void HeartBeat::timerEvent( QTimerEvent */*event*/ )
{
osg::ref_ptr< osgViewer::ViewerBase > viewer;
if( !_viewer.lock( viewer ) )
{
// viewer has been deleted -> stop timer
stopTimer();
return;
}
// limit the frame rate
if( viewer->getRunMaxFrameRate() > 0.0)
{
double dt = _lastFrameStartTime.time_s();
double minFrameTime = 1.0 / viewer->getRunMaxFrameRate();
if (dt < minFrameTime)
OpenThreads::Thread::microSleep(static_cast<unsigned int>(1000000.0*(minFrameTime-dt)));
}
else
{
// avoid excessive CPU loading when no frame is required in ON_DEMAND mode
if( viewer->getRunFrameScheme() == osgViewer::ViewerBase::ON_DEMAND )
{
double dt = _lastFrameStartTime.time_s();
if (dt < 0.01)
OpenThreads::Thread::microSleep(static_cast<unsigned int>(1000000.0*(0.01-dt)));
}
// record start frame time
_lastFrameStartTime.setStartTick();
// make frame
if( viewer->getRunFrameScheme() == osgViewer::ViewerBase::ON_DEMAND )
{
if( viewer->checkNeedToDoFrame() )
{
viewer->frame();
}
}
else
{
viewer->frame();
}
}
}
