PostGIS  3.1.6dev-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 1258 of file measures3d.c.

1259 {
1260  uint32_t i;
1261 
1262  if (pt_in_ring_3d(projp, poly->rings[0], plane))
1263  {
1264  for (i = 1; i < poly->nrings; i++)
1265  {
1266  /* Inside a hole. Distance = pt -> ring */
1267  if (pt_in_ring_3d(projp, poly->rings[i], plane))
1268  return lw_dist3d_pt_ptarray(p, poly->rings[i], dl);
1269  }
1270 
1271  /* if the projected point is inside the polygon the shortest distance is between that point and the
1272  * input point */
1273  return lw_dist3d_pt_pt(p, projp, dl);
1274  }
1275  else
1276  /* if the projected point is outside the polygon we search for the closest distance against the boundary
1277  * instead */
1278  return lw_dist3d_pt_ptarray(p, poly->rings[0], dl);
1279 
1280  return LW_TRUE;
1281 }
#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:1574
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:533
uint32_t nrings
Definition: liblwgeom.h:538

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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