public void OnDestroyed()
{
// Destroy presenter first (so that its backbuffer and render target are destroyed properly before other resources)
GraphicsDevice.Presenter.OnDestroyed();
foreach (var resource in GraphicsDevice.Resources)
{
resource.OnDestroyed();
resource.LifetimeState = GraphicsResourceLifetimeState.Destroyed;
}
// Clear various graphics device internal states (input layouts, FBOs, etc...)
GraphicsDevice.OnDestroyed();
}