1 /*
2 * Copyright 2013 Google Inc.
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 #include "SkLerpXfermode.h"
9 #include "SkColorPriv.h"
10 #include "SkReadBuffer.h"
11 #include "SkWriteBuffer.h"
12 #include "SkString.h"
13
Create(SkScalar scale)14 SkXfermode* SkLerpXfermode::Create(SkScalar scale) {
15 int scale256 = SkScalarRoundToInt(scale * 256);
16 if (scale256 >= 256) {
17 return SkXfermode::Create(SkXfermode::kSrc_Mode);
18 } else if (scale256 <= 0) {
19 return SkXfermode::Create(SkXfermode::kDst_Mode);
20 }
21 return SkNEW_ARGS(SkLerpXfermode, (scale256));
22 }
23
SkLerpXfermode(unsigned scale256)24 SkLerpXfermode::SkLerpXfermode(unsigned scale256) : fScale256(scale256) {}
25
26 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
SkLerpXfermode(SkReadBuffer & buffer)27 SkLerpXfermode::SkLerpXfermode(SkReadBuffer& buffer) : INHERITED(buffer) {
28 fScale256 = buffer.readUInt();
29 }
30 #endif
31
flatten(SkWriteBuffer & buffer) const32 void SkLerpXfermode::flatten(SkWriteBuffer& buffer) const {
33 buffer.writeUInt(fScale256);
34 }
35
CreateProc(SkReadBuffer & buffer)36 SkFlattenable* SkLerpXfermode::CreateProc(SkReadBuffer& buffer) {
37 return SkNEW_ARGS(SkLerpXfermode, (buffer.readUInt()));
38 }
39
xfer32(SkPMColor dst[],const SkPMColor src[],int count,const SkAlpha aa[]) const40 void SkLerpXfermode::xfer32(SkPMColor dst[], const SkPMColor src[], int count,
41 const SkAlpha aa[]) const {
42 const int scale = fScale256;
43
44 if (aa) {
45 for (int i = 0; i < count; ++i) {
46 unsigned a = aa[i];
47 if (a) {
48 SkPMColor dstC = dst[i];
49 SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale);
50 if (a < 255) {
51 resC = SkFastFourByteInterp256(resC, dstC, a + (a >> 7));
52 }
53 dst[i] = resC;
54 }
55 }
56 } else {
57 for (int i = 0; i < count; ++i) {
58 dst[i] = SkFastFourByteInterp256(src[i], dst[i], scale);
59 }
60 }
61 }
62
xfer16(uint16_t dst[],const SkPMColor src[],int count,const SkAlpha aa[]) const63 void SkLerpXfermode::xfer16(uint16_t dst[], const SkPMColor src[], int count,
64 const SkAlpha aa[]) const {
65 const int scale = fScale256;
66
67 if (aa) {
68 for (int i = 0; i < count; ++i) {
69 unsigned a = aa[i];
70 if (a) {
71 SkPMColor dstC = SkPixel16ToPixel32(dst[i]);
72 SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale);
73 if (a < 255) {
74 resC = SkFastFourByteInterp256(resC, dstC, a + (a >> 7));
75 }
76 dst[i] = SkPixel32ToPixel16(resC);
77 }
78 }
79 } else {
80 for (int i = 0; i < count; ++i) {
81 SkPMColor dstC = SkPixel16ToPixel32(dst[i]);
82 SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale);
83 dst[i] = SkPixel32ToPixel16(resC);
84 }
85 }
86 }
87
xferA8(SkAlpha dst[],const SkPMColor src[],int count,const SkAlpha aa[]) const88 void SkLerpXfermode::xferA8(SkAlpha dst[], const SkPMColor src[], int count,
89 const SkAlpha aa[]) const {
90 const int scale = fScale256;
91
92 if (aa) {
93 for (int i = 0; i < count; ++i) {
94 unsigned a = aa[i];
95 if (a) {
96 unsigned dstA = dst[i];
97 unsigned resA = SkAlphaBlend(SkGetPackedA32(src[i]), dstA, scale);
98 if (a < 255) {
99 resA = SkAlphaBlend(resA, dstA, a + (a >> 7));
100 }
101 dst[i] = resA;
102 }
103 }
104 } else {
105 for (int i = 0; i < count; ++i) {
106 dst[i] = SkAlphaBlend(SkGetPackedA32(src[i]), dst[i], scale);
107 }
108 }
109 }
110
111 #ifndef SK_IGNORE_TO_STRING
toString(SkString * str) const112 void SkLerpXfermode::toString(SkString* str) const {
113 str->printf("SkLerpXfermode: scale: %g", fScale256 / 256.0);
114 }
115 #endif
116