anchor.diff:      recip + c@
   ; blob defines brightness
   
  +
  +: new ( class -- o )  align here over @ allot tuck ! ;
  +
   : metaball
       GD.init
  +    GD.REG_HSIZE GD.@ 2/ 16 * to centerx
  +    GD.REG_VSIZE GD.@ 2/ 16 * to centery
  +
  +    GD.REG_HSIZE GD.@ 6 800 */ to scale
   
       \ Build the reciprocal table
       200 recip c!
  
positive.code:         0 GD.ColorRGB#
          GD.POINTS GD.Begin
          NBLOBS 3 do
              i 3 * GD.PointSize
              i b[] draw
          loop
  
  
negative.code: \   Requiring the String word set
  \
  
  51                      constant w
  31                      constant h
  80                      constant NBLOBS
  
  0 value centerx
  0 value centery
  0 value scale
  
  w h *       constant wh
  
  