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#include "TimeLord.h"
17
18namespace android {
19namespace uirenderer {
20namespace renderthread {
21
22TimeLord::TimeLord() : mFrameIntervalNanos(milliseconds_to_nanoseconds(16)), mFrameTimeNanos(0) {}
23
24bool TimeLord::vsyncReceived(nsecs_t vsync) {
25    if (vsync > mFrameTimeNanos) {
26        mFrameTimeNanos = vsync;
27        return true;
28    }
29    return false;
30}
31
32nsecs_t TimeLord::computeFrameTimeNanos() {
33    // Logic copied from Choreographer.java
34    nsecs_t now = systemTime(CLOCK_MONOTONIC);
35    nsecs_t jitterNanos = now - mFrameTimeNanos;
36    if (jitterNanos >= mFrameIntervalNanos) {
37        nsecs_t lastFrameOffset = jitterNanos % mFrameIntervalNanos;
38        mFrameTimeNanos = now - lastFrameOffset;
39    }
40    return mFrameTimeNanos;
41}
42
43} /* namespace renderthread */
44} /* namespace uirenderer */
45} /* namespace android */
46