// declare arrays
float x[],y[],speed[],dir[],dirD[];

void setup() {
  size(400,400);
  
  x=new float[100];
  y=new float[100];
  speed=new float[100];
  dir=new float[100];
  dirD=new float[100];
  
  for(int i=0; i<100; i++) {
    x[i]=random(width);
    y[i]=random(height);    
    speed[i]=random(1,5);
    dir[i]=random(360);
    dirD[i]=random(-3,3);
  }
  
}

void draw() {
  //background(200);
  
  for(int i=0; i<100; i++) {
    ellipse(x[i],y[i], 20,20);
    
    dir[i]=dir[i]+dirD[i];
    x[i]=x[i]+cos(radians(dir[i]))*speed[i];
    y[i]=y[i]+sin(radians(dir[i]))*speed[i];
    
    if(x[i]>width) x[i]=0;
    if(x[i]<0) x[i]=width;
    if(y[i]>height) y[i]=0;
    if(y[i]<0) y[i]=height;
  }
}