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[Tam WingChiu <>]

Hi,
 
   I am using the straight skeleton algorithm to expand a polygon. I think I have encountered a bug in the algorithm.
I have modified the Straight Skeleton example given (Straight_skeleton_2.cpp) and get back a result that I am sure it is wrong. See the attached picture. In this picture, I am trying to expand the red polygon in the middle by 700nm (0.7 um) and I get back the yellow polygon highlighted in the end. 
 
   FYI, the coordinates red polygon are given by:
 
   Point_2 pts[] = {
        Point_2(161930,83115),
        Point_2(162035,83115),
        Point_2(162035,83010),
        Point_2(162050,83010),
        Point_2(162050,82505),
        Point_2(162135,82420),
        Point_2(162135,81485),
        Point_2(162250,81485),
        Point_2(162250,82475),
        Point_2(162165,82560),
        Point_2(162165,83010),
        Point_2(162185,83010),
        Point_2(162185,83115),
        Point_2(162250,83115),
        Point_2(162250,83335),
        Point_2(162180,83335),
        Point_2(162180,83785),
        Point_2(162245,83850),
        Point_2(162245,84565),
        Point_2(162130,84565),
        Point_2(162130,83905),
        Point_2(162065,83840),
        Point_2(162065,83335),
        Point_2(161930,83335)
        };

   The result that I got in the end is: 
 
   161230 84035  
   161230 82415 
   161335 82415 
   161335 82310 
   161350 82310 
   161350 82215.1 
   161435 82130.1 
   161435 80785 
   162950 80785 
   162950 82764.9
  
   offset used is 700.
 
   It seems that for some reason, half of the expanded polgyon is gone.
 
   I tried both exact and inexact kernel and it gives back the same result. 
   Compiler and platform is: x86-64_Linux-2.6_g++-3.4.6
 
   Thanks a lot for your help and have a nice day.
 
Best,
Jason

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