michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkAvoidXfermode_DEFINED
michael@0: #define SkAvoidXfermode_DEFINED
michael@0: 
michael@0: #include "SkXfermode.h"
michael@0: 
michael@0: /** \class SkAvoidXfermode
michael@0: 
michael@0:     This xfermode will draw the src everywhere except on top of the specified
michael@0:     color.
michael@0: */
michael@0: class SK_API SkAvoidXfermode : public SkXfermode {
michael@0: public:
michael@0:     enum Mode {
michael@0:         kAvoidColor_Mode,   //!< draw everywhere except on the opColor
michael@0:         kTargetColor_Mode   //!< draw only on top of the opColor
michael@0:     };
michael@0: 
michael@0:     /** This xfermode draws, or doesn't draw, based on the destination's
michael@0:         distance from an op-color.
michael@0: 
michael@0:         There are two modes, and each mode interprets a tolerance value.
michael@0: 
michael@0:         Avoid: In this mode, drawing is allowed only on destination pixels that
michael@0:                are different from the op-color.
michael@0:                Tolerance near 0: avoid any colors even remotely similar to the op-color
michael@0:                Tolerance near 255: avoid only colors nearly identical to the op-color
michael@0: 
michael@0:         Target: In this mode, drawing only occurs on destination pixels that
michael@0:                 are similar to the op-color
michael@0:                 Tolerance near 0: draw only on colors that are nearly identical to the op-color
michael@0:                 Tolerance near 255: draw on any colors even remotely similar to the op-color
michael@0:      */
michael@0:     static SkAvoidXfermode* Create(SkColor opColor, U8CPU tolerance, Mode mode) {
michael@0:         return SkNEW_ARGS(SkAvoidXfermode, (opColor, tolerance, mode));
michael@0:     }
michael@0: 
michael@0:     // overrides from SkXfermode
michael@0:     virtual void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
michael@0:                         const SkAlpha aa[]) const SK_OVERRIDE;
michael@0:     virtual void xfer16(uint16_t dst[], const SkPMColor src[], int count,
michael@0:                         const SkAlpha aa[]) const SK_OVERRIDE;
michael@0:     virtual void xferA8(SkAlpha dst[], const SkPMColor src[], int count,
michael@0:                         const SkAlpha aa[]) const SK_OVERRIDE;
michael@0: 
michael@0:     SK_TO_STRING_OVERRIDE()
michael@0:     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkAvoidXfermode)
michael@0: 
michael@0: protected:
michael@0:     SkAvoidXfermode(SkReadBuffer&);
michael@0:     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
michael@0: 
michael@0: #ifdef SK_SUPPORT_LEGACY_PUBLICEFFECTCONSTRUCTORS
michael@0: public:
michael@0: #endif
michael@0:     SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode);
michael@0: 
michael@0: private:
michael@0:     SkColor     fOpColor;
michael@0:     uint32_t    fDistMul;   // x.14
michael@0:     Mode        fMode;
michael@0: 
michael@0:     typedef SkXfermode INHERITED;
michael@0: };
michael@0: 
michael@0: #endif