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 "GrPathRange.h" 13 #include "GrPipeline.h" 14 15 class GrGpu; 16 class GrPath; 17 class GrStencilSettings; 18 class GrStyle; 19 struct SkScalerContextEffects; 20 class SkDescriptor; 21 class SkTypeface; 22 23 /** 24 * Abstract class wrapping HW path rendering API. 25 * 26 * The subclasses of this class use the possible HW API to render paths (as opposed to path 27 * rendering implemented in Skia on top of a "3d" HW API). 28 * The subclasses hold the global state needed to render paths, including shadow of the global HW 29 * API state. Similar to GrGpu. 30 * 31 * It is expected that the lifetimes of GrGpuXX and GrXXPathRendering are the same. The call context 32 * interface (eg. * the concrete instance of GrGpu subclass) should be provided to the instance 33 * during construction. 34 */ 35 class GrPathRendering { 36 public: 37 virtual ~GrPathRendering() { } 38 39 typedef GrPathRange::PathIndexType PathIndexType; 40 41 enum PathTransformType { 42 kNone_PathTransformType, //!< [] 43 kTranslateX_PathTransformType, //!< [kMTransX] 44 kTranslateY_PathTransformType, //!< [kMTransY] 45 kTranslate_PathTransformType, //!< [kMTransX, kMTransY] 46 kAffine_PathTransformType, //!< [kMScaleX, kMSkewX, kMTransX, kMSkewY, kMScaleY, kMTransY] 47 48 kLast_PathTransformType = kAffine_PathTransformType 49 }; 50 51 static inline int PathTransformSize(PathTransformType type) { 52 switch (type) { 53 case kNone_PathTransformType: 54 return 0; 55 case kTranslateX_PathTransformType: 56 case kTranslateY_PathTransformType: 57 return 1; 58 case kTranslate_PathTransformType: 59 return 2; 60 case kAffine_PathTransformType: 61 return 6; 62 63 default: 64 SK_ABORT("Unknown path transform type"); 65 return 0; 66 } 67 } 68 69 // No native support for inverse at this time 70 enum FillType { 71 /** Specifies that "inside" is computed by a non-zero sum of signed 72 edge crossings 73 */ 74 kWinding_FillType, 75 /** Specifies that "inside" is computed by an odd number of edge 76 crossings 77 */ 78 kEvenOdd_FillType, 79 }; 80 81 static const GrUserStencilSettings& GetStencilPassSettings(FillType); 82 83 /** 84 * Creates a new gpu path, based on the specified path and stroke and returns it. 85 * 86 * @param SkPath the geometry. 87 * @param GrStyle the style applied to the path. Styles with non-dash path effects are not 88 * allowed. 89 * @return a new GPU path object. 90 */ 91 virtual sk_sp<GrPath> createPath(const SkPath&, const GrStyle&) = 0; 92 93 /** 94 * Creates a range of gpu paths with a common style. 95 * 96 * @param PathGenerator class that generates SkPath objects for each path in the range. 97 * @param GrStyle the common style applied to each path in the range. Styles with non-dash 98 * path effects are not allowed. 99 * @return a new path range. 100 */ 101 virtual sk_sp<GrPathRange> createPathRange(GrPathRange::PathGenerator*, const GrStyle&) = 0; 102 103 /** 104 * Creates a range of glyph paths, indexed by glyph id. The glyphs will have an 105 * inverted y-direction in order to match the raw font path data. 106 * 107 * @param SkTypeface Typeface that defines the glyphs. 108 * If null, the default typeface will be used. 109 * 110 * @param SkDescriptor Additional font configuration that specifies the font's size, 111 * stroke, and other flags. This will generally come from an 112 * SkGlyphCache. 113 * 114 * It is recommended to leave this value null when possible, in 115 * which case the glyphs will be loaded directly from the font's 116 * raw path data and sized at SkPaint::kCanonicalTextSizeForPaths. 117 * This will result in less memory usage and more efficient paths. 118 * 119 * If non-null, the glyph paths will match the font descriptor, 120 * including with the stroke information baked directly into 121 * the outlines. 122 * 123 * @param GrStyle Common style that the GPU will apply to every path. Note that 124 * if the glyph outlines contain baked-in styles from the font 125 * descriptor, the GPU style will be applied on top of those 126 * outlines. 127 * 128 * @return a new path range populated with glyphs. 129 */ 130 sk_sp<GrPathRange> createGlyphs(const SkTypeface*, const SkScalerContextEffects&, 131 const SkDescriptor*, const GrStyle&); 132 133 /** None of these params are optional, pointers used just to avoid making copies. */ 134 struct StencilPathArgs { 135 StencilPathArgs(bool useHWAA, 136 GrRenderTargetProxy* proxy, 137 const SkMatrix* viewMatrix, 138 const GrScissorState* scissor, 139 const GrStencilSettings* stencil) 140 : fUseHWAA(useHWAA) 141 , fProxy(proxy) 142 , fViewMatrix(viewMatrix) 143 , fScissor(scissor) 144 , fStencil(stencil) { 145 } 146 bool fUseHWAA; 147 GrRenderTargetProxy* fProxy; 148 const SkMatrix* fViewMatrix; 149 const GrScissorState* fScissor; 150 const GrStencilSettings* fStencil; 151 }; 152 153 void stencilPath(const StencilPathArgs& args, const GrPath* path); 154 155 void drawPath(const GrPipeline& pipeline, 156 const GrPrimitiveProcessor& primProc, 157 const GrStencilSettings& stencilPassSettings, // Cover pass settings in pipeline. 158 const GrPath* path); 159 160 void drawPaths(const GrPipeline& pipeline, 161 const GrPrimitiveProcessor& primProc, 162 const GrStencilSettings& stencilPassSettings, // Cover pass settings in pipeline. 163 const GrPathRange* pathRange, 164 const void* indices, 165 PathIndexType indexType, 166 const float transformValues[], 167 PathTransformType transformType, 168 int count); 169 170 protected: 171 GrPathRendering(GrGpu* gpu) : fGpu(gpu) { } 172 173 virtual void onStencilPath(const StencilPathArgs&, const GrPath*) = 0; 174 virtual void onDrawPath(const GrPipeline&, 175 const GrPrimitiveProcessor&, 176 const GrStencilSettings&, 177 const GrPath*) = 0; 178 virtual void onDrawPaths(const GrPipeline&, 179 const GrPrimitiveProcessor&, 180 const GrStencilSettings&, 181 const GrPathRange*, 182 const void* indices, 183 PathIndexType, 184 const float transformValues[], 185 PathTransformType, 186 int count) = 0; 187 188 GrGpu* fGpu; 189 private: 190 GrPathRendering& operator=(const GrPathRendering&); 191 }; 192 193 #endif 194
