawGlyphBuffer(GraphicsContext* context, const TextRunPaintInfo& runInfo, const GlyphBuffer& glyphBuffer, const FloatPoint& point) const
 {
     // Draw each contiguous run of glyphs that use the same font data.
     const SimpleFontData* fontData = glyphBuffer.fontDataAt(0);
     FloatPoint startPoint(point);
-    FloatPoint nextPoint = startPoint + glyphBuffer.advanceAt(0);
+    float advanceSoFar = 0;
     unsigned lastFrom = 0;
-    unsigned nextGlyph = 1;
+    unsigned nextGlyph = 0;
 #if ENABLE(SVG_FONTS)
     TextRun::RenderingContext* renderingContext = runInfo.run.renderingContext();
 #endif
 
-    float widthSoFar = 0;
-    widthSoFar += glyphBuffer.advanceAt(0).width();
     while (nextGlyph < glyphBuffer.size()) {
         const SimpleFontData* nextFontData = glyphBuffer.fontDataAt(nextGlyph);
 
         if (nextFontData != fontData) {
 #if ENABLE(SVG_FONTS)
             if (renderingContext && fontData->isSVGFont())
                 renderingContext->drawSVGGlyphs(context, runInfo.run, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, startPoint);
             else
 #endif
                 drawGlyphs(context, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, startPoint, runInfo.bounds);
 
             lastFrom = nextGlyph;
             fontData = nextFontData;
-            startPoint = nextPoint;
+            startPoint += FloatSize(advanceSoFar, 0);
+            advanceSoFar = 0;
         }
-        nextPoint += glyphBuffer.advanceAt(nextGlyph);
-        widthSoFar += glyphBuffer.advanceAt(nextGlyph).width();
+        advanceSoFar += glyphBuffer.advanceAt(nextGlyph);
         nextGlyph++;
     }
 
 #if ENABLE(SVG_FONTS)
     if (renderingContext && fontData->isSVGFont())
         renderingContext->drawSVGGlyphs(context, runInfo.run, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, startPoint);
     else
 #endif
         drawGlyphs(context, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, startPoint, runInfo.bounds);
-        return widthSoFar;
+
+    startPoint += FloatSize(advanceSoFar, 0);
+    return startPoint.x() - point.x();
 }
 
 inline static float offsetToMiddleOfGlyph(const SimpleFontData* fontData, Glyph glyph)
 {
     if (fontData->platformData().orientation() == Horizontal) {
         FloatRect bounds = fontData->boundsForGlyph(glyph);
         return bounds.x() + bounds.width() / 2;
     }
     // FIXME: Use glyph bounds once they make sense for vertical fonts.
     return fontData->widthForGlyph(glyph) / 2;
 }
 
 inline static float offsetToMiddleOfAdvanceAtIndex(const GlyphBuffer& glyphBuffer, size_t i)
 {
-    return glyphBuffer.advanceAt(i).width() / 2;
+    return glyphBuffer.advanceAt(i) / 2;
 }
 
 void Font::drawEmphasisMarks(GraphicsContext* context, const TextRunPaintInfo& runInfo, const GlyphBuffer& glyphBuffer, const AtomicString& mark, const FloatPoint& point) const
 {
     FontCachePurgePreventer purgePreventer;
 
     GlyphData markGlyphData;
     if (!getEmphasisMarkGlyphData(mark, markGlyphData))
         return;
 
     const SimpleFontData* markFontData = markGlyphData.fontData;
     ASSERT(markFontData);
     if (!markFontData)
         return;
 
     Glyph markGlyph = markGlyphData.glyph;
     Glyph spaceGlyph = markFontData->spaceGlyph();
 
     float middleOfLastGlyph = offsetToMiddleOfAdvanceAtIndex(glyphBuffer, 0);
     FloatPoint startPoint(point.x() + middleOfLastGlyph - offsetToMiddleOfGlyph(markFontData, markGlyph), point.y());
 
     GlyphBuffer markBuffer;
     for (unsigned i = 0; i + 1 < glyphBuffer.size(); ++i) {
         float middleOfNextGlyph = offsetToMiddleOfAdvanceAtIndex(glyphBuffer, i + 1);
-        float advance = glyphBuffer.advanceAt(i).width() - middleOfLastGlyph + middleOfNextGlyph;
+        float advance = glyphBuffer.advanceAt(i) - middleOfLastGlyph + middleOfNextGlyph;
         markBuffer.add(glyphBuffer.glyphAt(i) ? markGlyph : spaceGlyph, markFontData, advance);
         middleOfLastGlyph = middleOfNextGlyph;
     }
     markBuffer.add(glyphBuffer.glyphAt(glyphBuffer.size() - 1) ? markGlyph : spaceGlyph, markFontData, 0);
 
     drawGlyphBuffer(context, runInfo, markBuffer, startPoint);
 }
 
 float Font::floatWidthForSimpleText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, IntRectExtent* glyphBounds) const
 {
@@ skipping 76 matching lines @@
                 if (delta <= 0)
                     break;
             }
         }
     }
 
     return offset;
 }
 
 } // namespace blink