private void Update()
{
screen.Update();
if(SignalUpdate != null) SignalUpdate();
touchManager.Update();
for(int s = 0; s<_stages.Count; s++)
{
_stages[s].Redraw (false,_isDepthChangeNeeded);
}
_isDepthChangeNeeded = false;
if(shouldRunGCNextUpdate)
{
shouldRunGCNextUpdate = false;
GC.Collect();
}
}