float x,y,angle,angleD,speed;
int frame;

void setup() {
  size(300,300);
  ellipseMode(CENTER_DIAMETER);
  framerate(20);
  
  angle=random(0,360);
  angleD=random(-3,3);
  speed=random(1,5);
  x=width/2;
  y=height/2;
}

void loop() {
//  background(200);  
  
  x=x+cos(radians(angle))*speed;
  y=y+sin(radians(angle))*speed;
  angle=angle+angleD;

  angleD=angleD+random(-0.5,0.5);
  if(angleD<-5) angleD=-5;
  else if(angleD>5) angleD=5;
  
  frame++;
  if(frame%50==0) angleD=-angleD;
  
  
//  speed=speed+0.1;
  
  if(x<0) x=width;
  else if(x>width) x=0;
  if(y<0) y=height;
  else if(y>height) y=0;
  
  ellipse(x,y, 10,10);
}