PaddleBall

var radius;
var x, y, Vx, Vy;
var padX, padY;

/*Only runs once*/
function setup() {
  createCanvas(300, 400);
  radius = 35;
  x = 20;
  y = 40;
  Vx = 1;
  Vy = 2;
  padX = 0;
  padY = height - 50;
}

/*Runs on an infinite loop*/
function draw() {
  background(120);
  ball();
  paddle();
  bounce();
}

function bounce(){
  if(abs(x-padX)< 50+radius && abs(padY-y)<radius/2){
    //reverse y of the ball;
    Vy *= -1;
  }
}

function paddle(){
  padX = mouseX - 50;
  rect(padX, padY, 100, 20);
}

function ball(){
  ellipse(x, y, radius, radius);
  y+=Vy;  //y = y + Vy;
  x+=Vx;
  if(y > height){
    y = 0;
  }
  if(x > width){
    x = 0;
  }
}