| /* |
| * 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" |
| |
| //#define SK_SUPPORT_LEGACY_PORTER_DUFF |
| |
| // Temporary guard until we can remove the dependencies in android. Then we |
| // plan to remove this entirely. |
| #ifdef SK_SUPPORT_LEGACY_PORTER_DUFF |
| |
| 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 |
| |
| #endif |