/// <summary>Executes the state.</summary>
/// <param name="hovertank">The hover tank game.</param>
/// <returns>The next state to set or null.</returns>
public override State Execute(Hovertank hovertank)
{
if(!hovertank.verticalBlank)
return null;
hovertank.SetScreen(_crtc, _pel);
return _nextState;
}
