1 /*
2  * Copyright (C) 2014 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 #ifndef EGLMANAGER_H
17 #define EGLMANAGER_H
18 
19 #include <cutils/compiler.h>
20 #include <EGL/egl.h>
21 #include <SkRect.h>
22 #include <ui/GraphicBuffer.h>
23 #include <utils/StrongPointer.h>
24 
25 namespace android {
26 namespace uirenderer {
27 namespace renderthread {
28 
29 class RenderThread;
30 class EglManager;
31 
32 class Frame {
33 public:
width()34     EGLint width() const { return mWidth; }
height()35     EGLint height() const { return mHeight; }
36 
37     // See: https://www.khronos.org/registry/egl/extensions/EXT/EGL_EXT_buffer_age.txt
38     // for what this means
bufferAge()39     EGLint bufferAge() const { return mBufferAge; }
40 
41 private:
42     friend class EglManager;
43 
44     EGLSurface mSurface;
45     EGLint mWidth;
46     EGLint mHeight;
47     EGLint mBufferAge;
48 
49     // Maps from 0,0 in top-left to 0,0 in bottom-left
50     // If out is not an EGLint[4] you're going to have a bad time
51     void map(const SkRect& in, EGLint* out) const;
52 };
53 
54 // This class contains the shared global EGL objects, such as EGLDisplay
55 // and EGLConfig, which are re-used by CanvasContext
56 class EglManager {
57 public:
58     // Returns true on success, false on failure
59     void initialize();
60 
61     bool hasEglContext();
62 
63     EGLSurface createSurface(EGLNativeWindowType window);
64     void destroySurface(EGLSurface surface);
65 
66     void destroy();
67 
isCurrent(EGLSurface surface)68     bool isCurrent(EGLSurface surface) { return mCurrentSurface == surface; }
69     // Returns true if the current surface changed, false if it was already current
70     bool makeCurrent(EGLSurface surface, EGLint* errOut = nullptr);
71     Frame beginFrame(EGLSurface surface);
72     void damageFrame(const Frame& frame, const SkRect& dirty);
73     // If this returns true it is mandatory that swapBuffers is called
74     // if damageFrame is called without subsequent calls to damageFrame().
75     // See EGL_KHR_partial_update for more information
76     bool damageRequiresSwap();
77     bool swapBuffers(const Frame& frame, const SkRect& screenDirty);
78 
79     // Returns true iff the surface is now preserving buffers.
80     bool setPreserveBuffer(EGLSurface surface, bool preserve);
81 
82     void setTextureAtlas(const sp<GraphicBuffer>& buffer, int64_t* map, size_t mapSize);
83 
84     void fence();
85 
86 private:
87     friend class RenderThread;
88 
89     EglManager(RenderThread& thread);
90     // EglContext is never destroyed, method is purposely not implemented
91     ~EglManager();
92 
93     void initExtensions();
94     void createPBufferSurface();
95     void loadConfig();
96     void createContext();
97     void initAtlas();
98     EGLint queryBufferAge(EGLSurface surface);
99 
100     RenderThread& mRenderThread;
101 
102     EGLDisplay mEglDisplay;
103     EGLConfig mEglConfig;
104     EGLContext mEglContext;
105     EGLSurface mPBufferSurface;
106 
107     EGLSurface mCurrentSurface;
108 
109     sp<GraphicBuffer> mAtlasBuffer;
110     int64_t* mAtlasMap;
111     size_t mAtlasMapSize;
112 
113     enum class SwapBehavior {
114         Discard,
115         Preserved,
116         BufferAge,
117     };
118     SwapBehavior mSwapBehavior = SwapBehavior::Discard;
119 };
120 
121 } /* namespace renderthread */
122 } /* namespace uirenderer */
123 } /* namespace android */
124 
125 #endif /* EGLMANAGER_H */
126