lwmpoint_clip_to_ordinate_range()

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

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

Use for m- and z- clipping

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

Definition at line 415 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().

{
        LWCOLLECTION *lwgeom_out = NULL;
        char hasz, hasm;
        int i;

        /* Nothing to do with NULL */
        if ( ! mpoint )
                lwerror("Null input geometry.");

        /* Ensure 'from' is less than 'to'. */
        if ( to < from )
        {
                double t = from;
                from = to;
                to = t;
        }

        /* Read Z/M info */
        hasz = lwgeom_has_z(lwmpoint_as_lwgeom(mpoint));
        hasm = lwgeom_has_m(lwmpoint_as_lwgeom(mpoint));

        /* Prepare return object */
        lwgeom_out = lwcollection_construct_empty(MULTIPOINTTYPE, mpoint->srid, hasz, hasm);

        /* For each point, is its ordinate value between from and to? */
        for ( i = 0; i < mpoint->ngeoms; i ++ )
        {
                POINT4D p4d;
                double ordinate_value;

                lwpoint_getPoint4d_p(mpoint->geoms[i], &p4d);
                ordinate_value = lwpoint_get_ordinate(&p4d, ordinate);

                if ( from <= ordinate_value && to >= ordinate_value )
                {
                        LWPOINT *lwp = lwpoint_clone(mpoint->geoms[i]);
                        lwcollection_add_lwgeom(lwgeom_out, lwpoint_as_lwgeom(lwp));
                }
        }

        /* Set the bbox, if necessary */
        if ( lwgeom_out->bbox )
        {
                lwgeom_drop_bbox((LWGEOM*)lwgeom_out);
                lwgeom_add_bbox((LWGEOM*)lwgeom_out);
        }

        return lwgeom_out;
}

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