public override Double Get(Double x, Double y)
{
var d = this.Angle.Get(x, y) * 360.0 * 3.14159265 / 180.0;
var cos2D = Math.Cos(d);
var sin2D = Math.Sin(d);
var nx = x * cos2D - y * sin2D;
var ny = y * cos2D + x * sin2D;
return this.Source.Get(nx, ny);
}