A4. Bouncing Object

class Ball {

​

  //variables

  float x;

  float y;

  float radius;

  float velocityX;

  float velocityY;

  float gravity;

  float bounciness;

​

  //constructor 

  Ball( float newX, float newY, float newRadius ) {

    x = newX;

    y = newY;

    radius = newRadius;

​

    velocityX = random(2,4);

    velocityY = random(2,4);

    gravity = 0.5;

    bounciness = 0.9;

  }

​

  //ball drawing

  void render() {

    strokeWeight(3);

    fill(220);

    ellipse( x, y, radius * 2, radius * 2 );

  }

​

  //ball movement

  void move() {

    x = x + velocityX;

    y = y + velocityY;

​

    if ((x + radius) > width) {

      velocityX = velocityX * -1.0 * bounciness;

      velocityY = velocityY * bounciness;

      x = width - radius;

    }

    else if ((x - radius) < 0) {

      velocityX = velocityX * -1.0 * bounciness;

      velocityY = velocityY * bounciness;

      x = radius;

    }

    if ((y + radius) > height) {

      velocityX = velocityX * bounciness;

      velocityY = velocityY * -1.0 * bounciness;

      y = height - radius;

    }

    else if ((y - radius) < 0) {

      velocityX = velocityX * bounciness;

      velocityY = velocityY * -1.0 * bounciness;

      y = radius;

    }

​

    velocityY = velocityY + gravity;

  }

  //click to reset sketch

  void reset(float a, float b, float c) {

    x = a;

    y = b;

    radius = c;

  }

}

​

​