PostGIS  3.7.0dev-r@@SVN_REVISION@@

◆ LWGEOM_m_point()

Datum LWGEOM_m_point ( PG_FUNCTION_ARGS  )

Definition at line 806 of file lwgeom_ogc.c.

807 {
808  GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
809  POINT4D pt;
810 
811  if (gserialized_get_type(geom) != POINTTYPE)
812  lwpgerror("Argument to ST_M() must have type POINT");
813 
814  if (!gserialized_has_m(geom) || (gserialized_peek_first_point(geom, &pt) == LW_FAILURE))
815  {
816  PG_RETURN_NULL();
817  }
818  PG_RETURN_FLOAT8(pt.m);
819 }
int gserialized_has_m(const GSERIALIZED *g)
Check if a GSERIALIZED has an M ordinate.
Definition: gserialized.c:214
int gserialized_peek_first_point(const GSERIALIZED *g, POINT4D *out_point)
Pull the first point values of a GSERIALIZED.
Definition: gserialized.c:286
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 m
Definition: liblwgeom.h:414

References gserialized_get_type(), gserialized_has_m(), gserialized_peek_first_point(), LW_FAILURE, POINT4D::m, and POINTTYPE.

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