1 | /* |
2 | * Copyright 2013 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 GrGLSLGeometryProcessor_DEFINED |
9 | #define GrGLSLGeometryProcessor_DEFINED |
10 | |
11 | #include "src/gpu/glsl/GrGLSLPrimitiveProcessor.h" |
12 | |
13 | class GrGLSLGPBuilder; |
14 | |
15 | /** |
16 | * If a GL effect needs a GrGLFullShaderBuilder* object to emit vertex code, then it must inherit |
17 | * from this class. Since paths don't have vertices, this class is only meant to be used internally |
18 | * by skia, for special cases. |
19 | */ |
20 | class GrGLSLGeometryProcessor : public GrGLSLPrimitiveProcessor { |
21 | public: |
22 | /* Any general emit code goes in the base class emitCode. Subclasses override onEmitCode */ |
23 | void emitCode(EmitArgs&) final; |
24 | |
25 | protected: |
26 | // A helper which subclasses can use to upload coord transform matrices in setData(). |
27 | void setTransformDataHelper(const SkMatrix& localMatrix, |
28 | const GrGLSLProgramDataManager& pdman, |
29 | const CoordTransformRange&); |
30 | |
31 | // Emit transformed local coords from the vertex shader as a uniform matrix and varying per |
32 | // coord-transform. localCoordsVar must be a 2- or 3-component vector. If it is 3 then it is |
33 | // assumed to be a 2D homogeneous coordinate. |
34 | void emitTransforms(GrGLSLVertexBuilder*, |
35 | GrGLSLVaryingHandler*, |
36 | GrGLSLUniformHandler*, |
37 | const GrShaderVar& localCoordsVar, |
38 | const SkMatrix& localMatrix, |
39 | FPCoordTransformHandler*); |
40 | |
41 | // Version of above that assumes identity for the local matrix. |
42 | void emitTransforms(GrGLSLVertexBuilder* vb, |
43 | GrGLSLVaryingHandler* varyingHandler, |
44 | GrGLSLUniformHandler* uniformHandler, |
45 | const GrShaderVar& localCoordsVar, |
46 | FPCoordTransformHandler* handler) { |
47 | this->emitTransforms(vb, varyingHandler, uniformHandler, localCoordsVar, SkMatrix::I(), |
48 | handler); |
49 | } |
50 | |
51 | struct GrGPArgs { |
52 | // Used to specify the output variable used by the GP to store its device position. It can |
53 | // either be a float2 or a float3 (in order to handle perspective). The subclass sets this |
54 | // in its onEmitCode(). |
55 | GrShaderVar fPositionVar; |
56 | }; |
57 | |
58 | // Helpers for adding code to write the transformed vertex position. The first simple version |
59 | // just writes a variable named by 'posName' into the position output variable with the |
60 | // assumption that the position is 2D. The second version transforms the input position by a |
61 | // view matrix and the output variable is 2D or 3D depending on whether the view matrix is |
62 | // perspective. Both versions declare the output position variable and will set |
63 | // GrGPArgs::fPositionVar. |
64 | void writeOutputPosition(GrGLSLVertexBuilder*, GrGPArgs*, const char* posName); |
65 | void writeOutputPosition(GrGLSLVertexBuilder*, |
66 | GrGLSLUniformHandler* uniformHandler, |
67 | GrGPArgs*, |
68 | const char* posName, |
69 | const SkMatrix& mat, |
70 | UniformHandle* viewMatrixUniform); |
71 | |
72 | static uint32_t ComputePosKey(const SkMatrix& mat) { |
73 | if (mat.isIdentity()) { |
74 | return 0x0; |
75 | } else if (!mat.hasPerspective()) { |
76 | return 0x01; |
77 | } else { |
78 | return 0x02; |
79 | } |
80 | } |
81 | |
82 | private: |
83 | virtual void onEmitCode(EmitArgs&, GrGPArgs*) = 0; |
84 | |
85 | struct TransformUniform { |
86 | UniformHandle fHandle; |
87 | GrSLType fType = kVoid_GrSLType; |
88 | SkMatrix fCurrentValue = SkMatrix::InvalidMatrix(); |
89 | }; |
90 | |
91 | SkTArray<TransformUniform, true> fInstalledTransforms; |
92 | |
93 | typedef GrGLSLPrimitiveProcessor INHERITED; |
94 | }; |
95 | |
96 | #endif |
97 | |