/** 
circles by <a href="http://www.local-guru.net/blog">guru</a>
*/

void setup() {
  size(300,300, P2D);
  smooth();
}

void draw() {
  background(255);
  noFill();
  strokeWeight(3);
  for( int x = 0; x < 5; x++ ) {
    for( int y = 0; y < 5; y++ ) {
      for( int i =0; i < 4; i++) { 
        float a = x *PI/5 + y * PI/5 + map( mouseX, 0, width, 0, PI ) + map( mouseY, 0, width, 0, PI );
        int ofx = int( cos( a ) * i * 7);
        int ofy = int( sin( a ) * i * 7);
        ellipse( x * 60 + 30 + ofx, y * 60 + 30 + ofy, 60 - i * 14, 60 -i * 14);
      }
    }
  }
}