Code for IIPP Mini Project [Pong]

Pong.py

# Implementation of classic arcade game Pong by Anirudh Jayaraman
# coded on 24 June 2015 10:20 PM

from simplegui import *
from random import *

# 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
paddle_vel_increment_rate = 4
pause = True; not_pause = not pause
game_status = 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]
    if direction == RIGHT:
        ball_vel = [randrange(2,5), -randrange(1,4)]
    if direction == LEFT:
        ball_vel = [-randrange(2,5), -randrange(1,4)]

# define event handlers
def new_game():
    global paddle1_pos, paddle2_pos, paddle1_vel, paddle2_vel  # these are numbers
    global score1, score2  # these are ints
    global pause, not_pause; pause = True; not_pause = not pause
    paddle1_vel = paddle2_vel = 0
    score1 = 0; score2 = 0
    paddle1_pos, paddle2_pos = HEIGHT/2, HEIGHT/2
    left_or_right = randrange(2) ## to randomly spawn the ball
    if left_or_right == 1:       ## towards left or right direction
        left_or_right = RIGHT
    else:
        left_or_right = LEFT
    spawn_ball(left_or_right) 

def draw(canvas):
    global score1, score2, paddle1_pos, paddle2_pos, ball_pos, ball_vel, ball_vel_temp
    global paddle1_vel, paddle2_vel
    global game_status
    global frame
    
    if game_status == 0:
        frame.set_canvas_background("Yellow")
        canvas.draw_text("Implementation of classic arcade game Pong by Anirudh Jayaraman", [20, 20], 15, "Red", "monospace")        
        canvas.draw_text("Press SPACEBAR to start!", [20, 100], 30, "Red", "monospace")
        canvas.draw_text("~ RESTART button (top-left) starts a fresh game", [20, 150], 20, "Black", "monospace")
        canvas.draw_text("~ W/S keys move LEFT PADDLE up/down", [20, 170], 20, "Black", "monospace")
        canvas.draw_text("~ UP/DOWN ARROW keys move RIGHT PADDLE up/down", [20, 190], 20, "Black", "monospace")
        canvas.draw_text("~ Pressing the 'P' key pauses / unpauses game", [20, 210], 20, "Black", "monospace")
        canvas.draw_image(image, (600 / 2, 331 / 2), (600, 331), (300, 350), (600,150))
        
    if game_status == 1:
        
        frame.set_canvas_background("Green")
        # 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 paddle's vertical position, keep paddle on the screen    
        if (HEIGHT - HALF_PAD_HEIGHT) >= (paddle1_pos + paddle1_vel) >= HALF_PAD_HEIGHT:
            paddle1_pos += paddle1_vel
        if (HEIGHT - HALF_PAD_HEIGHT) >= (paddle2_pos + paddle2_vel) >= HALF_PAD_HEIGHT: 
            paddle2_pos += paddle2_vel

        # determine whether paddle and ball collide and update ball

        if ball_pos[0] <= BALL_RADIUS + PAD_WIDTH:
            if (paddle1_pos - HALF_PAD_HEIGHT) <= ball_pos[1] <= (paddle1_pos + HALF_PAD_HEIGHT):
                ball_vel[0] = - 1.1 * ball_vel[0]
            else:
                spawn_ball(RIGHT)
                score2 += 1
                if score2 == 10:
                    pause_game()  

                 
        if ball_pos[0] >= (WIDTH - BALL_RADIUS - PAD_WIDTH):
            if (paddle2_pos - HALF_PAD_HEIGHT) <= ball_pos[1] <= (paddle2_pos + HALF_PAD_HEIGHT):
                ball_vel[0] = - 1.1 * ball_vel[0]
            else:
                spawn_ball(LEFT)
                score1 += 1
                if score1 == 10:
                    pause_game()            


        if ball_pos[1] <= BALL_RADIUS:
            ball_vel[1] = - ball_vel[1]
        if ball_pos[1] >= (HEIGHT - BALL_RADIUS):
            ball_vel[1] = - ball_vel[1]

        ball_pos[0] += ball_vel[0]
        ball_pos[1] += ball_vel[1]

        # draw ball
        canvas.draw_circle(ball_pos, BALL_RADIUS, 1, "Aqua", "Aqua" )


        # draw paddles
        canvas.draw_polygon([[0, paddle1_pos - HALF_PAD_HEIGHT],\
                             [0, paddle1_pos + HALF_PAD_HEIGHT],\
                             [PAD_WIDTH, paddle1_pos + HALF_PAD_HEIGHT],\
                             [PAD_WIDTH, paddle1_pos - HALF_PAD_HEIGHT]],1, "Yellow", "Yellow")
        canvas.draw_polygon([[WIDTH - PAD_WIDTH, paddle2_pos - HALF_PAD_HEIGHT],\
                             [WIDTH - PAD_WIDTH, paddle2_pos + HALF_PAD_HEIGHT],\
                             [WIDTH, paddle2_pos + HALF_PAD_HEIGHT],\
                             [WIDTH, paddle2_pos - HALF_PAD_HEIGHT]],1, "Yellow", "Yellow")


        # draw scores
        canvas.draw_text(str(score1), [230,50], 40, "Yellow", "monospace")
        canvas.draw_text(str(score2), [340,50], 40, "Yellow", "monospace")
        
        if score2 == 10 or score1 == 10:
            canvas.draw_text("Game Over", [120, 300], 70,  "Yellow", "monospace")
         

        # instructions on how to play
        global instructions_line1; instructions_line1 = "W / S move left paddles up and down" 
        global instructions_line2; instructions_line2 = "Up / Down arrows move right paddles up and down"
        canvas.draw_text(instructions_line1, [25, HEIGHT - 55], 12, "Yellow", "monospace")
        canvas.draw_text(instructions_line2, [25, HEIGHT - 35], 12, "Yellow", "monospace")
        canvas.draw_text("P to pause / unpause", [25, HEIGHT - 15], 12, "Yellow", "monospace")
        
def start_game():
    global game_status; game_status = 1
        
def keydown(key):
    global paddle1_vel, paddle2_vel, paddle_vel_increment_rate
    if key == KEY_MAP["w"] and pause == True:
        paddle1_vel = - paddle_vel_increment_rate
    if key == KEY_MAP["s"] and pause == True:
        paddle1_vel = + paddle_vel_increment_rate
    if key == KEY_MAP["up"] and pause == True:
        paddle2_vel = - paddle_vel_increment_rate
    if key == KEY_MAP["down"] and pause == True:
        paddle2_vel = + paddle_vel_increment_rate
    if key == KEY_MAP["p"]:
        pause_game()
    if key == KEY_MAP["space"]:
        start_game()
   
def keyup(key):
    global paddle1_vel, paddle2_vel
    if key == KEY_MAP["s"]:
        paddle1_vel = 0
    if key == KEY_MAP["w"]:
        paddle1_vel = 0   
    if key == KEY_MAP["down"]:
        paddle2_vel = 0
    if key == KEY_MAP["up"]:
        paddle2_vel = 0
    if key == KEY_MAP["p"]:
        pass
    if key == KEY_MAP["space"]:
        pass

def new_game_button():
    global game_status; game_status = 1
    new_game()

def pause_game():
    global score1, score2, paddle1_pos, paddle2_pos, ball_pos, ball_vel, ball_vel_temp
    global paddle1_vel, paddle2_vel, paddle1_vel_temp, paddle2_vel_temp
    global pause;
    if score1 == 10 or score2 == 10:
        pause = True
    if pause == True:
        ball_vel_temp = ball_vel
        paddle1_vel_temp = paddle1_vel; paddle2_vel_temp = paddle2_vel
        ball_vel = [0, 0]
        paddle1_vel = paddle2_vel = 0
    else:
        ball_vel = ball_vel_temp
        paddle1_vel = paddle1_vel_temp; paddle2_vel = paddle2_vel_temp
    pause = not pause
    

# create frame
frame = create_frame("Pong", WIDTH, HEIGHT)
image = load_image('http://1.media.dorkly.cvcdn.com/46/35/a9397db865facf904b469a0b2bf29625-quiz-which-pong-character-are-you.jpg')
frame.set_draw_handler(draw)
frame.set_keydown_handler(keydown)
frame.set_keyup_handler(keyup)
frame.add_button("START / RESTART", new_game_button, 150)
frame.add_button("PAUSE / UNPAUSE", pause_game, 150)

# start frame
frame.start()
new_game()