#
# Copyright (C) 2006 Andre Stemper
# Written in 2006 for the Science Club
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

from Tkinter import *
#-----------------------------------------------------------            
def move():
    global x1, y1, dx, dy, playing, gwidth, gheight, ballsize, rfb
    global lplayer, rplayer, nextplayer, counter, rpos, lpos, rs
    # position the ball on the playground
    if playing > 0: 
    	x1, y1 = x1 +dx, (y1+dy) # calculate the next ball position 
    else: # follow racket
    	if nextplayer==0: # if the next player is the right player give him the ball
    		x1,y1,dx = rfb+10, lpos+(rs-ballsize)/2, abs(dx)
	else: # otherwise give the left player the ball 
    		x1,y1,dx = gwidth-rfb-10, rpos+(rs-ballsize)/2,-abs(dx)
    # test top/bottom boundary   
    if y1 > (gheight-ballsize):
    	 y1, dy = gheight-ballsize, -dy
    if y1 < 0:
    	 y1, dy= 0, -dy
    # give the left player a point
    if x1 > (gwidth-ballsize):
	lplayer=lplayer+1			# increment score for left player	
    	x1, y1 = rfb, (gheight/2)   		# give right player the ball
	nextplayer = 0
	playing    = 0				# stop the game
    # give the right player a point 
    if x1 < 0:
	rplayer=rplayer+1			# increment score for right player
    	x1, y1 = gwidth-rfb, (gheight/2)	# give left player the ball
	nextplayer = 1
	playing    = 0				# stop the game 
    # test if the ball hits the left racket 
    if x1 <= rfb:
	    if y1>lpos and y1 < (lpos+rs):
		    x1, dx = rfb+5, -dx
    # test if the ball hits the right racket 
    if x1 >= (gwidth-rfb-ballsize): 
    	if y1 >= rpos and y1 <= (rpos+rs):		    
    		x1, dx = (gwidth-rfb-ballsize-5), -dx
    # draw ball position 
    can.coords(oval1, x1, y1, x1+ballsize, y1+ballsize)
    # draw current score
    score = str(lplayer) + ":" + str(rplayer)
    can.itemconfigure(counter, text=score)
    # draw rackets
    can.coords(rracket, gwidth-rfb, rpos, gwidth-rfb, rpos+rs)
    can.coords(lracket, rfb, lpos, rfb, lpos+rs)
    # trigger next frame
    win.after(50, move) 
#-----------------------------------------------------------            
def lup(event):
    global lpos, rspeed 
    if lpos > rspeed:
	    lpos=lpos-rspeed	    
def ldown(event):
    global lpos, gheight, rspeed
    if lpos < (gheight-rs-rspeed):
	    lpos=lpos+rspeed    
def rmove(event):
    global rpos
    ypos = event.y   
    if ypos > rspeed and ypos < (gheight-rs-rspeed):	# if in range
	rpos = ypos

def startit(event):
    global playing
    playing = 1	
#-----------------------------------------------------------            
dx, dy = 15, 12 		 # Start directions of the ball
gwidth = 800; gheight = 400 	 # Size of the playground
ballsize = 20; rfb = 20; rs = 60 # Ball size, racket from border, racket size
rspeed = 20			 # Speed of the racket 
lplayer=rplayer=0 		 # Start with no points
#-----------------------------------------------------------            
x1, y1 = rfb, (gheight-ballsize)/2
rpos=lpos=(gheight-rs)/2
nextplayer = 0			# next player: 0=right, 1=left
playing    = 0  		# Do not play when starting the program
win = Tk(); 			# Create new window
win.title("Pong")		# Name it "Pong"
can = Canvas(win, bg='black',height=gheight, width=gwidth) 
can.pack(side=LEFT)
# Create the ball 
oval1 = can.create_oval(x1, y1, x1+ballsize, y1+ballsize, width=2, fill='white')
# Create mid line
line  = can.create_line(gwidth/2, 0, gwidth/2, gheight, width=4, fill="white", dash=(4, 8))
# Create to rackets
lracket  = can.create_line(rfb, lpos, rfb, lpos+rs, width=10, fill="white")
rracket  = can.create_line(gwidth-rfb, rpos, gwidth-rfb, rpos+rs, width=10, fill="white")
# Create the score text
font=('courier', 20)
counter=can.create_text(gwidth/2, 20, text='0:0', font=font, fill="white")
# Use the following keys to move the racket
win.bind('q', lup)
win.bind('p', ldown)
win.bind('<B1-Motion>', rmove)

win.bind('<space>', startit) 	# start game by hitting space
move()				# draw next sequence 
win.mainloop() 			# redraw window, watch for keys...