aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/gpu/effects/GrConstColorProcessor.cpp
blob: c51ab8e92f95439036605a58eff9598bf7e79509 (plain)
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
/*
 * 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/GrConstColorProcessor.h"
#include "GrInvariantOutput.h"
#include "glsl/GrGLSLFragmentProcessor.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"
#include "glsl/GrGLSLProgramDataManager.h"
#include "glsl/GrGLSLUniformHandler.h"

class GLConstColorProcessor : public GrGLSLFragmentProcessor {
public:
    GLConstColorProcessor() : fPrevColor(GrColor_ILLEGAL) {}

    void emitCode(EmitArgs& args) override {
        GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
        const char* colorUni;
        fColorUniform = args.fUniformHandler->addUniform(kFragment_GrShaderFlag,
                                                         kVec4f_GrSLType, kMedium_GrSLPrecision,
                                                         "constantColor",
                                                         &colorUni);
        GrConstColorProcessor::InputMode mode = args.fFp.cast<GrConstColorProcessor>().inputMode();
        if (!args.fInputColor) {
            mode = GrConstColorProcessor::kIgnore_InputMode;
        }
        switch (mode) {
            case GrConstColorProcessor::kIgnore_InputMode:
                fragBuilder->codeAppendf("%s = %s;", args.fOutputColor, colorUni);
                break;
            case GrConstColorProcessor::kModulateRGBA_InputMode:
                fragBuilder->codeAppendf("%s = %s * %s;", args.fOutputColor, args.fInputColor,
                                       colorUni);
                break;
            case GrConstColorProcessor::kModulateA_InputMode:
                fragBuilder->codeAppendf("%s = %s.a * %s;", args.fOutputColor, args.fInputColor,
                                       colorUni);
                break;
        }
    }

protected:
    void onSetData(const GrGLSLProgramDataManager& pdm, const GrProcessor& processor) override {
        GrColor color = processor.cast<GrConstColorProcessor>().color();
        // We use the "illegal" color value as an uninit sentinel. However, ut isn't inherently
        // illegal to use this processor with unpremul colors. So we correctly handle the case
        // when the "illegal" color is used but we will always upload it.
        if (GrColor_ILLEGAL == color || fPrevColor != color) {
            static const float scale = 1.f / 255.f;
            float floatColor[4] = {
                GrColorUnpackR(color) * scale,
                GrColorUnpackG(color) * scale,
                GrColorUnpackB(color) * scale,
                GrColorUnpackA(color) * scale,
            };
            pdm.set4fv(fColorUniform, 1, floatColor);
            fPrevColor = color;
        }
    }

private:
    GrGLSLProgramDataManager::UniformHandle fColorUniform;
    GrColor                                 fPrevColor;

    typedef GrGLSLFragmentProcessor INHERITED;
};

///////////////////////////////////////////////////////////////////////////////

void GrConstColorProcessor::onComputeInvariantOutput(GrInvariantOutput* inout) const {
    if (kIgnore_InputMode == fMode) {
        inout->setToOther(kRGBA_GrColorComponentFlags, fColor,
                          GrInvariantOutput::kWillNot_ReadInput);
    } else {
        GrColor r = GrColorUnpackR(fColor);
        bool colorIsSingleChannel = r == GrColorUnpackG(fColor) && r == GrColorUnpackB(fColor) &&
                                    r == GrColorUnpackA(fColor);
        if (kModulateRGBA_InputMode == fMode) {
            if (colorIsSingleChannel) {
                inout->mulByKnownSingleComponent(r);
            } else {
                inout->mulByKnownFourComponents(fColor);
            }
        } else {
            if (colorIsSingleChannel) {
                inout->mulAlphaByKnownSingleComponent(r);
            } else {
                inout->mulAlphaByKnownFourComponents(fColor);
            }
        }
    }
}

void GrConstColorProcessor::onGetGLSLProcessorKey(const GrGLSLCaps&,
                                                  GrProcessorKeyBuilder* b) const {
    b->add32(fMode);
}

GrGLSLFragmentProcessor* GrConstColorProcessor::onCreateGLSLInstance() const  {
    return new GLConstColorProcessor;
}

bool GrConstColorProcessor::onIsEqual(const GrFragmentProcessor& other) const {
    const GrConstColorProcessor& that = other.cast<GrConstColorProcessor>();
    return fMode == that.fMode && fColor == that.fColor;
}

///////////////////////////////////////////////////////////////////////////////

GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConstColorProcessor);

const GrFragmentProcessor* GrConstColorProcessor::TestCreate(GrProcessorTestData* d) {
    GrColor color SK_INIT_TO_AVOID_WARNING;
    int colorPicker = d->fRandom->nextULessThan(3);
    switch (colorPicker) {
        case 0: {
            uint32_t a = d->fRandom->nextULessThan(0x100);
            uint32_t r = d->fRandom->nextULessThan(a+1);
            uint32_t g = d->fRandom->nextULessThan(a+1);
            uint32_t b = d->fRandom->nextULessThan(a+1);
            color = GrColorPackRGBA(r, g, b, a);
            break;
        }
        case 1:
            color = 0;
            break;
        case 2:
            color = d->fRandom->nextULessThan(0x100);
            color = color | (color << 8) | (color << 16) | (color << 24);
            break;
    }
    InputMode mode = static_cast<InputMode>(d->fRandom->nextULessThan(kInputModeCnt));
    return GrConstColorProcessor::Create(color, mode);
}