Coursera_An Introduction to Interactive Programming in Python_Mini-project # 4 Pong

# Implementation of classic arcade game Pong

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
time = 0
# initialize the position and velocity of paddle
paddle1_pos = [HALF_PAD_WIDTH,HEIGHT/2]
paddle2_pos = [WIDTH-HALF_PAD_WIDTH,HEIGHT/2]
paddle1_vel = [0,0]
paddle2_vel = [0,0]
paddle_acc = 2
# initialize the score
score1 = 0
score2 = 0

# initialize ball_pos and ball_vel for new bal in middle of table
initial_ball_pos = [WIDTH/2,HEIGHT/2]
ball_pos = [WIDTH/2,HEIGHT/2]
ball_vel = [0,0]

# 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_vel[0] = random.randrange(120, 240)/100
ball_vel[1] = - random.randrange(60, 180) /100
if direction == "LEFT": # direct at upper left
ball_vel[0] = -1 *ball_vel[0]

# define event handlers
def new_game():
global paddle1_pos, paddle2_pos, paddle1_vel, paddle2_vel,ball_pos,ball_vel  # these are numbers
paddle1_pos = [HALF_PAD_WIDTH,HEIGHT/2]
paddle2_pos = [WIDTH-HALF_PAD_WIDTH,HEIGHT/2]
paddle1_vel = [0,0]
paddle2_vel = [0,0]
ball_pos = [WIDTH/2,HEIGHT/2]
ball_vel = [0,0]
global score1, score2  # these are ints
score1 =0
score2 =0
# determine the start direction of a ball
random_val = random.randint(0, 1)
direction = ""
if random_val == 1:
direction = "LEFT"
else:
direction = "RIGHT"
spawn_ball(direction)

def draw(canvas):
global score1, score2, paddle1_pos, paddle2_pos, ball_pos, ball_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_pos[0] + ball_vel[0]
ball_pos[1] = ball_pos[1] + ball_vel[1]
# reflection in upper and down gutter
if ball_pos[1] <= BALL_RADIUS:
ball_vel[1] = - ball_vel[1]
elif ball_pos[1] >= HEIGHT - BALL_RADIUS:
ball_vel[1] = - ball_vel[1]
# test if the ball touches/colides with the left and right gutters
if ball_pos[0] <= BALL_RADIUS:
ball_pos[0] = initial_ball_pos[0]
ball_pos[1] = initial_ball_pos[1]
spawn_ball("RIGHT")
score2 += 1
elif ball_pos[0] >= WIDTH:
ball_pos[0] = initial_ball_pos[0]
ball_pos[1] = initial_ball_pos[1]
spawn_ball("LEFT")
score1 += 1

# test if the ball touch the paddele
if ball_pos[0]-BALL_RADIUS <= paddle1_pos[0]+HALF_PAD_WIDTH and (ball_pos[1]>=paddle1_pos[1]-HALF_PAD_HEIGHT and ball_pos[1]<=paddle1_pos[1]+HALF_PAD_HEIGHT ):
ball_vel[0] =- ball_vel[0]
ball_vel[0] += ball_vel[0]*0.1
ball_vel[1] += ball_vel[1]*0.1
if ball_pos[0]+BALL_RADIUS >= paddle2_pos[0]-HALF_PAD_WIDTH and (ball_pos[1]>=paddle2_pos[1]-HALF_PAD_HEIGHT and ball_pos[1]<=paddle2_pos[1]+HALF_PAD_HEIGHT ):
ball_vel[0] =- ball_vel[0]
ball_vel[0] += ball_vel[0]*0.1
ball_vel[1] += ball_vel[1]*0.1
# draw ball
canvas.draw_circle(ball_pos, BALL_RADIUS, 12, 'White','White')
# update paddle's vertical position, keep paddle on the screen

# draw paddles
if paddle1_pos[1] > HALF_PAD_HEIGHT  and paddle1_pos[1] < HEIGHT-HALF_PAD_HEIGHT:
paddle1_pos[1] += paddle1_vel[1]
elif paddle1_pos[1] <= HALF_PAD_HEIGHT:
paddle1_pos[1] += paddle_acc
elif paddle1_pos[1] >= HEIGHT-HALF_PAD_HEIGHT:
paddle1_pos[1] -= paddle_acc

canvas.draw_polygon([[paddle1_pos[0]-HALF_PAD_WIDTH, paddle1_pos[1]-HALF_PAD_HEIGHT],
[paddle1_pos[0]-HALF_PAD_WIDTH, paddle1_pos[1]+HALF_PAD_HEIGHT],
[paddle1_pos[0]+HALF_PAD_WIDTH, paddle1_pos[1]+HALF_PAD_HEIGHT],
[paddle1_pos[0]+HALF_PAD_WIDTH, paddle1_pos[1]-HALF_PAD_HEIGHT]],
12, 'White', 'White')
if paddle2_pos[1] > HALF_PAD_HEIGHT and paddle2_pos[1] < HEIGHT-HALF_PAD_HEIGHT:
paddle2_pos[1] += paddle2_vel[1]
elif paddle2_pos[1] <= HALF_PAD_HEIGHT:
paddle2_pos[1] += paddle_acc
elif paddle2_pos[1] >= HEIGHT-HALF_PAD_HEIGHT:
paddle2_pos[1] -= paddle_acc
canvas.draw_polygon([[paddle2_pos[0]-HALF_PAD_WIDTH, paddle2_pos[1]-HALF_PAD_HEIGHT],
[paddle2_pos[0]-HALF_PAD_WIDTH, paddle2_pos[1]+HALF_PAD_HEIGHT],
[paddle2_pos[0]+HALF_PAD_WIDTH, paddle2_pos[1]+HALF_PAD_HEIGHT],
[paddle2_pos[0]+HALF_PAD_WIDTH, paddle2_pos[1]-HALF_PAD_HEIGHT]],
12, 'White', 'White')
# draw scores
canvas.draw_text(str(score1), (WIDTH/2-100, 100), 30, 'White')
canvas.draw_text(str(score2), (WIDTH/2+100, 100), 30, 'White')

def keydown(key):
global paddle1_vel, paddle2_vel
if key==simplegui.KEY_MAP["w"]:
paddle1_vel[1] = -paddle_acc
elif key==simplegui.KEY_MAP["s"]:
paddle1_vel[1] = paddle_acc
elif key==simplegui.KEY_MAP["down"]:
paddle2_vel[1] = paddle_acc
elif key==simplegui.KEY_MAP["up"]:
paddle2_vel[1] = -paddle_acc

def keyup(key):
global paddle1_vel, paddle2_vel
if key==simplegui.KEY_MAP["w"]:
paddle1_vel[1] = 0
elif key==simplegui.KEY_MAP["s"]:
paddle1_vel[1] = 0
elif key==simplegui.KEY_MAP["down"]:
paddle2_vel[1] = 0
elif key==simplegui.KEY_MAP["up"]:
paddle2_vel[1] = 0

def restart_handler():
new_game()

# create frame
frame = simplegui.create_frame("Pong", WIDTH, HEIGHT)
frame.set_draw_handler(draw)
frame.set_keydown_handler(keydown)
frame.set_keyup_handler(keyup)
button1 = frame.add_button('Restart', restart_handler)

# start frame
new_game()
frame.start()