1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "effects/GrXfermodeFragmentProcessor.h"
#include "GrFragmentProcessor.h"
#include "effects/GrConstColorProcessor.h"
#include "gl/GrGLBlend.h"
#include "gl/builders/GrGLProgramBuilder.h"
class GrComposeTwoFragmentProcessor : public GrFragmentProcessor {
public:
GrComposeTwoFragmentProcessor(const GrFragmentProcessor* src, const GrFragmentProcessor* dst,
SkXfermode::Mode mode)
: fMode(mode) {
// Only coefficient xfer modes are supported
SkASSERT(SkXfermode::kLastCoeffMode >= mode);
this->initClassID<GrComposeTwoFragmentProcessor>();
SkDEBUGCODE(int shaderAChildIndex = )this->registerChildProcessor(src);
SkDEBUGCODE(int shaderBChildIndex = )this->registerChildProcessor(dst);
SkASSERT(0 == shaderAChildIndex);
SkASSERT(1 == shaderBChildIndex);
}
const char* name() const override { return "ComposeShader"; }
void onGetGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
b->add32(fMode);
}
SkXfermode::Mode getMode() const { return fMode; }
protected:
bool onIsEqual(const GrFragmentProcessor& other) const override {
const GrComposeTwoFragmentProcessor& cs = other.cast<GrComposeTwoFragmentProcessor>();
return fMode == cs.fMode;
}
void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
inout->setToUnknown(GrInvariantOutput::kWill_ReadInput);
}
private:
GrGLFragmentProcessor* onCreateGLInstance() const override;
SkXfermode::Mode fMode;
GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
typedef GrFragmentProcessor INHERITED;
};
/////////////////////////////////////////////////////////////////////
class GrGLComposeTwoFragmentProcessor : public GrGLFragmentProcessor {
public:
GrGLComposeTwoFragmentProcessor(const GrProcessor& processor) {}
void emitCode(EmitArgs&) override;
private:
typedef GrGLFragmentProcessor INHERITED;
};
/////////////////////////////////////////////////////////////////////
GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrComposeTwoFragmentProcessor);
const GrFragmentProcessor* GrComposeTwoFragmentProcessor::TestCreate(GrProcessorTestData* d) {
// Create two random frag procs.
SkAutoTUnref<const GrFragmentProcessor> fpA(GrProcessorUnitTest::CreateChildFP(d));
SkAutoTUnref<const GrFragmentProcessor> fpB(GrProcessorUnitTest::CreateChildFP(d));
SkXfermode::Mode mode = static_cast<SkXfermode::Mode>(
d->fRandom->nextRangeU(0, SkXfermode::kLastCoeffMode));
return SkNEW_ARGS(GrComposeTwoFragmentProcessor, (fpA, fpB, mode));
}
GrGLFragmentProcessor* GrComposeTwoFragmentProcessor::onCreateGLInstance() const{
return SkNEW_ARGS(GrGLComposeTwoFragmentProcessor, (*this));
}
/////////////////////////////////////////////////////////////////////
void GrGLComposeTwoFragmentProcessor::emitCode(EmitArgs& args) {
GrGLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
const GrComposeTwoFragmentProcessor& cs = args.fFp.cast<GrComposeTwoFragmentProcessor>();
// Store alpha of input color and un-premultiply the input color by its alpha. We will
// re-multiply by this alpha after blending the output colors of the two child procs.
// This is because we don't want the paint's alpha to affect either child proc's output
// before the blend; we want to apply the paint's alpha AFTER the blend. This mirrors the
// software implementation of SkComposeShader.
const char* opaqueInput = nullptr;
const char* inputAlpha = nullptr;
if (args.fInputColor) {
inputAlpha = "inputAlpha";
opaqueInput = "opaqueInput";
fsBuilder->codeAppendf("float inputAlpha = %s.a;", args.fInputColor);
fsBuilder->codeAppendf("vec4 opaqueInput = vec4(%s.rgb / inputAlpha, 1);",
args.fInputColor);
}
// declare outputColor and emit the code for each of the two children
SkString outputColorSrc(args.fOutputColor);
outputColorSrc.append("_src");
fsBuilder->codeAppendf("vec4 %s;\n", outputColorSrc.c_str());
this->emitChild(0, opaqueInput, outputColorSrc.c_str(), args);
SkString outputColorDst(args.fOutputColor);
outputColorDst.append("_dst");
fsBuilder->codeAppendf("vec4 %s;\n", outputColorDst.c_str());
this->emitChild(1, opaqueInput, outputColorDst.c_str(), args);
// emit blend code
SkXfermode::Mode mode = cs.getMode();
fsBuilder->codeAppend("{");
fsBuilder->codeAppendf("// Compose Xfer Mode: %s\n", SkXfermode::ModeName(mode));
GrGLBlend::AppendPorterDuffBlend(fsBuilder, outputColorSrc.c_str(),
outputColorDst.c_str(), args.fOutputColor, mode);
fsBuilder->codeAppend("}");
// re-multiply the output color by the input color's alpha
if (inputAlpha) {
fsBuilder->codeAppendf("%s *= %s;", args.fOutputColor, inputAlpha);
}
}
const GrFragmentProcessor* GrXfermodeFragmentProcessor::CreateFromTwoProcessors(
const GrFragmentProcessor* src, const GrFragmentProcessor* dst, SkXfermode::Mode mode) {
if (SkXfermode::kLastCoeffMode < mode) {
return nullptr;
}
switch (mode) {
case SkXfermode::kClear_Mode:
return GrConstColorProcessor::Create(GrColor_TRANS_BLACK,
GrConstColorProcessor::kIgnore_InputMode);
break;
case SkXfermode::kSrc_Mode:
return SkRef(src);
break;
case SkXfermode::kDst_Mode:
return SkRef(dst);
break;
default:
return new GrComposeTwoFragmentProcessor(src, dst, mode);
}
}
|
