xref: /aosp_15_r20/frameworks/native/libs/renderengine/skia/filters/KawaseBlurDualFilter.h (revision 38e8c45f13ce32b0dcecb25141ffecaf386fa17f)
1 /*
2  * Copyright 2024 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 <SkCanvas.h>
20 #include <SkImage.h>
21 #include <SkRuntimeEffect.h>
22 #include <SkSurface.h>
23 #include "BlurFilter.h"
24 
25 namespace android {
26 namespace renderengine {
27 namespace skia {
28 
29 /**
30  * This is an implementation of a Kawase blur with dual-filtering passes, as described in here:
31  * https://community.arm.com/cfs-file/__key/communityserver-blogs-components-weblogfiles/00-00-00-20-66/siggraph2015_2D00_mmg_2D00_marius_2D00_slides.pdf
32  * https://community.arm.com/cfs-file/__key/communityserver-blogs-components-weblogfiles/00-00-00-20-66/siggraph2015_2D00_mmg_2D00_marius_2D00_notes.pdf
33  */
34 class KawaseBlurDualFilter : public BlurFilter {
35 public:
36     explicit KawaseBlurDualFilter();
~KawaseBlurDualFilter()37     virtual ~KawaseBlurDualFilter() {}
38 
39     // Execute blur, saving it to a texture
40     sk_sp<SkImage> generate(SkiaGpuContext* context, const uint32_t radius,
41                             const sk_sp<SkImage> blurInput, const SkRect& blurRect) const override;
42 
43 private:
44     sk_sp<SkRuntimeEffect> mBlurEffect;
45 
46     void blurInto(const sk_sp<SkSurface>& drawSurface, const sk_sp<SkImage>& readImage,
47                   const float radius, const float alpha) const;
48 
49     void blurInto(const sk_sp<SkSurface>& drawSurface, const sk_sp<SkShader> input,
50                   const float inverseScale, const float radius, const float alpha) const;
51 };
52 
53 } // namespace skia
54 } // namespace renderengine
55 } // namespace android
56