2010-07-09 W. James MacLean <wjmaclean@chromium.org>...

third_party/WebKit/WebCore/dom/CanvasSurface.cpp

 /*
  * Copyright (C) 2010 Google 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 27 matching lines @@
 
 // These values come from the WhatWG spec.
 const int CanvasSurface::DefaultWidth = 300;
 const int CanvasSurface::DefaultHeight = 150;
 
 // Firefox limits width/height to 32767 pixels, but slows down dramatically before it
 // reaches that limit. We limit by area instead, giving us larger maximum dimensions,
 // in exchange for a smaller maximum canvas size.
 const float CanvasSurface::MaxCanvasArea = 32768 * 8192; // Maximum canvas area in CSS pixels
 
+#if PLATFORM(SKIA)
+// In Skia, we will also limit width/height to 32767.
+const float CanvasSurface::MaxSkiaDim = 32767.0F; // Maximum width/height in CSS pixels.
+#endif
+
 CanvasSurface::CanvasSurface(float pageScaleFactor)
     : m_size(DefaultWidth, DefaultHeight)
     , m_pageScaleFactor(pageScaleFactor)
     , m_originClean(true)
     , m_hasCreatedImageBuffer(false)
 {
 }
 
 CanvasSurface::~CanvasSurface()
 {
@@ skipping 35 matching lines @@
 }
 
 IntSize CanvasSurface::convertLogicalToDevice(const FloatSize& logicalSize) const
 {
     float wf = ceilf(logicalSize.width() * m_pageScaleFactor);
     float hf = ceilf(logicalSize.height() * m_pageScaleFactor);
 
     if (!(wf >= 1 && hf >= 1 && wf * hf <= MaxCanvasArea))
         return IntSize();
 
+#if PLATFORM(SKIA)
+    if (wf > MaxSkiaDim || hf > MaxSkiaDim)
+        return IntSize();
+#endif
+
     return IntSize(static_cast<unsigned>(wf), static_cast<unsigned>(hf));
 }
 
 IntPoint CanvasSurface::convertLogicalToDevice(const FloatPoint& logicalPos) const
 {
     float xf = logicalPos.x() * m_pageScaleFactor;
     float yf = logicalPos.y() * m_pageScaleFactor;
 
     return IntPoint(static_cast<unsigned>(xf), static_cast<unsigned>(yf));
 }
@@ skipping 58 matching lines @@
 {
     return static_cast<HTMLCanvasElement*>(this)->computedStyle();
 }
 
 CSSStyleSelector* CanvasSurface::styleSelector()
 {
     return static_cast<HTMLCanvasElement*>(this)->document()->styleSelector();
 }
 
 } // namespace WebCore