core/SkColorShader.h

/*
 * Copyright 2007 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.
 */


#ifndef SkColorShader_DEFINED
#define SkColorShader_DEFINED

#include "SkShader.h"

/** \class SkColorShader
    A Shader that represents a single color. In general, this effect can be
    accomplished by just using the color field on the paint, but if an
    actual shader object is needed, this provides that feature.
*/
class SK_API SkColorShader : public SkShader {
public:
    /** Create a ColorShader that will inherit its color from the Paint
        at draw time.
    */
    SkColorShader();

    /** Create a ColorShader that ignores the color in the paint, and uses the
        specified color. Note: like all shaders, at draw time the paint's alpha
        will be respected, and is applied to the specified color.
    */
    SkColorShader(SkColor c);

    virtual ~SkColorShader();

    virtual uint32_t getFlags() SK_OVERRIDE;
    virtual uint8_t getSpan16Alpha() const SK_OVERRIDE;
    virtual bool isOpaque() const SK_OVERRIDE;
    virtual bool setContext(const SkBitmap& device, const SkPaint& paint,
                            const SkMatrix& matrix) SK_OVERRIDE;
    virtual void shadeSpan(int x, int y, SkPMColor span[], int count) SK_OVERRIDE;
    virtual void shadeSpan16(int x, int y, uint16_t span[], int count) SK_OVERRIDE;
    virtual void shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) SK_OVERRIDE;

    // we return false for this, use asAGradient
    virtual BitmapType asABitmap(SkBitmap* outTexture,
                                 SkMatrix* outMatrix,
                                 TileMode xy[2]) const SK_OVERRIDE;

    virtual GradientType asAGradient(GradientInfo* info) const SK_OVERRIDE;

    SK_DEVELOPER_TO_STRING()
    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkColorShader)

protected:
    SkColorShader(SkFlattenableReadBuffer&);
    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;

private:

    SkColor     fColor;         // ignored if fInheritColor is true
    SkPMColor   fPMColor;       // cached after setContext()
    uint32_t    fFlags;         // cached after setContext()
    uint16_t    fColor16;       // cached after setContext()
    SkBool8     fInheritColor;

    typedef SkShader INHERITED;
};

#endif