§bExperimental §bVisGraph
 §b~~~~~~~~~~~~~~~~~~~~~~~~

 §bChanges:
  
  §b- §bUses §bdifferent §bBitSet §boperations §bfor §bboth §bopaque §band 
      §bvisible §bblocks

  §b- §bUses §bIntStack §binstead §bof §bLinkedList, §bincreases 
      §bperformance §bon §blarger §brender §bdistances

  §b- §bKeeps §btrack §bof §btotal §bnumber §bof §btransparent §bblocks

  §b- §bStores §bprecomputed §bvisibility §bdata §band §bvisibility §bstate

  §b- §bChecks §bif §bvisibility §bupdate §bis §bactually §bneeded

  §b- §bSeperate §bfunctions §bfor §bgetting §bvisible §bfaces §bfrom §ba 
      §bblock §bposition