aUCBLogo Demos and Tests / ant2

be ant2
   cs ht
   t=timefine
   start=100
   finish=200
   d=finish
   field=mdArray list d d
   n=20000
   antx=(start+finish)/2
   anty=(start+finish)/2
   jump=5
   stepcount=0
   framedelay=20
;   setactivearea [-260 -260 260 260]
   append=false
   for [a 1 n]
   [   ifelse (or antx<start anty<start antx>finish anty>finish)
      [   print [ant went be far]
         (pr timefine-t "sec)
         stop
      ]
      [move]
      if (mod a 20)==0
      [   updateGraph
      ]
   ]
   (pr timefine-t "sec)

   be move
      ifelse (field.antx).anty==0
      [   setfc 0
         square jump
         rt 90 fd jump
         setitem anty field.antx 1
      ][   setfc 7
         square jump
         lt 90 fd jump
         setItem anty field.antx 0
      ]
      ifelse or heading==90 heading==270
      [   ifelse heading==90
         [   antx=antx+1
         ][   antx=antx-1
         ]
      ][   ifelse heading==0
         [   anty=anty+1
         ][   anty=anty-1
         ]
      ]
   end

   be square size
      pd
      local [sh]
      sh=size/2+0.5
      fillRect list -sh -sh  list sh sh
      penup
      stepcount=stepcount+1
   ;   if stepcount==framedelay
   ;   [   (gifsave "ant.gif 0 append 0)
   ;      stepcount=0
   ;      append=true
   ;   ]
   end
end