PFont font;
float ball_x;
float ball_y;
float dir_x = 1;
float dir_y = 0;
float ball_size = 10;

float paddle_y;
float paddle_width =15;
float paddle_height = 50;

int lose = 0;

void setup(){
  size(300,300);
  noStroke();
  smooth();

  ball_y = height/2;
  ball_x = 1;
  ellipseMode(CORNER);  
  font = loadFont("DialogInput-24.vlw");
  textFont(font);
}


void draw(){
  background(51);
  ball_x += dir_x;
  ball_y += dir_y;

  // constrain the paddle so it never moves off screen
  paddle_y = constrain(mouseY, 0 , height-paddle_height);

  // if the ball is touching the paddle
  // first condition checks if it is at the back wall
  // second two conditions check if it is touching the paddle
  if(ball_x > width-paddle_width-5-ball_size 
     && ball_y > paddle_y
     && ball_y < paddle_y + paddle_height){
       // changes direction
       dir_x = dir_x*-1;
  }
  
  // if it is touching the front wall change direction
  if(ball_x < 0){
     dir_x = dir_x*-1;
  }
  
  // if the ball misses the wall the game has been lost
  if(ball_x > width - ball_size){
     lose = 1;
   }
  
  // if the game has not been lost draw the shapes
  // otherwise write loser to the screen
  if(lose == 0){
    fill(255);
    ellipse(ball_x, ball_y, ball_size, ball_size);
    
    fill(153);
    rect(width-paddle_width-5, paddle_y, paddle_width, paddle_height);
  }
  
  else{
    text("loser", 100,100);
  }
}