Refactor PropertyTreeState as GeometryPropertyTreeState

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

 // Copyright 2016 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 GeometryMapper_h
 #define GeometryMapper_h
 
 #include "platform/geometry/FloatRect.h"
-#include "platform/graphics/paint/PropertyTreeState.h"
+#include "platform/graphics/paint/GeometryPropertyTreeState.h"
 #include "platform/transforms/TransformationMatrix.h"
 #include "wtf/HashMap.h"
 
 namespace blink {
 
 struct PrecomputedDataForAncestor {
     // Maps from a transform node that is a descendant of the ancestor to the combined
     // transform between the descendant's and the ancestor's coordinate space.
     HashMap<const TransformPaintPropertyNode*, TransformationMatrix> toAncestorTransforms;
 
     // Maps from a descendant clip node to its equivalent "clip visual rect" in the space of the ancestor.
     // The clip visual rect is defined as the intersection of all clips between the descendant
     // and the ancestor (*not* including the ancestor) in the clip tree, individually transformed from their
     // localTransformSpace into the ancestor's localTransformSpace.
     HashMap<const ClipPaintPropertyNode*, FloatRect> toAncestorClipRects;
 
     static std::unique_ptr<PrecomputedDataForAncestor> create()
     {
         return wrapUnique(new PrecomputedDataForAncestor());
     }
 };
 
-// GeometryMapper is a helper class for fast computations of transformed and visual rects in different
-// PropertyTreeStates. The design document has a number of details on use cases, algorithmic definitions,
-// and running times.
+// GeometryMapper is a helper class for fast computations of transformed and visual rects in
+// different GeometryPropertyTreeStates. The design document has a number of details on use cases,
+// algorithmic definitions, and running times.
 //
-// NOTE: a GeometryMapper object is only valid for property trees that do not change. If any mutation occurs,
-// a new GeometryMapper object must be allocated corresponding to the new state.
+// NOTE: A GeometryMapper object is only valid for property trees that do not change. If any
+// mutation occurs, a new GeometryMapper object must be allocated corresponding to the new state.
 //
 // Design document: http://bit.ly/28P4FDA
 //
-// TODO(chrishtr): take effect and scroll trees into account.
+// TODO(chrishtr): take effect tree into account.
 class PLATFORM_EXPORT GeometryMapper {
 public:
     GeometryMapper() {}
     // The runtime of m calls among localToVisualRectInAncestorSpace, localToAncestorRect or ancestorToLocalRect
     // with the same |ancestorState| parameter is guaranteed to be O(n + m),  where n is the number of transform and clip
     // nodes in their respective property trees.
 
     // If the clips and transforms of |sourceState| are equal to or descendants of those of |destinationState|, returns
     // the same value as localToVisualRectInAncestorSpace. Otherwise, maps the input rect to the transform state which is
     // the least common ancestor of |sourceState.transform| and |destinationState.transform|, then multiplies it by
     // the the inverse transform mapping from the least common ancestor to |destinationState.transform|.
     //
     // If that inverse transform is not invertible, sets |success| to false and returns the input rect. Otherwise, sets
     // |success| to true.
     FloatRect mapToVisualRectInDestinationSpace(const FloatRect&,
-        const PropertyTreeState& sourceState,
-        const PropertyTreeState& destinationState,
+        const GeometryPropertyTreeState& sourceState,
+        const GeometryPropertyTreeState& destinationState,
         bool& success);
 
     // Same as mapToVisualRectInDestinationSpace() except that *no* clip is applied.
     FloatRect mapRectToDestinationSpace(const FloatRect&,
-        const PropertyTreeState& sourceState,
-        const PropertyTreeState& destinationState,
+        const GeometryPropertyTreeState& sourceState,
+        const GeometryPropertyTreeState& destinationState,
         bool& success);
 
     // Maps from a rect in |localTransformSpace| to its visual rect in |ancestorState|. This is computed
     // by multiplying the rect by its combined transform between |localTransformSpace| and |ancestorSpace|,
     // then flattening into 2D space, then intersecting by the "clip visual rect" for |localTransformState|'s clips.
     // See above for the definition of "clip visual rect".
     //
     // Note that the clip of |ancestorState| is *not* applied.
     //
     // If any of the paint property tree nodes in |localTransformState| are not equal
     // to or a descendant of that in |ancestorState|, returns the passed-in rect and sets |success| to false. Otherwise,
     // sets |success| to true.
     FloatRect localToVisualRectInAncestorSpace(const FloatRect&,
-        const PropertyTreeState& localTransformState,
-        const PropertyTreeState& ancestorState,
+        const GeometryPropertyTreeState& localTransformState,
+        const GeometryPropertyTreeState& ancestorState,
         bool& success);
 
     // Maps from a rect in |localTransformSpace| to its transformed rect in |ancestorSpace|. This is computed
     // by multiplying the rect by the combined transform between |localTransformState| and |ancestorState|,
     // then flattening into 2D space.
     //
     // If any of the paint property tree nodes in |localTransformState| are not equal
     // to or a descendant of that in |ancestorState|, returns the passed-in rec and sets |success| to false. Otherwise,
     // sets |success| to true.
     //
     // If any of the paint property tree nodes in |localTransformState| are not equal
     // to or a descendant of that in |ancestorState|, returns the passed-in rect and sets |success| to false. Otherwise,
     // sets |success| to true.
     FloatRect localToAncestorRect(const FloatRect&,
-        const PropertyTreeState& localTransformState,
-        const PropertyTreeState& ancestorState,
+        const GeometryPropertyTreeState& localTransformState,
+        const GeometryPropertyTreeState& ancestorState,
         bool& success);
 
     // Maps from a rect in |ancestorSpace| to its transformed rect in |localTransformSpace|. This is computed
     // by multiplying the rect by the inverse combined transform between |localTransformState| and |ancestorState|,
     // if the transform is invertible.
     //
     // If any of the paint property tree nodes in |localTransformState| are not equal
     // to or a descendant of that in |ancestorState|, returns the passed-in rect and sets |success| to false. Otherwise,
     // sets |success| to true.
     FloatRect ancestorToLocalRect(const FloatRect&,
-        const PropertyTreeState& localTransformState,
-        const PropertyTreeState& ancestorState,
+        const GeometryPropertyTreeState& localTransformState,
+        const GeometryPropertyTreeState& ancestorState,
         bool& success);
 
 private:
     // Used by mapToVisualRectInDestinationSpace() after fast mapping (assuming destination is an ancestor of source) failed.
     FloatRect slowMapToVisualRectInDestinationSpace(const FloatRect&,
-        const PropertyTreeState& sourceState,
-        const PropertyTreeState& destinationState,
+        const GeometryPropertyTreeState& sourceState,
+        const GeometryPropertyTreeState& destinationState,
         bool& success);
 
     // Used by mapRectToDestinationSpace() after fast mapping (assuming destination is an ancestor of source) failed.
     FloatRect slowMapRectToDestinationSpace(const FloatRect&,
-        const PropertyTreeState& sourceState,
-        const PropertyTreeState& destinationState,
+        const GeometryPropertyTreeState& sourceState,
+        const GeometryPropertyTreeState& destinationState,
         bool& success);
 
     // Returns the matrix used in |LocalToAncestorRect|. Sets |success| to failse iff |localTransformNode| is not
     // equal to or a descendant of |ancestorState.transform|.
     const TransformationMatrix& localToAncestorMatrix(
         const TransformPaintPropertyNode* localTransformNode,
-        const PropertyTreeState& ancestorState,
+        const GeometryPropertyTreeState& ancestorState,
         bool& success);
 
     // Returns the "clip visual rect" between |localTransformState| and |ancestorState|. See above for the definition
     // of "clip visual rect".
     FloatRect localToAncestorClipRect(
-        const PropertyTreeState& localTransformState,
-        const PropertyTreeState& ancestorState,
+        const GeometryPropertyTreeState& localTransformState,
+        const GeometryPropertyTreeState& ancestorState,
         bool& success);
 
     // Returns the precomputed data if already set, or adds and memoizes a new PrecomputedDataForAncestor otherwise.
-    PrecomputedDataForAncestor& getPrecomputedDataForAncestor(const PropertyTreeState&);
+    PrecomputedDataForAncestor& getPrecomputedDataForAncestor(const GeometryPropertyTreeState&);
 
     // Returns the least common ancestor in the transform tree.
     PassRefPtr<TransformPaintPropertyNode> leastCommonAncestor(PassRefPtr<TransformPaintPropertyNode>, PassRefPtr<TransformPaintPropertyNode>);
 
     friend class GeometryMapperTest;
 
     HashMap<const TransformPaintPropertyNode*, std::unique_ptr<PrecomputedDataForAncestor>> m_data;
 
     const TransformationMatrix m_identity;
 
     DISALLOW_COPY_AND_ASSIGN(GeometryMapper);
 };
 
 } // namespace blink
 
 #endif // GeometryMapper_h