/*
 * Copyright (C) 2021 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. 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.
 */


#include "config.h"
#include "DisplayUpdate.h"

#include <wtf/MathExtras.h>
#include <wtf/text/TextStream.h>

namespace WebCore {

bool DisplayUpdate::relevantForUpdateFrequency(FramesPerSecond preferredFramesPerSecond) const
{
    // FIXME: Ideally this would be an assertion, but that may fire when windows move between screens with different refresh rates, because of webkit.org/b/212120.
    if (!preferredFramesPerSecond || !WTF::isIntegral(static_cast<float>(updatesPerSecond) / preferredFramesPerSecond))
        return true;

    unsigned rateFactor = updatesPerSecond / preferredFramesPerSecond;
    return !rateFactor || !(updateIndex % rateFactor);
}

TextStream& operator<<(TextStream& ts, const DisplayUpdate& update)
{
    ts << update.updateIndex << "/" << update.updatesPerSecond;
    return ts;
}

} // namespace WebCore