PostGIS  2.4.9dev-r@@SVN_REVISION@@

◆ gbox_centroid()

int gbox_centroid ( const GBOX gbox,
POINT2D out 
)

Computes the average(ish) center of the box and returns success.

Definition at line 267 of file lwgeodetic.c.

References cart2geog(), GEOGRAPHIC_POINT::lat, latitude_degrees_normalize(), GEOGRAPHIC_POINT::lon, longitude_degrees_normalize(), LW_SUCCESS, normalize(), rad2deg, POINT2D::x, POINT3D::x, GBOX::xmin, POINT2D::y, POINT3D::y, and POINT3D::z.

Referenced by geography_bestsrid(), and test_gbox_utils().

268 {
269  double d[6];
271  POINT3D pt;
272  int i;
273 
274  /* Take a copy of the box corners so we can treat them as a list */
275  /* Elements are xmin, xmax, ymin, ymax, zmin, zmax */
276  memcpy(d, &(gbox->xmin), 6*sizeof(double));
277 
278  /* Zero out our return vector */
279  pt.x = pt.y = pt.z = 0.0;
280 
281  for ( i = 0; i < 8; i++ )
282  {
283  POINT3D pt_n;
284 
285  pt_n.x = d[i / 4];
286  pt_n.y = d[2 + ((i % 4) / 2)];
287  pt_n.z = d[4 + (i % 2)];
288  normalize(&pt_n);
289 
290  pt.x += pt_n.x;
291  pt.y += pt_n.y;
292  pt.z += pt_n.z;
293  }
294 
295  pt.x /= 8.0;
296  pt.y /= 8.0;
297  pt.z /= 8.0;
298  normalize(&pt);
299 
300  cart2geog(&pt, &g);
303 
304  return LW_SUCCESS;
305 }
void normalize(POINT3D *p)
Normalize to a unit vector.
Definition: lwgeodetic.c:611
double y
Definition: liblwgeom.h:340
#define LW_SUCCESS
Definition: liblwgeom.h:80
void cart2geog(const POINT3D *p, GEOGRAPHIC_POINT *g)
Convert cartesion coordinates on unit sphere to spherical coordinates.
Definition: lwgeodetic.c:410
double x
Definition: liblwgeom.h:340
double longitude_degrees_normalize(double lon)
Convert a longitude to the range of -180,180.
Definition: lwgeodetic.c:106
Point in spherical coordinates on the world.
Definition: lwgeodetic.h:52
double latitude_degrees_normalize(double lat)
Convert a latitude to the range of -90,90.
Definition: lwgeodetic.c:133
double z
Definition: liblwgeom.h:340
double x
Definition: liblwgeom.h:328
double xmin
Definition: liblwgeom.h:292
#define rad2deg(r)
Definition: lwgeodetic.h:80
double y
Definition: liblwgeom.h:328
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