PostGIS  2.2.8dev-r@@SVN_REVISION@@

◆ lwmpoint_clip_to_ordinate_range()

LWCOLLECTION* lwmpoint_clip_to_ordinate_range ( const LWMPOINT mpoint,
char  ordinate,
double  from,
double  to 
)

Clip an input MULTIPOINT between two values, on any ordinate input.

Clip a multi-point based on the from/to range of one of its ordinates.

Definition at line 402 of file lwlinearreferencing.c.

References LWCOLLECTION::bbox, LWMPOINT::geoms, lwcollection_add_lwgeom(), lwcollection_construct_empty(), lwerror(), lwgeom_add_bbox(), lwgeom_drop_bbox(), lwgeom_has_m(), lwgeom_has_z(), lwmpoint_as_lwgeom(), lwpoint_as_lwgeom(), lwpoint_clone(), lwpoint_get_ordinate(), lwpoint_getPoint4d_p(), MULTIPOINTTYPE, LWMPOINT::ngeoms, and LWMPOINT::srid.

Referenced by lwgeom_clip_to_ordinate_range().

403 {
404  LWCOLLECTION *lwgeom_out = NULL;
405  char hasz, hasm;
406  int i;
407 
408  /* Nothing to do with NULL */
409  if ( ! mpoint )
410  lwerror("Null input geometry.");
411 
412  /* Ensure 'from' is less than 'to'. */
413  if ( to < from )
414  {
415  double t = from;
416  from = to;
417  to = t;
418  }
419 
420  /* Read Z/M info */
421  hasz = lwgeom_has_z(lwmpoint_as_lwgeom(mpoint));
422  hasm = lwgeom_has_m(lwmpoint_as_lwgeom(mpoint));
423 
424  /* Prepare return object */
425  lwgeom_out = lwcollection_construct_empty(MULTIPOINTTYPE, mpoint->srid, hasz, hasm);
426 
427  /* For each point, is its ordinate value between from and to? */
428  for ( i = 0; i < mpoint->ngeoms; i ++ )
429  {
430  POINT4D p4d;
431  double ordinate_value;
432 
433  lwpoint_getPoint4d_p(mpoint->geoms[i], &p4d);
434  ordinate_value = lwpoint_get_ordinate(&p4d, ordinate);
435 
436  if ( from <= ordinate_value && to >= ordinate_value )
437  {
438  LWPOINT *lwp = lwpoint_clone(mpoint->geoms[i]);
439  lwcollection_add_lwgeom(lwgeom_out, lwpoint_as_lwgeom(lwp));
440  }
441  }
442 
443  /* Set the bbox, if necessary */
444  if ( lwgeom_out->bbox )
445  {
446  lwgeom_drop_bbox((LWGEOM*)lwgeom_out);
447  lwgeom_add_bbox((LWGEOM*)lwgeom_out);
448  }
449 
450  return lwgeom_out;
451 }
double lwpoint_get_ordinate(const POINT4D *p, char ordinate)
Given a POINT4D and an ordinate number, return the value of the ordinate.
#define MULTIPOINTTYPE
Definition: liblwgeom.h:73
GBOX * bbox
Definition: liblwgeom.h:489
int lwgeom_has_z(const LWGEOM *geom)
Return LW_TRUE if geometry has Z ordinates.
Definition: lwgeom.c:836
void lwgeom_drop_bbox(LWGEOM *lwgeom)
Call this function to drop BBOX and SRID from LWGEOM.
Definition: lwgeom.c:586
LWPOINT * lwpoint_clone(const LWPOINT *lwgeom)
Definition: lwpoint.c:208
int lwpoint_getPoint4d_p(const LWPOINT *point, POINT4D *out)
Definition: lwpoint.c:44
LWPOINT ** geoms
Definition: liblwgeom.h:454
void lwgeom_add_bbox(LWGEOM *lwgeom)
Compute a bbox if not already computed.
Definition: lwgeom.c:599
LWGEOM * lwpoint_as_lwgeom(const LWPOINT *obj)
Definition: lwgeom.c:254
LWCOLLECTION * lwcollection_construct_empty(uint8_t type, int srid, char hasz, char hasm)
Definition: lwcollection.c:81
int ngeoms
Definition: liblwgeom.h:452
int32_t srid
Definition: liblwgeom.h:451
int lwgeom_has_m(const LWGEOM *geom)
Return LW_TRUE if geometry has M ordinates.
Definition: lwgeom.c:843
LWCOLLECTION * lwcollection_add_lwgeom(LWCOLLECTION *col, const LWGEOM *geom)
Appends geom to the collection managed by col.
Definition: lwcollection.c:174
void lwerror(const char *fmt,...)
Write a notice out to the error handler.
Definition: lwutil.c:74
LWGEOM * lwmpoint_as_lwgeom(const LWMPOINT *obj)
Definition: lwgeom.c:214
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