-- 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="е" DEAD="■"
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)