aUCBLogo Demos and Tests / explosion_video

to explosion_video
   setUpdateGraph false
   perspective
   setEye {0 0 600}{0 0 0}{0 1 0}
   clearScreen
   disdt
   ht
   t0=5
   t=t0
   t1=20
   radius=80
   maxlevel=4
   ex=Array 1000
   VideoStart "test
   until [or Key? t>1000]
   [   cs
      (reRandom 0)
      explode radius*(1-exp -t/t1) exp -t/t1 maxlevel
      updateGraph
      setXYZ -4*radius -4*radius 0
      ex.t=BitCopy 8*radius 8*radius
      home
      t=t+1
      VideoFrame
   ]
   VideoEnd
   if Key? [ignore readChar]
   pr t
   tend=t
   setXYZ -4*radius -4*radius 0
   until [Key?]
   [   for [t t0 tend-1]
      [   BitPaste ex.t
         updateGraph
      ]
      waitms 1000
   ]
   (GC true)
end

to explode r a level
   setPC hsba 0 1-(norm PosXYZ)/(4*radius) 0.7 a
   sphere r
   local [ori p r2 i]
   ori=Orientation
   p=PosXYZ
   if level > 1
   [   for [i 1 12]
      [   rightRoll 360*rnd
         up 180*rnd
         r2=r*(1-0.1*rnd)
         pu
         fd r2
         if r > 0
         [   explode r2*(1-exp -t/t1*r2/r) a*sqr r2/r level-1
         ]
         setPosXYZ p
         setOrientation ori
      ]
   ]
end