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

#ifndef GrProcessor_DEFINED
#define GrProcessor_DEFINED

#include "../private/SkAtomics.h"
#include "GrBuffer.h"
#include "GrColor.h"
#include "GrGpuResourceRef.h"
#include "GrProcessorUnitTest.h"
#include "GrProgramElement.h"
#include "GrSamplerState.h"
#include "GrShaderVar.h"
#include "GrSurfaceProxyPriv.h"
#include "GrSurfaceProxyRef.h"
#include "GrTextureProxy.h"
#include "SkMath.h"
#include "SkString.h"

class GrContext;
class GrResourceProvider;

/**
 * Used by processors to build their keys. It incorporates each per-processor key into a larger
 * shader key.
 */
class GrProcessorKeyBuilder {
public:
    GrProcessorKeyBuilder(SkTArray<unsigned char, true>* data) : fData(data), fCount(0) {
        SkASSERT(0 == fData->count() % sizeof(uint32_t));
    }

    void add32(uint32_t v) {
        ++fCount;
        fData->push_back_n(4, reinterpret_cast<uint8_t*>(&v));
    }

    /** Inserts count uint32_ts into the key. The returned pointer is only valid until the next
        add*() call. */
    uint32_t* SK_WARN_UNUSED_RESULT add32n(int count) {
        SkASSERT(count > 0);
        fCount += count;
        return reinterpret_cast<uint32_t*>(fData->push_back_n(4 * count));
    }

    size_t size() const { return sizeof(uint32_t) * fCount; }

private:
    SkTArray<uint8_t, true>* fData; // unowned ptr to the larger key.
    int fCount;                     // number of uint32_ts added to fData by the processor.
};

/** Provides custom shader code to the Ganesh shading pipeline. GrProcessor objects *must* be
    immutable: after being constructed, their fields may not change.

    Dynamically allocated GrProcessors are managed by a per-thread memory pool. The ref count of an
    processor must reach 0 before the thread terminates and the pool is destroyed.
 */
class GrProcessor {
public:
    enum ClassID {
        kBigKeyProcessor_ClassID,
        kBlockInputFragmentProcessor_ClassID,
        kButtCapStrokedCircleGeometryProcessor_ClassID,
        kCircleGeometryProcessor_ClassID,
        kCircularRRectEffect_ClassID,
        kClockwiseTestProcessor_ClassID,
        kColorMatrixEffect_ClassID,
        kColorTableEffect_ClassID,
        kComposeOneFragmentProcessor_ClassID,
        kComposeTwoFragmentProcessor_ClassID,
        kCoverageSetOpXP_ClassID,
        kCustomXP_ClassID,
        kDashingCircleEffect_ClassID,
        kDashingLineEffect_ClassID,
        kDefaultGeoProc_ClassID,
        kDIEllipseGeometryProcessor_ClassID,
        kDisableColorXP_ClassID,
        kTwoPointConicalEffect_ClassID,
        kEllipseGeometryProcessor_ClassID,
        kEllipticalRRectEffect_ClassID,
        kGP_ClassID,
        kVertexColorSpaceBenchGP_ClassID,
        kGrAARectEffect_ClassID,
        kGrAlphaThresholdFragmentProcessor_ClassID,
        kGrArithmeticFP_ClassID,
        kGrBicubicEffect_ClassID,
        kGrBitmapTextGeoProc_ClassID,
        kGrBlurredEdgeFragmentProcessor_ClassID,
        kGrCCClipProcessor_ClassID,
        kGrCCCoverageProcessor_ClassID,
        kGrCCPathProcessor_ClassID,
        kGrCircleBlurFragmentProcessor_ClassID,
        kGrCircleEffect_ClassID,
        kGrColorSpaceXformEffect_ClassID,
        kGrConfigConversionEffect_ClassID,
        kGrConicEffect_ClassID,
        kGrConstColorProcessor_ClassID,
        kGrConvexPolyEffect_ClassID,
        kGrCubicEffect_ClassID,
        kGrDeviceSpaceTextureDecalFragmentProcessor_ClassID,
        kGrDiffuseLightingEffect_ClassID,
        kGrDisplacementMapEffect_ClassID,
        kGrDistanceFieldA8TextGeoProc_ClassID,
        kGrDistanceFieldLCDTextGeoProc_ClassID,
        kGrDistanceFieldPathGeoProc_ClassID,
        kGrDitherEffect_ClassID,
        kGrEllipseEffect_ClassID,
        kGrGaussianConvolutionFragmentProcessor_ClassID,
        kGrImprovedPerlinNoiseEffect_ClassID,
        kGrLightingEffect_ClassID,
        kGrLinearGradient_ClassID,
        kGrLumaColorFilterEffect_ClassID,
        kGrMagnifierEffect_ClassID,
        kGrMatrixConvolutionEffect_ClassID,
        kGrMeshTestProcessor_ClassID,
        kGrMorphologyEffect_ClassID,
        kGrOverdrawFragmentProcessor_ClassID,
        kGrPathProcessor_ClassID,
        kGrPerlinNoise2Effect_ClassID,
        kGrPipelineDynamicStateTestProcessor_ClassID,
        kGrPremulInputFragmentProcessor_ClassID,
        kGrQuadEffect_ClassID,
        kGrRadialGradient_ClassID,
        kGrRectBlurEffect_ClassID,
        kGrRRectBlurEffect_ClassID,
        kGrRRectShadowGeoProc_ClassID,
        kGrSimpleTextureEffect_ClassID,
        kGrSpecularLightingEffect_ClassID,
        kGrSRGBEffect_ClassID,
        kGrSweepGradient_ClassID,
        kGrTextureDomainEffect_ClassID,
        kGrUnpremulInputFragmentProcessor_ClassID,
        kGrYUVtoRGBEffect_ClassID,
        kHighContrastFilterEffect_ClassID,
        kInstanceProcessor_ClassID,
        kLatticeGP_ClassID,
        kLumaColorFilterEffect_ClassID,
        kMSAAQuadProcessor_ClassID,
        kPDLCDXferProcessor_ClassID,
        kPorterDuffXferProcessor_ClassID,
        kPremulFragmentProcessor_ClassID,
        kQuadEdgeEffect_ClassID,
        kReplaceInputFragmentProcessor_ClassID,
        kRRectsGaussianEdgeFP_ClassID,
        kSeriesFragmentProcessor_ClassID,
        kShaderPDXferProcessor_ClassID,
        kSwizzleFragmentProcessor_ClassID,
        kTestFP_ClassID,
        kTextureGeometryProcessor_ClassID,
        kFlatNormalsFP_ClassID,
        kMappedNormalsFP_ClassID,
        kLightingFP_ClassID,
    };

    virtual ~GrProcessor() = default;

    /** Human-meaningful string to identify this prcoessor; may be embedded in generated shader
        code. */
    virtual const char* name() const = 0;

    /** Human-readable dump of all information */
    virtual SkString dumpInfo() const {
        SkString str;
        str.appendf("Missing data");
        return str;
    }

    void* operator new(size_t size);
    void operator delete(void* target);

    void* operator new(size_t size, void* placement) {
        return ::operator new(size, placement);
    }
    void operator delete(void* target, void* placement) {
        ::operator delete(target, placement);
    }

    /** Helper for down-casting to a GrProcessor subclass */
    template <typename T> const T& cast() const { return *static_cast<const T*>(this); }

    ClassID classID() const { return fClassID; }

protected:
    GrProcessor(ClassID classID) : fClassID(classID) {}

private:
    GrProcessor(const GrProcessor&) = delete;
    GrProcessor& operator=(const GrProcessor&) = delete;

    ClassID fClassID;
};

/** A GrProcessor with the ability to access textures, buffers, and image storages. */
class GrResourceIOProcessor : public GrProcessor {
public:
    class TextureSampler;

    int numTextureSamplers() const { return fNumTextureSamplers; }

    /** Gets a TextureSampler which is a combination of a GrTextureProxy and how it is sampled.
     * index must be valid according to numTextureSamplers(). */
    const TextureSampler& textureSampler(int index) const {
        SkASSERT(index >= 0 && index < fNumTextureSamplers);
        return this->onTextureSampler(index);
    }

    bool instantiate(GrResourceProvider* resourceProvider) const;

protected:
    template <typename... Args>
    static const TextureSampler& IthTextureSampler(int i, const TextureSampler& samp0,
                                                   const Args&... samps) {
        return (0 == i) ? samp0 : IthTextureSampler(i - 1, samps...);
    }
    inline static const TextureSampler& IthTextureSampler(int i);

    GrResourceIOProcessor(ClassID classID) : INHERITED(classID) {}

    void setTextureSamplerCnt(int numTextureSamplers) {
        SkASSERT(numTextureSamplers >= 0);
        fNumTextureSamplers = numTextureSamplers;
    }

    bool hasSameSamplers(const GrResourceIOProcessor&) const;

    // These methods can be used by derived classes that also derive from GrProgramElement.
    void addPendingIOs() const;
    void removeRefs() const;
    void pendingIOComplete() const;

private:
    virtual const TextureSampler& onTextureSampler(int index) const { return IthTextureSampler(0); }

    int fNumTextureSamplers = 0;
    typedef GrProcessor INHERITED;
};

/**
 * Used to represent a texture that is required by a GrResourceIOProcessor. It holds a GrTexture
 * along with an associated GrSamplerState. TextureSamplers don't perform any coord manipulation to
 * account for texture origin.
 */
class GrResourceIOProcessor::TextureSampler {
public:
    /**
     * Must be initialized before adding to a GrProcessor's texture access list.
     */
    TextureSampler();
    /**
     * This copy constructor is used by GrFragmentProcessor::clone() implementations. The copy
     * always takes a new ref on the texture proxy as the new fragment processor will not yet be
     * in pending execution state.
     */
    explicit TextureSampler(const TextureSampler& that)
            : fProxyRef(sk_ref_sp(that.fProxyRef.get()), that.fProxyRef.ioType())
            , fSamplerState(that.fSamplerState)
            , fVisibility(that.fVisibility) {}

    TextureSampler(sk_sp<GrTextureProxy>, const GrSamplerState&);

    explicit TextureSampler(sk_sp<GrTextureProxy>,
                            GrSamplerState::Filter = GrSamplerState::Filter::kNearest,
                            GrSamplerState::WrapMode wrapXAndY = GrSamplerState::WrapMode::kClamp,
                            GrShaderFlags visibility = kFragment_GrShaderFlag);

    TextureSampler& operator=(const TextureSampler&) = delete;

    void reset(sk_sp<GrTextureProxy>, const GrSamplerState&,
               GrShaderFlags visibility = kFragment_GrShaderFlag);
    void reset(sk_sp<GrTextureProxy>,
               GrSamplerState::Filter = GrSamplerState::Filter::kNearest,
               GrSamplerState::WrapMode wrapXAndY = GrSamplerState::WrapMode::kClamp,
               GrShaderFlags visibility = kFragment_GrShaderFlag);

    bool operator==(const TextureSampler& that) const {
        return this->proxy()->underlyingUniqueID() == that.proxy()->underlyingUniqueID() &&
               fSamplerState == that.fSamplerState && fVisibility == that.fVisibility;
    }

    bool operator!=(const TextureSampler& other) const { return !(*this == other); }

    // 'instantiate' should only ever be called at flush time.
    bool instantiate(GrResourceProvider* resourceProvider) const {
        return SkToBool(fProxyRef.get()->instantiate(resourceProvider));
    }

    // 'peekTexture' should only ever be called after a successful 'instantiate' call
    GrTexture* peekTexture() const {
        SkASSERT(fProxyRef.get()->priv().peekTexture());
        return fProxyRef.get()->priv().peekTexture();
    }

    GrTextureProxy* proxy() const { return fProxyRef.get()->asTextureProxy(); }
    GrShaderFlags visibility() const { return fVisibility; }
    const GrSamplerState& samplerState() const { return fSamplerState; }

    bool isInitialized() const { return SkToBool(fProxyRef.get()); }
    /**
     * For internal use by GrProcessor.
     */
    const GrSurfaceProxyRef* programProxy() const { return &fProxyRef; }

private:
    GrSurfaceProxyRef fProxyRef;
    GrSamplerState fSamplerState;
    GrShaderFlags fVisibility;
};

const GrResourceIOProcessor::TextureSampler& GrResourceIOProcessor::IthTextureSampler(int i) {
    SK_ABORT("Illegal texture sampler index");
    static const TextureSampler kBogus;
    return kBogus;
}

#endif