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 #include "SkString.h"
13
setContext(const SkBitmap & device,const SkPaint & paint,const SkMatrix & matrix)14 bool SkTransparentShader::setContext(const SkBitmap& device,
15 const SkPaint& paint,
16 const SkMatrix& matrix) {
17 fDevice = &device;
18 fAlpha = paint.getAlpha();
19
20 return this->INHERITED::setContext(device, paint, matrix);
21 }
22
getFlags()23 uint32_t SkTransparentShader::getFlags() {
24 uint32_t flags = this->INHERITED::getFlags();
25
26 switch (fDevice->config()) {
27 case SkBitmap::kRGB_565_Config:
28 flags |= kHasSpan16_Flag;
29 if (fAlpha == 255)
30 flags |= kOpaqueAlpha_Flag;
31 break;
32 case SkBitmap::kARGB_8888_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->config()) {
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::kIndex8_Config:
82 SkDEBUGFAIL("index8 not supported as a destination device");
83 break;
84 case SkBitmap::kA8_Config: {
85 const uint8_t* src = fDevice->getAddr8(x, y);
86 if (scale == 256) {
87 for (int i = count - 1; i >= 0; --i) {
88 span[i] = SkPackARGB32(src[i], 0, 0, 0);
89 }
90 } else {
91 for (int i = count - 1; i >= 0; --i) {
92 span[i] = SkPackARGB32(SkAlphaMul(src[i], scale), 0, 0, 0);
93 }
94 }
95 break;
96 }
97 default: // to avoid warnings
98 break;
99 }
100 }
101
shadeSpan16(int x,int y,uint16_t span[],int count)102 void SkTransparentShader::shadeSpan16(int x, int y, uint16_t span[], int count) {
103 SkASSERT(fDevice->config() == SkBitmap::kRGB_565_Config);
104
105 uint16_t* src = fDevice->getAddr16(x, y);
106 if (src != span) {
107 memcpy(span, src, count << 1);
108 }
109 }
110
111 #ifdef SK_DEVELOPER
toString(SkString * str) const112 void SkTransparentShader::toString(SkString* str) const {
113 str->append("SkTransparentShader: (");
114
115 this->INHERITED::toString(str);
116
117 str->append(")");
118 }
119 #endif
120