Source/WebCore/platform/graphics/DisplayUpdate.cpp

/*
 * Copyright (C) 2021 Apple Inc. All rights reserved.
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#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