Draw circle shape with vertex

[jeremydouglass]

Related past discussions about squircles / squarcles:

• Rect corner radius issue. Squircles!?
• https://forum.processing.org/two/discussion/1941/transform-a-square-into-a-circle
• https://forum.processing.org/two/discussion/1797/how-to-use-bezier-curve-to-approximate-one-quarter-of-a-circle
• https://www.processing.org/discourse/beta/num_1206172535.html