aUCBLogo Demos and Tests / scrolltest3

to scrolltest3
   norefresh
   WindowMode
   white=rgb 1 1 1
   setsc white
   cs ht
   setUpdateGraph false
   scc=scrollcal [2 0]
   stonesinit
   courtinit
   rim=[400 299]
   m=[0 0]
   scrolledX=1
   forever
   [   _setPos [-400 299]
      scroll [800 600] scc
      m=m+abs scc
      if m.1 > stonesize
      [   m=mod m stonesize
         scrolledX=scrolledX+1
      ]
      drawRim
      updateGraph
      gc
      if key? [stop]
   ]
end

to stonesinit
   cs
   stonesize=50
   differentStones=8
   stone=Array differentStones
   repeat differentStones
   [   hue=360*repcount/differentStones
      setpc hsb hue 1 1
      setfc hsb hue 1 1
      myfrbox stonesize
      stone.repcount=bitCopy stonesize stonesize
   ]
   setpc white
   setfc white
   myfrbox stonesize
   nostone=bitCopy stonesize stonesize
end

to myfrbox size
   pu rt 45  fd size/(sqrt 2)  lt 45 pd
   (frBox size)
   pu lt 135  fd size/(sqrt 2) rt 135 pd
end

to courtinit
   cs
   pu
   _setpos [-400 299]
   setheading 90
   sx=int 800/stonesize
   sy=int 400/stonesize
   stones=0
   repeat sy
   [   repeat sx
      [   bitPaste stone.(1+mod repcount differentStones)
         stones=stones+1
         fd stonesize
      ]
      bk sx*stonesize
      rt 90  fd stonesize  lt 90
   ]
end

to drawRim
   _setPos rim-m
   setHeading 180
   repeat sy
   [   bitPaste stone.(1+mod (sx+scrolledX) differentStones)
      fd stonesize
   ]
end