1-- life.lua 2-- original by Dave Bollinger <DBollinger@compuserve.com> posted to lua-l 3-- modified to use ANSI terminal escape sequences 4-- modified to use for instead of while 5 6local write=io.write 7 8ALIVE="�" DEAD="�" 9ALIVE="O" DEAD="-" 10 11function delay() -- NOTE: SYSTEM-DEPENDENT, adjust as necessary 12 for i=1,10000 do end 13 -- local i=os.clock()+1 while(os.clock()<i) do end 14end 15 16function ARRAY2D(w,h) 17 local t = {w=w,h=h} 18 for y=1,h do 19 t[y] = {} 20 for x=1,w do 21 t[y][x]=0 22 end 23 end 24 return t 25end 26 27_CELLS = {} 28 29-- give birth to a "shape" within the cell array 30function _CELLS:spawn(shape,left,top) 31 for y=0,shape.h-1 do 32 for x=0,shape.w-1 do 33 self[top+y][left+x] = shape[y*shape.w+x+1] 34 end 35 end 36end 37 38-- run the CA and produce the next generation 39function _CELLS:evolve(next) 40 local ym1,y,yp1,yi=self.h-1,self.h,1,self.h 41 while yi > 0 do 42 local xm1,x,xp1,xi=self.w-1,self.w,1,self.w 43 while xi > 0 do 44 local sum = self[ym1][xm1] + self[ym1][x] + self[ym1][xp1] + 45 self[y][xm1] + self[y][xp1] + 46 self[yp1][xm1] + self[yp1][x] + self[yp1][xp1] 47 next[y][x] = ((sum==2) and self[y][x]) or ((sum==3) and 1) or 0 48 xm1,x,xp1,xi = x,xp1,xp1+1,xi-1 49 end 50 ym1,y,yp1,yi = y,yp1,yp1+1,yi-1 51 end 52end 53 54-- output the array to screen 55function _CELLS:draw() 56 local out="" -- accumulate to reduce flicker 57 for y=1,self.h do 58 for x=1,self.w do 59 out=out..(((self[y][x]>0) and ALIVE) or DEAD) 60 end 61 out=out.."\n" 62 end 63 write(out) 64end 65 66-- constructor 67function CELLS(w,h) 68 local c = ARRAY2D(w,h) 69 c.spawn = _CELLS.spawn 70 c.evolve = _CELLS.evolve 71 c.draw = _CELLS.draw 72 return c 73end 74 75-- 76-- shapes suitable for use with spawn() above 77-- 78HEART = { 1,0,1,1,0,1,1,1,1; w=3,h=3 } 79GLIDER = { 0,0,1,1,0,1,0,1,1; w=3,h=3 } 80EXPLODE = { 0,1,0,1,1,1,1,0,1,0,1,0; w=3,h=4 } 81FISH = { 0,1,1,1,1,1,0,0,0,1,0,0,0,0,1,1,0,0,1,0; w=5,h=4 } 82BUTTERFLY = { 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 } 83 84-- the main routine 85function LIFE(w,h) 86 -- create two arrays 87 local thisgen = CELLS(w,h) 88 local nextgen = CELLS(w,h) 89 90 -- create some life 91 -- about 1000 generations of fun, then a glider steady-state 92 thisgen:spawn(GLIDER,5,4) 93 thisgen:spawn(EXPLODE,25,10) 94 thisgen:spawn(FISH,4,12) 95 96 -- run until break 97 local gen=1 98 write("\027[2J") -- ANSI clear screen 99 while 1 do 100 thisgen:evolve(nextgen) 101 thisgen,nextgen = nextgen,thisgen 102 write("\027[H") -- ANSI home cursor 103 thisgen:draw() 104 write("Life - generation ",gen,"\n") 105 gen=gen+1 106 if gen>2000 then break end 107 --delay() -- no delay 108 end 109end 110 111LIFE(40,20) 112