Vertex/image shading (in 2d, based on faked 3d..)

Is the Normalize method correct in my vector type?:

		Method Normalize() 
			Local magn:Float = GetMagnitude()
			
			If magn <> 0
				
				x:/magn
				y:/magn
				z:/magn
				
			End If
			
		End Method

Curious because of the method minib3d uses (klepto's version):

	Method Normalize()
	
		Local d#=1/Sqr(x*x+y*y+z*z)
		x:*d
		y:*d
		z:*d
		
	End Method

Also, what would I have to do to smooth the light coloring over a neighboring tiles?