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
onCreateContext(const ContextRec & rec,void * storage) const14 SkShader::Context* SkTransparentShader::onCreateContext(const ContextRec& rec,
15 void* storage) const {
16 return SkNEW_PLACEMENT_ARGS(storage, TransparentShaderContext, (*this, rec));
17 }
18
contextSize() const19 size_t SkTransparentShader::contextSize() const {
20 return sizeof(TransparentShaderContext);
21 }
22
TransparentShaderContext(const SkTransparentShader & shader,const ContextRec & rec)23 SkTransparentShader::TransparentShaderContext::TransparentShaderContext(
24 const SkTransparentShader& shader, const ContextRec& rec)
25 : INHERITED(shader, rec)
26 , fDevice(rec.fDevice) {}
27
~TransparentShaderContext()28 SkTransparentShader::TransparentShaderContext::~TransparentShaderContext() {}
29
getFlags() const30 uint32_t SkTransparentShader::TransparentShaderContext::getFlags() const {
31 uint32_t flags = this->INHERITED::getFlags();
32
33 switch (fDevice->colorType()) {
34 case kRGB_565_SkColorType:
35 flags |= kHasSpan16_Flag;
36 if (this->getPaintAlpha() == 255)
37 flags |= kOpaqueAlpha_Flag;
38 break;
39 case kN32_SkColorType:
40 if (this->getPaintAlpha() == 255 && fDevice->isOpaque())
41 flags |= kOpaqueAlpha_Flag;
42 break;
43 default:
44 break;
45 }
46 return flags;
47 }
48
shadeSpan(int x,int y,SkPMColor span[],int count)49 void SkTransparentShader::TransparentShaderContext::shadeSpan(int x, int y, SkPMColor span[],
50 int count) {
51 unsigned scale = SkAlpha255To256(this->getPaintAlpha());
52
53 switch (fDevice->colorType()) {
54 case kN32_SkColorType:
55 if (scale == 256) {
56 SkPMColor* src = fDevice->getAddr32(x, y);
57 if (src != span) {
58 memcpy(span, src, count * sizeof(SkPMColor));
59 }
60 } else {
61 const SkPMColor* src = fDevice->getAddr32(x, y);
62 for (int i = count - 1; i >= 0; --i) {
63 span[i] = SkAlphaMulQ(src[i], scale);
64 }
65 }
66 break;
67 case kRGB_565_SkColorType: {
68 const uint16_t* src = fDevice->getAddr16(x, y);
69 if (scale == 256) {
70 for (int i = count - 1; i >= 0; --i) {
71 span[i] = SkPixel16ToPixel32(src[i]);
72 }
73 } else {
74 unsigned alpha = this->getPaintAlpha();
75 for (int i = count - 1; i >= 0; --i) {
76 uint16_t c = src[i];
77 unsigned r = SkPacked16ToR32(c);
78 unsigned g = SkPacked16ToG32(c);
79 unsigned b = SkPacked16ToB32(c);
80
81 span[i] = SkPackARGB32( alpha,
82 SkAlphaMul(r, scale),
83 SkAlphaMul(g, scale),
84 SkAlphaMul(b, scale));
85 }
86 }
87 break;
88 }
89 case kAlpha_8_SkColorType: {
90 const uint8_t* src = fDevice->getAddr8(x, y);
91 if (scale == 256) {
92 for (int i = count - 1; i >= 0; --i) {
93 span[i] = SkPackARGB32(src[i], 0, 0, 0);
94 }
95 } else {
96 for (int i = count - 1; i >= 0; --i) {
97 span[i] = SkPackARGB32(SkAlphaMul(src[i], scale), 0, 0, 0);
98 }
99 }
100 break;
101 }
102 default:
103 SkDEBUGFAIL("colorType not supported as a destination device");
104 break;
105 }
106 }
107
shadeSpan16(int x,int y,uint16_t span[],int count)108 void SkTransparentShader::TransparentShaderContext::shadeSpan16(int x, int y, uint16_t span[],
109 int count) {
110 SkASSERT(fDevice->colorType() == kRGB_565_SkColorType);
111
112 uint16_t* src = fDevice->getAddr16(x, y);
113 if (src != span) {
114 memcpy(span, src, count << 1);
115 }
116 }
117
CreateProc(SkReadBuffer & buffer)118 SkFlattenable* SkTransparentShader::CreateProc(SkReadBuffer& buffer) {
119 return SkNEW(SkTransparentShader);
120 }
121
122 #ifndef SK_IGNORE_TO_STRING
toString(SkString * str) const123 void SkTransparentShader::toString(SkString* str) const {
124 str->append("SkTransparentShader: (");
125
126 this->INHERITED::toString(str);
127
128 str->append(")");
129 }
130 #endif
131