PostGIS  2.5.7dev-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.

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 }
#define LW_SUCCESS
Definition: liblwgeom.h:80
void normalize(POINT3D *p)
Normalize to a unit vector.
Definition: lwgeodetic.c:615
void cart2geog(const POINT3D *p, GEOGRAPHIC_POINT *g)
Convert cartesian coordinates on unit sphere to spherical coordinates.
Definition: lwgeodetic.c:414
double longitude_degrees_normalize(double lon)
Convert a longitude to the range of -180,180.
Definition: lwgeodetic.c:106
double latitude_degrees_normalize(double lat)
Convert a latitude to the range of -90,90.
Definition: lwgeodetic.c:133
Definition: lwgeodetic.h:80
double xmin
Definition: liblwgeom.h:295
Point in spherical coordinates on the world.
Definition: lwgeodetic.h:53
double y
Definition: liblwgeom.h:331
double x
Definition: liblwgeom.h:331
double z
Definition: liblwgeom.h:343
double x
Definition: liblwgeom.h:343
double y
Definition: liblwgeom.h:343

Referenced by geography_bestsrid(), and test_gbox_utils().

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