A dotted circle in Processing. Note that the dotted line is only faked by drawing lines in the background color on top.

DottedCircle.pde

size(512, 512);
background(255);
strokeWeight(20);

translate(width / 2, height / 2);

ellipse(0, 0, 400, 400);

stroke(255);

for(int i = 0; i < 360; i += 360 / 20) {
  rotate(radians(360 / 20));
  line(0, 0, 210, 0); 
}

int dx=0;
size(512, 512);
background(255);
strokeWeight(20);

translate(width / 2, height / 2);
ellipse(0, 0, 400, 400);
stroke(255);

for(int i = 0; i < 9; i += 1)
{
line (-dx, -400+dx, dx, 400+dx);
rotate (radians(20));
}