1/*
2 * Copyright 2020 Google LLC
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#include "src/gpu/effects/GrMatrixEffect.h"
9
10#include "src/gpu/GrTexture.h"
11#include "src/gpu/effects/GrTextureEffect.h"
12#include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h"
13#include "src/gpu/glsl/GrGLSLProgramBuilder.h"
14#include "src/sksl/SkSLUtil.h"
15
16std::unique_ptr<GrFragmentProcessor> GrMatrixEffect::Make(
17        const SkMatrix& matrix, std::unique_ptr<GrFragmentProcessor> child) {
18    if (child->classID() == kGrMatrixEffect_ClassID) {
19        auto me = static_cast<GrMatrixEffect*>(child.get());
20        // registerChild's sample usage records whether the matrix used has perspective or not,
21        // so we can't add perspective to 'me' if it doesn't already have it.
22        if (me->fMatrix.hasPerspective() || !matrix.hasPerspective()) {
23            me->fMatrix.preConcat(matrix);
24            return child;
25        }
26    }
27    return std::unique_ptr<GrFragmentProcessor>(new GrMatrixEffect(matrix, std::move(child)));
28}
29
30std::unique_ptr<GrFragmentProcessor::ProgramImpl> GrMatrixEffect::onMakeProgramImpl() const {
31    class Impl : public ProgramImpl {
32    public:
33        void emitCode(EmitArgs& args) override {
34            fMatrixVar = args.fUniformHandler->addUniform(&args.fFp,
35                                                          kFragment_GrShaderFlag,
36                                                          kFloat3x3_GrSLType,
37                                                          SkSL::SampleUsage::MatrixUniformName());
38            args.fFragBuilder->codeAppendf("return %s;\n",
39                                           this->invokeChildWithMatrix(0, args).c_str());
40        }
41
42    private:
43        void onSetData(const GrGLSLProgramDataManager& pdman,
44                       const GrFragmentProcessor& proc) override {
45            const GrMatrixEffect& mtx = proc.cast<GrMatrixEffect>();
46            if (auto te = mtx.childProcessor(0)->asTextureEffect()) {
47                SkMatrix m = te->coordAdjustmentMatrix();
48                m.preConcat(mtx.fMatrix);
49                pdman.setSkMatrix(fMatrixVar, m);
50            } else {
51                pdman.setSkMatrix(fMatrixVar, mtx.fMatrix);
52            }
53        }
54
55        UniformHandle fMatrixVar;
56    };
57
58    return std::make_unique<Impl>();
59}
60
61void GrMatrixEffect::onAddToKey(const GrShaderCaps& caps, GrProcessorKeyBuilder* b) const {}
62
63bool GrMatrixEffect::onIsEqual(const GrFragmentProcessor& other) const {
64    const GrMatrixEffect& that = other.cast<GrMatrixEffect>();
65    if (fMatrix != that.fMatrix) return false;
66    return true;
67}
68
69GrMatrixEffect::GrMatrixEffect(const GrMatrixEffect& src)
70        : INHERITED(src)
71        , fMatrix(src.fMatrix) {}
72
73std::unique_ptr<GrFragmentProcessor> GrMatrixEffect::clone() const {
74    return std::unique_ptr<GrFragmentProcessor>(new GrMatrixEffect(*this));
75}
76