aUCBLogo Demos and Tests / clovertest2

be clovertest2 [singleshot false][FrameNr 0]
   ; for aUCBLogo-4.7
   if singleshot [(reRandom 0)]
   hideTurtle
   WindowMode
   perspective
   setPenColor HSB 120 1 0.7
   setPenSize [5 5]
   enableCylinderLines

   cs
   GraphicStart
      PenDown
      fd 100
      down 80
      left 135
      rightRoll 180
      repeat 3
      [   petal 2 4 2
         right 180
      ]
   clover=GraphicEnd
;stop
   cs
   drawPlane
   setPenColor "forestGreen
   repeat 100
   [   PenUp
      setY 0
      setX (rnd-0.5)*800
      setZ (rnd-0.5)*800
      setRoll random 180
      setPitch 0
      setHeading 0
      down (random 20)-10
      setPenColor HSB 120 1 0.4+rnd*0.3
      (drawGraphic clover rnd)
   ]
   ifelse singleshot
   [   (rotatescene2 1 true FrameNr*10)
   ][   rotatescene2
   ]
end

be drawPlane
   p=PosXYZ
   o=Orientation
   down 90
   horizon=10000
   PenUp
   fd horizon  rt 90  fd horizon  rt 90
   setPenColor HSB 70 0.4 0.8
   PenDown
   PolyStart
      repeat 4 [fd horizon*2  rt 90]
   PolyEnd
   PenUp
   setPosXYZ p
   setOrientation o
end

be halfpetal1 l f ex
   for [a 0 90]
   [   fd l
      right f*(sin a)^ex
   ]
end

be halfpetal2 l f ex
   for [a 90 0]
   [   right f*(sin a)^ex
      fd l
   ]
end

be petal2D l f ex
   p0=Pos
   PenDown
   TessStart
      halfpetal1 l f ex
      hm=towards p0
      right 180-2*(Heading-hm)
      halfpetal2 l f ex
   TessEnd
end

be petal l f ex
   p0=PosXYZ
   PenDown
   TessStart
      halfpetal1 l f ex
      PenUp
      p1=PosXYZ
      v1=p1-p0
      v1=v1/Norm v1
      p2=PosXYZ
      fd 1
      p3=PosXYZ
      back 1
      v2=p3-p2
      v2=v2/Norm v2
      hm=arcCos 0+v1*v2
      right 180-2*hm
      PenDown
      halfpetal2 l f ex
   TessEnd
end