pingpong-ball.java

class Ball {
  // Current position
  PVector position;
  
  // Current direction
  PVector direction;
  
  // Diameter of the circle
  float d = 15;
  
  // The speed of the ball
  float s = 5;
  
  // Ball constructor
  public Ball() {
    resetMovement();
  }
  
  // Getter Methods
  
  public PVector getPosition() {
    return position;
  }
  
  // Reset position and randomize direction.
  
  public void resetMovement() {
    this.position = new PVector(width/2, height/2);
    // Get a random speed
    float speed = random(-s, s);
    // Set the y direction to half of the speed
    // to ensure it moves faster in the left or
    // right direction
    direction = new PVector(speed, speed/2);
  }
  
  // Set direction on the x-axis.
  
  public void setDirection(float x) {
     direction.x = x * speed;
  }
  
  // Updates the ball's position, add boundaries 
  // and draw its visuals.
  
  public void update() {
    // Add velocity
    position.add(direction);
    
    // Check if the ball has reached the top
    // or the bottom of the screen.
    if (position.y < 0 || position.y > height) {
      // Invert the direction on the y-axis.
      direction.y = -direction.y;
    }
    
    // Set the fill color to white.
    fill(255);
    // Draw the ball's circle.
    circle(position.x, position.y, d); 
  }
  
  public boolean overlapsWith(Player player) {
    // Get player position,
    // width, and height.
    var p = player.getPosition();
    var w = player.getWidth();
    var h = player.getHeight();
    
    // Calculate radius.
    var r = d/2;
    
    // Loop eight points.
    for (int i = 0; i < 8; i++) {
       
       // Convert i * 45 degrees to radians. 
       var degree = (i * 45) * (PI/180);
       
       // Calculate x and y points by rotating a vector
       // relative to the position 45 degrees
       var x = r * cos(position.x + degree) + position.x;
       var y = r * sin(position.y + degree) + position.y;

       // Return true if the point is within on both
       // the x-axis and the y-axis.
       if (p.x < x && x < p.x + w &&
           p.y < y && y < p.y + h) return true;
    }
    
    // If none of the points were within
    // the player, return false.
    return false;
  }
}