Fixes the rendering of a SVG filter (e.g. feFlood) by testing against total

Source/core/rendering/svg/RenderSVGResourceFilter.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2010. 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
@@ skipping 89 matching lines @@
         builder->appendEffectToEffectReferences(effect, effectElement->renderer());
         effectElement->setStandardAttributes(effect.get());
         effect->setEffectBoundaries(SVGLengthContext::resolveRectangle<SVGFilterPrimitiveStandardAttributes>(effectElement, filterElement->primitiveUnitsCurrentValue(), targetBoundingBox));
         effect->setOperatingColorSpace(
             effectElement->renderer()->style()->svgStyle()->colorInterpolationFilters() == CI_LINEARRGB ? ColorSpaceLinearRGB : ColorSpaceDeviceRGB);
         builder->add(AtomicString(effectElement->result()->currentValue()->value()), effect);
     }
     return builder.release();
 }
 
 bool RenderSVGResourceFilter::fitsInMaximumImageSize(const FloatSize& size, FloatSize& scale)

[Stephen Chennney, 2014/02/11 14:47:21]

The current implementation is wrong. It should compute the area, compare to the
max area, and reduce the scale by the sqrt of the ratio. (Preserve the aspect
ratio.)

 {
     bool matchesFilterSize = true;
-    if (size.width() * scale.width() > kMaxFilterSize) {
-        scale.setWidth(kMaxFilterSize / size.width());
+    if (size.width() * scale.width() > FilterEffect::maxFilterArea()) {

[fs, 2014/02/07 10:17:51]

This compares a distance to an area.

+        scale.setWidth(FilterEffect::maxFilterArea() / size.width());
         matchesFilterSize = false;
     }
-    if (size.height() * scale.height() > kMaxFilterSize) {
-        scale.setHeight(kMaxFilterSize / size.height());
+    if (size.height() * scale.height() > FilterEffect::maxFilterArea()) {

[fs, 2014/02/07 10:17:51]

Same as above.

+        scale.setHeight(FilterEffect::maxFilterArea() / size.height());
         matchesFilterSize = false;
     }
 
     return matchesFilterSize;
 }
 
 static bool createImageBuffer(const Filter* filter, OwnPtr<ImageBuffer>& imageBuffer, bool accelerated)
 {
     IntRect paintRect = filter->sourceImageRect();
     // Don't create empty ImageBuffers.
@@ skipping 280 matching lines @@
     markAllClientLayersForInvalidation();
 }
 
 FloatRect RenderSVGResourceFilter::drawingRegion(RenderObject* object) const
 {
     FilterData* filterData = m_filter.get(object);
     return filterData ? filterData->drawingRegion : FloatRect();
 }
 
 }