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


import random
from processing.core import PApplet

# make these self.scale? use global? just leave them out of scope?
scale = 10 # factor to magnify grid
cols, rows = 100, 100 # number of cols in world
world = []
# world = [[0]*cols]*rows DO NOT DO THIS!!
for n in range(rows):
  world.append([0]*cols) # initialize 2D array that will house the game

aliveFill = 128
backgroundFill = 0

# draw a cell
def drawCell(x, y, alive):
  if alive == 1:
    p.fill(aliveFill)
  else:
    p.fill(backgroundFill)
  p.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


class Processor(PApplet):
    
  def __init__(self):
    global p
    p = self

  def setup(self):
    p.size(1000,1000)
    p.frameRate(60)
    p.background(0)
    p.translate(5,5) # shifts everything to the right and down

    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(self):
#    p.background(0)
    p.translate(5,5)
    # check each cell
    
    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
     
  
import pawt
pawt.test(Processor())