By Ira Greenberg Generate a closed ring using vertex() function and beginShape(TRIANGLE_STRIP) mode. outerRad and innerRad variables control ring's outer/inner radii respectively. Trig functions generate ring.
Original Processing.org Example: TriangleStrip
// All Examples Written by Casey Reas and Ben Fry // unless otherwise stated. size(200, 200); background(204); smooth(); int x = width/2; int y = height/2; int outerRad = 80; int innerRad = 50; float px = 0, py = 0, angle = 0; float pts = 36; float rot = 360.0/pts; beginShape(TRIANGLE_STRIP); for (int i=0; i<pts; i++) { px = x+cos(radians(angle))*outerRad; py = y+sin(radians(angle))*outerRad; angle+=rot; vertex(px, py); px = x+cos(radians(angle))*innerRad; py = y+sin(radians(angle))*innerRad; vertex(px, py); angle+=rot; } endShape();