Line data Source code
1 :
2 : /*
3 : * Copyright 2011 Google Inc.
4 : *
5 : * Use of this source code is governed by a BSD-style license that can be
6 : * found in the LICENSE file.
7 : */
8 :
9 :
10 : #ifndef GrPaint_DEFINED
11 : #define GrPaint_DEFINED
12 :
13 : #include "GrColor.h"
14 : #include "GrColorSpaceXform.h"
15 : #include "GrFragmentProcessor.h"
16 : #include "SkBlendMode.h"
17 : #include "SkRefCnt.h"
18 : #include "SkRegion.h"
19 : #include "SkTLazy.h"
20 :
21 : class GrTextureProxy;
22 : class GrXPFactory;
23 :
24 : /**
25 : * The paint describes how color and coverage are computed at each pixel by GrContext draw
26 : * functions and the how color is blended with the destination pixel.
27 : *
28 : * The paint allows installation of custom color and coverage stages. New types of stages are
29 : * created by subclassing GrProcessor.
30 : *
31 : * The primitive color computation starts with the color specified by setColor(). This color is the
32 : * input to the first color stage. Each color stage feeds its output to the next color stage.
33 : *
34 : * Fractional pixel coverage follows a similar flow. The GrGeometryProcessor (specified elsewhere)
35 : * provides the initial coverage which is passed to the first coverage fragment processor, which
36 : * feeds its output to next coverage fragment processor.
37 : *
38 : * setXPFactory is used to control blending between the output color and dest. It also implements
39 : * the application of fractional coverage from the coverage pipeline.
40 : */
41 : class GrPaint {
42 : public:
43 0 : GrPaint() = default;
44 0 : explicit GrPaint(const GrPaint&) = default;
45 0 : ~GrPaint() = default;
46 :
47 : /**
48 : * The initial color of the drawn primitive. Defaults to solid white.
49 : */
50 0 : void setColor4f(const GrColor4f& color) { fColor = color; }
51 0 : const GrColor4f& getColor4f() const { return fColor; }
52 :
53 : /**
54 : * Legacy getter, until all code handles 4f directly.
55 : */
56 0 : GrColor getColor() const { return fColor.toGrColor(); }
57 :
58 : /**
59 : * Should shader output conversion from linear to sRGB be disabled.
60 : * Only relevant if the destination is sRGB. Defaults to false.
61 : */
62 0 : void setDisableOutputConversionToSRGB(bool srgb) { fDisableOutputConversionToSRGB = srgb; }
63 0 : bool getDisableOutputConversionToSRGB() const { return fDisableOutputConversionToSRGB; }
64 :
65 : /**
66 : * Should sRGB inputs be allowed to perform sRGB to linear conversion. With this flag
67 : * set to false, sRGB textures will be treated as linear (including filtering).
68 : */
69 0 : void setAllowSRGBInputs(bool allowSRGBInputs) { fAllowSRGBInputs = allowSRGBInputs; }
70 0 : bool getAllowSRGBInputs() const { return fAllowSRGBInputs; }
71 :
72 : /**
73 : * Does one of the fragment processors need a field of distance vectors to the nearest edge?
74 : */
75 0 : bool usesDistanceVectorField() const { return fUsesDistanceVectorField; }
76 :
77 : /**
78 : * Should rendering be gamma-correct, end-to-end. Causes sRGB render targets to behave
79 : * as such (with linear blending), and sRGB inputs to be filtered and decoded correctly.
80 : */
81 0 : void setGammaCorrect(bool gammaCorrect) {
82 0 : setDisableOutputConversionToSRGB(!gammaCorrect);
83 0 : setAllowSRGBInputs(gammaCorrect);
84 0 : }
85 :
86 0 : void setXPFactory(const GrXPFactory* xpFactory) { fXPFactory = xpFactory; }
87 :
88 : void setPorterDuffXPFactory(SkBlendMode mode);
89 :
90 : void setCoverageSetOpXPFactory(SkRegion::Op, bool invertCoverage = false);
91 :
92 : /**
93 : * Appends an additional color processor to the color computation.
94 : */
95 0 : void addColorFragmentProcessor(sk_sp<GrFragmentProcessor> fp) {
96 0 : SkASSERT(fp);
97 0 : fUsesDistanceVectorField |= fp->usesDistanceVectorField();
98 0 : fColorFragmentProcessors.push_back(std::move(fp));
99 0 : }
100 :
101 : /**
102 : * Appends an additional coverage processor to the coverage computation.
103 : */
104 0 : void addCoverageFragmentProcessor(sk_sp<GrFragmentProcessor> fp) {
105 0 : SkASSERT(fp);
106 0 : fUsesDistanceVectorField |= fp->usesDistanceVectorField();
107 0 : fCoverageFragmentProcessors.push_back(std::move(fp));
108 0 : }
109 :
110 : /**
111 : * Helpers for adding color or coverage effects that sample a texture. The matrix is applied
112 : * to the src space position to compute texture coordinates.
113 : */
114 : void addColorTextureProcessor(GrResourceProvider*, sk_sp<GrTextureProxy>,
115 : sk_sp<GrColorSpaceXform>, const SkMatrix&);
116 : void addColorTextureProcessor(GrResourceProvider*, sk_sp<GrTextureProxy>,
117 : sk_sp<GrColorSpaceXform>, const SkMatrix&,
118 : const GrSamplerParams&);
119 :
120 : void addCoverageTextureProcessor(GrResourceProvider*, sk_sp<GrTextureProxy>, const SkMatrix&);
121 : void addCoverageTextureProcessor(GrResourceProvider*, sk_sp<GrTextureProxy>,
122 : const SkMatrix&, const GrSamplerParams&);
123 :
124 0 : int numColorFragmentProcessors() const { return fColorFragmentProcessors.count(); }
125 0 : int numCoverageFragmentProcessors() const { return fCoverageFragmentProcessors.count(); }
126 0 : int numTotalFragmentProcessors() const { return this->numColorFragmentProcessors() +
127 0 : this->numCoverageFragmentProcessors(); }
128 :
129 0 : const GrXPFactory* getXPFactory() const { return fXPFactory; }
130 :
131 : GrFragmentProcessor* getColorFragmentProcessor(int i) const {
132 : return fColorFragmentProcessors[i].get();
133 : }
134 : GrFragmentProcessor* getCoverageFragmentProcessor(int i) const {
135 : return fCoverageFragmentProcessors[i].get();
136 : }
137 :
138 : /**
139 : * Returns true if the paint's output color will be constant after blending. If the result is
140 : * true, constantColor will be updated to contain the constant color. Note that we can conflate
141 : * coverage and color, so the actual values written to pixels with partial coverage may still
142 : * not seem constant, even if this function returns true.
143 : */
144 : bool isConstantBlendedColor(GrColor* constantColor) const;
145 :
146 : private:
147 : template <bool> class MoveOrImpl;
148 :
149 : public:
150 : /**
151 : * A temporary instance of this class can be used to select between moving an existing paint or
152 : * a temporary copy of an existing paint into a call site. MoveOrClone(paint, false) is a rvalue
153 : * reference to paint while MoveOrClone(paint, true) is a rvalue reference to a copy of paint.
154 : */
155 : using MoveOrClone = MoveOrImpl<true>;
156 :
157 : /**
158 : * A temporary instance of this class can be used to select between moving an existing or a
159 : * newly default constructed paint into a call site. MoveOrNew(paint, false) is a rvalue
160 : * reference to paint while MoveOrNew(paint, true) is a rvalue reference to a default paint.
161 : */
162 : using MoveOrNew = MoveOrImpl<false>;
163 :
164 : private:
165 : GrPaint& operator=(const GrPaint&) = delete;
166 :
167 : friend class GrProcessorSet;
168 :
169 : const GrXPFactory* fXPFactory = nullptr;
170 : SkSTArray<4, sk_sp<GrFragmentProcessor>> fColorFragmentProcessors;
171 : SkSTArray<2, sk_sp<GrFragmentProcessor>> fCoverageFragmentProcessors;
172 : bool fDisableOutputConversionToSRGB = false;
173 : bool fAllowSRGBInputs = false;
174 : bool fUsesDistanceVectorField = false;
175 : GrColor4f fColor = GrColor4f::OpaqueWhite();
176 : };
177 :
178 : /** This is the implementation of MoveOrCopy and MoveOrNew. */
179 : template <bool COPY_IF_NEW>
180 0 : class GrPaint::MoveOrImpl {
181 : public:
182 0 : MoveOrImpl(GrPaint& paint, bool newPaint) {
183 0 : if (newPaint) {
184 : if (COPY_IF_NEW) {
185 : fStorage.init(paint);
186 : } else {
187 0 : fStorage.init();
188 : };
189 0 : fPaint = fStorage.get();
190 : } else {
191 0 : fPaint = &paint;
192 : }
193 0 : }
194 :
195 0 : operator GrPaint&&() && { return std::move(*fPaint); }
196 0 : GrPaint& paint() { return *fPaint; }
197 :
198 : private:
199 : SkTLazy<GrPaint> fStorage;
200 : GrPaint* fPaint;
201 : };
202 :
203 : #endif
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