PostGIS  3.0.6dev-r@@SVN_REVISION@@

◆ lw_dist3d_pt_poly()

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.

If so the mindistance is between that projected point and our original point. If not we check from original point to the boundary. If the projected point is inside a hole of the polygon we check the distance to the boundary of that hole.

Definition at line 1251 of file measures3d.c.

1252 {
1253  uint32_t i;
1254 
1255  if (pt_in_ring_3d(projp, poly->rings[0], plane))
1256  {
1257  for (i = 1; i < poly->nrings; i++)
1258  {
1259  /* Inside a hole. Distance = pt -> ring */
1260  if (pt_in_ring_3d(projp, poly->rings[i], plane))
1261  return lw_dist3d_pt_ptarray(p, poly->rings[i], dl);
1262  }
1263 
1264  /* if the projected point is inside the polygon the shortest distance is between that point and the
1265  * input point */
1266  return lw_dist3d_pt_pt(p, projp, dl);
1267  }
1268  else
1269  /* if the projected point is outside the polygon we search for the closest distance against the boundary
1270  * instead */
1271  return lw_dist3d_pt_ptarray(p, poly->rings[0], dl);
1272 
1273  return LW_TRUE;
1274 }
#define LW_TRUE
Return types for functions with status returns.
Definition: liblwgeom.h:107
int pt_in_ring_3d(const POINT3DZ *p, const POINTARRAY *ring, PLANE3D *plane)
pt_in_ring_3d(): crossing number test for a point in a polygon input: p = a point,...
Definition: measures3d.c:1567
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:962
int lw_dist3d_pt_pt(POINT3DZ *thep1, POINT3DZ *thep2, DISTPTS3D *dl)
Compares incoming points and stores the points closest to each other or most far away from each other...
Definition: measures3d.c:1048
POINTARRAY ** rings
Definition: liblwgeom.h:505
uint32_t nrings
Definition: liblwgeom.h:510

References lw_dist3d_pt_pt(), lw_dist3d_pt_ptarray(), LW_TRUE, LWPOLY::nrings, pt_in_ring_3d(), and LWPOLY::rings.

Referenced by lw_dist3d_point_poly(), and lw_dist3d_ptarray_poly().

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