1 /* 2 * Copyright 2006 The Android Open Source Project 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SkAvoidXfermode_DEFINED 9 #define SkAvoidXfermode_DEFINED 10 11 #include "SkXfermode.h" 12 13 /** \class SkAvoidXfermode 14 15 This xfermode will draw the src everywhere except on top of the specified 16 color. 17 */ 18 class SK_API SkAvoidXfermode : public SkXfermode { 19 public: 20 enum Mode { 21 kAvoidColor_Mode, //!< draw everywhere except on the opColor 22 kTargetColor_Mode //!< draw only on top of the opColor 23 }; 24 25 /** This xfermode draws, or doesn't draw, based on the destination's 26 distance from an op-color. 27 28 There are two modes, and each mode interprets a tolerance value. 29 30 Avoid: In this mode, drawing is allowed only on destination pixels that 31 are different from the op-color. 32 Tolerance near 0: avoid any colors even remotely similar to the op-color 33 Tolerance near 255: avoid only colors nearly identical to the op-color 34 35 Target: In this mode, drawing only occurs on destination pixels that 36 are similar to the op-color 37 Tolerance near 0: draw only on colors that are nearly identical to the op-color 38 Tolerance near 255: draw on any colors even remotely similar to the op-color 39 */ 40 static SkAvoidXfermode* Create(SkColor opColor, U8CPU tolerance, Mode mode) { 41 return SkNEW_ARGS(SkAvoidXfermode, (opColor, tolerance, mode)); 42 } 43 44 // overrides from SkXfermode 45 virtual void xfer32(SkPMColor dst[], const SkPMColor src[], int count, 46 const SkAlpha aa[]) const SK_OVERRIDE; 47 virtual void xfer16(uint16_t dst[], const SkPMColor src[], int count, 48 const SkAlpha aa[]) const SK_OVERRIDE; 49 virtual void xferA8(SkAlpha dst[], const SkPMColor src[], int count, 50 const SkAlpha aa[]) const SK_OVERRIDE; 51 52 SK_TO_STRING_OVERRIDE() 53 SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkAvoidXfermode) 54 55 protected: 56 SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode); 57 explicit SkAvoidXfermode(SkReadBuffer&); 58 virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE; 59 60 private: 61 SkColor fOpColor; 62 uint32_t fDistMul; // x.14 63 Mode fMode; 64 65 typedef SkXfermode INHERITED; 66 }; 67 68 #endif 69
