PostGIS  2.1.10dev-r@@SVN_REVISION@@
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 393 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().

394 {
395  LWCOLLECTION *lwgeom_out = NULL;
396  char hasz, hasm;
397  int i;
398 
399  /* Nothing to do with NULL */
400  if ( ! mpoint )
401  lwerror("Null input geometry.");
402 
403  /* Ensure 'from' is less than 'to'. */
404  if ( to < from )
405  {
406  double t = from;
407  from = to;
408  to = t;
409  }
410 
411  /* Read Z/M info */
412  hasz = lwgeom_has_z(lwmpoint_as_lwgeom(mpoint));
413  hasm = lwgeom_has_m(lwmpoint_as_lwgeom(mpoint));
414 
415  /* Prepare return object */
416  lwgeom_out = lwcollection_construct_empty(MULTIPOINTTYPE, mpoint->srid, hasz, hasm);
417 
418  /* For each point, is its ordinate value between from and to? */
419  for ( i = 0; i < mpoint->ngeoms; i ++ )
420  {
421  POINT4D p4d;
422  double ordinate_value;
423 
424  lwpoint_getPoint4d_p(mpoint->geoms[i], &p4d);
425  ordinate_value = lwpoint_get_ordinate(&p4d, ordinate);
426 
427  if ( from <= ordinate_value && to >= ordinate_value )
428  {
429  LWPOINT *lwp = lwpoint_clone(mpoint->geoms[i]);
430  lwcollection_add_lwgeom(lwgeom_out, lwpoint_as_lwgeom(lwp));
431  }
432  }
433 
434  /* Set the bbox, if necessary */
435  if ( lwgeom_out->bbox )
436  {
437  lwgeom_drop_bbox((LWGEOM*)lwgeom_out);
438  lwgeom_add_bbox((LWGEOM*)lwgeom_out);
439  }
440 
441  return lwgeom_out;
442 }
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:63
GBOX * bbox
Definition: liblwgeom.h:461
int lwgeom_has_z(const LWGEOM *geom)
Return LW_TRUE if geometry has Z ordinates.
Definition: lwgeom.c:792
void lwgeom_drop_bbox(LWGEOM *lwgeom)
Call this function to drop BBOX and SRID from LWGEOM.
Definition: lwgeom.c:542
void lwerror(const char *fmt,...)
Write a notice out to the error handler.
Definition: lwutil.c:67
LWPOINT * lwpoint_clone(const LWPOINT *lwgeom)
Definition: lwpoint.c:206
int lwpoint_getPoint4d_p(const LWPOINT *point, POINT4D *out)
Definition: lwpoint.c:42
LWPOINT ** geoms
Definition: liblwgeom.h:426
void lwgeom_add_bbox(LWGEOM *lwgeom)
Compute a bbox if not already computed.
Definition: lwgeom.c:555
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:424
int32_t srid
Definition: liblwgeom.h:423
int lwgeom_has_m(const LWGEOM *geom)
Return LW_TRUE if geometry has M ordinates.
Definition: lwgeom.c:799
LWCOLLECTION * lwcollection_add_lwgeom(LWCOLLECTION *col, const LWGEOM *geom)
Appends geom to the collection managed by col.
Definition: lwcollection.c:174
LWGEOM * lwmpoint_as_lwgeom(const LWMPOINT *obj)
Definition: lwgeom.c:214

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