SkPerlinNoiseShader.h

/*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkPerlinNoiseShader_DEFINED
#define SkPerlinNoiseShader_DEFINED

#include "SkShader.h"

class SK_API SkPerlinNoiseShader : public SkShader {
public:
    struct StitchData;
    struct PaintingData;

    enum Type {
        kFractalNoise_Type,
        kTurbulence_Type,
        kFirstType = kFractalNoise_Type,
        kLastType = kTurbulence_Type
    };
    static sk_sp<SkShader> MakeFractalNoise(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                                            int numOctaves, SkScalar seed,
                                            const SkISize* tileSize = nullptr);
    static sk_sp<SkShader> MakeTurbulence(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                                          int numOctaves, SkScalar seed,
                                          const SkISize* tileSize = nullptr);

#ifdef SK_SUPPORT_LEGACY_CREATESHADER_PTR
    static SkShader* CreateFractalNoise(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                                        int numOctaves, SkScalar seed,
                                        const SkISize* tileSize = NULL) {
        return MakeFractalNoise(baseFrequencyX, baseFrequencyY, numOctaves, seed, tileSize).release();
    }
    static SkShader* CreateTurbulence(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                                      int numOctaves, SkScalar seed,
                                      const SkISize* tileSize = NULL) {
        return MakeTurbulence(baseFrequencyX, baseFrequencyY, numOctaves, seed, tileSize).release();
    }
    static SkShader* CreateTubulence(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                                     int numOctaves, SkScalar seed,
                                     const SkISize* tileSize = NULL) {
        return CreateTurbulence(baseFrequencyX, baseFrequencyY, numOctaves, seed, tileSize);
    }
#endif

    class PerlinNoiseShaderContext : public SkShader::Context {
    public:
        PerlinNoiseShaderContext(const SkPerlinNoiseShader& shader, const ContextRec&);
        virtual ~PerlinNoiseShaderContext();

        void shadeSpan(int x, int y, SkPMColor[], int count) override;

    private:
        SkPMColor shade(const SkPoint& point, StitchData& stitchData) const;
        SkScalar calculateTurbulenceValueForPoint(
            int channel,
            StitchData& stitchData, const SkPoint& point) const;
        SkScalar noise2D(int channel,
                         const StitchData& stitchData, const SkPoint& noiseVector) const;

        SkMatrix fMatrix;
        PaintingData* fPaintingData;

        typedef SkShader::Context INHERITED;
    };

#if SK_SUPPORT_GPU
    sk_sp<GrFragmentProcessor> asFragmentProcessor(const AsFPArgs&) const override;
#endif

    SK_TO_STRING_OVERRIDE()
    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPerlinNoiseShader)

protected:
    void flatten(SkWriteBuffer&) const override;
    Context* onCreateContext(const ContextRec&, void* storage) const override;
    size_t onContextSize(const ContextRec&) const override;

private:
    SkPerlinNoiseShader(SkPerlinNoiseShader::Type type, SkScalar baseFrequencyX,
                        SkScalar baseFrequencyY, int numOctaves, SkScalar seed,
                        const SkISize* tileSize);
    virtual ~SkPerlinNoiseShader();

    const SkPerlinNoiseShader::Type fType;
    const SkScalar                  fBaseFrequencyX;
    const SkScalar                  fBaseFrequencyY;
    const int                       fNumOctaves;
    const SkScalar                  fSeed;
    const SkISize                   fTileSize;
    const bool                      fStitchTiles;

    typedef SkShader INHERITED;
};

#endif