pong.py

# Implementation of classic arcade game Pong by 2ba

# How to play
# Player 1: Controls the left paddles, "w" for up and "s" for down
# player 2: Controls the right paddles, "up"key for up "down" key for down
# Just click Run/Play in the top/left



import simplegui
import random

# initialize globals - pos and vel encode vertical info for paddles
WIDTH = 600
HEIGHT = 400       
BALL_RADIUS = 20
PAD_WIDTH = 8
PAD_HEIGHT = 80
HALF_PAD_WIDTH = PAD_WIDTH / 2
HALF_PAD_HEIGHT = PAD_HEIGHT / 2
LEFT = False
RIGHT = True
ball_pos =[(WIDTH/2), (HEIGHT/2)]
ball_vel = [1, 1]
paddle1_pos = 0
paddle2_pos = 0
paddle1_vel =0
paddle2_vel =0
score1= 0
score2 = 0

# initialize ball_pos and ball_vel for new bal in middle of table
# if direction is RIGHT, the ball's velocity is upper right, else upper left
def spawn_ball(direction):
    global ball_pos, ball_vel # these are vectors stored as lists
    ball_pos =[(WIDTH/2), (HEIGHT/2)]
    ball_vel[0] = random.randrange(120,240)/60.0
    ball_vel[1] = random.randrange(60,180)/60.0
    if direction == RIGHT:
        ball_vel[1] = ball_vel[1]*-1
        ball_pos[0] += ball_vel[0]
        ball_pos[1] += ball_vel[1]
    elif direction == LEFT:
        ball_vel[0] = ball_vel[0]*-1
        ball_vel[1] = ball_vel[1]*-1
        ball_pos[0] += ball_vel[0]
        ball_pos[1] += ball_vel[1]

# define event handlers
def new_game():
    global paddle1_pos, paddle2_pos, paddle1_vel, paddle2_vel  # these are numbers
    global score1, score2  # these are ints
    score1=0
    score2=0
    spawn_ball(RIGHT)

   
def draw(canvas):
    global score1, score2, paddle1_pos, paddle2_pos, ball_pos, ball_vel
    global paddle1_vel, paddle2_vel    
    # draw mid line and gutters
    canvas.draw_line([WIDTH / 2, 0],[WIDTH / 2, HEIGHT], 1, "White")
    canvas.draw_line([PAD_WIDTH, 0],[PAD_WIDTH, HEIGHT], 1, "White")
    canvas.draw_line([WIDTH - PAD_WIDTH, 0],[WIDTH - PAD_WIDTH, HEIGHT], 1, "White")
        
    # update ball
    ball_pos[0]+= ball_vel[0]
    ball_pos[1]+= ball_vel[1]
    if ball_pos[1]-BALL_RADIUS <= 0:
        ball_vel[1] = ball_vel[1]*-1
    elif ball_pos[1] + BALL_RADIUS >= HEIGHT-1:
        ball_vel[1] = ball_vel[1]*-1
    

               
    # draw ball
    canvas.draw_circle(ball_pos, BALL_RADIUS, 2, "Red", "White")
    
    
    # update paddle's vertical position, keep paddle on the screen
    paddle1_pos +=  paddle1_vel
    if paddle1_pos <= 0:
        paddle1_pos =0
    elif paddle1_pos >= HEIGHT-1-PAD_HEIGHT:
        paddle1_pos = HEIGHT-1-PAD_HEIGHT
    
    paddle2_pos +=  paddle2_vel
    if paddle2_pos <= 0:
        paddle2_pos =0
    elif paddle2_pos >= HEIGHT-1-PAD_HEIGHT:
        paddle2_pos = HEIGHT-1-PAD_HEIGHT 
    # draw paddles
 
    canvas.draw_line([PAD_WIDTH/2, paddle1_pos], 
                     [PAD_WIDTH/2, paddle1_pos + PAD_HEIGHT ], PAD_WIDTH, 'White')
    
    canvas.draw_line([WIDTH-1-(PAD_WIDTH/2), paddle2_pos], 
                     [WIDTH-1-(PAD_WIDTH/2), paddle2_pos + PAD_HEIGHT ], PAD_WIDTH, 'White')
    
# determine whether paddle and ball collide   
    if ball_pos[0] <= (PAD_WIDTH + BALL_RADIUS):
        #Collision with Paddle1
        if ball_pos[1] >= paddle1_pos and ball_pos[1] <= paddle1_pos + PAD_HEIGHT:
            ball_vel[0] = -1.10*( ball_vel[0])
        else:
            score2 +=1
            spawn_ball(RIGHT)
    elif ball_pos[0] >= WIDTH-1-PAD_WIDTH - BALL_RADIUS: 
        if ball_pos[1] >= paddle2_pos and ball_pos[1] <= paddle2_pos + PAD_HEIGHT:
            ball_vel[0] = - 1.10*(ball_vel[0])
        else:
            score1 += 1
            spawn_ball(LEFT)

    # draw scores
    canvas.draw_text(str(score1)+ "/"+ str(score2), (500, 20), 20, 'White')       
def keydown(key):
    global paddle1_vel, paddle2_vel
    if key ==  simplegui.KEY_MAP['s']:
        paddle1_vel = 3
    elif key == simplegui.KEY_MAP['w']:
        paddle1_vel = -3
        
    if key ==  simplegui.KEY_MAP['down']:
        paddle2_vel = 3
    elif key == simplegui.KEY_MAP['up']:
        paddle2_vel = -3
       
   
def keyup(key):
    global paddle1_vel, paddle2_vel
    if key ==  simplegui.KEY_MAP['s']:
        paddle1_vel = 0
    elif key == simplegui.KEY_MAP['w']:
        paddle1_vel = 0    
    if key ==  simplegui.KEY_MAP['down']:
        paddle2_vel = 0
    elif key == simplegui.KEY_MAP['up']:
        paddle2_vel = 0

# create frame
frame = simplegui.create_frame("Pong", WIDTH, HEIGHT)
frame.set_draw_handler(draw)
frame.set_keydown_handler(keydown)
frame.set_keyup_handler(keyup)
frame.add_button("Restart",new_game, 200)
frame.set_canvas_background('Green')
# start frame
new_game()
frame.start()