// two sets of lines
// around two circles of random center, in dufferent speed
// parameters:
int n = 20;      // n lines to be drawn
int sw = 1;      // initial stroke weight = line width
int s = 400;     // size of square canvas
int x0, y0, x1, y1;      // internal points to be connected
int r = 50;       // radius of circle 


void setup() { 
  size (s, s);
  stroke(255);    // lines in white 
  strokeWeight(sw);
  // two random points to be used as centers
  x0 = int(random(s/4, 3*s/4));
  y0= int(random(s/4, 3*s/4));
  x1 = int(random(s/4, 3*s/4));
  y1= int(random(s/4, 3*s/4));
  smooth();         // to render lines smooth
  frameRate(5);
}

void draw() {
  background(0);

  pushMatrix();
  translate(x0+ int(r*sin(2*PI*frameCount/10)), y0+ int(r*cos(2*PI*frameCount/10)));
  for (int j=0; j<n+1; j++) {
    line(0, 0, s*1.5, 0); 
    rotate(2*PI/n);
  }
  popMatrix();
  pushMatrix();
  translate(x1+ int(r*sin(2*PI*frameCount/17)), y1+ int(r*cos(2*PI*frameCount/17)));
  for (int j=0; j<n+1; j++) {
    line(0, 0, s*1.5, 0); 
    rotate(2*PI/n);
  }
  popMatrix();

}