• branch=trunk inherited from [9165bd3629]
• sym-trunk inherited from [9165bd3629]

Modified lib/geo/ccw.cpp from [bec880bc3280bac9] to [d88a2122970afda1].

    18     18   }
    19     19   
    20     20   
    21     21   // intersection of two line segments.
    22     22   bool cross(CMP p1, CMP p2, CMP P1, CMP P2) {
    23     23    return ccw(p1,p2,P1)*ccw(p1,p2,P2)<=0 && ccw(P1,P2,p1)*ccw(P1,P2,p2)<=0;
    24     24   }
           25  +
           26  +
           27  +// Intersection of two line segments, by p1+(*pos)(p2-p1) where 0<=*pos<=1.
           28  +// only tested by local simple unittest. be careful.
           29  +template<typename T>
           30  +bool cross(const std::complex<T>& p1, const std::complex<T>& p2,
           31  +           const std::complex<T>& P1, const std::complex<T>& P2, T* pos) {
           32  + if( ccw(p1,p2,P1)*ccw(p1,p2,P2)<=0 && ccw(P1,P2,p1)*ccw(P1,P2,p2)<=0 ) {
           33  +  if(outer_prod(p2-p1, P2-P1) == 0)
           34  +   return false; // parallel
           35  +  *pos = outer_prod(P1-p1, P2-P1) / outer_prod(p2-p1, P2-P1);
           36  +  return true;
           37  + }
           38  + return false;
           39  +}