// bouncing ball within a box


float boxX=80, boxY=38, boxW=445, boxH=398;
float ballX=30, ballY=10, ballDX=5, ballDY=9;
float ball0X=50, ball0Y=20, ball0DX=3, ball0DY=2;

void setup() {
  // size
  size( 640, 480 );
  reset();
}

void draw() {
  scene(); 
  action();
  ball();
  ball0();
}

void scene(){
  background( 200, 255, 200);
}

void action() {
 stroke(255);
 strokeWeight(10);
 rectMode( CORNER );
 fill(100,100,255);
//-- rect(40, 40, 450, 400);
  rect( boxX, boxY, 450, 400);

}

void ball(){
  ballX += ballDX;
  ballY += ballDY;
  if (ballX < 0 || ballX > boxW) ballDX=  -ballDX;
  if (ballY < 0 || ballY > boxH) ballDY=  -ballDY;
  fill( 0,0,0 );
  strokeWeight(2);
  noStroke();
  ellipseMode(CENTER);
  ellipse( boxX+10+ballX, boxY+ballY, 15,15 );
}

void ball0(){
  ball0X += ball0DX;
  ball0Y += ball0DY;
  if (ball0X < 0 || ball0X > boxW) ball0DX=  -ball0DX;
  if (ball0Y < 0 || ball0Y > boxH) ball0DY=  -ball0DY;
  fill( 150,0,150 );
  strokeWeight(3);
  noStroke();
  ellipseMode(CENTER);
  ellipse( boxX-20+ball0X, boxY+ball0Y, 15,15 );

}

void reset() {
    ballDX=  random(10);
    ballDY=  random(4);
}