// UdK Computational design
// Marius Watz 2003
// http://www.evolutionzone.com/udk/
//
// UDK02_02_direction
//
// Changing speed and direction by using states.

float x,y,xD,yD;
float dir,speed;
int state,stateCnt;
int SLOW=0,FAST=1;

void setup() {
  size(300,400);
  ellipseMode(CENTER_DIAMETER);

  state=SLOW;
  stateCnt=200;
  speed=1;
  dir=random(radians(360));
  x=random(width);
  y=random(height);
}

void loop() {
  background(150,140,140);

  stateCnt--;
  if(stateCnt==0) newMove();
  
  xD=cos(dir)*speed;
  yD=sin(dir)*speed;
  
  x=x+xD;
  y=y+yD;
  if(x<0) x=width;
  else if(x>width) x=0;
  if(y<0) y=height;
  else if(y>height) y=0;

  noStroke();
  fill(255,170,0);  
  ellipse(x,y, 20,20);
}

void newMove() {
  stateCnt=100+(int)random(100);
  if(state==SLOW) {
    state=FAST;
    speed=3+random(2);
  }
  else {
    state=SLOW;
    speed=0.5+random(1);
  }
  
  dir=random(radians(360));
}