xref: /aosp_15_r20/external/skia/src/gpu/ganesh/tessellate/GrTessellationShader.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2020 Google LLC.
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 #ifndef GrTessellationShader_DEFINED
8 #define GrTessellationShader_DEFINED
9 
10 #include "include/core/SkMatrix.h"
11 #include "include/private/SkColorData.h"
12 #include "src/base/SkArenaAlloc.h"
13 #include "src/gpu/ganesh/GrGeometryProcessor.h"
14 #include "src/gpu/ganesh/GrProgramInfo.h"
15 
16 #include <cstdint>
17 
18 class GrAppliedClip;
19 class GrCaps;
20 class GrDstProxyView;
21 class GrPipeline;
22 class GrProcessorSet;
23 class GrSurfaceProxyView;
24 enum class GrAAType : unsigned int;
25 enum class GrLoadOp;
26 enum class GrPrimitiveType : uint8_t;
27 enum class GrXferBarrierFlags;
28 struct GrUserStencilSettings;
29 
30 // This is a common base class for shaders in the GPU tessellator.
31 class GrTessellationShader : public GrGeometryProcessor {
32 public:
GrTessellationShader(ClassID classID,GrPrimitiveType primitiveType,const SkMatrix & viewMatrix,const SkPMColor4f & color)33     GrTessellationShader(ClassID classID, GrPrimitiveType primitiveType,
34                          const SkMatrix& viewMatrix,
35                          const SkPMColor4f& color)
36             : GrGeometryProcessor(classID)
37             , fPrimitiveType(primitiveType)
38             , fViewMatrix(viewMatrix)
39             , fColor(color) {
40     }
41 
primitiveType()42     GrPrimitiveType primitiveType() const { return fPrimitiveType; }
viewMatrix()43     const SkMatrix& viewMatrix() const { return fViewMatrix; }
color()44     const SkPMColor4f& color() const { return fColor;}
45 
46     struct ProgramArgs {
47         SkArenaAlloc* fArena;
48         const GrSurfaceProxyView& fWriteView;
49         bool fUsesMSAASurface;
50         const GrDstProxyView* fDstProxyView;
51         GrXferBarrierFlags fXferBarrierFlags;
52         GrLoadOp fColorLoadOp;
53         const GrCaps* fCaps;
54     };
55 
56     static const GrPipeline* MakePipeline(const ProgramArgs&, GrAAType,
57                                           GrAppliedClip&&, GrProcessorSet&&);
58 
MakeProgram(const ProgramArgs & args,const GrTessellationShader * shader,const GrPipeline * pipeline,const GrUserStencilSettings * stencil)59     static GrProgramInfo* MakeProgram(const ProgramArgs& args,
60                                       const GrTessellationShader* shader,
61                                       const GrPipeline* pipeline,
62                                       const GrUserStencilSettings* stencil) {
63         return args.fArena->make<GrProgramInfo>(*args.fCaps, args.fWriteView, args.fUsesMSAASurface,
64                                                 pipeline, stencil, shader, shader->fPrimitiveType,
65                                                 args.fXferBarrierFlags, args.fColorLoadOp);
66     }
67 
68     // SkSL functions that calculate Wang's formula for cubics or conics.
69     static const char* WangsFormulaSkSL();
70 
71 private:
72     const GrPrimitiveType fPrimitiveType;
73     const SkMatrix fViewMatrix;
74     const SkPMColor4f fColor;
75 };
76 
77 #endif
78