Conway's Game of Life for Minecraft

gol.lua

--[[ mickkay/gol.lua
  Conway's Game of Life for Minecraft
  Created with Wizards of Lua Magic
  by MickKay

  ## How To Run this Spell Inside Minecraft?
  
  1) Install the Wizards of Lua modification into your Minecraft game.
     Instructions available at http://www.wizards-of-lua.net/installation
  
  2) Execute the following command from the Minecraft chat:
     /wol shared-file gist get 3398d37f4cf076a13773d3d496cad231 mickkay
  
  3) Find some nice place and put a new command block there with 
     the following contents:
     /lua spell:move("forward"); wol=require("mickkay.gol"); wol.random(32,32); wol.start(32,32)
  
  4) Execute this command block.
  
  5) To stop the game any time later please execute the following command:
     /wol spell break byName mickkay.gol
  
  Have fun!
  More infomation about Conway's Game of Life can be found at https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life
--]]

local pkg = {}

local ALIVE = Blocks.get("obsidian")
local DEAD = Blocks.get("wool")
local readGen
local createVectors
local makeTorus
local evaluate
local log

function Vec3:floor() 
  return Vec3(math.floor(self.x),math.floor(self.y),math.floor(self.z))
end

function pkg.random(length, width)
  for l=1,length do
    for w=1,width do
      if math.random() <0.5 then
        spell.block=ALIVE
      else
        spell.block=DEAD
      end
      spell:move("right")
    end
    spell:move("left", width)
    spell:move("forward")
  end
  spell:move("back", length)
end

function pkg.stripes(length, width, bw, ww, rot)
  for l=1,length do
    for w=1,width do
      if (l*rot+w)%(bw+ww)<bw then
        spell.block=ALIVE
      else
        spell.block=DEAD
      end
      spell:move("right")
    end
    spell:move("left", width)
    spell:move("forward")
  end
  spell:move("back", length)
end

function pkg.clear(length, width)
  for l=1,length do
    for w=1,width do
      spell.block=DEAD
      spell:move("right")
    end
    spell:move("left", width)
    spell:move("forward")
  end
  spell:move("back", length)
end

function pkg.start(length, width)
  spell:execute("wol spell break byName mickkay.gol")
  spell.name = "mickkay.gol"
  vecs = createVectors(length, width)
  nextGen = readGen(length, width)
  while true do
    local tStart = Time.realtime
    gen = nextGen
    nextGen = {}
    nextGen[0]={}
    nextGen[length+1]={}
    for l=1,length do
      nextGen[l]={}
      for w=1,width do
        local n = 0
        for z=-1,1 do
          for x=-1,1 do
            if not (x==0 and z==0) then
              if gen[l+x] and gen[l+x][w+z]==1 then
                n = n + 1
              end
            end
          end
        end
        local c = gen[l][w]
        local e = evaluate(c,n)
        nextGen[l][w] = e
      end
    end
    makeTorus(nextGen,length,width)
    
    for l=1,length do
      for w=1,width do
        spell.pos = vecs[l][w]
        if nextGen[l][w]==1 then
          spell.block=ALIVE
        else
          spell.block=DEAD
        end
      end
    end
  
    local tEnd = Time.realtime
    --log(tEnd-tStart)
    sleep(1)
  end
end

function createVectors(length, width)
  local res = {}
  res[0]={}
  res[length+1]={}
  for l=1,length do
    res[l]={}
    for w=1,width do
      res[l][w]=spell.pos
      spell:move("right")
    end
    spell:move("left", width)
    spell:move("forward")
  end
  spell:move("back", length)
  makeTorus(res,length,width)
  return res
end

function readGen(length, width)
  local res = {}
  for l=1,length do
    res[l]={}
    for w=1,width do
      if spell.block.name==ALIVE.name then
        res[l][w]=1
      else
        res[l][w]=0
      end
      spell:move("right")
    end
    spell:move("left", width)
    spell:move("forward")
  end
  spell:move("back", length)
  makeTorus(res,length,width)
  return res
end

function makeTorus(tbl, length, width)
  tbl[0]={}
  tbl[length+1]={}
  for l=1,length do
    tbl[l][width+1]=tbl[l][1]
    tbl[l][0]=tbl[l][width]
  end
  for w=1,width do
    tbl[length+1][w]=tbl[1][w]
    tbl[0][w]=tbl[length][w]
  end
  tbl[0][0]=tbl[length][width]
  tbl[0][width+1]=tbl[length][1]
  tbl[length+1][width+1]=tbl[1][1]
  tbl[length+1][0]=tbl[1][width]
end

function evaluate(c,n)
  if c == 1 then
    if n < 2 then
      return 0
    elseif n == 2 or n == 3 then
      return 1
    else 
      return 0
    end
  else 
    if n == 3 then
      return 1
    else
      return 0
    end
  end
end

-- Logs the given message into the chat
function log( message, ...)
  local n = select('#', ...)
  if n>0 then
    message = string.format(message, ...)
  end
  spell:execute([[
    /say %s
    ]], message)
end

return pkg