/*
 * Copyright 2012 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrSimpleTextureEffect.h"
#include "GrInvariantOutput.h"
#include "GrTexture.h"
#include "glsl/GrGLSLColorSpaceXformHelper.h"
#include "glsl/GrGLSLFragmentProcessor.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"

class GrGLSimpleTextureEffect : public GrGLSLFragmentProcessor {
public:
    void emitCode(EmitArgs& args) override {
        const GrSimpleTextureEffect& textureEffect = args.fFp.cast<GrSimpleTextureEffect>();
        GrGLSLColorSpaceXformHelper colorSpaceHelper(args.fUniformHandler,
                                                     textureEffect.colorSpaceXform(),
                                                     &fColorSpaceXformUni);

        GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
        fragBuilder->codeAppendf("%s = ", args.fOutputColor);
        fragBuilder->appendTextureLookupAndModulate(args.fInputColor,
                                                    args.fTexSamplers[0],
                                                    args.fTransformedCoords[0].c_str(),
                                                    args.fTransformedCoords[0].getType(),
                                                    &colorSpaceHelper);
        fragBuilder->codeAppend(";");
    }

    static inline void GenKey(const GrProcessor& effect, const GrShaderCaps&,
                              GrProcessorKeyBuilder* b) {
        const GrSimpleTextureEffect& textureEffect = effect.cast<GrSimpleTextureEffect>();
        b->add32(GrColorSpaceXform::XformKey(textureEffect.colorSpaceXform()));
    }

protected:
    void onSetData(const GrGLSLProgramDataManager& pdman, const GrProcessor& processor) override {
        const GrSimpleTextureEffect& textureEffect = processor.cast<GrSimpleTextureEffect>();
        if (SkToBool(textureEffect.colorSpaceXform())) {
            pdman.setSkMatrix44(fColorSpaceXformUni, textureEffect.colorSpaceXform()->srcToDst());
        }
    }

private:
    typedef GrGLSLFragmentProcessor INHERITED;

    UniformHandle fColorSpaceXformUni;
};

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

void GrSimpleTextureEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
    this->updateInvariantOutputForModulation(inout);
}

void GrSimpleTextureEffect::onGetGLSLProcessorKey(const GrShaderCaps& caps,
                                                  GrProcessorKeyBuilder* b) const {
    GrGLSimpleTextureEffect::GenKey(*this, caps, b);
}

GrGLSLFragmentProcessor* GrSimpleTextureEffect::onCreateGLSLInstance() const  {
    return new GrGLSimpleTextureEffect;
}

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

GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrSimpleTextureEffect);

sk_sp<GrFragmentProcessor> GrSimpleTextureEffect::TestCreate(GrProcessorTestData* d) {
    int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
                                          GrProcessorUnitTest::kAlphaTextureIdx;
    static const SkShader::TileMode kTileModes[] = {
        SkShader::kClamp_TileMode,
        SkShader::kRepeat_TileMode,
        SkShader::kMirror_TileMode,
    };
    SkShader::TileMode tileModes[] = {
        kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
        kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
    };
    GrSamplerParams params(tileModes, d->fRandom->nextBool() ? GrSamplerParams::kBilerp_FilterMode :
                                                               GrSamplerParams::kNone_FilterMode);

    const SkMatrix& matrix = GrTest::TestMatrix(d->fRandom);
    auto colorSpaceXform = GrTest::TestColorXform(d->fRandom);
    return GrSimpleTextureEffect::Make(d->fTextures[texIdx], colorSpaceXform, matrix);
}