/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "include/core/SkRefCnt.h"
#include "include/core/SkString.h"
#include "include/core/SkUnPreMultiply.h"
#include "include/effects/SkRuntimeEffect.h"
#include "include/private/base/SkTDArray.h"
#include "modules/skcms/skcms.h"
#include "src/base/SkArenaAlloc.h"
#include "src/base/SkNoDestructor.h"
#include "src/core/SkColorFilterBase.h"
#include "src/core/SkColorFilterPriv.h"
#include "src/core/SkColorSpacePriv.h"
#include "src/core/SkColorSpaceXformSteps.h"
#include "src/core/SkMatrixProvider.h"
#include "src/core/SkRasterPipeline.h"
#include "src/core/SkReadBuffer.h"
#include "src/core/SkRuntimeEffectPriv.h"
#include "src/core/SkVM.h"
#include "src/core/SkWriteBuffer.h"

#if defined(SK_GANESH)
#include "src/gpu/ganesh/GrColorInfo.h"
#include "src/gpu/ganesh/GrColorSpaceXform.h"
#include "src/gpu/ganesh/GrFragmentProcessor.h"
#endif

#if defined(SK_GRAPHITE)
#include "src/gpu/graphite/KeyContext.h"
#include "src/gpu/graphite/KeyHelpers.h"
#include "src/gpu/graphite/PaintParamsKey.h"
#endif

bool SkColorFilter::asAColorMode(SkColor* color, SkBlendMode* mode) const {
    return as_CFB(this)->onAsAColorMode(color, mode);
}

bool SkColorFilter::asAColorMatrix(float matrix[20]) const {
    return as_CFB(this)->onAsAColorMatrix(matrix);
}

bool SkColorFilter::isAlphaUnchanged() const {
    return as_CFB(this)->onIsAlphaUnchanged();
}

sk_sp<SkColorFilter> SkColorFilter::Deserialize(const void* data, size_t size,
                                                const SkDeserialProcs* procs) {
    return sk_sp<SkColorFilter>(static_cast<SkColorFilter*>(
                                SkFlattenable::Deserialize(
                                kSkColorFilter_Type, data, size, procs).release()));
}

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

bool SkColorFilterBase::onAsAColorMode(SkColor*, SkBlendMode*) const {
    return false;
}

bool SkColorFilterBase::onAsAColorMatrix(float matrix[20]) const {
    return false;
}

#if defined(SK_GANESH)
GrFPResult SkColorFilterBase::asFragmentProcessor(std::unique_ptr<GrFragmentProcessor> inputFP,
                                                  GrRecordingContext* context,
                                                  const GrColorInfo& dstColorInfo,
                                                  const SkSurfaceProps& props) const {
    // This color filter doesn't implement `asFragmentProcessor`.
    return GrFPFailure(std::move(inputFP));
}
#endif
#if defined(SK_ENABLE_SKVM)
skvm::Color SkColorFilterBase::program(skvm::Builder* p, skvm::Color c,
                                       const SkColorInfo& dst,
                                       skvm::Uniforms* uniforms, SkArenaAlloc* alloc) const {
    skvm::F32 original = c.a;
    if ((c = this->onProgram(p,c, dst, uniforms,alloc))) {
        if (this->isAlphaUnchanged()) {
            c.a = original;
        }
        return c;
    }
    //SkDebugf("cannot program %s\n", this->getTypeName());
    return {};
}
#endif

SkColor SkColorFilter::filterColor(SkColor c) const {
    // This is mostly meaningless. We should phase-out this call entirely.
    SkColorSpace* cs = nullptr;
    return this->filterColor4f(SkColor4f::FromColor(c), cs, cs).toSkColor();
}

SkColor4f SkColorFilter::filterColor4f(const SkColor4f& origSrcColor, SkColorSpace* srcCS,
                                       SkColorSpace* dstCS) const {
    SkPMColor4f color = { origSrcColor.fR, origSrcColor.fG, origSrcColor.fB, origSrcColor.fA };
    SkColorSpaceXformSteps(srcCS, kUnpremul_SkAlphaType,
                           dstCS, kPremul_SkAlphaType).apply(color.vec());

    return as_CFB(this)->onFilterColor4f(color, dstCS).unpremul();
}

SkPMColor4f SkColorFilterBase::onFilterColor4f(const SkPMColor4f& color,
                                               SkColorSpace* dstCS) const {
    constexpr size_t kEnoughForCommonFilters = 2048;  // big enough for a tiny SkSL program
    SkSTArenaAlloc<kEnoughForCommonFilters> alloc;
    SkRasterPipeline    pipeline(&alloc);
    pipeline.append_constant_color(&alloc, color.vec());
    SkMatrixProvider matrixProvider(SkMatrix::I());
    SkSurfaceProps props{}; // default OK; colorFilters don't render text
    SkStageRec rec = {&pipeline, &alloc, kRGBA_F32_SkColorType, dstCS, color.unpremul(), props};

    if (as_CFB(this)->appendStages(rec, color.fA == 1)) {
        SkPMColor4f dst;
        SkRasterPipeline_MemoryCtx dstPtr = { &dst, 0 };
        pipeline.append(SkRasterPipelineOp::store_f32, &dstPtr);
        pipeline.run(0,0, 1,1);
        return dst;
    }

#if defined(SK_ENABLE_SKVM)
    // This filter doesn't support SkRasterPipeline... try skvm.
    skvm::Builder b;
    skvm::Uniforms uni(b.uniform(), 4);
    SkColor4f uniColor = {color.fR, color.fG, color.fB, color.fA};
    SkColorInfo dstInfo = {kRGBA_F32_SkColorType, kPremul_SkAlphaType, sk_ref_sp(dstCS)};
    if (skvm::Color filtered =
            as_CFB(this)->program(&b, b.uniformColor(uniColor, &uni), dstInfo, &uni, &alloc)) {

        b.store({skvm::PixelFormat::FLOAT, 32,32,32,32, 0,32,64,96},
                b.varying<SkColor4f>(), filtered);

        const bool allow_jit = false;  // We're only filtering one color, no point JITing.
        b.done("filterColor4f", allow_jit).eval(1, uni.buf.data(), &color);
        return color;
    }
#endif

    SkDEBUGFAIL("onFilterColor4f unimplemented for this filter");
    return SkPMColor4f{0,0,0,0};
}

#if defined(SK_GRAPHITE)
void SkColorFilterBase::addToKey(const skgpu::graphite::KeyContext& keyContext,
                                 skgpu::graphite::PaintParamsKeyBuilder* builder,
                                 skgpu::graphite::PipelineDataGatherer* gatherer) const {
    using namespace skgpu::graphite;

    // Return the input color as-is.
    PriorOutputBlock::BeginBlock(keyContext, builder, gatherer);
    builder->endBlock();
}
#endif

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

class SkComposeColorFilter final : public SkColorFilterBase {
public:
    bool onIsAlphaUnchanged() const override {
        // Can only claim alphaunchanged support if both our proxys do.
        return fOuter->isAlphaUnchanged() && fInner->isAlphaUnchanged();
    }

    bool appendStages(const SkStageRec& rec, bool shaderIsOpaque) const override {
        bool innerIsOpaque = shaderIsOpaque;
        if (!fInner->isAlphaUnchanged()) {
            innerIsOpaque = false;
        }
        return fInner->appendStages(rec, shaderIsOpaque) &&
               fOuter->appendStages(rec, innerIsOpaque);
    }

#if defined(SK_ENABLE_SKVM)
    skvm::Color onProgram(skvm::Builder* p, skvm::Color c,
                          const SkColorInfo& dst,
                          skvm::Uniforms* uniforms, SkArenaAlloc* alloc) const override {
               c = fInner->program(p, c, dst, uniforms, alloc);
        return c ? fOuter->program(p, c, dst, uniforms, alloc) : skvm::Color{};
    }
#endif
#if defined(SK_GANESH)
    GrFPResult asFragmentProcessor(std::unique_ptr<GrFragmentProcessor> inputFP,
                                   GrRecordingContext* context,
                                   const GrColorInfo& dstColorInfo,
                                   const SkSurfaceProps& props) const override {
        // Unfortunately, we need to clone the input before we know we need it. This lets us return
        // the original FP if either internal color filter fails.
        auto inputClone = inputFP ? inputFP->clone() : nullptr;

        auto [innerSuccess, innerFP] =
                fInner->asFragmentProcessor(std::move(inputFP), context, dstColorInfo, props);
        if (!innerSuccess) {
            return GrFPFailure(std::move(inputClone));
        }

        auto [outerSuccess, outerFP] =
                fOuter->asFragmentProcessor(std::move(innerFP), context, dstColorInfo, props);
        if (!outerSuccess) {
            return GrFPFailure(std::move(inputClone));
        }

        return GrFPSuccess(std::move(outerFP));
    }
#endif

#if defined(SK_GRAPHITE)
    void addToKey(const skgpu::graphite::KeyContext& keyContext,
                  skgpu::graphite::PaintParamsKeyBuilder* builder,
                  skgpu::graphite::PipelineDataGatherer* gatherer) const override {
        using namespace skgpu::graphite;

        ComposeColorFilterBlock::BeginBlock(keyContext, builder, gatherer);

        as_CFB(fInner)->addToKey(keyContext, builder, gatherer);
        as_CFB(fOuter)->addToKey(keyContext, builder, gatherer);

        builder->endBlock();
    }
#endif // SK_GRAPHITE

protected:
    void flatten(SkWriteBuffer& buffer) const override {
        buffer.writeFlattenable(fOuter.get());
        buffer.writeFlattenable(fInner.get());
    }

private:
    friend void ::SkRegisterComposeColorFilterFlattenable();
    SK_FLATTENABLE_HOOKS(SkComposeColorFilter)

    SkComposeColorFilter(sk_sp<SkColorFilter> outer, sk_sp<SkColorFilter> inner)
        : fOuter(as_CFB_sp(std::move(outer)))
        , fInner(as_CFB_sp(std::move(inner)))
    {}

    sk_sp<SkColorFilterBase> fOuter;
    sk_sp<SkColorFilterBase> fInner;

    friend class SkColorFilter;

    using INHERITED = SkColorFilter;
};

sk_sp<SkFlattenable> SkComposeColorFilter::CreateProc(SkReadBuffer& buffer) {
    sk_sp<SkColorFilter> outer(buffer.readColorFilter());
    sk_sp<SkColorFilter> inner(buffer.readColorFilter());
    return outer ? outer->makeComposed(std::move(inner)) : inner;
}

sk_sp<SkColorFilter> SkColorFilter::makeComposed(sk_sp<SkColorFilter> inner) const {
    if (!inner) {
        return sk_ref_sp(this);
    }

    return sk_sp<SkColorFilter>(new SkComposeColorFilter(sk_ref_sp(this), std::move(inner)));
}

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

class ColorSpaceXformColorFilter final : public SkColorFilterBase {
public:
    ColorSpaceXformColorFilter(sk_sp<SkColorSpace> src, sk_sp<SkColorSpace> dst)
            : fSrc(std::move(src))
            , fDst(std::move(dst))
            , fSteps(
                      // We handle premul/unpremul separately, so here just always upm->upm.
                      fSrc.get(),
                      kUnpremul_SkAlphaType,
                      fDst.get(),
                      kUnpremul_SkAlphaType)

    {}

#if defined(SK_GANESH)
    GrFPResult asFragmentProcessor(std::unique_ptr<GrFragmentProcessor> inputFP,
                                   GrRecordingContext* context,
                                   const GrColorInfo& dstColorInfo,
                                   const SkSurfaceProps& props) const override {
        // wish our caller would let us know if our input was opaque...
        constexpr SkAlphaType alphaType = kPremul_SkAlphaType;
        return GrFPSuccess(GrColorSpaceXformEffect::Make(
                std::move(inputFP), fSrc.get(), alphaType, fDst.get(), alphaType));
        SkUNREACHABLE;
    }
#endif

#if defined(SK_GRAPHITE)
    void addToKey(const skgpu::graphite::KeyContext& keyContext,
                  skgpu::graphite::PaintParamsKeyBuilder* builder,
                  skgpu::graphite::PipelineDataGatherer* gatherer) const override {
        using namespace skgpu::graphite;

        constexpr SkAlphaType alphaType = kPremul_SkAlphaType;
        ColorSpaceTransformBlock::ColorSpaceTransformData data(
                fSrc.get(), alphaType, fDst.get(), alphaType);
        ColorSpaceTransformBlock::BeginBlock(keyContext, builder, gatherer, &data);
        builder->endBlock();
    }
#endif

    bool appendStages(const SkStageRec& rec, bool shaderIsOpaque) const override {
        if (!shaderIsOpaque) {
            rec.fPipeline->append(SkRasterPipelineOp::unpremul);
        }

        fSteps.apply(rec.fPipeline);

        if (!shaderIsOpaque) {
            rec.fPipeline->append(SkRasterPipelineOp::premul);
        }
        return true;
    }

#if defined(SK_ENABLE_SKVM)
    skvm::Color onProgram(skvm::Builder* p, skvm::Color c, const SkColorInfo& dst,
                          skvm::Uniforms* uniforms, SkArenaAlloc* alloc) const override {
        return premul(fSteps.program(p, uniforms, unpremul(c)));
    }
#endif

protected:
    void flatten(SkWriteBuffer& buffer) const override {
        buffer.writeDataAsByteArray(fSrc->serialize().get());
        buffer.writeDataAsByteArray(fDst->serialize().get());
    }

private:
    friend void ::SkRegisterColorSpaceXformColorFilterFlattenable();
    SK_FLATTENABLE_HOOKS(ColorSpaceXformColorFilter)
    static sk_sp<SkFlattenable> LegacyGammaOnlyCreateProc(SkReadBuffer& buffer);

    const sk_sp<SkColorSpace> fSrc;
    const sk_sp<SkColorSpace> fDst;
    SkColorSpaceXformSteps fSteps;

    friend class SkColorFilter;
    using INHERITED = SkColorFilterBase;
};

sk_sp<SkFlattenable> ColorSpaceXformColorFilter::LegacyGammaOnlyCreateProc(SkReadBuffer& buffer) {
    uint32_t dir = buffer.read32();
    if (!buffer.validate(dir <= 1)) {
        return nullptr;
    }
    if (dir == 0) {
      return SkColorFilters::LinearToSRGBGamma();
    }
	return SkColorFilters::SRGBToLinearGamma();
}

sk_sp<SkFlattenable> ColorSpaceXformColorFilter::CreateProc(SkReadBuffer& buffer) {
    sk_sp<SkColorSpace> colorSpaces[2];
    for (int i = 0; i < 2; ++i) {
        auto data = buffer.readByteArrayAsData();
        if (!buffer.validate(data != nullptr)) {
            return nullptr;
        }
        colorSpaces[i] = SkColorSpace::Deserialize(data->data(), data->size());
        if (!buffer.validate(colorSpaces[i] != nullptr)) {
            return nullptr;
        }
    }
    return sk_sp<SkFlattenable>(
            new ColorSpaceXformColorFilter(std::move(colorSpaces[0]), std::move(colorSpaces[1])));
}

sk_sp<SkColorFilter> SkColorFilters::LinearToSRGBGamma() {
    static SkNoDestructor<ColorSpaceXformColorFilter> gSingleton(SkColorSpace::MakeSRGBLinear(),
                                                                 SkColorSpace::MakeSRGB());
    return sk_ref_sp(gSingleton.get());
}

sk_sp<SkColorFilter> SkColorFilters::SRGBToLinearGamma() {
    static SkNoDestructor<ColorSpaceXformColorFilter> gSingleton(SkColorSpace::MakeSRGB(),
                                                                 SkColorSpace::MakeSRGBLinear());
    return sk_ref_sp(gSingleton.get());
}

sk_sp<SkColorFilter> SkColorFilterPriv::MakeColorSpaceXform(sk_sp<SkColorSpace> src,
                                                            sk_sp<SkColorSpace> dst) {
    return sk_make_sp<ColorSpaceXformColorFilter>(std::move(src), std::move(dst));
}

class SkWorkingFormatColorFilter final : public SkColorFilterBase {
public:
    SkWorkingFormatColorFilter(sk_sp<SkColorFilter>          child,
                               const skcms_TransferFunction* tf,
                               const skcms_Matrix3x3*        gamut,
                               const SkAlphaType*            at) {
        fChild = std::move(child);
        if (tf)    { fTF    = *tf;    fUseDstTF    = false; }
        if (gamut) { fGamut = *gamut; fUseDstGamut = false; }
        if (at)    { fAT    = *at;    fUseDstAT    = false; }
    }

    sk_sp<SkColorSpace> workingFormat(const sk_sp<SkColorSpace>& dstCS, SkAlphaType* at) const {
        skcms_TransferFunction tf    = fTF;
        skcms_Matrix3x3        gamut = fGamut;

        if (fUseDstTF   ) { SkAssertResult(dstCS->isNumericalTransferFn(&tf)); }
        if (fUseDstGamut) { SkAssertResult(dstCS->toXYZD50             (&gamut)); }

        *at = fUseDstAT ? kPremul_SkAlphaType : fAT;
        return SkColorSpace::MakeRGB(tf, gamut);
    }

#if defined(SK_GANESH)
    GrFPResult asFragmentProcessor(std::unique_ptr<GrFragmentProcessor> inputFP,
                                   GrRecordingContext* context,
                                   const GrColorInfo& dstColorInfo,
                                   const SkSurfaceProps& props) const override {
        sk_sp<SkColorSpace> dstCS = dstColorInfo.refColorSpace();
        if (!dstCS) { dstCS = SkColorSpace::MakeSRGB(); }

        SkAlphaType workingAT;
        sk_sp<SkColorSpace> workingCS = this->workingFormat(dstCS, &workingAT);

        GrColorInfo dst = {dstColorInfo.colorType(), dstColorInfo.alphaType(), dstCS},
                working = {dstColorInfo.colorType(), workingAT, workingCS};

        auto [ok, fp] = as_CFB(fChild)->asFragmentProcessor(
                GrColorSpaceXformEffect::Make(std::move(inputFP), dst,working), context, working,
                                              props);

        return ok ? GrFPSuccess(GrColorSpaceXformEffect::Make(std::move(fp), working,dst))
                  : GrFPFailure(std::move(fp));
    }
#endif

#if defined(SK_GRAPHITE)
    void addToKey(const skgpu::graphite::KeyContext& keyContext,
                  skgpu::graphite::PaintParamsKeyBuilder* builder,
                  skgpu::graphite::PipelineDataGatherer* gatherer) const override {
        using namespace skgpu::graphite;

        const SkAlphaType dstAT = keyContext.dstColorInfo().alphaType();
        sk_sp<SkColorSpace> dstCS = keyContext.dstColorInfo().refColorSpace();
        if (!dstCS) {
            dstCS = SkColorSpace::MakeSRGB();
        }

        SkAlphaType workingAT;
        sk_sp<SkColorSpace> workingCS = this->workingFormat(dstCS, &workingAT);

        ColorSpaceTransformBlock::ColorSpaceTransformData data1(
                dstCS.get(), dstAT, workingCS.get(), workingAT);
        ColorSpaceTransformBlock::BeginBlock(keyContext, builder, gatherer, &data1);
        builder->endBlock();

        as_CFB(fChild)->addToKey(keyContext, builder, gatherer);

        ColorSpaceTransformBlock::ColorSpaceTransformData data2(
                workingCS.get(), workingAT, dstCS.get(), dstAT);
        ColorSpaceTransformBlock::BeginBlock(keyContext, builder, gatherer, &data2);
        builder->endBlock();
    }
#endif

    bool appendStages(const SkStageRec& rec, bool shaderIsOpaque) const override {
        sk_sp<SkColorSpace> dstCS = sk_ref_sp(rec.fDstCS);

        if (!dstCS) { dstCS = SkColorSpace::MakeSRGB(); }

        SkAlphaType workingAT;
        sk_sp<SkColorSpace> workingCS = this->workingFormat(dstCS, &workingAT);

        SkColorInfo dst = {rec.fDstColorType, kPremul_SkAlphaType, dstCS},
                working = {rec.fDstColorType, workingAT, workingCS};

        const auto* dstToWorking = rec.fAlloc->make<SkColorSpaceXformSteps>(dst, working);
        const auto* workingToDst = rec.fAlloc->make<SkColorSpaceXformSteps>(working, dst);

        // Any SkSL effects might reference the paint color, which is already in the destination
        // color space. We need to transform it to the working space for consistency.
        SkColor4f paintColorInWorkingSpace = rec.fPaintColor;
        dstToWorking->apply(paintColorInWorkingSpace.vec());

        SkStageRec workingRec = {rec.fPipeline,
                                 rec.fAlloc,
                                 rec.fDstColorType,
                                 workingCS.get(),
                                 paintColorInWorkingSpace,
                                 rec.fSurfaceProps};

        dstToWorking->apply(rec.fPipeline);
        if (!as_CFB(fChild)->appendStages(workingRec, shaderIsOpaque)) {
            return false;
        }
        workingToDst->apply(rec.fPipeline);
        return true;
    }

#if defined(SK_ENABLE_SKVM)
    skvm::Color onProgram(skvm::Builder* p, skvm::Color c, const SkColorInfo& rawDst,
                          skvm::Uniforms* uniforms, SkArenaAlloc* alloc) const override {
        sk_sp<SkColorSpace> dstCS = rawDst.refColorSpace();
        if (!dstCS) { dstCS = SkColorSpace::MakeSRGB(); }

        SkAlphaType workingAT;
        sk_sp<SkColorSpace> workingCS = this->workingFormat(dstCS, &workingAT);

        SkColorInfo dst = {rawDst.colorType(), kPremul_SkAlphaType, dstCS},
                working = {rawDst.colorType(), workingAT, workingCS};

        c = SkColorSpaceXformSteps{dst,working}.program(p, uniforms, c);
        c = as_CFB(fChild)->program(p, c, working, uniforms, alloc);
        return c ? SkColorSpaceXformSteps{working,dst}.program(p, uniforms, c)
                 : c;
    }
#endif

    SkPMColor4f onFilterColor4f(const SkPMColor4f& origColor,
                                SkColorSpace* rawDstCS) const override {
        sk_sp<SkColorSpace> dstCS = sk_ref_sp(rawDstCS);
        if (!dstCS) { dstCS = SkColorSpace::MakeSRGB(); }

        SkAlphaType workingAT;
        sk_sp<SkColorSpace> workingCS = this->workingFormat(dstCS, &workingAT);

        SkColorInfo dst = {kUnknown_SkColorType, kPremul_SkAlphaType, dstCS},
                working = {kUnknown_SkColorType, workingAT, workingCS};

        SkPMColor4f color = origColor;
        SkColorSpaceXformSteps{dst,working}.apply(color.vec());
        color = as_CFB(fChild)->onFilterColor4f(color, working.colorSpace());
        SkColorSpaceXformSteps{working,dst}.apply(color.vec());
        return color;
    }

    bool onIsAlphaUnchanged() const override { return fChild->isAlphaUnchanged(); }

private:
    friend void ::SkRegisterWorkingFormatColorFilterFlattenable();
    SK_FLATTENABLE_HOOKS(SkWorkingFormatColorFilter)

    void flatten(SkWriteBuffer& buffer) const override {
        buffer.writeFlattenable(fChild.get());
        buffer.writeBool(fUseDstTF);
        buffer.writeBool(fUseDstGamut);
        buffer.writeBool(fUseDstAT);
        if (!fUseDstTF)    { buffer.writeScalarArray(&fTF.g, 7); }
        if (!fUseDstGamut) { buffer.writeScalarArray(&fGamut.vals[0][0], 9); }
        if (!fUseDstAT)    { buffer.writeInt(fAT); }
    }

    sk_sp<SkColorFilter>   fChild;
    skcms_TransferFunction fTF;     bool fUseDstTF    = true;
    skcms_Matrix3x3        fGamut;  bool fUseDstGamut = true;
    SkAlphaType            fAT;     bool fUseDstAT    = true;
};

sk_sp<SkFlattenable> SkWorkingFormatColorFilter::CreateProc(SkReadBuffer& buffer) {
    sk_sp<SkColorFilter> child = buffer.readColorFilter();
    bool useDstTF    = buffer.readBool(),
         useDstGamut = buffer.readBool(),
         useDstAT    = buffer.readBool();

    skcms_TransferFunction tf;
    skcms_Matrix3x3        gamut;
    SkAlphaType            at;

    if (!useDstTF)    { buffer.readScalarArray(&tf.g, 7); }
    if (!useDstGamut) { buffer.readScalarArray(&gamut.vals[0][0], 9); }
    if (!useDstAT)    { at = buffer.read32LE(kLastEnum_SkAlphaType); }

    return SkColorFilterPriv::WithWorkingFormat(std::move(child),
                                                useDstTF    ? nullptr : &tf,
                                                useDstGamut ? nullptr : &gamut,
                                                useDstAT    ? nullptr : &at);
}

sk_sp<SkColorFilter> SkColorFilterPriv::WithWorkingFormat(sk_sp<SkColorFilter> child,
                                                          const skcms_TransferFunction* tf,
                                                          const skcms_Matrix3x3* gamut,
                                                          const SkAlphaType* at) {
    return sk_make_sp<SkWorkingFormatColorFilter>(std::move(child), tf, gamut, at);
}

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

sk_sp<SkColorFilter> SkColorFilters::Lerp(float weight, sk_sp<SkColorFilter> cf0,
                                                        sk_sp<SkColorFilter> cf1) {
#ifdef SK_ENABLE_SKSL
    if (!cf0 && !cf1) {
        return nullptr;
    }
    if (SkScalarIsNaN(weight)) {
        return nullptr;
    }

    if (cf0 == cf1) {
        return cf0; // or cf1
    }

    if (weight <= 0) {
        return cf0;
    }
    if (weight >= 1) {
        return cf1;
    }

    static const SkRuntimeEffect* effect = SkMakeCachedRuntimeEffect(
        SkRuntimeEffect::MakeForColorFilter,
        "uniform colorFilter cf0;"
        "uniform colorFilter cf1;"
        "uniform half   weight;"
        "half4 main(half4 color) {"
            "return mix(cf0.eval(color), cf1.eval(color), weight);"
        "}"
    ).release();
    SkASSERT(effect);

    sk_sp<SkColorFilter> inputs[] = {cf0,cf1};
    return effect->makeColorFilter(SkData::MakeWithCopy(&weight, sizeof(weight)),
                                   inputs, std::size(inputs));
#else
    // TODO(skia:12197)
    return nullptr;
#endif
}

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

void SkRegisterComposeColorFilterFlattenable() {
    SK_REGISTER_FLATTENABLE(SkComposeColorFilter);
}

void SkRegisterColorSpaceXformColorFilterFlattenable() {
    SK_REGISTER_FLATTENABLE(ColorSpaceXformColorFilter);
    // TODO(ccameron): Remove after grace period for SKPs to stop using old serialization.
    SkFlattenable::Register("SkSRGBGammaColorFilter",
                            ColorSpaceXformColorFilter::LegacyGammaOnlyCreateProc);
}

void SkRegisterWorkingFormatColorFilterFlattenable() {
    SK_REGISTER_FLATTENABLE(SkWorkingFormatColorFilter);
}