transform()

Datum transform

(

PG_FUNCTION_ARGS

)

Definition at line 47 of file postgis/lwgeom_transform.c.

References LWGEOM::bbox, geometry_serialize(), gserialized_get_srid(), LW_FAILURE, lwgeom_add_bbox(), lwgeom_drop_bbox(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_transform(), PG_FUNCTION_INFO_V1(), LWGEOM::srid, SRID_UNKNOWN, and transform_geom().

{
        GSERIALIZED *geom;
        GSERIALIZED *result=NULL;
        LWGEOM *lwgeom;
        projPJ input_pj, output_pj;
        int32 output_srid, input_srid;

        output_srid = PG_GETARG_INT32(1);
        if (output_srid == SRID_UNKNOWN)
        {
                elog(ERROR,"%d is an invalid target SRID",SRID_UNKNOWN);
                PG_RETURN_NULL();
        }

        geom = PG_GETARG_GSERIALIZED_P_COPY(0);
        input_srid = gserialized_get_srid(geom);
        if ( input_srid == SRID_UNKNOWN )
        {
                PG_FREE_IF_COPY(geom, 0);
                elog(ERROR,"Input geometry has unknown (%d) SRID",SRID_UNKNOWN);
                PG_RETURN_NULL();
        }

        /*
         * If input SRID and output SRID are equal, return geometry
         * without transform it
         */
        if ( input_srid == output_srid )
                PG_RETURN_POINTER(PG_GETARG_DATUM(0));

        if ( GetProjectionsUsingFCInfo(fcinfo, input_srid, output_srid, &input_pj, &output_pj) == LW_FAILURE )
        {
                PG_FREE_IF_COPY(geom, 0);
                elog(ERROR,"Failure reading projections from spatial_ref_sys.");
                PG_RETURN_NULL();
        }

        /* now we have a geometry, and input/output PJ structs. */
        lwgeom = lwgeom_from_gserialized(geom);
        lwgeom_transform(lwgeom, input_pj, output_pj);
        lwgeom->srid = output_srid;

        /* Re-compute bbox if input had one (COMPUTE_BBOX TAINTING) */
        if ( lwgeom->bbox )
        {
                lwgeom_drop_bbox(lwgeom);
                lwgeom_add_bbox(lwgeom);
        }

        result = geometry_serialize(lwgeom);
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(geom, 0);

        PG_RETURN_POINTER(result); /* new geometry */
}

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