Revert of Revamp filter primitive region calculations for Filter Effects

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

Index: third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp b/third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp
index cec0220ca90ccdf722737863637aeb6096ae0166..4cbb72d65edbb79b619a8703b3f0a4017f68ecdc 100644
--- a/third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp
+++ b/third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp
@@ -33,6 +33,10 @@
 
 FilterEffect::FilterEffect(Filter* filter)
     : m_filter(filter)
+    , m_hasX(false)
+    , m_hasY(false)
+    , m_hasWidth(false)
+    , m_hasHeight(false)
     , m_clipsToBounds(true)
     , m_originTainted(false)
     , m_operatingColorSpace(ColorSpaceLinearRGB)
@@ -129,44 +133,58 @@
     return ts;
 }
 
-FloatRect FilterEffect::determineMaximumEffectRect(DetermineMaxEffectRectFlags flags)
-{
-    DCHECK(getFilter());
-    Filter* filter = getFilter();
-
-    // Compute the union of the inputs. Always do this because it has
-    // side-effects. (It computes the maximum effect rect of the input.)
-    FloatRect absoluteInputUnion;
-    for (auto& effect : m_inputEffects)
-        absoluteInputUnion.unite(effect->determineMaximumEffectRect(flags));
-
-    FloatRect absoluteSubregion;
-    switch (getFilterEffectType()) {
-    default:
-        if (m_inputEffects.size()) {
-            absoluteSubregion = absoluteInputUnion;
-            if (clipsToBounds())
-                absoluteSubregion.intersect(filter->mapLocalRectToAbsoluteRect(filterPrimitiveSubregion()));
-            break;
-        }
-        // Else fall-through and use the primitive region. (FETurbulence/FEFlood/FEImage)
-    case FilterEffectTypeTile:
-        absoluteSubregion = filter->mapLocalRectToAbsoluteRect(filterPrimitiveSubregion());
-        break;
-    case FilterEffectTypeSourceInput:
-        absoluteSubregion = filter->absoluteFilterRegion();
-        break;
-    }
-
-    if (flags & MapRectForward)
-        absoluteSubregion = mapRect(absoluteSubregion);
+FloatRect FilterEffect::applyEffectBoundaries(const FloatRect& rect) const
+{
+    FloatRect clippedRect = rect;
+    if (hasX())
+        clippedRect.setX(effectBoundaries().x());
+    if (hasY())
+        clippedRect.setY(effectBoundaries().y());
+    if (hasWidth())
+        clippedRect.setWidth(effectBoundaries().width());
+    if (hasHeight())
+        clippedRect.setHeight(effectBoundaries().height());
+    return clippedRect;
+}
+
+FloatRect FilterEffect::determineFilterPrimitiveSubregion(DetermineSubregionFlags flags)
+{
+    Filter* filter = this->getFilter();
+    ASSERT(filter);
+
+    // FETile, FETurbulence, FEFlood don't have input effects, take the filter region as unite rect.
+    FloatRect subregion;
+    if (unsigned numberOfInputEffects = inputEffects().size()) {
+        subregion = inputEffect(0)->determineFilterPrimitiveSubregion(flags);
+        for (unsigned i = 1; i < numberOfInputEffects; ++i)
+            subregion.unite(inputEffect(i)->determineFilterPrimitiveSubregion(flags));
+    } else {
+        subregion = filter->filterRegion();
+    }
+
+    // After calling determineFilterPrimitiveSubregion on the target effect, reset the subregion again for <feTile>.
+    if (getFilterEffectType() == FilterEffectTypeTile)
+        subregion = filter->filterRegion();
+
+    if (flags & MapRectForward) {
+        // mapRect works on absolute rectangles.
+        subregion = filter->mapAbsoluteRectToLocalRect(mapRect(
+            filter->mapLocalRectToAbsoluteRect(subregion)));
+    }
+
+    subregion = applyEffectBoundaries(subregion);
+
+    setFilterPrimitiveSubregion(subregion);
+
+    FloatRect absoluteSubregion = filter->mapLocalRectToAbsoluteRect(subregion);
 
     // Clip every filter effect to the filter region.
-    if (flags & ClipToFilterRegion)
+    if (flags & ClipToFilterRegion) {
         absoluteSubregion.intersect(filter->absoluteFilterRegion());
-
-    m_maxEffectRect = absoluteSubregion;
-    return absoluteSubregion;
+    }
+
+    setMaxEffectRect(absoluteSubregion);
+    return subregion;
 }
 
 sk_sp<SkImageFilter> FilterEffect::createImageFilter()
@@ -198,7 +216,8 @@
 SkImageFilter::CropRect FilterEffect::getCropRect() const
 {
     if (!filterPrimitiveSubregion().isEmpty()) {
-        FloatRect rect = getFilter()->mapLocalRectToAbsoluteRect(filterPrimitiveSubregion());
+        FloatRect rect = filterPrimitiveSubregion();
+        rect.scale(getFilter()->scale());
         return SkImageFilter::CropRect(rect);
     } else {
         return SkImageFilter::CropRect(SkRect::MakeEmpty(), 0);