PostGIS  2.4.9dev-r@@SVN_REVISION@@

◆ lw_dist3d_point_poly()

int lw_dist3d_point_poly ( LWPOINT point,
LWPOLY poly,

Computes point to polygon distance For mindistance that means: 1)find the plane of the polygon 2)projecting the point to the plane of the polygon 3)finding if that projected point is inside the polygon, if so the distance is measured to that projected point 4) if not in polygon above, check the distance against the boundary of the polygon for max distance it is always point against boundary.

Definition at line 622 of file measures3d.c.

References define_plane(), DIST_MAX, getPoint3dz_p(), lw_dist3d_pt_poly(), lw_dist3d_pt_ptarray(), LWDEBUG, DISTPTS3D::mode, LWPOINT::point, project_point_on_plane(), and LWPOLY::rings.

Referenced by lw_dist3d_distribute_bruteforce().

623 {
624  POINT3DZ p, projp;/*projp is "point projected on plane"*/
625  PLANE3D plane;
626  LWDEBUG(2, "lw_dist3d_point_poly is called");
627  getPoint3dz_p(point->point, 0, &p);
629  /*If we are lookig for max distance, longestline or dfullywithin*/
630  if (dl->mode == DIST_MAX)
631  {
632  LWDEBUG(3, "looking for maxdistance");
633  return lw_dist3d_pt_ptarray(&p, poly->rings[0], dl);
634  }
636  /*Find the plane of the polygon, the "holes" have to be on the same plane. so we only care about the boudary*/
637  if(!define_plane(poly->rings[0], &plane))
638  {
639  /* Polygon does not define a plane: Return distance point -> line */
640  return lw_dist3d_pt_ptarray(&p, poly->rings[0], dl);
641  }
643  /*get our point projected on the plane of the polygon*/
644  project_point_on_plane(&p, &plane, &projp);
646  return lw_dist3d_pt_poly(&p, poly,&plane, &projp, dl);
647 }
#define LWDEBUG(level, msg)
Definition: lwgeom_log.h:83
Definition: liblwgeom.h:411
double project_point_on_plane(POINT3DZ *p, PLANE3D *pl, POINT3DZ *p0)
Finds a point on a plane from where the original point is perpendicular to the plane.
Definition: measures3d.c:1237
int lw_dist3d_pt_poly(POINT3DZ *p, LWPOLY *poly, PLANE3D *plane, POINT3DZ *projp, DISTPTS3D *dl)
Checking if the point projected on the plane of the polygon actually is inside that polygon...
Definition: measures3d.c:1043
int getPoint3dz_p(const POINTARRAY *pa, int n, POINT3DZ *point)
Definition: lwgeom_api.c:214
Definition: liblwgeom.h:457
int mode
Definition: measures3d.h:44
int define_plane(POINTARRAY *pa, PLANE3D *pl)
Definition: measures3d.c:1173
#define DIST_MAX
Definition: measures.h:43
int lw_dist3d_pt_ptarray(POINT3DZ *p, POINTARRAY *pa, DISTPTS3D *dl)
search all the segments of pointarray to see which one is closest to p Returns distance between point...
Definition: measures3d.c:740
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