Subversion Repositories WoWGM

-- life.lua

-- original by Dave Bollinger <DBollinger@compuserve.com> posted to lua-l

-- modified to use ANSI terminal escape sequences

-- modified to use for instead of while

local write=io.write

ALIVE="¥"	DEAD="þ"

ALIVE="O"	DEAD="-"

function delay() -- NOTE: SYSTEM-DEPENDENT, adjust as necessary

  for i=1,10000 do end

  -- local i=os.clock()+1 while(os.clock()<i) do end

end

function ARRAY2D(w,h)

  local t = {w=w,h=h}

  for y=1,h do

    t[y] = {}

    for x=1,w do

      t[y][x]=0

    end

  end

  return t

end

_CELLS = {}

-- give birth to a "shape" within the cell array

function _CELLS:spawn(shape,left,top)

  for y=0,shape.h-1 do

    for x=0,shape.w-1 do

      self[top+y][left+x] = shape[y*shape.w+x+1]

    end

  end

end

-- run the CA and produce the next generation

function _CELLS:evolve(next)

  local ym1,y,yp1,yi=self.h-1,self.h,1,self.h

  while yi > 0 do

    local xm1,x,xp1,xi=self.w-1,self.w,1,self.w

    while xi > 0 do

      local sum = self[ym1][xm1] + self[ym1][x] + self[ym1][xp1] +

                  self[y][xm1] + self[y][xp1] +

                  self[yp1][xm1] + self[yp1][x] + self[yp1][xp1]

      next[y][x] = ((sum==2) and self[y][x]) or ((sum==3) and 1) or 0

      xm1,x,xp1,xi = x,xp1,xp1+1,xi-1

    end

    ym1,y,yp1,yi = y,yp1,yp1+1,yi-1

  end

end

-- output the array to screen

function _CELLS:draw()

  local out="" -- accumulate to reduce flicker

  for y=1,self.h do

   for x=1,self.w do

      out=out..(((self[y][x]>0) and ALIVE) or DEAD)

    end

    out=out.."\n"

  end

  write(out)

end

-- constructor

function CELLS(w,h)

  local c = ARRAY2D(w,h)

  c.spawn = _CELLS.spawn

  c.evolve = _CELLS.evolve

  c.draw = _CELLS.draw

  return c

end

--

-- shapes suitable for use with spawn() above

--

HEART = { 1,0,1,1,0,1,1,1,1; w=3,h=3 }

GLIDER = { 0,0,1,1,0,1,0,1,1; w=3,h=3 }

EXPLODE = { 0,1,0,1,1,1,1,0,1,0,1,0; w=3,h=4 }

FISH = { 0,1,1,1,1,1,0,0,0,1,0,0,0,0,1,1,0,0,1,0; w=5,h=4 }

BUTTERFLY = { 1,0,0,0,1,0,1,1,1,0,1,0,0,0,1,1,0,1,0,1,1,0,0,0,1; w=5,h=5 }

-- the main routine

function LIFE(w,h)

  -- create two arrays

  local thisgen = CELLS(w,h)

  local nextgen = CELLS(w,h)

  -- create some life

  -- about 1000 generations of fun, then a glider steady-state

  thisgen:spawn(GLIDER,5,4)

  thisgen:spawn(EXPLODE,25,10)

  thisgen:spawn(FISH,4,12)

  -- run until break

  local gen=1

  write("\027[2J")	-- ANSI clear screen

  while 1 do

    thisgen:evolve(nextgen)

    thisgen,nextgen = nextgen,thisgen

    write("\027[H")	-- ANSI home cursor

    thisgen:draw()

    write("Life - generation ",gen,"\n")

    gen=gen+1

    if gen>2000 then break end

    --delay()		-- no delay

  end

end

LIFE(40,20)