1
2 /*
3 * Copyright 2006 The Android Open Source Project
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 "SkTransparentShader.h"
11 #include "SkColorPriv.h"
12
setContext(const SkBitmap & device,const SkPaint & paint,const SkMatrix & matrix)13 bool SkTransparentShader::setContext(const SkBitmap& device,
14 const SkPaint& paint,
15 const SkMatrix& matrix) {
16 fDevice = &device;
17 fAlpha = paint.getAlpha();
18
19 return this->INHERITED::setContext(device, paint, matrix);
20 }
21
getFlags()22 uint32_t SkTransparentShader::getFlags() {
23 uint32_t flags = this->INHERITED::getFlags();
24
25 switch (fDevice->getConfig()) {
26 case SkBitmap::kRGB_565_Config:
27 flags |= kHasSpan16_Flag;
28 if (fAlpha == 255)
29 flags |= kOpaqueAlpha_Flag;
30 break;
31 case SkBitmap::kARGB_8888_Config:
32 case SkBitmap::kARGB_4444_Config:
33 if (fAlpha == 255 && fDevice->isOpaque())
34 flags |= kOpaqueAlpha_Flag;
35 break;
36 default:
37 break;
38 }
39 return flags;
40 }
41
shadeSpan(int x,int y,SkPMColor span[],int count)42 void SkTransparentShader::shadeSpan(int x, int y, SkPMColor span[], int count) {
43 unsigned scale = SkAlpha255To256(fAlpha);
44
45 switch (fDevice->getConfig()) {
46 case SkBitmap::kARGB_8888_Config:
47 if (scale == 256) {
48 SkPMColor* src = fDevice->getAddr32(x, y);
49 if (src != span) {
50 memcpy(span, src, count * sizeof(SkPMColor));
51 }
52 } else {
53 const SkPMColor* src = fDevice->getAddr32(x, y);
54 for (int i = count - 1; i >= 0; --i) {
55 span[i] = SkAlphaMulQ(src[i], scale);
56 }
57 }
58 break;
59 case SkBitmap::kRGB_565_Config: {
60 const uint16_t* src = fDevice->getAddr16(x, y);
61 if (scale == 256) {
62 for (int i = count - 1; i >= 0; --i) {
63 span[i] = SkPixel16ToPixel32(src[i]);
64 }
65 } else {
66 unsigned alpha = fAlpha;
67 for (int i = count - 1; i >= 0; --i) {
68 uint16_t c = src[i];
69 unsigned r = SkPacked16ToR32(c);
70 unsigned g = SkPacked16ToG32(c);
71 unsigned b = SkPacked16ToB32(c);
72
73 span[i] = SkPackARGB32( alpha,
74 SkAlphaMul(r, scale),
75 SkAlphaMul(g, scale),
76 SkAlphaMul(b, scale));
77 }
78 }
79 break;
80 }
81 case SkBitmap::kARGB_4444_Config: {
82 const uint16_t* src = fDevice->getAddr16(x, y);
83 if (scale == 256) {
84 for (int i = count - 1; i >= 0; --i) {
85 span[i] = SkPixel4444ToPixel32(src[i]);
86 }
87 } else {
88 unsigned scale16 = scale >> 4;
89 for (int i = count - 1; i >= 0; --i) {
90 uint32_t c = SkExpand_4444(src[i]) * scale16;
91 span[i] = SkCompact_8888(c);
92 }
93 }
94 break;
95 }
96 case SkBitmap::kIndex8_Config:
97 SkDEBUGFAIL("index8 not supported as a destination device");
98 break;
99 case SkBitmap::kA8_Config: {
100 const uint8_t* src = fDevice->getAddr8(x, y);
101 if (scale == 256) {
102 for (int i = count - 1; i >= 0; --i) {
103 span[i] = SkPackARGB32(src[i], 0, 0, 0);
104 }
105 } else {
106 for (int i = count - 1; i >= 0; --i) {
107 span[i] = SkPackARGB32(SkAlphaMul(src[i], scale), 0, 0, 0);
108 }
109 }
110 break;
111 }
112 case SkBitmap::kA1_Config:
113 SkDEBUGFAIL("kA1_Config umimplemented at this time");
114 break;
115 default: // to avoid warnings
116 break;
117 }
118 }
119
shadeSpan16(int x,int y,uint16_t span[],int count)120 void SkTransparentShader::shadeSpan16(int x, int y, uint16_t span[], int count) {
121 SkASSERT(fDevice->getConfig() == SkBitmap::kRGB_565_Config);
122
123 uint16_t* src = fDevice->getAddr16(x, y);
124 if (src != span) {
125 memcpy(span, src, count << 1);
126 }
127 }
128
getFactory()129 SkFlattenable::Factory SkTransparentShader::getFactory() {
130 return Create;
131 }
132
flatten(SkFlattenableWriteBuffer & buffer)133 void SkTransparentShader::flatten(SkFlattenableWriteBuffer& buffer) {
134 this->INHERITED::flatten(buffer);
135 }
136
137