1 /*
2 * Copyright 2017 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 GrCCPathProcessor_DEFINED
9 #define GrCCPathProcessor_DEFINED
10
11 #include <array>
12 #include "include/core/SkPath.h"
13 #include "src/gpu/GrCaps.h"
14 #include "src/gpu/GrGeometryProcessor.h"
15 #include "src/gpu/GrPipeline.h"
16 #include "src/gpu/ccpr/GrOctoBounds.h"
17
18 class GrCCPathCacheEntry;
19 class GrCCPerFlushResources;
20 class GrOnFlushResourceProvider;
21 class GrOpFlushState;
22
23 /**
24 * This class draws AA paths using the coverage count masks produced by GrCCCoverageProcessor.
25 *
26 * Paths are drawn as bloated octagons, and coverage is derived from the coverage count mask and
27 * fill rule.
28 *
29 * To draw paths, the caller must set up an instance buffer as detailed below, then call drawPaths()
30 * providing its own instance buffer alongside the buffers found by calling FindIndexBuffer/
31 * FindVertexBuffer.
32 */
33 class GrCCPathProcessor : public GrGeometryProcessor {
34 public:
35 struct Instance {
36 SkRect fDevBounds; // "right < left" indicates even-odd fill type.
37 SkRect fDevBounds45; // Bounding box in "| 1 -1 | * devCoords" space. See GrOctoBounds.
38 // | 1 1 |
39 SkIVector fDevToAtlasOffset; // Translation from device space to location in atlas.
40 uint64_t fColor; // Color always stored as 4 x fp16
41
42 void set(const GrOctoBounds&, const SkIVector& devToAtlasOffset, uint64_t, GrFillRule);
43 void set(const GrCCPathCacheEntry&, const SkIVector& shift, uint64_t, GrFillRule);
44 };
45
46 static_assert(4 * 12 == sizeof(Instance));
47
48 static sk_sp<const GrGpuBuffer> FindVertexBuffer(GrOnFlushResourceProvider*);
49 static sk_sp<const GrGpuBuffer> FindIndexBuffer(GrOnFlushResourceProvider*);
50
51 enum class CoverageMode : bool {
52 kCoverageCount,
53 kLiteral
54 };
55
GetColorTypeFromCoverageMode(CoverageMode mode)56 static GrColorType GetColorTypeFromCoverageMode(CoverageMode mode) {
57 return mode == CoverageMode::kCoverageCount ? GrColorType::kAlpha_F16
58 : GrColorType::kAlpha_8;
59 }
60
61 GrCCPathProcessor(CoverageMode, const GrTexture* atlasTexture, const GrSwizzle&,
62 GrSurfaceOrigin atlasOrigin,
63 const SkMatrix& viewMatrixIfUsingLocalCoords = SkMatrix::I());
64
name()65 const char* name() const override { return "GrCCPathProcessor"; }
getGLSLProcessorKey(const GrShaderCaps &,GrProcessorKeyBuilder * b)66 void getGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder* b) const override {
67 b->add32((uint32_t)fCoverageMode);
68 }
69 GrGLSLPrimitiveProcessor* createGLSLInstance(const GrShaderCaps&) const override;
70
71 void drawPaths(GrOpFlushState*, const GrPipeline&, const GrPipeline::FixedDynamicState*,
72 const GrCCPerFlushResources&, int baseInstance, int endInstance,
73 const SkRect& bounds) const;
74
75 private:
onTextureSampler(int)76 const TextureSampler& onTextureSampler(int) const override { return fAtlasAccess; }
77
78 const CoverageMode fCoverageMode;
79 const TextureSampler fAtlasAccess;
80 SkISize fAtlasDimensions;
81 GrSurfaceOrigin fAtlasOrigin;
82
83 SkMatrix fLocalMatrix;
84 static constexpr Attribute kInstanceAttribs[] = {
85 {"devbounds", kFloat4_GrVertexAttribType, kFloat4_GrSLType},
86 {"devbounds45", kFloat4_GrVertexAttribType, kFloat4_GrSLType},
87 {"dev_to_atlas_offset", kInt2_GrVertexAttribType, kInt2_GrSLType},
88 {"color", kHalf4_GrVertexAttribType, kHalf4_GrSLType}
89 };
90 static constexpr int kColorAttribIdx = 3;
91 static constexpr Attribute kCornersAttrib =
92 {"corners", kFloat4_GrVertexAttribType, kFloat4_GrSLType};
93
94 class Impl;
95
96 typedef GrGeometryProcessor INHERITED;
97 };
98
set(const GrOctoBounds & octoBounds,const SkIVector & devToAtlasOffset,uint64_t color,GrFillRule fillRule)99 inline void GrCCPathProcessor::Instance::set(
100 const GrOctoBounds& octoBounds, const SkIVector& devToAtlasOffset, uint64_t color,
101 GrFillRule fillRule) {
102 if (GrFillRule::kNonzero == fillRule) {
103 // We cover "nonzero" paths with clockwise triangles, which is the default result from
104 // normal octo bounds.
105 fDevBounds = octoBounds.bounds();
106 fDevBounds45 = octoBounds.bounds45();
107 } else {
108 // We cover "even/odd" paths with counterclockwise triangles. Here we reorder the bounding
109 // box vertices so the output is flipped horizontally.
110 fDevBounds.setLTRB(
111 octoBounds.right(), octoBounds.top(), octoBounds.left(), octoBounds.bottom());
112 fDevBounds45.setLTRB(
113 octoBounds.bottom45(), octoBounds.right45(), octoBounds.top45(),
114 octoBounds.left45());
115 }
116 fDevToAtlasOffset = devToAtlasOffset;
117 fColor = color;
118 }
119
120 #endif
121