diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/include/effects/SkPorterDuff.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/skia/trunk/include/effects/SkPorterDuff.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,79 @@ +/* + * Copyright 2006 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 SkPorterDuff_DEFINED +#define SkPorterDuff_DEFINED + +#include "SkColor.h" +#include "SkXfermode.h" + +class SkXfermode; + +class SK_API SkPorterDuff { +public: + /** List of predefined xfermodes. In general, the algebra for the modes + uses the following symbols: + Sa, Sc - source alpha and color + Da, Dc - destination alpha and color (before compositing) + [a, c] - Resulting (alpha, color) values + For these equations, the colors are in premultiplied state. + If no xfermode is specified, kSrcOver is assumed. + */ + enum Mode { + kClear_Mode, //!< [0, 0] + kSrc_Mode, //!< [Sa, Sc] + kDst_Mode, //!< [Da, Dc] + kSrcOver_Mode, //!< [Sa + Da - Sa*Da, Rc = Sc + (1 - Sa)*Dc] + kDstOver_Mode, //!< [Sa + Da - Sa*Da, Rc = Dc + (1 - Da)*Sc] + kSrcIn_Mode, //!< [Sa * Da, Sc * Da] + kDstIn_Mode, //!< [Sa * Da, Sa * Dc] + kSrcOut_Mode, //!< [Sa * (1 - Da), Sc * (1 - Da)] + kDstOut_Mode, //!< [Da * (1 - Sa), Dc * (1 - Sa)] + kSrcATop_Mode, //!< [Da, Sc * Da + (1 - Sa) * Dc] + kDstATop_Mode, //!< [Sa, Sa * Dc + Sc * (1 - Da)] + kXor_Mode, //!< [Sa + Da - 2 * Sa * Da, Sc * (1 - Da) + (1 - Sa) * Dc] + kDarken_Mode, //!< [Sa + Da - Sa*Da, Sc*(1 - Da) + Dc*(1 - Sa) + min(Sc, Dc)] + kLighten_Mode, //!< [Sa + Da - Sa*Da, Sc*(1 - Da) + Dc*(1 - Sa) + max(Sc, Dc)] + kModulate_Mode, //!< [Sa * Da, Sc * Dc] multiplies all components + kScreen_Mode, //!< [Sa + Da - Sa * Da, Sc + Dc - Sc * Dc] + kAdd_Mode, //!< Saturate(S + D) +#ifdef SK_BUILD_FOR_ANDROID + kOverlay_Mode, +#endif + + kModeCount + }; + + /** Return an SkXfermode object for the specified mode. + */ + static SkXfermode* CreateXfermode(Mode mode); + + /** Return a function pointer to a routine that applies the specified + porter-duff transfer mode. + */ + static SkXfermodeProc GetXfermodeProc(Mode mode); + + /** Return a function pointer to a routine that applies the specified + porter-duff transfer mode and srcColor to a 16bit device color. Note, + if the mode+srcColor might return a non-opaque color, then there is not + 16bit proc, and this will return NULL. + */ + static SkXfermodeProc16 GetXfermodeProc16(Mode mode, SkColor srcColor); + + /** If the specified xfermode advertises itself as one of the porterduff + modes (via SkXfermode::Coeff), return true and if not null, set mode + to the corresponding porterduff mode. If it is not recognized as a one, + return false and ignore the mode parameter. + */ + static bool IsMode(SkXfermode*, Mode* mode); + + /** Return the corersponding SkXfermode::Mode + */ + static SkXfermode::Mode ToXfermodeMode(Mode); +} SK_ATTR_DEPRECATED("use SkXfermode::Mode"); + +#endif