PostGIS  3.4.0dev-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 1248 of file measures3d.c.

1249 {
1250  uint32_t i;
1251 
1252  if (pt_in_ring_3d(projp, poly->rings[0], plane))
1253  {
1254  for (i = 1; i < poly->nrings; i++)
1255  {
1256  /* Inside a hole. Distance = pt -> ring */
1257  if (pt_in_ring_3d(projp, poly->rings[i], plane))
1258  return lw_dist3d_pt_ptarray(p, poly->rings[i], dl);
1259  }
1260 
1261  /* if the projected point is inside the polygon the shortest distance is between that point and the
1262  * input point */
1263  return lw_dist3d_pt_pt(p, projp, dl);
1264  }
1265  else
1266  /* if the projected point is outside the polygon we search for the closest distance against the boundary
1267  * instead */
1268  return lw_dist3d_pt_ptarray(p, poly->rings[0], dl);
1269 
1270  return LW_TRUE;
1271 }
#define LW_TRUE
Return types for functions with status returns.
Definition: liblwgeom.h:93
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:1564
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:959
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:1045
POINTARRAY ** rings
Definition: liblwgeom.h:519
uint32_t nrings
Definition: liblwgeom.h:524

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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