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
|
/*
* Copyright 2021 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define ATRACE_TAG ATRACE_TAG_GRAPHICS
#include "BlurFilter.h"
#include <SkCanvas.h>
#include <SkData.h>
#include <SkPaint.h>
#include <SkRRect.h>
#include <SkRuntimeEffect.h>
#include <SkSize.h>
#include <SkString.h>
#include <SkSurface.h>
#include <log/log.h>
#include <utils/Trace.h>
namespace android {
namespace renderengine {
namespace skia {
static sk_sp<SkRuntimeEffect> createMixEffect() {
SkString mixString(R"(
uniform shader blurredInput;
uniform shader originalInput;
uniform float mixFactor;
half4 main(float2 xy) {
return half4(mix(originalInput.eval(xy), blurredInput.eval(xy), mixFactor)).rgb1;
}
)");
auto [mixEffect, mixError] = SkRuntimeEffect::MakeForShader(mixString);
if (!mixEffect) {
LOG_ALWAYS_FATAL("RuntimeShader error: %s", mixError.c_str());
}
return mixEffect;
}
static SkMatrix getShaderTransform(const SkCanvas* canvas, const SkRect& blurRect,
const float scale) {
// 1. Apply the blur shader matrix, which scales up the blurred surface to its real size
auto matrix = SkMatrix::Scale(scale, scale);
// 2. Since the blurred surface has the size of the layer, we align it with the
// top left corner of the layer position.
matrix.postConcat(SkMatrix::Translate(blurRect.fLeft, blurRect.fTop));
// 3. Finally, apply the inverse canvas matrix. The snapshot made in the BlurFilter is in the
// original surface orientation. The inverse matrix has to be applied to align the blur
// surface with the current orientation/position of the canvas.
SkMatrix drawInverse;
if (canvas != nullptr && canvas->getTotalMatrix().invert(&drawInverse)) {
matrix.postConcat(drawInverse);
}
return matrix;
}
BlurFilter::BlurFilter(const float maxCrossFadeRadius)
: mMaxCrossFadeRadius(maxCrossFadeRadius),
mMixEffect(maxCrossFadeRadius > 0 ? createMixEffect() : nullptr) {}
float BlurFilter::getMaxCrossFadeRadius() const {
return mMaxCrossFadeRadius;
}
void BlurFilter::drawBlurRegion(SkCanvas* canvas, const SkRRect& effectRegion,
const uint32_t blurRadius, const float blurAlpha,
const SkRect& blurRect, sk_sp<SkImage> blurredImage,
sk_sp<SkImage> input) {
ATRACE_CALL();
SkPaint paint;
paint.setAlphaf(blurAlpha);
const auto blurMatrix = getShaderTransform(canvas, blurRect, kInverseInputScale);
SkSamplingOptions linearSampling(SkFilterMode::kLinear, SkMipmapMode::kNone);
const auto blurShader = blurredImage->makeShader(SkTileMode::kClamp, SkTileMode::kClamp,
linearSampling, &blurMatrix);
if (blurRadius < mMaxCrossFadeRadius) {
// For sampling Skia's API expects the inverse of what logically seems appropriate. In this
// case you might expect the matrix to simply be the canvas matrix.
SkMatrix inputMatrix;
if (!canvas->getTotalMatrix().invert(&inputMatrix)) {
ALOGE("matrix was unable to be inverted");
}
SkRuntimeShaderBuilder blurBuilder(mMixEffect);
blurBuilder.child("blurredInput") = blurShader;
blurBuilder.child("originalInput") =
input->makeShader(SkTileMode::kClamp, SkTileMode::kClamp, linearSampling,
inputMatrix);
blurBuilder.uniform("mixFactor") = blurRadius / mMaxCrossFadeRadius;
paint.setShader(blurBuilder.makeShader());
} else {
paint.setShader(blurShader);
}
if (effectRegion.isRect()) {
if (blurAlpha == 1.0f) {
paint.setBlendMode(SkBlendMode::kSrc);
}
canvas->drawRect(effectRegion.rect(), paint);
} else {
paint.setAntiAlias(true);
canvas->drawRRect(effectRegion, paint);
}
}
} // namespace skia
} // namespace renderengine
} // namespace android
|
