private void PrerenderSourceAndTargetAndMakeTransition(Screen oldScreen, Screen currentScreen)
{
_executingScreenTransition = true;
var currentRenderTarget = Game.GraphicsDevice.GetRenderTargets();
Game.GraphicsDevice.SetRenderTarget(_sourceRenderTarget);
oldScreen.OnDraw(new GameTime());
Game.GraphicsDevice.SetRenderTarget(_targetRenderTarget);
currentScreen.OnUpdate(new GameTime(TimeSpan.Zero, TimeSpan.FromSeconds(1.0/60.0d)));
currentScreen.OnDraw(new GameTime());
Game.GraphicsDevice.SetRenderTargets(currentRenderTarget);
_currentTransition.StartTransition(_sourceRenderTarget, _targetRenderTarget);
}