1
2 /*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10 #include "SkPorterDuff.h"
11 #include "SkXfermode.h"
12
13 /* This file just exists as a compatibility layer, gluing the PorterDuff API
14 into the (extended) SkXfermode API
15 */
16
17 #define MAKE_PAIR(mode) { SkPorterDuff::k##mode##_Mode, SkXfermode::k##mode##_Mode }
18
19 // this table must be in SkPorterDuff::Mode order, so it can be indexed directly
20 // with a porterduff mode.
21 static const struct Pair {
22 SkPorterDuff::Mode fPD;
23 SkXfermode::Mode fXF;
24 } gPairs[] = {
25 MAKE_PAIR(Clear),
26 MAKE_PAIR(Src),
27 MAKE_PAIR(Dst),
28 MAKE_PAIR(SrcOver),
29 MAKE_PAIR(DstOver),
30 MAKE_PAIR(SrcIn),
31 MAKE_PAIR(DstIn),
32 MAKE_PAIR(SrcOut),
33 MAKE_PAIR(DstOut),
34 MAKE_PAIR(SrcATop),
35 MAKE_PAIR(DstATop),
36 MAKE_PAIR(Xor),
37 MAKE_PAIR(Darken),
38 MAKE_PAIR(Lighten),
39 MAKE_PAIR(Modulate),
40 MAKE_PAIR(Screen),
41 { SkPorterDuff::kAdd_Mode, SkXfermode::kPlus_Mode },
42 #ifdef SK_BUILD_FOR_ANDROID
43 MAKE_PAIR(Overlay),
44 #endif
45 };
46
find_pdmode(SkXfermode::Mode src,SkPorterDuff::Mode * dst)47 static bool find_pdmode(SkXfermode::Mode src, SkPorterDuff::Mode* dst) {
48 const Pair* pairs = gPairs;
49 for (size_t i = 0; i < SK_ARRAY_COUNT(gPairs); i++) {
50 if (pairs[i].fXF == src) {
51 if (dst) {
52 *dst = pairs[i].fPD;
53 }
54 return true;
55 }
56 }
57 return false;
58 }
59
ToXfermodeMode(Mode mode)60 SkXfermode::Mode SkPorterDuff::ToXfermodeMode(Mode mode) {
61 SkASSERT((unsigned)mode < SkPorterDuff::kModeCount);
62 const Pair& pair = gPairs[mode];
63 SkASSERT(pair.fPD == mode);
64 return pair.fXF;
65 }
66
CreateXfermode(SkPorterDuff::Mode mode)67 SkXfermode* SkPorterDuff::CreateXfermode(SkPorterDuff::Mode mode) {
68 const Pair& pair = gPairs[mode];
69 SkASSERT(pair.fPD == mode);
70 return SkXfermode::Create(pair.fXF);
71 }
72
IsMode(SkXfermode * xfer,Mode * pdmode)73 bool SkPorterDuff::IsMode(SkXfermode* xfer, Mode* pdmode) {
74 SkXfermode::Mode xfmode;
75 if (!SkXfermode::AsMode(xfer, &xfmode)) {
76 return false;
77 }
78 return find_pdmode(xfmode, pdmode);
79 }
80
GetXfermodeProc(Mode mode)81 SkXfermodeProc SkPorterDuff::GetXfermodeProc(Mode mode) {
82 return SkXfermode::GetProc(gPairs[mode].fXF);
83 }
84
GetXfermodeProc16(Mode mode,SkColor srcColor)85 SkXfermodeProc16 SkPorterDuff::GetXfermodeProc16(Mode mode, SkColor srcColor) {
86 return SkXfermode::GetProc16(gPairs[mode].fXF, srcColor);
87 }
88