public Matrix GetTransformation()
{
_transform =
Matrix.CreateTranslation(new Vector3(-_center.X, -_center.Y, 0)) *
Matrix.CreateRotationZ(Rotation) *
Matrix.CreateScale(new Vector3(Zoom, Zoom, 1)) *
Matrix.CreateTranslation(new Vector3(_viewportWidth * 0.5f, _viewportHeight * 0.5f, 0)
);
return _transform;
}