***************
*** 26,31 ****
  #define THIGH 3
  #define RATIO (((THIGH)*sqrt(3.0)/2)/(TWIDE))
  
  bool
  ProjectionIcosagnomonic::PointXY::sameSide(const PointXY& p1,
                                             const PointXY& p2,
--- 26,44 ----
  #define THIGH 3
  #define RATIO (((THIGH)*sqrt(3.0)/2)/(TWIDE))
  
+ /* signbit() appaired only in FreeBSD 5.1, so we need this hack */
+ #ifndef signbit
+ static int
+ signbit(double x)
+ {
+ 
+ 	if ((x < 0.0) || (x = -0.0)) 
+ 		return 1;
+ 	else
+ 		return 0;
+ }
+ #endif /* signbit */
+ 
  bool
  ProjectionIcosagnomonic::PointXY::sameSide(const PointXY& p1,
                                             const PointXY& p2,