Consolidate FilterOperation and FilterEffect mapRect implementations

third_party/WebKit/Source/platform/graphics/filters/FEDropShadow.cpp

 /*
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  * Copyright (C) 2013 Google 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 36 matching lines @@
                                    float stdX,
                                    float stdY,
                                    float dx,
                                    float dy,
                                    const Color& shadowColor,
                                    float shadowOpacity) {
   return new FEDropShadow(filter, stdX, stdY, dx, dy, shadowColor,
                           shadowOpacity);
 }
 
+FloatRect FEDropShadow::mapEffect(const FloatSize& stdDeviation,
+                                  const FloatPoint& offset,
+                                  const FloatRect& rect) {
+  FloatRect offsetRect = rect;
+  offsetRect.moveBy(offset);
+  FloatRect blurredRect = FEGaussianBlur::mapEffect(stdDeviation, offsetRect);
+  return unionRect(blurredRect, rect);
+}
+
 FloatRect FEDropShadow::mapEffect(const FloatRect& rect) const {
   const Filter* filter = this->getFilter();
   DCHECK(filter);
-
-  FloatRect offsetRect = rect;
-  offsetRect.move(filter->applyHorizontalScale(m_dx),
-                  filter->applyVerticalScale(m_dy));
-
-  IntSize kernelSize =
-      FEGaussianBlur::calculateKernelSize(filter, FloatPoint(m_stdX, m_stdY));
-
-  // We take the half kernel size and multiply it by three, because we run box
-  // blur three times.
-  FloatRect result = unionRect(rect, offsetRect);
-  result.inflateX(3.0f * kernelSize.width() * 0.5f);
-  result.inflateY(3.0f * kernelSize.height() * 0.5f);
-  return result;
+  FloatPoint offset(filter->applyHorizontalScale(m_dx),
+                    filter->applyVerticalScale(m_dy));
+  FloatSize stdError(filter->applyHorizontalScale(m_stdX),
+                     filter->applyVerticalScale(m_stdY));
+  return mapEffect(stdError, offset, rect);
 }
 
 sk_sp<SkImageFilter> FEDropShadow::createImageFilter() {
   sk_sp<SkImageFilter> input(
       SkiaImageFilterBuilder::build(inputEffect(0), operatingColorSpace()));
   float dx = getFilter()->applyHorizontalScale(m_dx);
   float dy = getFilter()->applyVerticalScale(m_dy);
   float stdX = getFilter()->applyHorizontalScale(m_stdX);
   float stdY = getFilter()->applyVerticalScale(m_stdY);
   Color color = adaptColorToOperatingColorSpace(
@@ skipping 13 matching lines @@
   FilterEffect::externalRepresentation(ts);
   ts << " stdDeviation=\"" << m_stdX << ", " << m_stdY << "\" dx=\"" << m_dx
      << "\" dy=\"" << m_dy << "\" flood-color=\""
      << m_shadowColor.nameForLayoutTreeAsText() << "\" flood-opacity=\""
      << m_shadowOpacity << "]\n";
   inputEffect(0)->externalRepresentation(ts, indent + 1);
   return ts;
 }
 
 }  // namespace blink