com32/lua/test/life.lua

   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
   6 local write=io.write
   7
   8 ALIVE="¥"       DEAD="þ"
   9 ALIVE="O"       DEAD="-"
  10
  11 function 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
  14 end
  15
  16 function 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
  25 end
  26
  27 _CELLS = {}
  28
  29 -- give birth to a "shape" within the cell array
  30 function _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
  36 end
  37
  38 -- run the CA and produce the next generation
  39 function _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
  52 end
  53
  54 -- output the array to screen
  55 function _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)
  64 end
  65
  66 -- constructor
  67 function 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
  73 end
  74
  75 --
  76 -- shapes suitable for use with spawn() above
  77 --
  78 HEART = { 1,0,1,1,0,1,1,1,1; w=3,h=3 }
  79 GLIDER = { 0,0,1,1,0,1,0,1,1; w=3,h=3 }
  80 EXPLODE = { 0,1,0,1,1,1,1,0,1,0,1,0; w=3,h=4 }
  81 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 }
  82 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 }
  83
  84 -- the main routine
  85 function 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
 109 end
 110
 111 LIFE(40,20)