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 "SkTableMaskFilter.h"
11
SkTableMaskFilter()12 SkTableMaskFilter::SkTableMaskFilter() {
13 for (int i = 0; i < 256; i++) {
14 fTable[i] = i;
15 }
16 }
17
SkTableMaskFilter(const uint8_t table[256])18 SkTableMaskFilter::SkTableMaskFilter(const uint8_t table[256]) {
19 this->setTable(table);
20 }
21
~SkTableMaskFilter()22 SkTableMaskFilter::~SkTableMaskFilter() {}
23
setTable(const uint8_t table[256])24 void SkTableMaskFilter::setTable(const uint8_t table[256]) {
25 memcpy(fTable, table, 256);
26 }
27
filterMask(SkMask * dst,const SkMask & src,const SkMatrix &,SkIPoint * margin)28 bool SkTableMaskFilter::filterMask(SkMask* dst, const SkMask& src,
29 const SkMatrix&, SkIPoint* margin) {
30 if (src.fFormat != SkMask::kA8_Format) {
31 return false;
32 }
33
34 dst->fBounds = src.fBounds;
35 dst->fRowBytes = SkAlign4(dst->fBounds.width());
36 dst->fFormat = SkMask::kA8_Format;
37 dst->fImage = NULL;
38
39 if (src.fImage) {
40 dst->fImage = SkMask::AllocImage(dst->computeImageSize());
41
42 const uint8_t* srcP = src.fImage;
43 uint8_t* dstP = dst->fImage;
44 const uint8_t* table = fTable;
45 int dstWidth = dst->fBounds.width();
46 int extraZeros = dst->fRowBytes - dstWidth;
47
48 for (int y = dst->fBounds.height() - 1; y >= 0; --y) {
49 for (int x = dstWidth - 1; x >= 0; --x) {
50 dstP[x] = table[srcP[x]];
51 }
52 srcP += src.fRowBytes;
53 // we can't just inc dstP by rowbytes, because if it has any
54 // padding between its width and its rowbytes, we need to zero those
55 // so that the bitters can read those safely if that is faster for
56 // them
57 dstP += dstWidth;
58 for (int i = extraZeros - 1; i >= 0; --i) {
59 *dstP++ = 0;
60 }
61 }
62 }
63
64 if (margin) {
65 margin->set(0, 0);
66 }
67 return true;
68 }
69
getFormat()70 SkMask::Format SkTableMaskFilter::getFormat() {
71 return SkMask::kA8_Format;
72 }
73
flatten(SkFlattenableWriteBuffer & wb)74 void SkTableMaskFilter::flatten(SkFlattenableWriteBuffer& wb) {
75 this->INHERITED::flatten(wb);
76 wb.writePad(fTable, 256);
77 }
78
SkTableMaskFilter(SkFlattenableReadBuffer & rb)79 SkTableMaskFilter::SkTableMaskFilter(SkFlattenableReadBuffer& rb)
80 : INHERITED(rb) {
81 rb.read(fTable, 256);
82 }
83
Factory(SkFlattenableReadBuffer & rb)84 SkFlattenable* SkTableMaskFilter::Factory(SkFlattenableReadBuffer& rb) {
85 return SkNEW_ARGS(SkTableMaskFilter, (rb));
86 }
87
getFactory()88 SkFlattenable::Factory SkTableMaskFilter::getFactory() {
89 return SkTableMaskFilter::Factory;
90 }
91
92 ///////////////////////////////////////////////////////////////////////////////
93
MakeGammaTable(uint8_t table[256],SkScalar gamma)94 void SkTableMaskFilter::MakeGammaTable(uint8_t table[256], SkScalar gamma) {
95 const float dx = 1 / 255.0f;
96 const float g = SkScalarToFloat(gamma);
97
98 float x = 0;
99 for (int i = 0; i < 256; i++) {
100 float ee = powf(x, g) * 255;
101 table[i] = SkPin32(sk_float_round2int(powf(x, g) * 255), 0, 255);
102 x += dx;
103 }
104 }
105
MakeClipTable(uint8_t table[256],uint8_t min,uint8_t max)106 void SkTableMaskFilter::MakeClipTable(uint8_t table[256], uint8_t min,
107 uint8_t max) {
108 if (0 == max) {
109 max = 1;
110 }
111 if (min >= max) {
112 min = max - 1;
113 }
114 SkASSERT(min < max);
115
116 SkFixed scale = (1 << 16) * 255 / (max - min);
117 memset(table, 0, min + 1);
118 for (int i = min + 1; i < max; i++) {
119 int value = SkFixedRound(scale * (i - min));
120 SkASSERT(value <= 255);
121 table[i] = value;
122 }
123 memset(table + max, 255, 256 - max);
124
125 #if 0
126 int j;
127 for (j = 0; j < 256; j++) {
128 if (table[j]) {
129 break;
130 }
131 }
132 SkDebugf("%d %d start [%d]", min, max, j);
133 for (; j < 256; j++) {
134 SkDebugf(" %d", table[j]);
135 }
136 SkDebugf("\n\n");
137 #endif
138 }
139
140