1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkComposeShader.h"
#include "SkColorFilter.h"
#include "SkColorPriv.h"
#include "SkColorShader.h"
#include "SkReadBuffer.h"
#include "SkWriteBuffer.h"
#include "SkXfermode.h"
#include "SkString.h"
///////////////////////////////////////////////////////////////////////////////
SkComposeShader::SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode) {
fShaderA = sA; sA->ref();
fShaderB = sB; sB->ref();
// mode may be null
fMode = mode;
SkSafeRef(mode);
}
SkComposeShader::SkComposeShader(SkReadBuffer& buffer) :
INHERITED(buffer) {
fShaderA = buffer.readShader();
if (NULL == fShaderA) {
fShaderA = SkNEW_ARGS(SkColorShader, ((SkColor)0));
}
fShaderB = buffer.readShader();
if (NULL == fShaderB) {
fShaderB = SkNEW_ARGS(SkColorShader, ((SkColor)0));
}
fMode = buffer.readXfermode();
}
SkComposeShader::~SkComposeShader() {
SkSafeUnref(fMode);
fShaderB->unref();
fShaderA->unref();
}
size_t SkComposeShader::contextSize() const {
return sizeof(ComposeShaderContext) + fShaderA->contextSize() + fShaderB->contextSize();
}
class SkAutoAlphaRestore {
public:
SkAutoAlphaRestore(SkPaint* paint, uint8_t newAlpha) {
fAlpha = paint->getAlpha();
fPaint = paint;
paint->setAlpha(newAlpha);
}
~SkAutoAlphaRestore() {
fPaint->setAlpha(fAlpha);
}
private:
SkPaint* fPaint;
uint8_t fAlpha;
};
#define SkAutoAlphaRestore(...) SK_REQUIRE_LOCAL_VAR(SkAutoAlphaRestore)
void SkComposeShader::flatten(SkWriteBuffer& buffer) const {
this->INHERITED::flatten(buffer);
buffer.writeFlattenable(fShaderA);
buffer.writeFlattenable(fShaderB);
buffer.writeFlattenable(fMode);
}
/* We call validContext/createContext on our two worker shaders.
However, we always let them see opaque alpha, and if the paint
really is translucent, then we apply that after the fact.
*/
bool SkComposeShader::validContext(const SkBitmap& device,
const SkPaint& paint,
const SkMatrix& matrix,
SkMatrix* totalInverse) const {
if (!this->INHERITED::validContext(device, paint, matrix, totalInverse)) {
return false;
}
// we preconcat our localMatrix (if any) with the device matrix
// before calling our sub-shaders
SkMatrix tmpM;
tmpM.setConcat(matrix, this->getLocalMatrix());
return fShaderA->validContext(device, paint, tmpM) &&
fShaderB->validContext(device, paint, tmpM);
}
SkShader::Context* SkComposeShader::createContext(const SkBitmap& device, const SkPaint& paint,
const SkMatrix& matrix, void* storage) const {
if (!this->validContext(device, paint, matrix)) {
return NULL;
}
// we preconcat our localMatrix (if any) with the device matrix
// before calling our sub-shaders
SkMatrix tmpM;
tmpM.setConcat(matrix, this->getLocalMatrix());
SkAutoAlphaRestore restore(const_cast<SkPaint*>(&paint), 0xFF);
char* aStorage = (char*) storage + sizeof(ComposeShaderContext);
char* bStorage = aStorage + fShaderA->contextSize();
SkShader::Context* contextA = fShaderA->createContext(device, paint, tmpM, aStorage);
SkShader::Context* contextB = fShaderB->createContext(device, paint, tmpM, bStorage);
// Both functions must succeed; otherwise validContext should have returned
// false.
SkASSERT(contextA);
SkASSERT(contextB);
return SkNEW_PLACEMENT_ARGS(storage, ComposeShaderContext,
(*this, device, paint, matrix, contextA, contextB));
}
SkComposeShader::ComposeShaderContext::ComposeShaderContext(
const SkComposeShader& shader, const SkBitmap& device,
const SkPaint& paint, const SkMatrix& matrix,
SkShader::Context* contextA, SkShader::Context* contextB)
: INHERITED(shader, device, paint, matrix)
, fShaderContextA(contextA)
, fShaderContextB(contextB) {}
SkComposeShader::ComposeShaderContext::~ComposeShaderContext() {
fShaderContextA->~Context();
fShaderContextB->~Context();
}
// larger is better (fewer times we have to loop), but we shouldn't
// take up too much stack-space (each element is 4 bytes)
#define TMP_COLOR_COUNT 64
void SkComposeShader::ComposeShaderContext::shadeSpan(int x, int y, SkPMColor result[], int count) {
SkShader::Context* shaderContextA = fShaderContextA;
SkShader::Context* shaderContextB = fShaderContextB;
SkXfermode* mode = static_cast<const SkComposeShader&>(fShader).fMode;
unsigned scale = SkAlpha255To256(this->getPaintAlpha());
SkPMColor tmp[TMP_COLOR_COUNT];
if (NULL == mode) { // implied SRC_OVER
// TODO: when we have a good test-case, should use SkBlitRow::Proc32
// for these loops
do {
int n = count;
if (n > TMP_COLOR_COUNT) {
n = TMP_COLOR_COUNT;
}
shaderContextA->shadeSpan(x, y, result, n);
shaderContextB->shadeSpan(x, y, tmp, n);
if (256 == scale) {
for (int i = 0; i < n; i++) {
result[i] = SkPMSrcOver(tmp[i], result[i]);
}
} else {
for (int i = 0; i < n; i++) {
result[i] = SkAlphaMulQ(SkPMSrcOver(tmp[i], result[i]),
scale);
}
}
result += n;
x += n;
count -= n;
} while (count > 0);
} else { // use mode for the composition
do {
int n = count;
if (n > TMP_COLOR_COUNT) {
n = TMP_COLOR_COUNT;
}
shaderContextA->shadeSpan(x, y, result, n);
shaderContextB->shadeSpan(x, y, tmp, n);
mode->xfer32(result, tmp, n, NULL);
if (256 == scale) {
for (int i = 0; i < n; i++) {
result[i] = SkAlphaMulQ(result[i], scale);
}
}
result += n;
x += n;
count -= n;
} while (count > 0);
}
}
#ifndef SK_IGNORE_TO_STRING
void SkComposeShader::toString(SkString* str) const {
str->append("SkComposeShader: (");
str->append("ShaderA: ");
fShaderA->toString(str);
str->append(" ShaderB: ");
fShaderB->toString(str);
str->append(" Xfermode: ");
fMode->toString(str);
this->INHERITED::toString(str);
str->append(")");
}
#endif
|
