DisplayRefreshMonitorMac.cpp [plain text]
#include "config.h"
#if USE(REQUEST_ANIMATION_FRAME_DISPLAY_MONITOR)
#include "DisplayRefreshMonitor.h"
#include <QuartzCore/QuartzCore.h>
#include <wtf/CurrentTime.h>
#include <wtf/MainThread.h>
namespace WebCore {
static CVReturn displayLinkCallback(CVDisplayLinkRef, const CVTimeStamp* now, const CVTimeStamp* outputTime, CVOptionFlags, CVOptionFlags*, void* data)
{
DisplayRefreshMonitor* monitor = static_cast<DisplayRefreshMonitor*>(data);
double nowSeconds = static_cast<double>(now->videoTime) / static_cast<double>(now->videoTimeScale);
double outputTimeSeconds = static_cast<double>(outputTime->videoTime) / static_cast<double>(outputTime->videoTimeScale);
monitor->displayLinkFired(nowSeconds, outputTimeSeconds);
return kCVReturnSuccess;
}
DisplayRefreshMonitor::~DisplayRefreshMonitor()
{
if (m_displayLink) {
CVDisplayLinkStop(m_displayLink);
CVDisplayLinkRelease(m_displayLink);
m_displayLink = 0;
}
cancelCallOnMainThread(DisplayRefreshMonitor::refreshDisplayOnMainThread, this);
}
bool DisplayRefreshMonitor::requestRefreshCallback()
{
if (!m_active)
return false;
if (!m_displayLink) {
m_active = false;
CVReturn error = CVDisplayLinkCreateWithCGDisplay(m_displayID, &m_displayLink);
if (error)
return false;
error = CVDisplayLinkSetOutputCallback(m_displayLink, displayLinkCallback, this);
if (error)
return false;
error = CVDisplayLinkStart(m_displayLink);
if (error)
return false;
m_active = true;
}
MutexLocker lock(m_mutex);
m_scheduled = true;
return true;
}
void DisplayRefreshMonitor::displayLinkFired(double nowSeconds, double outputTimeSeconds)
{
MutexLocker lock(m_mutex);
if (!m_scheduled || !m_previousFrameDone)
return;
m_previousFrameDone = false;
double webKitNow = currentTime();
m_timestamp = webKitNow - nowSeconds + outputTimeSeconds;
callOnMainThread(refreshDisplayOnMainThread, this);
}
}
#endif // USE(REQUEST_ANIMATION_FRAME_DISPLAY_MONITOR)