/// <summary>
/// Must be called prior to any Draw() calls.
/// Prepares the PrimitiveBatch.
/// </summary>
public static void Begin()
{
basicEffect.Projection = Matrix.OrthoOffCenterRH(0f, graphicsDevice.Viewport.Width, graphicsDevice.Viewport.Height, 0f, 0f, 1f);
ApplyEffect();
batch.Begin();
}
