Bouncing Ball

When the shape hits the edge of the window, it reverses its direction. In this version, we assume that the bounce surface is hard (rigid), and that air resistance is negligible

Dictionary: Bouncing Ball

Code Inspired From: Processing/Examples/Bounce

Ball b; 

void setup() {
  size(650, 450);
  //frameRate(20);
  smooth();
  b = new Ball(new PVector(width/2, height/2));
}

void draw() {
  background(200);
  b.draw();
}

void mousePressed() {
  b = new Ball(new PVector(width/2, height/2));
}

class Ball {

  PVector pos; 
  PVector dir = new PVector(mouseX-width/2, mouseY-height/2);
  PVector vel; 
  int rad = 20; 

  Ball(PVector pos) {
    this.pos = pos;
    vel = PVector.div(dir, (width/2)/5);
  }

  void draw() {
    display();
    bound();
    run();
    fill(0, 102, 153);
    text("Ball Position = " + (int)pos.x + ", " + (int)pos.y, 10, 20);
    text("Ball Velocity = " + vel.mag(), 10, 40);
  }

  void bound() {
    if (pos.x > width-rad || pos.x < rad)
      vel.x *= -1; 
    if (pos.y > height-rad || pos.y < rad)
      vel.y *= -1;
  }

  void run() {
    pos.add(vel);
  }

  void display() {
    fill(255);
    noStroke();
    ellipse(pos.x, pos.y, rad*2, rad*2);
    displayArrow();
  }

  void displayArrow() {
    strokeWeight(dist(width/2, height/2, mouseX, mouseY)/100);
    stroke(255, 100);
    line(width/2, height/2, mouseX, mouseY);
    stroke(255, 255, 0);
    fill(255, 255, 0, 100);
    ellipse(mouseX, mouseY, 20, 20);
    if (mousePressed) {
      stroke(255, 255, 0);
      fill(255, 255, 0);
      ellipse(mouseX, mouseY, 40, 40);
    }
  }
}