## Conway's Game of Life - Teaching 2D Arrays
##
# python version
# see: http://www.16kb.com/portfolio/display/automata/
from pyprocessing import *

import random

# make these self.scale? use global? just leave them out of scope?
scale = 10 # factor to magnify grid
cols, rows = 50, 40 # number of cols in world
world = []
# world = [[0]*cols]*rows DO NOT DO THIS!!
for n in range(cols):
  world.append([0]*rows) # initialize 2D array that will house the game

aliveFill = 128
backgroundFill = 0

# draw a cell
def drawCell(x, y, alive):
  if alive == 1:
    fill(aliveFill)
  else:
    fill(backgroundFill)
  ellipse(x*scale, y*scale, 8, 8)


def checkNeighbours(x, y):
  # check how neighbours a position has
  neighbours = 0

  for dx in [-1,0,1]:
    for dy in [-1,0,1]: 
      if dy==0 and dx==0: # skip checking ourselves
        continue 
      if (x+dx >= 0 and x+dx < cols) and (y+dy >= 0 and y+dy < rows) and (world[x+dx][y+dy] == 1 or world[x+dx][y+dy] == -1):
        neighbours = neighbours + 1
  return neighbours



def setup():
  size(500,400)
  frameRate(5)
  background(0)
  
  for x in range(cols): # loop through every column
    for y in range(rows): # loop through every row
      world[x][y] = random.randint(0,1) # place a 0 or 1 into the world
      # note we have y first!
      if world[x][y] == 1:
        drawCell(x, y, 1)   # if world holds a 1 then draw a circle

def draw():
  # check each cell
  print "test"
  for x in range(cols): # loop through every column
    for y in range(rows): # loop through every row  
      num = checkNeighbours(x,y)
      
      if world[x][y] == 0 and num == 3: # bring cell to life 
        world[x][y] = 8 # 0 = dead, 8 dead, but alive next
        drawCell(x, y, 1)
        
            
      elif world[x][y] == 1 and (num < 2 or num > 3): # kill cell
        world[x][y] = -1 #  1 = alive, -1 = alive, but dead next round
        drawCell(x, y, 0)
                  
  # set all changing state codes (ie. -1 and 8)
  for x in range(cols): # loop through every column
    for y in range(rows): # loop through every row
      
      if world[x][y] == 8:
        world[x][y] = 1  
      elif world[x][y] == -1:
        world[x][y] = 0
     
  
run()