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 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 */ ibounds()30 const SkIRect& ibounds() const { SkASSERT(fHasIBounds); return fIBounds; } left()31 int left() const { return this->ibounds().left(); } top()32 int top() const { return this->ibounds().top(); } width()33 int width() const { return this->ibounds().width(); } height()34 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 */ hasIBounds()40 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 */ windowRectangles()46 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 */ elements()53 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 */ elementsGenID()59 uint32_t elementsGenID() const { SkASSERT(!fElements.isEmpty()); return fElementsGenID; } 60 61 /** 62 * Indicates whether antialiasing is required to process any of the clip elements. 63 */ requiresAA()64 bool requiresAA() const { return fRequiresAA; } 65 66 enum class InitialState : bool { 67 kAllIn, 68 kAllOut 69 }; 70 initialState()71 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 uint32_t fElementsGenID; 87 bool fRequiresAA; 88 InitialState fInitialState; 89 }; 90 91 #endif 92