int[] r = new int [1000];
float[] x = new float [1000];
float[] y = new float [1000];
int event=0;

void setup(){
  for(int j=0;j<100;j++) r[j]=0;
  size(640,480);
  smooth();
  colorMode(HSB,360,100,100);
  background(0,0,0);
  noFill();
  frameRate(60);
}

void draw(){
  if(mousePressed){
    r[event]++;
    x[event]=mouseX;
    y[event]=mouseY;
    event++;
  }
  for(int j=0;j<event;j++){
    circ(j);
  }
  fill(0,0,0,99);
  noStroke();
  rect(0,0,640,480);
  noFill();
  if(event>999) exit();
}
  
void circ(int i){
  if(r[i]<801){
  stroke((i*5)%360,99,99);
  ellipse(x[i],y[i],2*r[i],2*r[i]);
  r[i]+=10;
  }
}