Code

void setup() {
 size(600, 600, P2D);
}

int dots = 4;
PVector coords[] = new PVector[9999];

void mouseClicked() {
  dots++;
  clear();
  background(80);
  drawCircle(dots,width/2);
}
void draw() {
  background(80);
 translate(width/2,height/2);
 drawCircle(dots,width/3);
}

void drawCircle(int sides, float r)
{
 float angle = 360 / sides;
 noFill();
 beginShape();
 for (int i = 0; i < sides; i++) {
 float x = cos( radians( i * angle ) ) * r;
 float y = sin( radians( i * angle ) ) * r;
 coords[i] = new PVector(x,y);
 vertex(x,y);
 }
 endShape(CLOSE);
 connect(coords);
}

void connect(PVector[] coords) {
 for(PVector coord : coords) {
   if(coord != null) {
 for(PVector coord1 : coords) {
   if(coord1 != null) {
 line(coord.x, coord.y, coord1.x, coord1.y);
 }
 }
 }
 }
}