1 /*
2  * Copyright 2021 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include "BlurFilter.h"
20 #include <SkCanvas.h>
21 #include <SkImage.h>
22 #include <SkRuntimeEffect.h>
23 #include <SkSurface.h>
24 
25 using namespace std;
26 
27 namespace android {
28 namespace renderengine {
29 namespace skia {
30 
31 /**
32  * This is an implementation of a Kawase blur, as described in here:
33  * https://community.arm.com/cfs-file/__key/communityserver-blogs-components-weblogfiles/
34  * 00-00-00-20-66/siggraph2015_2D00_mmg_2D00_marius_2D00_notes.pdf
35  */
36 class KawaseBlurFilter: public BlurFilter {
37 public:
38     // Maximum number of render passes
39     static constexpr uint32_t kMaxPasses = 4;
40 
41     explicit KawaseBlurFilter();
~KawaseBlurFilter()42     virtual ~KawaseBlurFilter(){}
43 
44     // Execute blur, saving it to a texture
45     sk_sp<SkImage> generate(SkiaGpuContext* context, const uint32_t radius,
46                             const sk_sp<SkImage> blurInput, const SkRect& blurRect) const override;
47 
48 private:
49     sk_sp<SkRuntimeEffect> mBlurEffect;
50 };
51 
52 } // namespace skia
53 } // namespace renderengine
54 } // namespace android
55