Incremental Construction of Generalized Voronoi Diagrams on Pointerless Quadtrees

Algorithm 2

Pseudocode for updating a GVD.

MarkSiteCell (𝑚(𝑠; 𝑥_𝑚, 𝑦_𝑚), 𝑠𝐼𝐷)

31. Dist [𝑥_𝑚][𝑦_𝑚]← 0

32. Obst.UpdateANode(𝑚, 𝑠𝐼𝐷)

33. Check.UpdateANode(𝑚, true)

34. Open.push(𝑚, 0)

End

FreeSiteCell (𝑚(𝑠; 𝑥_𝑚, 𝑦_𝑚))

35. Obst.UpdateANode(𝑚, 1)

36. Raise. UpdateANode(𝑚, true)

37. Dist [𝑥_𝑚][𝑦_𝑚]← ∞

38. Check.UpdateANode(𝑚, true)

39.  Open.push(𝑚, 0)

End

UpdateGVD ()

40.  while  Open is not empty

41.   𝑚(𝑠; 𝑥_𝑚, 𝑦_𝑚)← 𝑝𝑜𝑝(Open)

42.   𝑏← 𝑅𝑎𝑖𝑠𝑒.QueryANode(𝑚)

43.   if  𝑏 = true

44.   ProcessRaise(𝑚)

45.  else

46.   𝑐← 𝑂𝑏𝑠𝑡.QueryANode(m)

47.    if  𝑐≠1

48.    Voro.UpdateANode(m,false)

49.     ProcessLower(m)

End