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 #include "SkKernel33MaskFilter.h"
9 #include "SkColorPriv.h"
10
getFormat()11 SkMask::Format SkKernel33ProcMaskFilter::getFormat() {
12 return SkMask::kA8_Format;
13 }
14
filterMask(SkMask * dst,const SkMask & src,const SkMatrix &,SkIPoint * margin)15 bool SkKernel33ProcMaskFilter::filterMask(SkMask* dst, const SkMask& src,
16 const SkMatrix&, SkIPoint* margin) {
17 // margin???
18 dst->fImage = NULL;
19 dst->fBounds = src.fBounds;
20 dst->fBounds.inset(-1, -1);
21 dst->fFormat = SkMask::kA8_Format;
22
23 if (NULL == src.fImage) {
24 return true;
25 }
26
27 dst->fRowBytes = dst->fBounds.width();
28 size_t size = dst->computeImageSize();
29 if (0 == size) {
30 return false; // too big to allocate, abort
31 }
32 dst->fImage = SkMask::AllocImage(size);
33
34 const int h = src.fBounds.height();
35 const int w = src.fBounds.width();
36 const int srcRB = src.fRowBytes;
37 const uint8_t* srcImage = src.fImage;
38 uint8_t* dstImage = dst->fImage;
39
40 uint8_t* srcRows[3];
41 uint8_t storage[3][3];
42
43 srcRows[0] = storage[0];
44 srcRows[1] = storage[1];
45 srcRows[2] = storage[2];
46
47 unsigned scale = fPercent256;
48
49 for (int y = -1; y <= h; y++) {
50 uint8_t* dstRow = dstImage;
51 for (int x = -1; x <= w; x++) {
52 memset(storage, 0, sizeof(storage));
53 uint8_t* storagePtr = &storage[0][0];
54
55 for (int ky = y - 1; ky <= y + 1; ky++) {
56 const uint8_t* srcRow = srcImage + ky * srcRB; // may be out-of-range
57 for (int kx = x - 1; kx <= x + 1; kx++) {
58 if ((unsigned)ky < (unsigned)h && (unsigned)kx < (unsigned)w) {
59 *storagePtr = srcRow[kx];
60 }
61 storagePtr++;
62 }
63 }
64 int value = this->computeValue(srcRows);
65
66 if (scale < 256) {
67 value = SkAlphaBlend(value, srcRows[1][1], scale);
68 }
69 *dstRow++ = SkToU8(value);
70 }
71 dstImage += dst->fRowBytes;
72 }
73 return true;
74 }
75
flatten(SkFlattenableWriteBuffer & wb)76 void SkKernel33ProcMaskFilter::flatten(SkFlattenableWriteBuffer& wb) {
77 this->INHERITED::flatten(wb);
78 wb.write32(fPercent256);
79 }
80
SkKernel33ProcMaskFilter(SkFlattenableReadBuffer & rb)81 SkKernel33ProcMaskFilter::SkKernel33ProcMaskFilter(SkFlattenableReadBuffer& rb)
82 : SkMaskFilter(rb) {
83 fPercent256 = rb.readS32();
84 }
85
86 ///////////////////////////////////////////////////////////////////////////////
87
computeValue(uint8_t * const * srcRows)88 uint8_t SkKernel33MaskFilter::computeValue(uint8_t* const* srcRows) {
89 int value = 0;
90
91 for (int i = 0; i < 3; i++) {
92 for (int j = 0; j < 3; j++) {
93 value += fKernel[i][j] * srcRows[i][j];
94 }
95 }
96
97 value >>= fShift;
98
99 if (value < 0) {
100 value = 0;
101 } else if (value > 255) {
102 value = 255;
103 }
104 return (uint8_t)value;
105 }
106
flatten(SkFlattenableWriteBuffer & wb)107 void SkKernel33MaskFilter::flatten(SkFlattenableWriteBuffer& wb) {
108 this->INHERITED::flatten(wb);
109 wb.writeMul4(fKernel, 9 * sizeof(int));
110 wb.write32(fShift);
111 }
112
getFactory()113 SkFlattenable::Factory SkKernel33MaskFilter::getFactory() {
114 return Create;
115 }
116
Create(SkFlattenableReadBuffer & rb)117 SkFlattenable* SkKernel33MaskFilter::Create(SkFlattenableReadBuffer& rb) {
118 return new SkKernel33MaskFilter(rb);
119 }
120
SkKernel33MaskFilter(SkFlattenableReadBuffer & rb)121 SkKernel33MaskFilter::SkKernel33MaskFilter(SkFlattenableReadBuffer& rb)
122 : SkKernel33ProcMaskFilter(rb) {
123 rb.read(fKernel, 9 * sizeof(int));
124 fShift = rb.readS32();
125 }
126
127