1 /* 2 * Copyright 2014 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 GrPathRendering_DEFINED 9 #define GrPathRendering_DEFINED 10 11 #include "SkPath.h" 12 #include "GrPipeline.h" 13 14 class GrGpu; 15 class GrPath; 16 class GrStencilSettings; 17 class GrStyle; 18 struct SkScalerContextEffects; 19 class SkDescriptor; 20 class SkTypeface; 21 22 /** 23 * Abstract class wrapping HW path rendering API. 24 * 25 * The subclasses of this class use the possible HW API to render paths (as opposed to path 26 * rendering implemented in Skia on top of a "3d" HW API). 27 * The subclasses hold the global state needed to render paths, including shadow of the global HW 28 * API state. Similar to GrGpu. 29 * 30 * It is expected that the lifetimes of GrGpuXX and GrXXPathRendering are the same. The call context 31 * interface (eg. * the concrete instance of GrGpu subclass) should be provided to the instance 32 * during construction. 33 */ 34 class GrPathRendering { 35 public: ~GrPathRendering()36 virtual ~GrPathRendering() { } 37 38 enum PathTransformType { 39 kNone_PathTransformType, //!< [] 40 kTranslateX_PathTransformType, //!< [kMTransX] 41 kTranslateY_PathTransformType, //!< [kMTransY] 42 kTranslate_PathTransformType, //!< [kMTransX, kMTransY] 43 kAffine_PathTransformType, //!< [kMScaleX, kMSkewX, kMTransX, kMSkewY, kMScaleY, kMTransY] 44 45 kLast_PathTransformType = kAffine_PathTransformType 46 }; 47 PathTransformSize(PathTransformType type)48 static inline int PathTransformSize(PathTransformType type) { 49 switch (type) { 50 case kNone_PathTransformType: 51 return 0; 52 case kTranslateX_PathTransformType: 53 case kTranslateY_PathTransformType: 54 return 1; 55 case kTranslate_PathTransformType: 56 return 2; 57 case kAffine_PathTransformType: 58 return 6; 59 60 default: 61 SK_ABORT("Unknown path transform type"); 62 return 0; 63 } 64 } 65 66 // No native support for inverse at this time 67 enum FillType { 68 /** Specifies that "inside" is computed by a non-zero sum of signed 69 edge crossings 70 */ 71 kWinding_FillType, 72 /** Specifies that "inside" is computed by an odd number of edge 73 crossings 74 */ 75 kEvenOdd_FillType, 76 }; 77 78 static const GrUserStencilSettings& GetStencilPassSettings(FillType); 79 80 /** 81 * Creates a new gpu path, based on the specified path and stroke and returns it. 82 * 83 * @param SkPath the geometry. 84 * @param GrStyle the style applied to the path. Styles with non-dash path effects are not 85 * allowed. 86 * @return a new GPU path object. 87 */ 88 virtual sk_sp<GrPath> createPath(const SkPath&, const GrStyle&) = 0; 89 90 /** None of these params are optional, pointers used just to avoid making copies. */ 91 struct StencilPathArgs { StencilPathArgsStencilPathArgs92 StencilPathArgs(bool useHWAA, 93 GrRenderTargetProxy* proxy, 94 const SkMatrix* viewMatrix, 95 const GrScissorState* scissor, 96 const GrStencilSettings* stencil) 97 : fUseHWAA(useHWAA) 98 , fProxy(proxy) 99 , fViewMatrix(viewMatrix) 100 , fScissor(scissor) 101 , fStencil(stencil) { 102 } 103 bool fUseHWAA; 104 GrRenderTargetProxy* fProxy; 105 const SkMatrix* fViewMatrix; 106 const GrScissorState* fScissor; 107 const GrStencilSettings* fStencil; 108 }; 109 110 void stencilPath(const StencilPathArgs& args, const GrPath* path); 111 112 void drawPath(GrRenderTarget*, GrSurfaceOrigin, 113 const GrPrimitiveProcessor& primProc, 114 const GrPipeline& pipeline, 115 const GrPipeline::FixedDynamicState&, 116 const GrStencilSettings& stencilPassSettings, // Cover pass settings in pipeline. 117 const GrPath* path); 118 119 protected: GrPathRendering(GrGpu * gpu)120 GrPathRendering(GrGpu* gpu) : fGpu(gpu) { } 121 122 virtual void onStencilPath(const StencilPathArgs&, const GrPath*) = 0; 123 virtual void onDrawPath(GrRenderTarget*, GrSurfaceOrigin, 124 const GrPrimitiveProcessor&, 125 const GrPipeline&, 126 const GrPipeline::FixedDynamicState&, 127 const GrStencilSettings&, 128 const GrPath*) = 0; 129 130 GrGpu* fGpu; 131 private: 132 GrPathRendering& operator=(const GrPathRendering&); 133 }; 134 135 #endif 136