// Example OOP: Ball as a class
class Ball {
  // Attributes/Properties of all Ball objects
  float x, y;     // location in sketch
  float radius;  // ball radius
  color ballColor;
  
  // Move and gravity attributes
  float dx = random(-2, 2);
  float speed = 5.0;
  float gravity = 0.1;
  float dampen = 0.95;
  
  // Constuctor
  Ball() {
    //x = random(width);
    y = random(height/2);
    x = width/2;
    radius = 25;
    ballColor = color(random(255), random(255), random(255));
  } // end of Ball constructor
  
  Ball(float r) {
    x = width/2;
    y = random(height/2);
    radius = r;
    ballColor = color(random(255), random(255), random(255));
  } // end of Ball constructor
  
  // behaviors
  void display() {
    push();
    fill(ballColor);
    noStroke();
    circle(x, y, 2*radius);
    pop();
  } // display()
  
  void move() {
    x = x + dx;
    y = y + speed;
    speed = speed + gravity;
    
    bounce();
  } // move()
  
  void bounce() {
    if (x > (width-radius)) {
      dx = -dx;
    }
    if (x < radius) {
      dx = -dx;
    }
    if (y > (height-radius)) {
      speed = -speed*dampen;
    }
  } // bounce()
  
} // end of class Ball