Revamp filter primitive region calculations for Filter Effects

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DState.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/canvas2d/CanvasRenderingContext2DState.h"
 
 #include "core/css/CSSFontSelector.h"
 #include "core/css/resolver/FilterOperationResolver.h"
 #include "core/css/resolver/StyleBuilder.h"
 #include "core/css/resolver/StyleResolverState.h"
@@ skipping 304 matching lines @@
         SkPaint fillPaintForFilter;
         SkPaint strokePaintForFilter;
         m_fillStyle->applyToPaint(fillPaintForFilter);
         m_strokeStyle->applyToPaint(strokePaintForFilter);
         fillPaintForFilter.setColor(m_fillStyle->paintColor());
         strokePaintForFilter.setColor(m_strokeStyle->paintColor());
         FloatSize floatCanvasSize(canvasSize);
         const double effectiveZoom = 1.0; // Deliberately ignore zoom on the canvas element
         filterEffectBuilder->build(styleResolutionHost, filterStyle->filter(), effectiveZoom, &floatCanvasSize, &fillPaintForFilter, &strokePaintForFilter);
 
-        FilterEffect* lastEffect = filterEffectBuilder->lastEffect();
-        if (lastEffect) {
-            lastEffect->determineFilterPrimitiveSubregion();
-        }
-        m_resolvedFilter = SkiaImageFilterBuilder::build(lastEffect, ColorSpaceDeviceRGB);
-        if (m_resolvedFilter) {
-            updateFilterReferences(toHTMLCanvasElement(styleResolutionHost), context, filterStyle->filter());
-            if (lastEffect->originTainted())
-                context->setOriginTainted();
+        if (FilterEffect* lastEffect = filterEffectBuilder->lastEffect()) {
+            lastEffect->determineMaximumEffectRect(DetermineMaxEffectRectNone);
+            m_resolvedFilter = SkiaImageFilterBuilder::build(lastEffect, ColorSpaceDeviceRGB);
+            if (m_resolvedFilter) {
+                updateFilterReferences(toHTMLCanvasElement(styleResolutionHost), context, filterStyle->filter());
+                if (lastEffect->originTainted())
+                    context->setOriginTainted();
+            }
         }
     }
 
     return m_resolvedFilter.get();
 }
 
 bool CanvasRenderingContext2DState::hasFilter(Element* styleResolutionHost, IntSize canvasSize, CanvasRenderingContext2D* context) const
 {
     // Checking for a non-null m_filterValue isn't sufficient, since this value
     // might refer to a non-existent filter.
@@ skipping 218 matching lines @@
         paint->setLooper(0);
         paint->setImageFilter(shadowAndForegroundImageFilter());
         return paint;
     }
     paint->setLooper(sk_ref_sp(shadowAndForegroundDrawLooper()));
     paint->setImageFilter(0);
     return paint;
 }
 
 } // namespace blink