PostGIS  3.7.0dev-r@@SVN_REVISION@@

◆ ptarray_closest_vertex_2d()

int ptarray_closest_vertex_2d ( const POINTARRAY pa,
const POINT2D qp,
double *  dist 
)
Parameters
pathe subject pointarray
qpthe query point
distoptional output for actual distance from vertex

Definition at line 1357 of file ptarray.c.

1358 {
1359  uint32_t t, pn=0;
1360  const POINT2D *p;
1361  double mindist = DBL_MAX;
1362 
1363  /* Loop through pointarray looking for nearest segment */
1364  for (t=0; t<pa->npoints; t++)
1365  {
1366  double dist_sqr;
1367  p = getPoint2d_cp(pa, t);
1368  dist_sqr = distance2d_sqr_pt_pt(p, qp);
1369 
1370  if (dist_sqr < mindist)
1371  {
1372  mindist = dist_sqr;
1373  pn = t;
1374  if ( mindist == 0 )
1375  {
1376  LWDEBUG(3, "Breaking on mindist=0");
1377  break;
1378  }
1379  }
1380  }
1381  if ( dist ) *dist = sqrt(mindist);
1382  return pn;
1383 }
#define LWDEBUG(level, msg)
Definition: lwgeom_log.h:101
static const POINT2D * getPoint2d_cp(const POINTARRAY *pa, uint32_t n)
Returns a POINT2D pointer into the POINTARRAY serialized_ptlist, suitable for reading from.
Definition: lwinline.h:97
static double distance2d_sqr_pt_pt(const POINT2D *p1, const POINT2D *p2)
Definition: lwinline.h:33
uint32_t npoints
Definition: liblwgeom.h:427

References distance2d_sqr_pt_pt(), getPoint2d_cp(), LWDEBUG, and POINTARRAY::npoints.

Referenced by test_ptarray_closest_vertex_2d().

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