public void GradientLinearlyInterpolatesColors()
{
var pattern = new Gradient(RTF.Color.White, RTF.Color.Black);
Assert.Equal(RTF.Color.White, pattern.At(pt.Point(0, 0, 0)));
Assert.Equal(new RTF.Color(0.75, 0.75, 0.75), pattern.At(pt.Point(0.25, 0, 0)));
Assert.Equal(new RTF.Color(0.5, 0.5, 0.5), pattern.At(pt.Point(0.5, 0, 0)));
Assert.Equal(new RTF.Color(0.25, 0.25, 0.25), pattern.At(pt.Point(0.75, 0, 0)));
}