PostGIS  2.1.10dev-r@@SVN_REVISION@@
int lw_dist2d_selected_seg_seg ( const POINT2D A,
const POINT2D B,
const POINT2D C,
const POINT2D D,
DISTPTS dl 
)

This is the same function as lw_dist2d_seg_seg but without any calculations to determine intersection since we already know they do not intersect.

Definition at line 1965 of file measures.c.

References lw_dist2d_pt_seg(), LW_FALSE, LWDEBUGF, DISTPTS::twisted, POINT2D::x, and POINT2D::y.

Referenced by lw_dist2d_pre_seg_seg().

1966 {
1967  LWDEBUGF(2, "lw_dist2d_selected_seg_seg [%g,%g]->[%g,%g] by [%g,%g]->[%g,%g]",
1968  A->x,A->y,B->x,B->y, C->x,C->y, D->x, D->y);
1969 
1970  /*A and B are the same point */
1971  if ( ( A->x == B->x) && (A->y == B->y) )
1972  {
1973  return lw_dist2d_pt_seg(A,C,D,dl);
1974  }
1975  /*U and V are the same point */
1976 
1977  if ( ( C->x == D->x) && (C->y == D->y) )
1978  {
1979  dl->twisted= ((dl->twisted) * (-1));
1980  return lw_dist2d_pt_seg(D,A,B,dl);
1981  }
1982 
1983  if ((lw_dist2d_pt_seg(A,C,D,dl)) && (lw_dist2d_pt_seg(B,C,D,dl)))
1984  {
1985  dl->twisted= ((dl->twisted) * (-1)); /*here we change the order of inputted geometrys and that we notice by changing sign on dl->twisted*/
1986  return ((lw_dist2d_pt_seg(C,A,B,dl)) && (lw_dist2d_pt_seg(D,A,B,dl))); /*if all is successful we return true*/
1987  }
1988  else
1989  {
1990  return LW_FALSE; /* if any of the calls to lw_dist2d_pt_seg goes wrong we return false*/
1991  }
1992 }
double x
Definition: liblwgeom.h:284
#define LW_FALSE
Definition: liblwgeom.h:52
int lw_dist2d_pt_seg(const POINT2D *p, const POINT2D *A, const POINT2D *B, DISTPTS *dl)
lw_dist2d_comp from p to line A->B This one is now sending every occation to lw_dist2d_pt_pt Before i...
Definition: measures.c:2011
double y
Definition: liblwgeom.h:284
int twisted
Definition: measures.h:27
#define LWDEBUGF(level, msg,...)
Definition: lwgeom_log.h:55

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