PostGIS  3.6.1dev-r@@SVN_REVISION@@

◆ LWGEOM_z_point()

Datum LWGEOM_z_point ( PG_FUNCTION_ARGS  )

Definition at line 780 of file lwgeom_ogc.c.

781 {
782  GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
783  POINT4D pt;
784 
785  if (gserialized_get_type(geom) != POINTTYPE)
786  lwpgerror("Argument to ST_Z() must have type POINT");
787 
788  if (!gserialized_has_z(geom) || (gserialized_peek_first_point(geom, &pt) == LW_FAILURE))
789  {
790  PG_RETURN_NULL();
791  }
792  PG_RETURN_FLOAT8(pt.z);
793 }
int gserialized_peek_first_point(const GSERIALIZED *g, POINT4D *out_point)
Pull the first point values of a GSERIALIZED.
Definition: gserialized.c:286
int gserialized_has_z(const GSERIALIZED *g)
Check if a GSERIALIZED has a Z ordinate.
Definition: gserialized.c:203
uint32_t gserialized_get_type(const GSERIALIZED *g)
Extract the geometry type from the serialized form (it hides in the anonymous data area,...
Definition: gserialized.c:118
#define LW_FAILURE
Definition: liblwgeom.h:96
#define POINTTYPE
LWTYPE numbers, used internally by PostGIS.
Definition: liblwgeom.h:102
double z
Definition: liblwgeom.h:414

References gserialized_get_type(), gserialized_has_z(), gserialized_peek_first_point(), LW_FAILURE, POINTTYPE, and POINT4D::z.

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