src/core/SkFilterShader.h

/*
 * 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 SkFilterShader_DEFINED
#define SkFilterShader_DEFINED

#include "SkShader.h"

class SkColorFilter;

class SkFilterShader : public SkShader {
public:
    SkFilterShader(SkShader* shader, SkColorFilter* filter);
    virtual ~SkFilterShader();

    virtual bool validContext(const SkBitmap&, const SkPaint&,
                              const SkMatrix&, SkMatrix* totalInverse = NULL) const SK_OVERRIDE;
    virtual SkShader::Context* createContext(const SkBitmap&, const SkPaint&,
                                             const SkMatrix&, void* storage) const SK_OVERRIDE;
    virtual size_t contextSize() const SK_OVERRIDE;

    class FilterShaderContext : public SkShader::Context {
    public:
        // Takes ownership of shaderContext and calls its destructor.
        FilterShaderContext(const SkFilterShader& filterShader, SkShader::Context* shaderContext,
                            const SkBitmap& device, const SkPaint& paint, const SkMatrix& matrix);
        virtual ~FilterShaderContext();

        virtual uint32_t getFlags() const SK_OVERRIDE;

        virtual void shadeSpan(int x, int y, SkPMColor[], int count) SK_OVERRIDE;
        virtual void shadeSpan16(int x, int y, uint16_t[], int count) SK_OVERRIDE;

    private:
        SkShader::Context* fShaderContext;

        typedef SkShader::Context INHERITED;
    };

    SK_TO_STRING_OVERRIDE()
    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkFilterShader)

protected:
    SkFilterShader(SkReadBuffer& );
    virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;

private:
    SkShader*       fShader;
    SkColorFilter*  fFilter;

    typedef SkShader INHERITED;
};

#endif