Line data    Source code

       1             : /*
       2             :  * Copyright 2016 Google Inc.
       3             :  *
       4             :  * Use of this source code is governed by a BSD-style license that can be
       5             :  * found in the LICENSE file.
       6             :  */
       7             : 
       8             : #ifndef GrReducedClip_DEFINED
       9             : #define GrReducedClip_DEFINED
      10             : 
      11             : #include "GrWindowRectangles.h"
      12             : #include "SkClipStack.h"
      13             : #include "SkTLList.h"
      14             : 
      15             : class GrContext;
      16             : class GrRenderTargetContext;
      17             : 
      18             : /**
      19             :  * This class takes a clip stack and produces a reduced set of elements that are equivalent to
      20             :  * applying that full stack within a specified query rectangle.
      21             :  */
      22           0 : class SK_API GrReducedClip {
      23             : public:
      24             :     GrReducedClip(const SkClipStack&, const SkRect& queryBounds, int maxWindowRectangles = 0);
      25             : 
      26             :     /**
      27             :      * If hasIBounds() is true, this is the bounding box within which the clip elements are valid.
      28             :      * The caller must not modify any pixels outside this box. Undefined if hasIBounds() is false.
      29             :      */
      30           0 :     const SkIRect& ibounds() const { SkASSERT(fHasIBounds); return fIBounds; }
      31           0 :     int left() const { return this->ibounds().left(); }
      32           0 :     int top() const { return this->ibounds().top(); }
      33           0 :     int width() const { return this->ibounds().width(); }
      34           0 :     int height() const { return this->ibounds().height(); }
      35             : 
      36             :     /**
      37             :      * Indicates whether ibounds() are defined. They will always be defined if the elements() are
      38             :      * nonempty.
      39             :      */
      40           0 :     bool hasIBounds() const { return fHasIBounds; }
      41             : 
      42             :     /**
      43             :      * If nonempty, this is a set of "exclusive" windows within which the clip elements are NOT
      44             :      * valid. The caller must not modify any pixels inside these windows.
      45             :      */
      46           0 :     const GrWindowRectangles& windowRectangles() const { return fWindowRects; }
      47             : 
      48             :     typedef SkTLList<SkClipStack::Element, 16> ElementList;
      49             : 
      50             :     /**
      51             :      * Populated with a minimal list of elements required to fully implement the clip.
      52             :      */
      53           0 :     const ElementList& elements() const { return fElements; }
      54             : 
      55             :     /**
      56             :      * If elements() are nonempty, uniquely identifies the list of elements within ibounds().
      57             :      * Otherwise undefined.
      58             :      */
      59           0 :     int32_t elementsGenID() const { SkASSERT(!fElements.isEmpty()); return fElementsGenID; }
      60             : 
      61             :     /**
      62             :      * Indicates whether antialiasing is required to process any of the clip elements.
      63             :      */
      64           0 :     bool requiresAA() const { return fRequiresAA; }
      65             : 
      66             :     enum class InitialState : bool {
      67             :         kAllIn,
      68             :         kAllOut
      69             :     };
      70             : 
      71           0 :     InitialState initialState() const { return fInitialState; }
      72             : 
      73             :     bool drawAlphaClipMask(GrRenderTargetContext*) const;
      74             :     bool drawStencilClipMask(GrContext*, GrRenderTargetContext*) const;
      75             : 
      76             : private:
      77             :     void walkStack(const SkClipStack&, const SkRect& queryBounds, int maxWindowRectangles);
      78             :     void addInteriorWindowRectangles(int maxWindowRectangles);
      79             :     void addWindowRectangle(const SkRect& elementInteriorRect, bool elementIsAA);
      80             :     bool intersectIBounds(const SkIRect&);
      81             : 
      82             :     SkIRect              fIBounds;
      83             :     bool                 fHasIBounds;
      84             :     GrWindowRectangles   fWindowRects;
      85             :     ElementList          fElements;
      86             :     int32_t              fElementsGenID;
      87             :     bool                 fRequiresAA;
      88             :     InitialState         fInitialState;
      89             : };
      90             : 
      91             : #endif