1 /*
2  * Copyright 2022 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 <utils/Timers.h>
20 
21 namespace android::gui {
22 
23 // Expected timing of the next composited frame, based on the timing of the latest frames.
24 struct CompositorTiming {
25     static constexpr nsecs_t kDefaultVsyncPeriod = 16'666'667;
26 
27     CompositorTiming() = default;
28     CompositorTiming(nsecs_t vsyncDeadline, nsecs_t vsyncPeriod, nsecs_t vsyncPhase,
29                      nsecs_t presentLatency);
30 
31     // Time point when compositing is expected to start.
32     nsecs_t deadline = 0;
33 
34     // Duration between consecutive frames. In other words, the VSYNC period.
35     nsecs_t interval = kDefaultVsyncPeriod;
36 
37     // Duration between composite start and present. For missed frames, the extra latency is rounded
38     // to a multiple of the VSYNC period, such that the remainder (presentLatency % interval) always
39     // evaluates to the VSYNC phase offset.
40     nsecs_t presentLatency = kDefaultVsyncPeriod;
41 };
42 
43 } // namespace android::gui
44