>There must be a way to calculate that using another value, like 100 for a circle (or >ellipse) and 0 for a square (or rectangle) and create the array used to create the >shape.


you can create as many (x,y) points on the graph as you like.

suppose you have a circle of radius r
given the x coordinate you can calculate the y coordinate in this way

y = (r^2 - x^2)^(1/2)

crank as many points as necessary.

this is just a rearrangement of ( x^2 + y^2 = r^2 ) the pythagorean theorem.

have fun!
Dave.