Rename and change parameter type of some GeometryMapper methods

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/transforms/TransformationMatrix.h"
@@ skipping 27 matching lines @@
 // 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 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.
+  // The runtime of m calls among localToAncestorVisualRect, 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
+  // localToAncestorVisualRect. 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|.
   //
   // Sets |success| to whether that inverse transform is invertible. If it is
   // not, returns the input rect.
-  FloatRect mapToVisualRectInDestinationSpace(
+  FloatRect sourceToDestinationVisualRect(
       const FloatRect&,
       const PropertyTreeState& sourceState,
       const PropertyTreeState& destinationState,
       bool& success);
 
-  // Same as mapToVisualRectInDestinationSpace() except that *no* clip is
+  // Same as sourceToDestinationVisualRect() except that only transforms are
   // applied.
-  FloatRect mapRectToDestinationSpace(const FloatRect&,
-                                      const PropertyTreeState& sourceState,
-                                      const PropertyTreeState& destinationState,
-                                      bool& success);
+  FloatRect sourceToDestinationRect(
+      const FloatRect&,
+      const TransformPaintPropertyNode* sourceTransformNode,

[chrishtr, 2017/01/11 22:23:08]

Curious: what is the new call site you're planning to add?

[Xianzhu, 2017/01/11 22:51:32]

I will use this for handle geometry effects of filters for crbug.com/637313 (WIP
CL https://codereview.chromium.org/2625133003). This is used to map a rect from
localTransformSpace of one effect node to that of another.

Actually we already have similar usage when handling clipping. Previously we
created a temporary PropertyTreeState to meet the requirement of this method.

I think this change also makes it clear that only transform nodes are used in
this method.

+      const TransformPaintPropertyNode* destinationTransformNode,
+      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(
+  FloatRect localToAncestorVisualRect(
       const FloatRect&,
       const PropertyTreeState& localTransformState,
       const PropertyTreeState& 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.
+  // Maps from a rect in |localTransformNode| space to its transformed rect in
+  // |ancestorTransformNode| space. This is computed by multiplying the rect by
+  // the combined transform between |localTransformNode| and
+  // |ancestorTransformNode|, 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.
-  FloatRect localToAncestorRect(const FloatRect&,
-                                const PropertyTreeState& localTransformState,
-                                const PropertyTreeState& ancestorState,
-                                bool& success);
+  // If |localTransformNode| is not equal to or a descendant of
+  // |ancestorTransformNode|, returns the passed-in rec and sets |success| to
+  // false. Otherwise, sets |success| to true.
+  FloatRect localToAncestorRect(
+      const FloatRect&,
+      const TransformPaintPropertyNode* localTransformNode,
+      const TransformPaintPropertyNode* ancestorTransformNode,
+      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.
+  // Maps from a rect in |ancestorTransformNode| space to its transformed rect
+  // in |localTransformNode| space. This is computed by multiplying the rect by
+  // the inverse combined transform between |localTransformNode| and
+  // |ancestorTransformNode|, 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
+  // If the combined transform is not invertible, or |localTransformNode| is not
+  // equal to or a descendant of |ancestorTransformNode|, 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,
-                                bool& success);
+  FloatRect ancestorToLocalRect(
+      const FloatRect&,
+      const TransformPaintPropertyNode* ancestorTransformNode,
+      const TransformPaintPropertyNode* localTransformNode,
+      bool& success);
 
   // Returns the matrix used in |LocalToAncestorRect|. Sets |success| to false
   // iff |localTransformNode| is not equal to or a descendant of
-  // |ancestorState.transform|.
+  // |ancestorTransformNode|.
   const TransformationMatrix& localToAncestorMatrix(
       const TransformPaintPropertyNode* localTransformNode,
-      const PropertyTreeState& ancestorState,
+      const TransformPaintPropertyNode* ancestorTransformNode,
       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,
       bool& success);
 
  private:
-  // Used by mapToVisualRectInDestinationSpace() after fast mapping (assuming
+  // Used by sourceToDestinationVisualRect() after fast mapping (assuming
   // destination is an ancestor of source) failed.
-  FloatRect slowMapToVisualRectInDestinationSpace(
+  FloatRect slowSourceToDestinationVisualRect(
       const FloatRect&,
       const PropertyTreeState& sourceState,
       const PropertyTreeState& destinationState,
       bool& success);
 
-  // Used by mapRectToDestinationSpace() after fast mapping (assuming
-  // destination is an ancestor of source) failed.
-  FloatRect slowMapRectToDestinationSpace(
+  // Used by sourceToDestinationRect() after fast mapping (assuming destination
+  // is an ancestor of source) failed.
+  FloatRect slowSourceToDestinationRect(
       const FloatRect&,
-      const PropertyTreeState& sourceState,
-      const PropertyTreeState& destinationState,
+      const TransformPaintPropertyNode* sourceTransformNode,
+      const TransformPaintPropertyNode* destinationTransformNode,
       bool& success);
 
   // Returns the precomputed data if already set, or adds and memoizes a new
   // PrecomputedDataForAncestor otherwise.
   PrecomputedDataForAncestor& getPrecomputedDataForAncestor(
-      const PropertyTreeState&);
+      const TransformPaintPropertyNode*);
 
   // Returns the least common ancestor in the transform tree.
   static const TransformPaintPropertyNode* leastCommonAncestor(
       const TransformPaintPropertyNode*,
       const 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