xref: /aosp_15_r20/external/skia/src/shaders/SkLocalMatrixShader.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
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 SkLocalMatrixShader_DEFINED
9 #define SkLocalMatrixShader_DEFINED
10 
11 #include "include/core/SkColor.h"
12 #include "include/core/SkFlattenable.h"
13 #include "include/core/SkMatrix.h"
14 #include "include/core/SkRefCnt.h"
15 #include "include/core/SkShader.h"
16 #include "include/core/SkTypes.h"
17 #include "src/shaders/SkShaderBase.h"
18 
19 #include <type_traits>
20 #include <utility>
21 
22 class SkArenaAlloc;
23 class SkImage;
24 class SkReadBuffer;
25 class SkWriteBuffer;
26 enum class SkTileMode;
27 struct SkStageRec;
28 
29 class SkLocalMatrixShader final : public SkShaderBase {
30 public:
31     template <typename T, typename... Args>
32     static std::enable_if_t<std::is_base_of_v<SkShader, T>, sk_sp<SkShader>>
MakeWrapped(const SkMatrix * localMatrix,Args &&...args)33     MakeWrapped(const SkMatrix* localMatrix, Args&&... args) {
34         auto t = sk_make_sp<T>(std::forward<Args>(args)...);
35         if (localMatrix) {
36             return t->makeWithLocalMatrix(*localMatrix);
37         }
38         return t;
39     }
40 
SkLocalMatrixShader(sk_sp<SkShader> wrapped,const SkMatrix & localMatrix)41     SkLocalMatrixShader(sk_sp<SkShader> wrapped, const SkMatrix& localMatrix)
42             : fLocalMatrix(localMatrix), fWrappedShader(std::move(wrapped)) {}
43 
isOpaque()44     bool isOpaque() const override { return as_SB(fWrappedShader)->isOpaque(); }
45 
46     bool isConstant() const override;
47     GradientType asGradient(GradientInfo* info, SkMatrix* localMatrix) const override;
type()48     ShaderType type() const override { return ShaderType::kLocalMatrix; }
49 
makeAsALocalMatrixShader(SkMatrix * localMatrix)50     sk_sp<SkShader> makeAsALocalMatrixShader(SkMatrix* localMatrix) const override {
51         if (localMatrix) {
52             *localMatrix = fLocalMatrix;
53         }
54         return fWrappedShader;
55     }
56 
localMatrix()57     const SkMatrix& localMatrix() const { return fLocalMatrix; }
wrappedShader()58     sk_sp<SkShader> wrappedShader() const { return fWrappedShader; }
59 
60 protected:
61     void flatten(SkWriteBuffer&) const override;
62 
63 #ifdef SK_ENABLE_LEGACY_SHADERCONTEXT
64     Context* onMakeContext(const ContextRec&, SkArenaAlloc*) const override;
65 #endif
66 
67     SkImage* onIsAImage(SkMatrix* matrix, SkTileMode* mode) const override;
68 
69     bool onAsLuminanceColor(SkColor4f*) const override;
70 
71     bool appendStages(const SkStageRec&, const SkShaders::MatrixRec&) const override;
72 
73 private:
74     SK_FLATTENABLE_HOOKS(SkLocalMatrixShader)
75 
76     SkMatrix fLocalMatrix;
77     sk_sp<SkShader> fWrappedShader;
78 };
79 
80 /**
81  *  Replaces the CTM when used. Created to support clipShaders, which have to be evaluated
82  *  using the CTM that was present at the time they were specified (which may be different
83  *  from the CTM at the time something is drawn through the clip.
84  */
85 class SkCTMShader final : public SkShaderBase {
86 public:
87     SkCTMShader(sk_sp<SkShader> proxy, const SkMatrix& ctm);
88 
isOpaque()89     bool isOpaque() const override { return fProxyShader->isOpaque(); }
90 
91     bool isConstant() const override;
92     GradientType asGradient(GradientInfo* info, SkMatrix* localMatrix) const override;
93 
type()94     ShaderType type() const override { return ShaderType::kCTM; }
95 
ctm()96     const SkMatrix& ctm() const { return fCTM; }
proxyShader()97     sk_sp<SkShader> proxyShader() const { return fProxyShader; }
98 
99 protected:
flatten(SkWriteBuffer &)100     void flatten(SkWriteBuffer&) const override { SkASSERT(false); }
101 
102     bool appendStages(const SkStageRec& rec, const SkShaders::MatrixRec&) const override;
103 
104 private:
105     SK_FLATTENABLE_HOOKS(SkCTMShader)
106 
107     sk_sp<SkShader> fProxyShader;
108     SkMatrix fCTM;
109 };
110 
111 #endif
112