TextBlob: Start caching a text blob per InlineTextBox.

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 185 matching lines @@
 #if ENABLE(SVG_FONTS)
     if (TextRun::RenderingContext* renderingContext = run.renderingContext())
         return renderingContext->floatWidthUsingSVGFont(*this, run, charsConsumed, glyphId);
 #endif
 
     charsConsumed = run.length();
     glyphId = 0;
     return width(run);
 }
 
+PassTextBlobPtr Font::buildTextBlob(const TextRunPaintInfo& runInfo, const FloatPoint& textOrigin, bool couldUseLCDRenderedText, CustomFontNotReadyAction customFontNotReadyAction) const
+{
+    ASSERT(RuntimeEnabledFeatures::textBlobEnabled());
+
+    // FIXME: Some logic in common with Font::drawText. Would be nice to
+    // deduplicate.
+    if (shouldSkipDrawing() && customFontNotReadyAction == DoNotPaintIfFontNotReady)
+        return nullptr;
+
+    CodePath codePathToUse = codePath(runInfo.run);
+    // FIXME: Use the fast code path once it handles partial runs with kerning and ligatures. See http://webkit.org/b/100050
+    if (codePathToUse != ComplexPath && fontDescription().typesettingFeatures() && (runInfo.from || runInfo.to != runInfo.run.length()))
+        codePathToUse = ComplexPath;
+
+    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);
+}
+
 FloatRect Font::selectionRectForText(const TextRun& run, const FloatPoint& point, int h, int from, int to, bool accountForGlyphBounds) const
 {
     to = (to == -1 ? run.length() : to);
 
     CodePath codePathToUse = codePath(run);
     // FIXME: Use the fast code path once it handles partial runs with kerning and ligatures. See http://webkit.org/b/100050
     if (codePathToUse != ComplexPath && fontDescription().typesettingFeatures() && (from || to != run.length()))
         codePathToUse = ComplexPath;
 
     if (codePathToUse != ComplexPath)
@@ skipping 640 matching lines @@
                 if (delta <= 0)
                     break;
             }
         }
     }
 
     return offset;
 }
 
 } // namespace blink