1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
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
|
