frameworks_native/services/surfaceflinger/FrameRateHelper.h

/*
 * Copyright (c) 2014, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *     * Neither the name of The Linux Foundation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ANDROID_SF_FRAME_RATE_HELPER_H
#define ANDROID_SF_FRAME_RATE_HELPER_H

#include <utils/Timers.h>

namespace android {

class FrameRateHelper {
public:
        FrameRateHelper() : mTime(0), mFps(0), mFpsCount(0) {}
        ~FrameRateHelper() {}

    bool update() {
        mFpsCount++;

        nsecs_t now = systemTime();
        if (ns2ms(now - mTime) > 1000) {
            mFps = mFpsCount;
            mFpsCount = 0;
            mTime = now;
            return true;
        }

        return false;
    }

    unsigned int get() const {
        return mFps;
    }

private:
    nsecs_t mTime;
    unsigned int mFps;
    unsigned int mFpsCount;
};

// ---------------------------------------------------------------------------
}; // namespace android

#endif // ANDROID_SF_FRAME_RATE_HELPER_H