Handle geometry effects of filters in GeometryMapper

third_party/WebKit/Source/platform/graphics/paint/EffectPaintPropertyNode.h

 // 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.
 
 #ifndef EffectPaintPropertyNode_h
 #define EffectPaintPropertyNode_h
 
 #include "cc/layers/layer.h"
 #include "platform/PlatformExport.h"
 #include "platform/graphics/CompositorElementId.h"
@@ skipping 21 matching lines @@
   static EffectPaintPropertyNode* root();
 
   static PassRefPtr<EffectPaintPropertyNode> create(
       PassRefPtr<const EffectPaintPropertyNode> parent,
       PassRefPtr<const TransformPaintPropertyNode> localTransformSpace,
       PassRefPtr<const ClipPaintPropertyNode> outputClip,
       CompositorFilterOperations filter,
       float opacity,
       SkBlendMode blendMode,
       CompositingReasons directCompositingReasons = CompositingReasonNone,
-      const CompositorElementId& compositorElementId = CompositorElementId()) {
+      const CompositorElementId& compositorElementId = CompositorElementId(),
+      const FloatPoint& offset = FloatPoint()) {
     return adoptRef(new EffectPaintPropertyNode(
         std::move(parent), std::move(localTransformSpace),
         std::move(outputClip), std::move(filter), opacity, blendMode,
-        directCompositingReasons, compositorElementId));
+        directCompositingReasons, compositorElementId, offset));
   }
 
   void update(
       PassRefPtr<const EffectPaintPropertyNode> parent,
       PassRefPtr<const TransformPaintPropertyNode> localTransformSpace,
       PassRefPtr<const ClipPaintPropertyNode> outputClip,
       CompositorFilterOperations filter,
       float opacity,
       SkBlendMode blendMode,
       CompositingReasons directCompositingReasons = CompositingReasonNone,
-      CompositorElementId compositorElementId = CompositorElementId()) {
+      const CompositorElementId& compositorElementId = CompositorElementId(),
+      const FloatPoint& offset = FloatPoint()) {
     DCHECK(!isRoot());
     DCHECK(parent != this);
     m_parent = parent;
     m_localTransformSpace = localTransformSpace;
     m_outputClip = outputClip;
     m_filter = std::move(filter);
     m_opacity = opacity;
     m_blendMode = blendMode;
     m_directCompositingReasons = directCompositingReasons;
     m_compositorElementId = compositorElementId;
+    m_offset = offset;
   }
 
   const TransformPaintPropertyNode* localTransformSpace() const {
     return m_localTransformSpace.get();
   }
   const ClipPaintPropertyNode* outputClip() const { return m_outputClip.get(); }
 
   SkBlendMode blendMode() const { return m_blendMode; }
   float opacity() const { return m_opacity; }
   const CompositorFilterOperations& filter() const { return m_filter; }
 
   // Parent effect or nullptr if this is the root effect.
   const EffectPaintPropertyNode* parent() const { return m_parent.get(); }
   bool isRoot() const { return !m_parent; }
 
+  bool hasFilterThanMovesPixels() const {
+    return m_filter.hasFilterThatMovesPixels();
+  }
+
+  // Returns a rect covering the pixels that can be affected by pixels in the
+  // input rect. The rects are in the space of localTransformSpace.
+  FloatRect mapRect(const FloatRect&) const;

[chrishtr, 2017/02/01 02:59:12]

Nit: name the argument inputRect.

[Xianzhu, 2017/02/03 01:38:16]

Done.

+
   cc::Layer* ensureDummyLayer() const;
 
 #if DCHECK_IS_ON()
   // The clone function is used by FindPropertiesNeedingUpdate.h for recording
   // an effect node before it has been updated, to later detect changes.
   PassRefPtr<EffectPaintPropertyNode> clone() const {
     return adoptRef(new EffectPaintPropertyNode(
         m_parent, m_localTransformSpace, m_outputClip, m_filter, m_opacity,
-        m_blendMode, m_directCompositingReasons, m_compositorElementId));
+        m_blendMode, m_directCompositingReasons, m_compositorElementId,
+        m_offset));
   }
 
   // The equality operator is used by FindPropertiesNeedingUpdate.h for checking
   // if an effect node has changed. It ignores changes of reference filters
   // because SkImageFilter doesn't have an equality operator.
   bool operator==(const EffectPaintPropertyNode& o) const {
     return m_parent == o.m_parent &&
            m_localTransformSpace == o.m_localTransformSpace &&
            m_outputClip == o.m_outputClip &&
            m_filter.equalsIgnoringReferenceFilters(o.m_filter) &&
            m_opacity == o.m_opacity && m_blendMode == o.m_blendMode &&
            m_directCompositingReasons == o.m_directCompositingReasons &&
-           m_compositorElementId == o.m_compositorElementId;
+           m_compositorElementId == o.m_compositorElementId &&
+           m_offset == o.m_offset;
   }
 
   String toTreeString() const;
 #endif
 
   String toString() const;
 
   bool hasDirectCompositingReasons() const {
     return m_directCompositingReasons != CompositingReasonNone;
   }
 
   const CompositorElementId& compositorElementId() const {
     return m_compositorElementId;
   }
 
  private:
   EffectPaintPropertyNode(
       PassRefPtr<const EffectPaintPropertyNode> parent,
       PassRefPtr<const TransformPaintPropertyNode> localTransformSpace,
       PassRefPtr<const ClipPaintPropertyNode> outputClip,
       CompositorFilterOperations filter,
       float opacity,
       SkBlendMode blendMode,
       CompositingReasons directCompositingReasons,
-      CompositorElementId compositorElementId)
+      CompositorElementId compositorElementId,
+      const FloatPoint& offset)
       : m_parent(parent),
         m_localTransformSpace(localTransformSpace),
         m_outputClip(outputClip),
         m_filter(std::move(filter)),
         m_opacity(opacity),
         m_blendMode(blendMode),
         m_directCompositingReasons(directCompositingReasons),
-        m_compositorElementId(compositorElementId) {}
+        m_compositorElementId(compositorElementId),
+        m_offset(offset) {}
 
   RefPtr<const EffectPaintPropertyNode> m_parent;
   // The local transform space serves two purposes:
   // 1. Assign a depth mapping for 3D depth sorting against other paint chunks
   //    and effects under the same parent.
   // 2. Some effects are spatial (namely blur filter and reflection), the
   //    effect parameters will be specified in the local space.
   RefPtr<const TransformPaintPropertyNode> m_localTransformSpace;
   // The output of the effect can be optionally clipped when composited onto
   // the current backdrop.
   RefPtr<const ClipPaintPropertyNode> m_outputClip;
 
   // Optionally a number of effects can be applied to the composited output.
   // The chain of effects will be applied in the following order:
   // === Begin of effects ===
   CompositorFilterOperations m_filter;
   float m_opacity;
   SkBlendMode m_blendMode;
   // === End of effects ===
 
   // TODO(trchen): Remove the dummy layer.
   // The main purpose of the dummy layer is to maintain a permanent identity
   // to associate with cc::RenderSurfaceImpl for damage tracking. This shall
   // be removed in favor of a stable ID once cc::LayerImpl no longer owns
   // RenderSurfaceImpl.
   mutable scoped_refptr<cc::Layer> m_dummyLayer;
 
   CompositingReasons m_directCompositingReasons;
   CompositorElementId m_compositorElementId;
+
+  // The offset of the effect's local space in m_localTransformSpace. Some
+  // effects e.g. reflection need this to apply geometry effects in the local
+  // space.
+  FloatPoint m_offset;

[chrishtr, 2017/02/01 02:59:12]

Why not m_paintOffset?

[Xianzhu, 2017/02/03 01:38:16]

No specific reason :)
Modified to paintOffset to keep consistency with other modules.

 };
 
 // Redeclared here to avoid ODR issues.
 // See platform/testing/PaintPrinters.h.
 void PrintTo(const EffectPaintPropertyNode&, std::ostream*);
 
 }  // namespace blink
 
 #endif  // EffectPaintPropertyNode_h