float [] xp = new float[0]; //used to store the allocated elements
float [] yp = new float[0];
int numObjects = 0; //used to count the number of allocated elements
void setup(){
  size(300,300);
}
void draw(){
  background(255);
  for(int i=0; i<xp.length; i++) //draw anything that has been allocated
    rect(xp[i],yp[i],10,10);
}
void keyPressed(){
  int k = 0;
  while(true){ //until you find a successful location (i.e. without an overlap)
    boolean overlap = false; //use it to mark overlaps
    float xrand = random(10,width-10); //produce a random possible location
    float yrand = random(10,height-10);
    for(int j=0; j<xp.length; j++){ //go through all the remaining elements
      float distance = dist(xrand,yrand,xp[j],yp[j]); //find distance
      if(distance < 10) overlap = true; //if too short then it will overlap
    }
    if(overlap==false){ //if no overlap then this is a successful location
      xp = append(xp,xrand); //add it to memory
      yp = append(yp,yrand);
      break;
    }
    k++;
    if(k>10000){ // will exit if after 10,000 attempts no space is found
      println(xp.length + " impass"); //warn the user
      break;
    }
  }
  println(numObjects++);
}