1 /*
2  * Copyright 2013 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 <cinttypes>
20 
21 #include <ui/Size.h>
22 #include <utils/Errors.h>
23 #include <utils/RefBase.h>
24 #include <utils/StrongPointer.h>
25 
26 namespace android {
27 
28 class Fence;
29 class IGraphicBufferProducer;
30 class String8;
31 
32 namespace compositionengine {
33 
34 /**
35  * An abstraction for working with a display surface (buffer queue)
36  */
37 class DisplaySurface : public virtual RefBase {
38 public:
39     virtual ~DisplaySurface();
40 
41     // beginFrame is called at the beginning of the composition loop, before
42     // the configuration is known. The DisplaySurface should do anything it
43     // needs to do to enable HWComposer to decide how to compose the frame.
44     // We pass in mustRecompose so we can keep VirtualDisplaySurface's state
45     // machine happy without actually queueing a buffer if nothing has changed.
46     virtual status_t beginFrame(bool mustRecompose) = 0;
47 
48     // prepareFrame is called after the composition configuration is known but
49     // before composition takes place. The DisplaySurface can use the
50     // composition type to decide how to manage the flow of buffers between
51     // GPU and HWC for this frame.
52     enum class CompositionType : uint8_t { Unknown = 0, Gpu = 0b1, Hwc = 0b10, Mixed = Gpu | Hwc };
53     virtual status_t prepareFrame(CompositionType) = 0;
54 
55     // Inform the surface that GPU composition is complete for this frame, and
56     // the surface should make sure that HWComposer has the correct buffer for
57     // this frame. Some implementations may only push a new buffer to
58     // HWComposer if GPU composition took place, others need to push a new
59     // buffer on every frame.
60     //
61     // advanceFrame must be followed by a call to  onFrameCommitted before
62     // advanceFrame may be called again.
63     virtual status_t advanceFrame(float hdrSdrRatio) = 0;
64 
65     // onFrameCommitted is called after the frame has been committed to the
66     // hardware composer. The surface collects the release fence for this
67     // frame's buffer.
68     virtual void onFrameCommitted() = 0;
69 
70     virtual void dumpAsString(String8& result) const = 0;
71 
72     virtual void resizeBuffers(const ui::Size&) = 0;
73 
74     virtual const sp<Fence>& getClientTargetAcquireFence() const = 0;
75 
76     // Returns true if the render surface supports client composition prediction.
77     virtual bool supportsCompositionStrategyPrediction() const;
78 };
79 
80 } // namespace compositionengine
81 } // namespace android
82