pong_copycat.rb

#
#  Pong Challenge, copycat version
#
#  Created by Emanuel Carnevale on 2008-11-18.
#  Shamelessly adapted by http://billmill.org/pong.html


Shoes.app :width => 400, :height => 400, :resizable => false do

  paddle_size = 75
  v_x, v_y = [3,4]
  p_x, p_y = [10,10]
  bounce = 1.2
  ball_diameter = 20
  paddle_size = 75
  points = []
  computer = app.width / 2
  compuspeed = 30
  
  paddle1 = rect computer, 0, paddle_size, 4
  paddle2 = rect app.width/2, app.height-4, paddle_size, 4

  ball = oval(p_x, p_y, ball_diameter, ball_diameter)
  
  animate do    
    if not -ball_diameter < p_y and p_y < app.height + ball_diameter
      clear
      para "Game Over"
      if p_y < 0
        para "You win!"
      else
        para "Computer wins"
      end
      return
    end

    button, left, top = self.mouse
    paddle_left = [[left,0].min,400-paddle_size].max
    ny = p_y + v_y
    nx = p_x + v_x
    
    if nx + (ball_diameter/2) > computer + paddle_size
      computer += compuspeed
    elsif nx < computer
      computer -= compuspeed
    end
      
    paddle1.move(computer,0)
    
    one = (ny + ball_diameter) > app.height
    two = v_y > 0
    three = paddle_left < (nx + (ball_diameter / 2)) 
    four = (nx + (ball_diameter / 2)) < (paddle_left + paddle_size)
    if  one and two and three and four
      v_y = -v_y * bounce
      v_x = (nx - paddle_left - (paddle_size / 2)) * 0.25
      ny = app.height - ball_diameter
    end
    
    if ny < 0 and v_y < 0 and computer < nx + (ball_diameter / 2) and nx + (ball_diameter / 2) < computer + paddle_size
      v_y = -v_y * bounce
      v_x = (nx - computer - (paddle_size / 2)) * 0.25
      ny = 0
    elsif nx + ball_diameter > app.width or nx < 0
      v_x = -v_x
    end
      
    mx = [0, [left, app.width - paddle_size].min].max
    
    paddle2.move(mx,app.height-4)

    p_x = nx
    p_y = ny
    
    ball.move(p_x, p_y)
  end
end