Conway's game of life

life.coffee

start_game = ->
  canvas = document.getElementById "canvas"
  context = canvas.getContext "2d"
  blockHeight = canvas.height / 10
  blockWidth = canvas.width / 10

  draw_cell = (x, y, alive) ->
    x = x * blockWidth
    y = y * blockHeight
    if alive
      context.fillRect x, y, blockWidth, blockHeight
    else
      context.clearRect x, y, blockWidth, blockHeight

  cells = create_cells()
  draw_cells cells, draw_cell

  setInterval (-> update cells, draw_cell), 500

update = (cells, draw_cell) ->
  cells = update_cells cells
  draw_cells cells, draw_cell

update_cells = (cells) ->
  newCells = cells
  for x in [0..9]
    for y in [0..9]
      liveNeighbours = count_live_neighbours cells, x, y

      if liveNeighbours < 2
        newCells[x][y] = 0
      else if liveNeighbours == 3
        newCells[x][y] = 1
      else if liveNeighbours > 3
        newCells[x][y] = 0
      else
        newCells[x][y] = cells[x][y]

  console.log cells
  console.log newCells
  newCells

draw_cells = (cells, draw_cell) ->
  for x in [0..9]
    for y in [0..9]
      draw_cell x, y, cells[x][y]

create_cells = (columns, rows) ->
  cells = []
  cells.push [] for i in [1..10]
  for column in cells
    for i in [1..10]
      column.push Math.floor Math.random() * 2

  cells

count_live_neighbours = (cells, x, y) ->
  liveBorderingCells = 0
  liveBorderingCells += 1 if cell_above cells, x, y
  liveBorderingCells += 1 if cell_below cells, x, y
  liveBorderingCells += 1 if cell_left cells, x, y
  liveBorderingCells += 1 if cell_right cells, x, y
  liveBorderingCells += 1 if cell_top_left cells, x, y
  liveBorderingCells += 1 if cell_top_right cells, x, y
  liveBorderingCells += 1 if cell_bottom_left cells, x, y
  liveBorderingCells += 1 if cell_bottom_right cells, x, y

  liveBorderingCells

cell_above = (cells, x, y) ->
  if cells[x][y - 1]
    cells[x][y - 1]
  else
    false

cell_below = (cells, x, y) ->
  if cells[x][y + 1]
    cells[x][y + 1]
  else
    false

cell_left = (cells, x, y) ->
  if cells[x - 1]
    cells[x - 1][y]
  else
    false

cell_right = (cells, x, y) ->
  if cells[x + 1]
    cells[x + 1][y]
  else
    false

cell_top_left = (cells, x, y) ->
  if cells[x - 1] and cells[x - 1][y - 1]
    cells[x - 1][y - 1]
  else
    false

cell_top_right = (cells, x, y) ->
  if cells[x + 1] and cells[x + 1][y - 1]
    cells[x + 1][y - 1]
  else
    false

cell_bottom_left = (cells, x, y) ->
  if cells[x - 1] and cells[x - 1][y + 1]
    cells[x - 1][y + 1]
  else
    false

cell_bottom_right = (cells, x, y) ->
  if cells[x + 1] and cells[x + 1][y + 1]
    cells[x + 1][y + 1]
  else
    false

jQuery ->
  $("#start_game").on "click", ->
    start_game()