lwgeom_functions_basic.c

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/**********************************************************************
 *
 * PostGIS - Spatial Types for PostgreSQL
 * http://postgis.net
 *
 * PostGIS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * PostGIS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with PostGIS.  If not, see <http://www.gnu.org/licenses/>.
 *
 **********************************************************************
 *
 * Copyright 2001-2006 Refractions Research Inc.
 * Copyright 2017-2018 Daniel Baston <dbaston@gmail.com>
 *
 **********************************************************************/
 
#include "postgres.h"
#include "fmgr.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/elog.h"
#include "utils/geo_decls.h"
 
#include "../postgis_config.h"
#include "liblwgeom.h"
#include "liblwgeom_internal.h"
#include "lwgeom_pg.h"
 
#include <math.h>
#include <float.h>
#include <string.h>
#include <stdio.h>
 
#define xstr(s) str(s)
#define str(s) #s
 
Datum LWGEOM_mem_size(PG_FUNCTION_ARGS);
Datum LWGEOM_summary(PG_FUNCTION_ARGS);
Datum LWGEOM_npoints(PG_FUNCTION_ARGS);
Datum LWGEOM_nrings(PG_FUNCTION_ARGS);
Datum ST_Area(PG_FUNCTION_ARGS);
Datum postgis_scripts_released(PG_FUNCTION_ARGS);
Datum postgis_version(PG_FUNCTION_ARGS);
Datum postgis_liblwgeom_version(PG_FUNCTION_ARGS);
Datum postgis_lib_version(PG_FUNCTION_ARGS);
Datum postgis_svn_version(PG_FUNCTION_ARGS);
Datum postgis_lib_revision(PG_FUNCTION_ARGS);
Datum postgis_libxml_version(PG_FUNCTION_ARGS);
Datum postgis_lib_build_date(PG_FUNCTION_ARGS);
Datum LWGEOM_length2d_linestring(PG_FUNCTION_ARGS);
Datum LWGEOM_length_linestring(PG_FUNCTION_ARGS);
Datum LWGEOM_perimeter2d_poly(PG_FUNCTION_ARGS);
Datum LWGEOM_perimeter_poly(PG_FUNCTION_ARGS);
 
Datum LWGEOM_maxdistance2d_linestring(PG_FUNCTION_ARGS);
Datum ST_Distance(PG_FUNCTION_ARGS);
Datum LWGEOM_closestpoint(PG_FUNCTION_ARGS);
Datum LWGEOM_shortestline2d(PG_FUNCTION_ARGS);
Datum LWGEOM_longestline2d(PG_FUNCTION_ARGS);
Datum LWGEOM_dwithin(PG_FUNCTION_ARGS);
 
Datum LWGEOM_maxdistance3d(PG_FUNCTION_ARGS);
Datum LWGEOM_mindistance3d(PG_FUNCTION_ARGS);
Datum LWGEOM_closestpoint3d(PG_FUNCTION_ARGS);
Datum LWGEOM_shortestline3d(PG_FUNCTION_ARGS);
Datum LWGEOM_longestline3d(PG_FUNCTION_ARGS);
Datum LWGEOM_dwithin3d(PG_FUNCTION_ARGS);
Datum LWGEOM_dfullywithin3d(PG_FUNCTION_ARGS);
 
Datum LWGEOM_inside_circle_point(PG_FUNCTION_ARGS);
Datum LWGEOM_collect(PG_FUNCTION_ARGS);
Datum LWGEOM_collect_garray(PG_FUNCTION_ARGS);
Datum LWGEOM_expand(PG_FUNCTION_ARGS);
Datum LWGEOM_to_BOX(PG_FUNCTION_ARGS);
Datum LWGEOM_envelope(PG_FUNCTION_ARGS);
Datum LWGEOM_isempty(PG_FUNCTION_ARGS);
Datum LWGEOM_segmentize2d(PG_FUNCTION_ARGS);
Datum LWGEOM_reverse(PG_FUNCTION_ARGS);
Datum LWGEOM_force_clockwise_poly(PG_FUNCTION_ARGS);
Datum LWGEOM_force_sfs(PG_FUNCTION_ARGS);
Datum LWGEOM_noop(PG_FUNCTION_ARGS);
Datum LWGEOM_zmflag(PG_FUNCTION_ARGS);
Datum LWGEOM_hasz(PG_FUNCTION_ARGS);
Datum LWGEOM_hasm(PG_FUNCTION_ARGS);
Datum LWGEOM_ndims(PG_FUNCTION_ARGS);
Datum LWGEOM_makepoint(PG_FUNCTION_ARGS);
Datum LWGEOM_makepoint3dm(PG_FUNCTION_ARGS);
Datum LWGEOM_makeline_garray(PG_FUNCTION_ARGS);
Datum LWGEOM_makeline(PG_FUNCTION_ARGS);
Datum LWGEOM_makepoly(PG_FUNCTION_ARGS);
Datum LWGEOM_line_from_mpoint(PG_FUNCTION_ARGS);
Datum LWGEOM_addpoint(PG_FUNCTION_ARGS);
Datum LWGEOM_removepoint(PG_FUNCTION_ARGS);
Datum LWGEOM_setpoint_linestring(PG_FUNCTION_ARGS);
Datum LWGEOM_asEWKT(PG_FUNCTION_ARGS);
Datum LWGEOM_hasBBOX(PG_FUNCTION_ARGS);
Datum LWGEOM_azimuth(PG_FUNCTION_ARGS);
Datum geometry_project_direction(PG_FUNCTION_ARGS);
Datum geometry_project_geometry(PG_FUNCTION_ARGS);
Datum geometry_line_extend(PG_FUNCTION_ARGS);
Datum LWGEOM_angle(PG_FUNCTION_ARGS);
Datum LWGEOM_affine(PG_FUNCTION_ARGS);
Datum LWGEOM_longitude_shift(PG_FUNCTION_ARGS);
Datum optimistic_overlap(PG_FUNCTION_ARGS);
Datum ST_GeoHash(PG_FUNCTION_ARGS);
Datum ST_MakeEnvelope(PG_FUNCTION_ARGS);
Datum ST_TileEnvelope(PG_FUNCTION_ARGS);
Datum ST_CollectionExtract(PG_FUNCTION_ARGS);
Datum ST_CollectionHomogenize(PG_FUNCTION_ARGS);
Datum ST_IsCollection(PG_FUNCTION_ARGS);
Datum ST_QuantizeCoordinates(PG_FUNCTION_ARGS);
Datum ST_WrapX(PG_FUNCTION_ARGS);
Datum ST_Scroll(PG_FUNCTION_ARGS);
Datum LWGEOM_FilterByM(PG_FUNCTION_ARGS);
Datum ST_Point(PG_FUNCTION_ARGS);
Datum ST_PointZ(PG_FUNCTION_ARGS);
Datum ST_PointM(PG_FUNCTION_ARGS);
Datum ST_PointZM(PG_FUNCTION_ARGS);
 
/*------------------------------------------------------------------*/
 
PG_FUNCTION_INFO_V1(LWGEOM_mem_size);
Datum LWGEOM_mem_size(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        size_t size = VARSIZE(geom);
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_INT32(size);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_summary);
Datum LWGEOM_summary(PG_FUNCTION_ARGS)
{
        text *summary;
        GSERIALIZED *g = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwg = lwgeom_from_gserialized(g);
        char *lwresult = lwgeom_summary(lwg, 0);
        uint32_t gver = gserialized_get_version(g);
        size_t result_sz = strlen(lwresult) + 8;
        char *result;
        if (gver == 0)
        {
                result = lwalloc(result_sz + 2);
                snprintf(result, result_sz, "0:%s", lwresult);
        }
        else
        {
                result = lwalloc(result_sz);
                snprintf(result, result_sz, "%s", lwresult);
        }
        lwgeom_free(lwg);
        lwfree(lwresult);
 
        /* create a text obj to return */
        summary = cstring_to_text(result);
        lwfree(result);
 
        PG_FREE_IF_COPY(g, 0);
        PG_RETURN_TEXT_P(summary);
}
 
PG_FUNCTION_INFO_V1(postgis_version);
Datum postgis_version(PG_FUNCTION_ARGS)
{
        char *ver = POSTGIS_VERSION;
        text *result = cstring_to_text(ver);
        PG_RETURN_TEXT_P(result);
}
 
PG_FUNCTION_INFO_V1(postgis_liblwgeom_version);
Datum postgis_liblwgeom_version(PG_FUNCTION_ARGS)
{
        const char *ver = lwgeom_version();
        text *result = cstring_to_text(ver);
        PG_RETURN_TEXT_P(result);
}
 
PG_FUNCTION_INFO_V1(postgis_lib_version);
Datum postgis_lib_version(PG_FUNCTION_ARGS)
{
        char *ver = POSTGIS_LIB_VERSION;
        text *result = cstring_to_text(ver);
        PG_RETURN_TEXT_P(result);
}
 
PG_FUNCTION_INFO_V1(postgis_lib_revision);
Datum postgis_lib_revision(PG_FUNCTION_ARGS)
{
        static char *rev = xstr(POSTGIS_REVISION);
        char ver[32];
        if (rev && rev[0] != '\0')
        {
                snprintf(ver, 32, "%s", rev);
                ver[31] = '\0';
                PG_RETURN_TEXT_P(cstring_to_text(ver));
        }
        else PG_RETURN_NULL();
}
 
PG_FUNCTION_INFO_V1(postgis_lib_build_date);
Datum postgis_lib_build_date(PG_FUNCTION_ARGS)
{
        char *ver = POSTGIS_BUILD_DATE;
        text *result = cstring_to_text(ver);
        PG_RETURN_TEXT_P(result);
}
 
PG_FUNCTION_INFO_V1(postgis_scripts_released);
Datum postgis_scripts_released(PG_FUNCTION_ARGS)
{
        char ver[64];
        text *result;
 
        snprintf(ver, 64, "%s %s", POSTGIS_LIB_VERSION, xstr(POSTGIS_REVISION));
        ver[63] = '\0';
 
        result = cstring_to_text(ver);
        PG_RETURN_TEXT_P(result);
}
 
PG_FUNCTION_INFO_V1(postgis_libxml_version);
Datum postgis_libxml_version(PG_FUNCTION_ARGS)
{
        char *ver = POSTGIS_LIBXML2_VERSION;
        text *result = cstring_to_text(ver);
        PG_RETURN_TEXT_P(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_npoints);
Datum LWGEOM_npoints(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        int npoints = 0;
 
        npoints = lwgeom_count_vertices(lwgeom);
        lwgeom_free(lwgeom);
 
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_INT32(npoints);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_nrings);
Datum LWGEOM_nrings(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        int nrings = 0;
 
        nrings = lwgeom_count_rings(lwgeom);
        lwgeom_free(lwgeom);
 
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_INT32(nrings);
}
 
PG_FUNCTION_INFO_V1(ST_Area);
Datum ST_Area(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        double area = 0.0;
 
        area = lwgeom_area(lwgeom);
 
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(geom, 0);
 
        PG_RETURN_FLOAT8(area);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_length2d_linestring);
Datum LWGEOM_length2d_linestring(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        double dist = lwgeom_length_2d(lwgeom);
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_FLOAT8(dist);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_length_linestring);
Datum LWGEOM_length_linestring(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        double dist = lwgeom_length(lwgeom);
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_FLOAT8(dist);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_perimeter_poly);
Datum LWGEOM_perimeter_poly(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        double perimeter = 0.0;
 
        perimeter = lwgeom_perimeter(lwgeom);
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_FLOAT8(perimeter);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_perimeter2d_poly);
Datum LWGEOM_perimeter2d_poly(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        double perimeter = 0.0;
 
        perimeter = lwgeom_perimeter_2d(lwgeom);
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_FLOAT8(perimeter);
}
 
/* transform input geometry to 2d if not 2d already */
PG_FUNCTION_INFO_V1(LWGEOM_force_2d);
Datum LWGEOM_force_2d(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pg_geom_in = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *pg_geom_out;
        LWGEOM *lwg_in, *lwg_out;
 
        /* already 2d */
        if (gserialized_ndims(pg_geom_in) == 2)
                PG_RETURN_POINTER(pg_geom_in);
 
        lwg_in = lwgeom_from_gserialized(pg_geom_in);
        lwg_out = lwgeom_force_2d(lwg_in);
        pg_geom_out = geometry_serialize(lwg_out);
        lwgeom_free(lwg_out);
        lwgeom_free(lwg_in);
 
        PG_FREE_IF_COPY(pg_geom_in, 0);
        PG_RETURN_POINTER(pg_geom_out);
}
 
/* transform input geometry to 3dz if not 3dz already */
PG_FUNCTION_INFO_V1(LWGEOM_force_3dz);
Datum LWGEOM_force_3dz(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pg_geom_in = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *pg_geom_out;
        LWGEOM *lwg_in, *lwg_out;
        double z = PG_NARGS() < 2 ? 0 : PG_GETARG_FLOAT8(1);
 
        /* already 3d */
        if (gserialized_ndims(pg_geom_in) == 3 && gserialized_has_z(pg_geom_in))
                PG_RETURN_POINTER(pg_geom_in);
 
        lwg_in = lwgeom_from_gserialized(pg_geom_in);
        lwg_out = lwgeom_force_3dz(lwg_in, z);
        pg_geom_out = geometry_serialize(lwg_out);
        lwgeom_free(lwg_out);
        lwgeom_free(lwg_in);
 
        PG_FREE_IF_COPY(pg_geom_in, 0);
        PG_RETURN_POINTER(pg_geom_out);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_force_3dm);
Datum LWGEOM_force_3dm(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pg_geom_in = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *pg_geom_out;
        LWGEOM *lwg_in, *lwg_out;
        double m = PG_NARGS() < 2 ? 0 : PG_GETARG_FLOAT8(1);
 
        /* already 3d */
        if (gserialized_ndims(pg_geom_in) == 3 && gserialized_has_m(pg_geom_in))
                PG_RETURN_POINTER(pg_geom_in);
 
        lwg_in = lwgeom_from_gserialized(pg_geom_in);
        lwg_out = lwgeom_force_3dm(lwg_in, m);
        pg_geom_out = geometry_serialize(lwg_out);
        lwgeom_free(lwg_out);
        lwgeom_free(lwg_in);
 
        PG_FREE_IF_COPY(pg_geom_in, 0);
        PG_RETURN_POINTER(pg_geom_out);
}
 
/* transform input geometry to 4d if not 4d already */
PG_FUNCTION_INFO_V1(LWGEOM_force_4d);
Datum LWGEOM_force_4d(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pg_geom_in = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *pg_geom_out;
        LWGEOM *lwg_in, *lwg_out;
        double z = PG_NARGS() < 3 ? 0 : PG_GETARG_FLOAT8(1);
        double m = PG_NARGS() < 3 ? 0 : PG_GETARG_FLOAT8(2);
 
        /* already 4d */
        if (gserialized_ndims(pg_geom_in) == 4)
                PG_RETURN_POINTER(pg_geom_in);
 
        lwg_in = lwgeom_from_gserialized(pg_geom_in);
        lwg_out = lwgeom_force_4d(lwg_in, z, m);
        pg_geom_out = geometry_serialize(lwg_out);
        lwgeom_free(lwg_out);
        lwgeom_free(lwg_in);
 
        PG_FREE_IF_COPY(pg_geom_in, 0);
        PG_RETURN_POINTER(pg_geom_out);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_force_collection);
Datum LWGEOM_force_collection(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *result;
        LWGEOM **lwgeoms;
        LWGEOM *lwgeom;
        int32_t srid;
        GBOX *bbox;
 
        POSTGIS_DEBUG(2, "LWGEOM_force_collection called");
 
        /*
         * This funx is a no-op only if a bbox cache is already present
         * in input. If bbox cache is not there we'll need to handle
         * automatic bbox addition FOR_COMPLEX_GEOMS.
         */
        if (gserialized_get_type(geom) == COLLECTIONTYPE && gserialized_has_bbox(geom))
        {
                PG_RETURN_POINTER(geom);
        }
 
        /* deserialize into lwgeoms[0] */
        lwgeom = lwgeom_from_gserialized(geom);
 
        /* already a multi*, just make it a collection */
        if (lwgeom_is_collection(lwgeom))
        {
                lwgeom->type = COLLECTIONTYPE;
        }
 
        /* single geom, make it a collection */
        else
        {
                srid = lwgeom->srid;
                /* We transfer bbox ownership from input to output */
                bbox = lwgeom->bbox;
                lwgeom->srid = SRID_UNKNOWN;
                lwgeom->bbox = NULL;
                lwgeoms = palloc(sizeof(LWGEOM *));
                lwgeoms[0] = lwgeom;
                lwgeom = (LWGEOM *)lwcollection_construct(COLLECTIONTYPE, srid, bbox, 1, lwgeoms);
        }
 
        result = geometry_serialize(lwgeom);
        lwgeom_free(lwgeom);
 
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_force_multi);
Datum LWGEOM_force_multi(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *result;
        LWGEOM *lwgeom;
        LWGEOM *ogeom;
 
        POSTGIS_DEBUG(2, "LWGEOM_force_multi called");
 
        /*
        ** This funx is a no-op only if a bbox cache is already present
        ** in input. If bbox cache is not there we'll need to handle
        ** automatic bbox addition FOR_COMPLEX_GEOMS.
        */
        if (gserialized_has_bbox(geom))
        {
                switch (gserialized_get_type(geom))
                {
                case MULTIPOINTTYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case COLLECTIONTYPE:
                case MULTICURVETYPE:
                case MULTISURFACETYPE:
                case TINTYPE:
                        PG_RETURN_POINTER(geom);
                default:
                        break;
                }
        }
 
        /* deserialize into lwgeoms[0] */
        lwgeom = lwgeom_from_gserialized(geom);
        ogeom = lwgeom_as_multi(lwgeom);
 
        result = geometry_serialize(ogeom);
 
        PG_FREE_IF_COPY(geom, 0);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_force_curve);
Datum LWGEOM_force_curve(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *result;
        LWGEOM *lwgeom;
        LWGEOM *ogeom;
 
        POSTGIS_DEBUG(2, "LWGEOM_force_curve called");
 
        /* TODO: early out if input is already a curve */
 
        lwgeom = lwgeom_from_gserialized(geom);
        ogeom = lwgeom_as_curve(lwgeom);
 
        result = geometry_serialize(ogeom);
 
        PG_FREE_IF_COPY(geom, 0);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_force_sfs);
Datum LWGEOM_force_sfs(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *result;
        LWGEOM *lwgeom;
        LWGEOM *ogeom;
        text *ver;
        int version = 110; /* default version is SFS 1.1 */
 
        POSTGIS_DEBUG(2, "LWGEOM_force_sfs called");
 
        /* If user specified version, respect it */
        if ((PG_NARGS() > 1) && (!PG_ARGISNULL(1)))
        {
                ver = PG_GETARG_TEXT_P(1);
 
                if (!strncmp(VARDATA(ver), "1.2", 3))
                {
                        version = 120;
                }
        }
 
        lwgeom = lwgeom_from_gserialized(geom);
        ogeom = lwgeom_force_sfs(lwgeom, version);
 
        result = geometry_serialize(ogeom);
 
        PG_FREE_IF_COPY(geom, 0);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_closestpoint);
Datum LWGEOM_closestpoint(PG_FUNCTION_ARGS)
{
        GSERIALIZED *result;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *point;
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        point = lwgeom_closest_point(lwgeom1, lwgeom2);
 
        if (lwgeom_is_empty(point))
                PG_RETURN_NULL();
 
        result = geometry_serialize(point);
        lwgeom_free(point);
        lwgeom_free(lwgeom1);
        lwgeom_free(lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_shortestline2d);
Datum LWGEOM_shortestline2d(PG_FUNCTION_ARGS)
{
        GSERIALIZED *result;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *theline;
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        theline = lwgeom_closest_line(lwgeom1, lwgeom2);
 
        if (lwgeom_is_empty(theline))
                PG_RETURN_NULL();
 
        result = geometry_serialize(theline);
        lwgeom_free(theline);
        lwgeom_free(lwgeom1);
        lwgeom_free(lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_longestline2d);
Datum LWGEOM_longestline2d(PG_FUNCTION_ARGS)
{
        GSERIALIZED *result;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *theline;
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        theline = lwgeom_furthest_line(lwgeom1, lwgeom2);
 
        if (lwgeom_is_empty(theline))
                PG_RETURN_NULL();
 
        result = geometry_serialize(theline);
        lwgeom_free(theline);
        lwgeom_free(lwgeom1);
        lwgeom_free(lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        PG_RETURN_POINTER(result);
}
PG_FUNCTION_INFO_V1(ST_Distance);
Datum ST_Distance(PG_FUNCTION_ARGS)
{
        double mindist;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        mindist = lwgeom_mindistance2d(lwgeom1, lwgeom2);
 
        lwgeom_free(lwgeom1);
        lwgeom_free(lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
 
        /* if called with empty geometries the ingoing mindistance is untouched, and makes us return NULL*/
        if (mindist < FLT_MAX)
                PG_RETURN_FLOAT8(mindist);
 
        PG_RETURN_NULL();
}
 
PG_FUNCTION_INFO_V1(LWGEOM_dwithin);
Datum LWGEOM_dwithin(PG_FUNCTION_ARGS)
{
        double mindist;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        double tolerance = PG_GETARG_FLOAT8(2);
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
 
        if (tolerance < 0)
        {
                elog(ERROR, "Tolerance cannot be less than zero\n");
                PG_RETURN_NULL();
        }
 
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        if (lwgeom_is_empty(lwgeom1) || lwgeom_is_empty(lwgeom2))
        {
                PG_RETURN_BOOL(false);
        }
 
        mindist = lwgeom_mindistance2d_tolerance(lwgeom1, lwgeom2, tolerance);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        /*empty geometries cases should be right handled since return from underlying
         functions should be FLT_MAX which causes false as answer*/
        PG_RETURN_BOOL(tolerance >= mindist);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_maxdistance2d_linestring);
Datum LWGEOM_maxdistance2d_linestring(PG_FUNCTION_ARGS)
{
        double maxdist;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        maxdist = lwgeom_maxdistance2d(lwgeom1, lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
 
        /*if called with empty geometries the ingoing mindistance is untouched, and makes us return NULL*/
        if (maxdist > -1)
                PG_RETURN_FLOAT8(maxdist);
 
        PG_RETURN_NULL();
}
 
PG_FUNCTION_INFO_V1(LWGEOM_closestpoint3d);
Datum LWGEOM_closestpoint3d(PG_FUNCTION_ARGS)
{
        GSERIALIZED *result;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *point;
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        point = lwgeom_closest_point_3d(lwgeom1, lwgeom2);
        // point = lw_dist3d_distancepoint(lwgeom1, lwgeom2, lwgeom1->srid, DIST_MIN);
 
        if (lwgeom_is_empty(point))
                PG_RETURN_NULL();
 
        result = geometry_serialize(point);
 
        lwgeom_free(point);
        lwgeom_free(lwgeom1);
        lwgeom_free(lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_shortestline3d);
Datum LWGEOM_shortestline3d(PG_FUNCTION_ARGS)
{
        GSERIALIZED *result;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *theline;
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        theline = lwgeom_closest_line_3d(lwgeom1, lwgeom2);
        // theline = lw_dist3d_distanceline(lwgeom1, lwgeom2, lwgeom1->srid, DIST_MIN);
 
        if (lwgeom_is_empty(theline))
                PG_RETURN_NULL();
 
        result = geometry_serialize(theline);
 
        lwgeom_free(theline);
        lwgeom_free(lwgeom1);
        lwgeom_free(lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_longestline3d);
Datum LWGEOM_longestline3d(PG_FUNCTION_ARGS)
{
        GSERIALIZED *result;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *theline;
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        theline = lwgeom_furthest_line_3d(lwgeom1, lwgeom2);
        // theline = lw_dist3d_distanceline(lwgeom1, lwgeom2, lwgeom1->srid, DIST_MAX);
 
        if (lwgeom_is_empty(theline))
                PG_RETURN_NULL();
 
        result = geometry_serialize(theline);
 
        lwgeom_free(theline);
        lwgeom_free(lwgeom1);
        lwgeom_free(lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        PG_RETURN_POINTER(result);
}
PG_FUNCTION_INFO_V1(ST_3DDistance);
Datum ST_3DDistance(PG_FUNCTION_ARGS)
{
        double mindist;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        mindist = lwgeom_mindistance3d(lwgeom1, lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
 
        /*if called with empty geometries the ingoing mindistance is untouched, and makes us return NULL*/
        if (mindist < FLT_MAX)
                PG_RETURN_FLOAT8(mindist);
 
        PG_RETURN_NULL();
}
 
/* intersects3d through dwithin */
PG_FUNCTION_INFO_V1(ST_3DIntersects);
Datum ST_3DIntersects(PG_FUNCTION_ARGS)
{
        double mindist;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        mindist = lwgeom_mindistance3d_tolerance(lwgeom1, lwgeom2, 0.0);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        /*empty geometries cases should be right handled since return from underlying
          functions should be FLT_MAX which causes false as answer*/
        PG_RETURN_BOOL(0.0 == mindist);
}
 
 
PG_FUNCTION_INFO_V1(LWGEOM_dwithin3d);
Datum LWGEOM_dwithin3d(PG_FUNCTION_ARGS)
{
        double mindist;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        double tolerance = PG_GETARG_FLOAT8(2);
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
 
        if (tolerance < 0)
        {
                elog(ERROR, "Tolerance cannot be less than zero\n");
                PG_RETURN_NULL();
        }
 
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        mindist = lwgeom_mindistance3d_tolerance(lwgeom1, lwgeom2, tolerance);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
 
        /*empty geometries cases should be right handled since return from underlying
         functions should be FLT_MAX which causes false as answer*/
        PG_RETURN_BOOL(tolerance >= mindist);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_dfullywithin3d);
Datum LWGEOM_dfullywithin3d(PG_FUNCTION_ARGS)
{
        double maxdist;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        double tolerance = PG_GETARG_FLOAT8(2);
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
 
        if (tolerance < 0)
        {
                elog(ERROR, "Tolerance cannot be less than zero\n");
                PG_RETURN_NULL();
        }
 
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
        maxdist = lwgeom_maxdistance3d_tolerance(lwgeom1, lwgeom2, tolerance);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
 
        /*If function is feed with empty geometries we should return false*/
        if (maxdist > -1)
                PG_RETURN_BOOL(tolerance >= maxdist);
 
        PG_RETURN_BOOL(LW_FALSE);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_maxdistance3d);
Datum LWGEOM_maxdistance3d(PG_FUNCTION_ARGS)
{
        double maxdist;
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *lwgeom1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lwgeom2 = lwgeom_from_gserialized(geom2);
 
        gserialized_error_if_srid_mismatch(geom1, geom2, __func__);
 
        maxdist = lwgeom_maxdistance3d(lwgeom1, lwgeom2);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
 
        /*if called with empty geometries the ingoing mindistance is untouched, and makes us return NULL*/
        if (maxdist > -1)
                PG_RETURN_FLOAT8(maxdist);
 
        PG_RETURN_NULL();
}
 
PG_FUNCTION_INFO_V1(LWGEOM_longitude_shift);
Datum LWGEOM_longitude_shift(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        GSERIALIZED *ret;
 
        POSTGIS_DEBUG(2, "LWGEOM_longitude_shift called.");
 
        geom = PG_GETARG_GSERIALIZED_P_COPY(0);
        lwgeom = lwgeom_from_gserialized(geom);
 
        /* Drop bbox, will be recomputed */
        lwgeom_drop_bbox(lwgeom);
 
        /* Modify geometry */
        lwgeom_longitude_shift(lwgeom);
 
        /* Construct GSERIALIZED */
        ret = geometry_serialize(lwgeom);
 
        /* Release deserialized geometry */
        lwgeom_free(lwgeom);
 
        /* Release detoasted geometry */
        pfree(geom);
 
        PG_RETURN_POINTER(ret);
}
 
PG_FUNCTION_INFO_V1(ST_WrapX);
Datum ST_WrapX(PG_FUNCTION_ARGS)
{
        Datum gdatum;
        GSERIALIZED *geom_in;
        LWGEOM *lwgeom_in, *lwgeom_out;
        GSERIALIZED *geom_out;
        double cutx;
        double amount;
 
        POSTGIS_DEBUG(2, "ST_WrapX called.");
 
        gdatum = PG_GETARG_DATUM(0);
        cutx = PG_GETARG_FLOAT8(1);
        amount = PG_GETARG_FLOAT8(2);
 
        // if ( ! amount ) PG_RETURN_DATUM(gdatum);
 
        geom_in = ((GSERIALIZED *)PG_DETOAST_DATUM(gdatum));
        lwgeom_in = lwgeom_from_gserialized(geom_in);
 
        lwgeom_out = lwgeom_wrapx(lwgeom_in, cutx, amount);
        geom_out = geometry_serialize(lwgeom_out);
 
        lwgeom_free(lwgeom_in);
        lwgeom_free(lwgeom_out);
        PG_FREE_IF_COPY(geom_in, 0);
 
        PG_RETURN_POINTER(geom_out);
}
 
PG_FUNCTION_INFO_V1(ST_Scroll);
Datum ST_Scroll(PG_FUNCTION_ARGS)
{
        Datum datum_line, datum_point;
        GSERIALIZED *ser_line, *ser_point;
        LWGEOM *lwgeom_line, *lwgeom_point;
        LWLINE *line;
        LWPOINT *point;
        POINT4D p;
        GSERIALIZED *ser_out;
        int rv;
 
        POSTGIS_DEBUG(2, "ST_Scroll called.");
 
        datum_line = PG_GETARG_DATUM(0);
        datum_point = PG_GETARG_DATUM(1);
 
        ser_line = ((GSERIALIZED *)PG_DETOAST_DATUM(datum_line));
        lwgeom_line = lwgeom_from_gserialized(ser_line);
        line = lwgeom_as_lwline(lwgeom_line);
        if ( ! line ) {
                lwpgerror("First argument must be a line");
                PG_RETURN_NULL();
        }
 
        ser_point = ((GSERIALIZED *)PG_DETOAST_DATUM(datum_point));
        lwgeom_point = lwgeom_from_gserialized(ser_point);
        point = lwgeom_as_lwpoint(lwgeom_point);
        if ( ! point ) {
                lwpgerror("Second argument must be a point");
                PG_RETURN_NULL();
        }
        if ( ! lwpoint_getPoint4d_p(point, &p) ) {
                lwpgerror("Second argument must be a non-empty point");
                PG_RETURN_NULL();
        }
 
        rv = ptarray_scroll_in_place(line->points, &p);
        if ( LW_FAILURE == rv ) {
                PG_RETURN_NULL();
        }
 
        ser_out = geometry_serialize(lwgeom_line);
 
        lwgeom_free(lwgeom_point);
        PG_FREE_IF_COPY(ser_line, 0);
        PG_FREE_IF_COPY(ser_point, 0);
 
        PG_RETURN_POINTER(ser_out);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_inside_circle_point);
Datum LWGEOM_inside_circle_point(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        double cx = PG_GETARG_FLOAT8(1);
        double cy = PG_GETARG_FLOAT8(2);
        double rr = PG_GETARG_FLOAT8(3);
        LWPOINT *lwpoint;
        LWGEOM *lwgeom;
        int inside;
 
        geom = PG_GETARG_GSERIALIZED_P(0);
        lwgeom = lwgeom_from_gserialized(geom);
        lwpoint = lwgeom_as_lwpoint(lwgeom);
        if (lwpoint == NULL || lwgeom_is_empty(lwgeom))
        {
                PG_FREE_IF_COPY(geom, 0);
                PG_RETURN_NULL(); /* not a point */
        }
 
        inside = lwpoint_inside_circle(lwpoint, cx, cy, rr);
        lwpoint_free(lwpoint);
 
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_BOOL(inside);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_collect);
Datum LWGEOM_collect(PG_FUNCTION_ARGS)
{
        GSERIALIZED *gser1, *gser2, *result;
        LWGEOM *lwgeoms[2], *outlwg;
        uint32 type1, type2;
        uint8_t outtype;
        int32_t srid;
 
        POSTGIS_DEBUG(2, "LWGEOM_collect called.");
 
        /* return null if both geoms are null */
        if (PG_ARGISNULL(0) && PG_ARGISNULL(1))
                PG_RETURN_NULL();
 
        /* Return the second geom if the first geom is null */
        if (PG_ARGISNULL(0))
                PG_RETURN_DATUM(PG_GETARG_DATUM(1));
 
        /* Return the first geom if the second geom is null */
        if (PG_ARGISNULL(1))
                PG_RETURN_DATUM(PG_GETARG_DATUM(0));
 
        gser1 = PG_GETARG_GSERIALIZED_P(0);
        gser2 = PG_GETARG_GSERIALIZED_P(1);
        gserialized_error_if_srid_mismatch(gser1, gser2, __func__);
 
        POSTGIS_DEBUGF(3,
                       "LWGEOM_collect(%s, %s): call",
                       lwtype_name(gserialized_get_type(gser1)),
                       lwtype_name(gserialized_get_type(gser2)));
 
        if ((gserialized_has_z(gser1) != gserialized_has_z(gser2)) ||
                (gserialized_has_m(gser1) != gserialized_has_m(gser2)))
        {
                elog(ERROR, "Cannot ST_Collect geometries with differing dimensionality.");
                PG_RETURN_NULL();
        }
 
        srid = gserialized_get_srid(gser1);
 
        lwgeoms[0] = lwgeom_from_gserialized(gser1);
        lwgeoms[1] = lwgeom_from_gserialized(gser2);
 
        type1 = lwgeoms[0]->type;
        type2 = lwgeoms[1]->type;
 
        if ((type1 == type2) && (!lwgeom_is_collection(lwgeoms[0])))
                outtype = lwtype_get_collectiontype(type1);
        else
                outtype = COLLECTIONTYPE;
 
        POSTGIS_DEBUGF(3, " outtype = %d", outtype);
 
        /* Drop input geometries bbox and SRID */
        lwgeom_drop_bbox(lwgeoms[0]);
        lwgeom_drop_srid(lwgeoms[0]);
        lwgeom_drop_bbox(lwgeoms[1]);
        lwgeom_drop_srid(lwgeoms[1]);
 
        outlwg = (LWGEOM *)lwcollection_construct(outtype, srid, NULL, 2, lwgeoms);
        result = geometry_serialize(outlwg);
 
        lwgeom_free(lwgeoms[0]);
        lwgeom_free(lwgeoms[1]);
 
        PG_FREE_IF_COPY(gser1, 0);
        PG_FREE_IF_COPY(gser2, 1);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_collect_garray);
Datum LWGEOM_collect_garray(PG_FUNCTION_ARGS)
{
        ArrayType *array;
        int nelems;
        /*GSERIALIZED **geoms; */
        GSERIALIZED *result = NULL;
        LWGEOM **lwgeoms, *outlwg;
        uint32 outtype;
        int count;
        int32_t srid = SRID_UNKNOWN;
        GBOX *box = NULL;
 
        ArrayIterator iterator;
        Datum value;
        bool isnull;
 
        POSTGIS_DEBUG(2, "LWGEOM_collect_garray called.");
 
        if (PG_ARGISNULL(0))
                PG_RETURN_NULL();
 
        /* Get actual ArrayType */
        array = PG_GETARG_ARRAYTYPE_P(0);
        nelems = ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array));
 
        POSTGIS_DEBUGF(3,
                       " array is %d-bytes in size, %ld w/out header",
                       ARR_SIZE(array),
                       ARR_SIZE(array) - ARR_OVERHEAD_NONULLS(ARR_NDIM(array)));
 
        POSTGIS_DEBUGF(3, "LWGEOM_collect_garray: array has %d elements", nelems);
 
        /* Return null on 0-elements input array */
        if (nelems == 0)
                PG_RETURN_NULL();
 
        /*
         * Deserialize all geometries in array into the lwgeoms pointers
         * array. Check input types to form output type.
         */
        lwgeoms = palloc(sizeof(LWGEOM *) * nelems);
        count = 0;
        outtype = 0;
 
        iterator = array_create_iterator(array, 0, NULL);
 
        while (array_iterate(iterator, &value, &isnull))
        {
                GSERIALIZED *geom;
                uint8_t intype;
 
                /* Don't do anything for NULL values */
                if (isnull)
                        continue;
 
                geom = (GSERIALIZED *)DatumGetPointer(value);
                intype = gserialized_get_type(geom);
 
                lwgeoms[count] = lwgeom_from_gserialized(geom);
 
                POSTGIS_DEBUGF(3, "%s: geom %d deserialized", __func__, count);
 
                if (!count)
                {
                        /* Get first geometry SRID */
                        srid = lwgeoms[count]->srid;
 
                        /* COMPUTE_BBOX WHEN_SIMPLE */
                        if (lwgeoms[count]->bbox)
                                box = gbox_copy(lwgeoms[count]->bbox);
                }
                else
                {
                        /* Check SRID homogeneity */
                        gserialized_error_if_srid_mismatch_reference(geom, srid, __func__);
 
                        /* COMPUTE_BBOX WHEN_SIMPLE */
                        if (box)
                        {
                                if (lwgeoms[count]->bbox)
                                        gbox_merge(lwgeoms[count]->bbox, box);
                                else
                                {
                                        pfree(box);
                                        box = NULL;
                                }
                        }
                }
 
                lwgeom_drop_srid(lwgeoms[count]);
                lwgeom_drop_bbox(lwgeoms[count]);
 
                /* Output type not initialized */
                if (!outtype)
                {
                        outtype = lwtype_get_collectiontype(intype);
                }
                /* Input type not compatible with output */
                /* make output type a collection */
                else if (outtype != COLLECTIONTYPE && lwtype_get_collectiontype(intype) != outtype)
                {
                        outtype = COLLECTIONTYPE;
                }
 
                count++;
        }
        array_free_iterator(iterator);
 
        POSTGIS_DEBUGF(3, "LWGEOM_collect_garray: outtype = %d", outtype);
 
        /* If we have been passed a complete set of NULLs then return NULL */
        if (!outtype)
        {
                PG_RETURN_NULL();
        }
        else
        {
                outlwg = (LWGEOM *)lwcollection_construct(outtype, srid, box, count, lwgeoms);
 
                result = geometry_serialize(outlwg);
 
                PG_RETURN_POINTER(result);
        }
}
 
PG_FUNCTION_INFO_V1(LWGEOM_line_from_mpoint);
Datum LWGEOM_line_from_mpoint(PG_FUNCTION_ARGS)
{
        GSERIALIZED *ingeom, *result;
        LWLINE *lwline;
        LWMPOINT *mpoint;
 
        POSTGIS_DEBUG(2, "LWGEOM_line_from_mpoint called");
 
        /* Get input GSERIALIZED and deserialize it */
        ingeom = PG_GETARG_GSERIALIZED_P(0);
 
        if (gserialized_get_type(ingeom) != MULTIPOINTTYPE)
        {
                elog(ERROR, "makeline: input must be a multipoint");
                PG_RETURN_NULL(); /* input is not a multipoint */
        }
 
        mpoint = lwgeom_as_lwmpoint(lwgeom_from_gserialized(ingeom));
        lwline = lwline_from_lwmpoint(mpoint->srid, mpoint);
        if (!lwline)
        {
                PG_FREE_IF_COPY(ingeom, 0);
                elog(ERROR, "makeline: lwline_from_lwmpoint returned NULL");
                PG_RETURN_NULL();
        }
 
        result = geometry_serialize(lwline_as_lwgeom(lwline));
 
        PG_FREE_IF_COPY(ingeom, 0);
        lwline_free(lwline);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_makeline_garray);
Datum LWGEOM_makeline_garray(PG_FUNCTION_ARGS)
{
        ArrayType *array;
        int nelems;
        GSERIALIZED *result = NULL;
        LWGEOM **geoms;
        LWGEOM *outlwg;
        uint32 ngeoms;
        int32_t srid = SRID_UNKNOWN;
 
        ArrayIterator iterator;
        Datum value;
        bool isnull;
 
        POSTGIS_DEBUGF(2, "%s called", __func__);
 
        /* Return null on null input */
        if (PG_ARGISNULL(0))
                PG_RETURN_NULL();
 
        /* Get actual ArrayType */
        array = PG_GETARG_ARRAYTYPE_P(0);
 
        /* Get number of geometries in array */
        nelems = ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array));
 
        POSTGIS_DEBUGF(3, "%s: array has %d elements", __func__, nelems);
 
        /* Return null on 0-elements input array */
        if (nelems == 0)
                PG_RETURN_NULL();
 
        /*
         * Deserialize all point geometries in array into the
         * geoms pointers array.
         * Count actual number of points.
         */
 
        /* possibly more then required */
        geoms = palloc(sizeof(LWGEOM *) * nelems);
        ngeoms = 0;
 
        iterator = array_create_iterator(array, 0, NULL);
 
        while (array_iterate(iterator, &value, &isnull))
        {
                GSERIALIZED *geom;
 
                if (isnull)
                        continue;
 
                geom = (GSERIALIZED *)DatumGetPointer(value);
 
                if (gserialized_get_type(geom) != POINTTYPE &&
                    gserialized_get_type(geom) != MULTIPOINTTYPE &&
                    gserialized_get_type(geom) != LINETYPE &&
                    gserialized_get_type(geom) != MULTILINETYPE)
                {
                        continue;
                }
 
                geoms[ngeoms++] = lwgeom_from_gserialized(geom);
 
                /* Check SRID homogeneity */
                if (ngeoms == 1)
                {
                        /* Get first geometry SRID */
                        srid = geoms[ngeoms - 1]->srid;
                        /* TODO: also get ZMflags */
                }
                else
                        gserialized_error_if_srid_mismatch_reference(geom, srid, __func__);
 
                POSTGIS_DEBUGF(3, "%s: element %d deserialized", __func__, ngeoms);
        }
        array_free_iterator(iterator);
 
        /* Return null on 0-points input array */
        if (ngeoms == 0)
        {
                /* TODO: should we return LINESTRING EMPTY here ? */
                elog(NOTICE, "No points or linestrings in input array");
                PG_RETURN_NULL();
        }
 
        POSTGIS_DEBUGF(3, "LWGEOM_makeline_garray: elements: %d", ngeoms);
 
        outlwg = (LWGEOM *)lwline_from_lwgeom_array(srid, ngeoms, geoms);
 
        result = geometry_serialize(outlwg);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_makeline);
Datum LWGEOM_makeline(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pglwg1, *pglwg2;
        GSERIALIZED *result = NULL;
        LWGEOM *lwgeoms[2];
        LWLINE *outline;
 
        POSTGIS_DEBUG(2, "LWGEOM_makeline called.");
 
        /* Get input datum */
        pglwg1 = PG_GETARG_GSERIALIZED_P(0);
        pglwg2 = PG_GETARG_GSERIALIZED_P(1);
 
        if ((gserialized_get_type(pglwg1) != POINTTYPE && gserialized_get_type(pglwg1) != LINETYPE) ||
            (gserialized_get_type(pglwg2) != POINTTYPE && gserialized_get_type(pglwg2) != LINETYPE))
        {
                elog(ERROR, "Input geometries must be points or lines");
                PG_RETURN_NULL();
        }
 
        gserialized_error_if_srid_mismatch(pglwg1, pglwg2, __func__);
 
        lwgeoms[0] = lwgeom_from_gserialized(pglwg1);
        lwgeoms[1] = lwgeom_from_gserialized(pglwg2);
 
        outline = lwline_from_lwgeom_array(lwgeoms[0]->srid, 2, lwgeoms);
 
        result = geometry_serialize((LWGEOM *)outline);
 
        PG_FREE_IF_COPY(pglwg1, 0);
        PG_FREE_IF_COPY(pglwg2, 1);
        lwgeom_free(lwgeoms[0]);
        lwgeom_free(lwgeoms[1]);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_makepoly);
Datum LWGEOM_makepoly(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pglwg1;
        ArrayType *array = NULL;
        GSERIALIZED *result = NULL;
        const LWLINE *shell = NULL;
        const LWLINE **holes = NULL;
        LWPOLY *outpoly;
        uint32 nholes = 0;
        uint32 i;
        size_t offset = 0;
 
        POSTGIS_DEBUG(2, "LWGEOM_makepoly called.");
 
        /* Get input shell */
        pglwg1 = PG_GETARG_GSERIALIZED_P(0);
        if (gserialized_get_type(pglwg1) != LINETYPE)
        {
                lwpgerror("Shell is not a line");
        }
        shell = lwgeom_as_lwline(lwgeom_from_gserialized(pglwg1));
 
        /* Get input holes if any */
        if (PG_NARGS() > 1)
        {
                array = PG_GETARG_ARRAYTYPE_P(1);
                nholes = ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array));
                holes = lwalloc(sizeof(LWLINE *) * nholes);
                for (i = 0; i < nholes; i++)
                {
#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wsign-compare"
#endif
                        GSERIALIZED *g = (GSERIALIZED *)(ARR_DATA_PTR(array) + offset);
#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
#pragma GCC diagnostic pop
#endif
                        LWLINE *hole;
                        offset += INTALIGN(VARSIZE(g));
                        if (gserialized_get_type(g) != LINETYPE)
                        {
                                lwpgerror("Hole %d is not a line", i);
                        }
                        hole = lwgeom_as_lwline(lwgeom_from_gserialized(g));
                        holes[i] = hole;
                }
        }
 
        outpoly = lwpoly_from_lwlines(shell, nholes, holes);
        POSTGIS_DEBUGF(3, "%s", lwgeom_summary((LWGEOM *)outpoly, 0));
        result = geometry_serialize((LWGEOM *)outpoly);
 
        lwline_free((LWLINE *)shell);
        PG_FREE_IF_COPY(pglwg1, 0);
 
        for (i = 0; i < nholes; i++)
        {
                lwline_free((LWLINE *)holes[i]);
        }
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_expand);
Datum LWGEOM_expand(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        int32_t srid = lwgeom_get_srid(lwgeom);
        LWPOLY *poly;
        GSERIALIZED *result;
        GBOX gbox;
 
        POSTGIS_DEBUG(2, "LWGEOM_expand called.");
 
        /* Can't expand an empty */
        if (lwgeom_is_empty(lwgeom))
        {
                lwgeom_free(lwgeom);
                PG_RETURN_POINTER(geom);
        }
 
        /* Can't expand something with no gbox! */
        if (LW_FAILURE == lwgeom_calculate_gbox(lwgeom, &gbox))
        {
                lwgeom_free(lwgeom);
                PG_RETURN_POINTER(geom);
        }
 
        if (PG_NARGS() == 2)
        {
                /* Expand the box the same amount in all directions */
                double d = PG_GETARG_FLOAT8(1);
                gbox_expand(&gbox, d);
        }
        else
        {
                double dx = PG_GETARG_FLOAT8(1);
                double dy = PG_GETARG_FLOAT8(2);
                double dz = PG_GETARG_FLOAT8(3);
                double dm = PG_GETARG_FLOAT8(4);
 
                gbox_expand_xyzm(&gbox, dx, dy, dz, dm);
        }
 
        {
                POINT4D p1 = {gbox.xmin, gbox.ymin, gbox.zmin, gbox.mmin};
                POINT4D p2 = {gbox.xmin, gbox.ymax, gbox.zmin, gbox.mmin};
                POINT4D p3 = {gbox.xmax, gbox.ymax, gbox.zmax, gbox.mmax};
                POINT4D p4 = {gbox.xmax, gbox.ymin, gbox.zmax, gbox.mmax};
 
                poly = lwpoly_construct_rectangle(lwgeom_has_z(lwgeom), lwgeom_has_m(lwgeom), &p1, &p2, &p3, &p4);
        }
 
        lwgeom_add_bbox(lwpoly_as_lwgeom(poly));
        lwgeom_set_srid(lwpoly_as_lwgeom(poly), srid);
 
        /* Construct GSERIALIZED  */
        result = geometry_serialize(lwpoly_as_lwgeom(poly));
 
        lwgeom_free(lwpoly_as_lwgeom(poly));
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(geom, 0);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_to_BOX);
Datum LWGEOM_to_BOX(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pg_lwgeom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(pg_lwgeom);
        GBOX gbox;
        int result;
        BOX *out = NULL;
 
        /* Zero out flags */
        gbox_init(&gbox);
 
        /* Calculate the GBOX of the geometry */
        result = lwgeom_calculate_gbox(lwgeom, &gbox);
 
        /* Clean up memory */
        lwfree(lwgeom);
        PG_FREE_IF_COPY(pg_lwgeom, 0);
 
        /* Null on failure */
        if (!result)
                PG_RETURN_NULL();
 
        out = lwalloc(sizeof(BOX));
        out->low.x = gbox.xmin;
        out->low.y = gbox.ymin;
        out->high.x = gbox.xmax;
        out->high.y = gbox.ymax;
        PG_RETURN_POINTER(out);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_envelope);
Datum LWGEOM_envelope(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        int32_t srid = lwgeom->srid;
        POINT4D pt;
        GBOX box;
        POINTARRAY *pa;
        GSERIALIZED *result;
 
        if (lwgeom_is_empty(lwgeom))
        {
                /* must be the EMPTY geometry */
                PG_RETURN_POINTER(geom);
        }
 
        if (lwgeom_calculate_gbox(lwgeom, &box) == LW_FAILURE)
        {
                /* must be the EMPTY geometry */
                PG_RETURN_POINTER(geom);
        }
 
        /*
         * Alter envelope type so that a valid geometry is always
         * returned depending upon the size of the geometry. The
         * code makes the following assumptions:
         *     - If the bounding box is a single point then return a
         *     POINT geometry
         *     - If the bounding box represents either a horizontal or
         *     vertical line, return a LINESTRING geometry
         *     - Otherwise return a POLYGON
         */
 
        if ((box.xmin == box.xmax) && (box.ymin == box.ymax))
        {
                /* Construct and serialize point */
                LWPOINT *point = lwpoint_make2d(srid, box.xmin, box.ymin);
                result = geometry_serialize(lwpoint_as_lwgeom(point));
                lwpoint_free(point);
        }
        else if ((box.xmin == box.xmax) || (box.ymin == box.ymax))
        {
                LWLINE *line;
                /* Construct point array */
                pa = ptarray_construct_empty(0, 0, 2);
 
                /* Assign coordinates to POINT2D array */
                pt.x = box.xmin;
                pt.y = box.ymin;
                ptarray_append_point(pa, &pt, LW_TRUE);
                pt.x = box.xmax;
                pt.y = box.ymax;
                ptarray_append_point(pa, &pt, LW_TRUE);
 
                /* Construct and serialize linestring */
                line = lwline_construct(srid, NULL, pa);
                result = geometry_serialize(lwline_as_lwgeom(line));
                lwline_free(line);
        }
        else
        {
                LWPOLY *poly;
                POINTARRAY **ppa = lwalloc(sizeof(POINTARRAY *));
                pa = ptarray_construct_empty(0, 0, 5);
                ppa[0] = pa;
 
                /* Assign coordinates to POINT2D array */
                pt.x = box.xmin;
                pt.y = box.ymin;
                ptarray_append_point(pa, &pt, LW_TRUE);
                pt.x = box.xmin;
                pt.y = box.ymax;
                ptarray_append_point(pa, &pt, LW_TRUE);
                pt.x = box.xmax;
                pt.y = box.ymax;
                ptarray_append_point(pa, &pt, LW_TRUE);
                pt.x = box.xmax;
                pt.y = box.ymin;
                ptarray_append_point(pa, &pt, LW_TRUE);
                pt.x = box.xmin;
                pt.y = box.ymin;
                ptarray_append_point(pa, &pt, LW_TRUE);
 
                /* Construct polygon  */
                poly = lwpoly_construct(srid, NULL, 1, ppa);
                result = geometry_serialize(lwpoly_as_lwgeom(poly));
                lwpoly_free(poly);
        }
 
        PG_FREE_IF_COPY(geom, 0);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_isempty);
Datum LWGEOM_isempty(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        PG_RETURN_BOOL(gserialized_is_empty(geom));
}
 
PG_FUNCTION_INFO_V1(LWGEOM_segmentize2d);
Datum LWGEOM_segmentize2d(PG_FUNCTION_ARGS)
{
        GSERIALIZED *outgeom, *ingeom;
        double dist;
        LWGEOM *inlwgeom, *outlwgeom;
        int type;
 
        POSTGIS_DEBUG(2, "LWGEOM_segmentize2d called");
 
        ingeom = PG_GETARG_GSERIALIZED_P(0);
        dist = PG_GETARG_FLOAT8(1);
        type = gserialized_get_type(ingeom);
 
        /* Avoid types we cannot segmentize. */
        if ((type == POINTTYPE) || (type == MULTIPOINTTYPE) || (type == TRIANGLETYPE) || (type == TINTYPE) ||
            (type == POLYHEDRALSURFACETYPE))
        {
                PG_RETURN_POINTER(ingeom);
        }
 
        if (dist <= 0)
        {
                /* Protect from knowingly infinite loops, see #1799 */
                /* Note that we'll end out of memory anyway for other small distances */
                elog(ERROR, "ST_Segmentize: invalid max_distance %g (must be >= 0)", dist);
                PG_RETURN_NULL();
        }
 
        LWGEOM_INIT();
 
        inlwgeom = lwgeom_from_gserialized(ingeom);
        if (lwgeom_is_empty(inlwgeom))
        {
                /* Should only happen on interruption */
                lwgeom_free(inlwgeom);
                PG_RETURN_POINTER(ingeom);
        }
 
        outlwgeom = lwgeom_segmentize2d(inlwgeom, dist);
        if (!outlwgeom)
        {
                /* Should only happen on interruption */
                PG_FREE_IF_COPY(ingeom, 0);
                PG_RETURN_NULL();
        }
 
        /* Copy input bounding box if any */
        if (inlwgeom->bbox)
                outlwgeom->bbox = gbox_copy(inlwgeom->bbox);
 
        outgeom = geometry_serialize(outlwgeom);
 
        // lwgeom_free(outlwgeom); /* TODO fix lwgeom_clone / ptarray_clone_deep for consistent semantics */
        lwgeom_free(inlwgeom);
 
        PG_FREE_IF_COPY(ingeom, 0);
 
        PG_RETURN_POINTER(outgeom);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_reverse);
Datum LWGEOM_reverse(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
 
        POSTGIS_DEBUG(2, "LWGEOM_reverse called");
 
        geom = PG_GETARG_GSERIALIZED_P_COPY(0);
 
        lwgeom = lwgeom_from_gserialized(geom);
        lwgeom_reverse_in_place(lwgeom);
 
        geom = geometry_serialize(lwgeom);
 
        PG_RETURN_POINTER(geom);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_force_clockwise_poly);
Datum LWGEOM_force_clockwise_poly(PG_FUNCTION_ARGS)
{
        GSERIALIZED *ingeom, *outgeom;
        LWGEOM *lwgeom;
 
        POSTGIS_DEBUG(2, "LWGEOM_force_clockwise_poly called");
 
        ingeom = PG_GETARG_GSERIALIZED_P_COPY(0);
 
        lwgeom = lwgeom_from_gserialized(ingeom);
        lwgeom_force_clockwise(lwgeom);
 
        outgeom = geometry_serialize(lwgeom);
 
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(ingeom, 0);
        PG_RETURN_POINTER(outgeom);
}
 
 
PG_FUNCTION_INFO_V1(ST_ForcePolygonCCW);
Datum ST_ForcePolygonCCW(PG_FUNCTION_ARGS)
{
        GSERIALIZED *ingeom, *outgeom;
        LWGEOM *lwgeom;
 
        POSTGIS_DEBUG(2, "ST_ForcePolygonCCW called");
 
        ingeom = PG_GETARG_GSERIALIZED_P_COPY(0);
 
        lwgeom = lwgeom_from_gserialized(ingeom);
        lwgeom_force_counterclockwise(lwgeom);
 
        outgeom = geometry_serialize(lwgeom);
 
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(ingeom, 0);
        PG_RETURN_POINTER(outgeom);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_noop);
Datum LWGEOM_noop(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(in);
        GSERIALIZED *out = geometry_serialize(lwgeom);
        PG_RETURN_POINTER(out);
}
 
Datum ST_Normalize(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(ST_Normalize);
Datum ST_Normalize(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in, *out;
        LWGEOM *lwgeom_in, *lwgeom_out;
 
        POSTGIS_DEBUG(2, "ST_Normalize called");
 
        in = PG_GETARG_GSERIALIZED_P_COPY(0);
 
        lwgeom_in = lwgeom_from_gserialized(in);
        POSTGIS_DEBUGF(3, "Deserialized: %s", lwgeom_summary(lwgeom_in, 0));
 
        lwgeom_out = lwgeom_normalize(lwgeom_in);
        POSTGIS_DEBUGF(3, "Normalized: %s", lwgeom_summary(lwgeom_out, 0));
 
        out = geometry_serialize(lwgeom_out);
        lwgeom_free(lwgeom_in);
        lwgeom_free(lwgeom_out);
 
        PG_FREE_IF_COPY(in, 0);
 
        PG_RETURN_POINTER(out);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_zmflag);
Datum LWGEOM_zmflag(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in = PG_GETARG_GSERIALIZED_HEADER(0);
        int ret = 0;
 
        if (gserialized_has_z(in))
                ret += 2;
        if (gserialized_has_m(in))
                ret += 1;
        PG_FREE_IF_COPY(in, 0);
        PG_RETURN_INT16(ret);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_hasz);
Datum LWGEOM_hasz(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in = PG_GETARG_GSERIALIZED_HEADER(0);
        PG_RETURN_BOOL(gserialized_has_z(in));
}
 
PG_FUNCTION_INFO_V1(LWGEOM_hasm);
Datum LWGEOM_hasm(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in = PG_GETARG_GSERIALIZED_HEADER(0);
        PG_RETURN_BOOL(gserialized_has_m(in));
}
 
PG_FUNCTION_INFO_V1(LWGEOM_hasBBOX);
Datum LWGEOM_hasBBOX(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in = PG_GETARG_GSERIALIZED_HEADER(0);
        char res = gserialized_has_bbox(in);
        PG_FREE_IF_COPY(in, 0);
        PG_RETURN_BOOL(res);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_ndims);
Datum LWGEOM_ndims(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in = PG_GETARG_GSERIALIZED_HEADER(0);
        int ret = gserialized_ndims(in);
        PG_FREE_IF_COPY(in, 0);
        PG_RETURN_INT16(ret);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_same);
Datum LWGEOM_same(PG_FUNCTION_ARGS)
{
        GSERIALIZED *g1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *g2 = PG_GETARG_GSERIALIZED_P(1);
 
        PG_RETURN_BOOL(gserialized_cmp(g1, g2) == 0);
}
 
PG_FUNCTION_INFO_V1(ST_MakeEnvelope);
Datum ST_MakeEnvelope(PG_FUNCTION_ARGS)
{
        LWPOLY *poly;
        GSERIALIZED *result;
        double x1, y1, x2, y2;
        int32_t srid = SRID_UNKNOWN;
 
        POSTGIS_DEBUG(2, "ST_MakeEnvelope called");
 
        x1 = PG_GETARG_FLOAT8(0);
        y1 = PG_GETARG_FLOAT8(1);
        x2 = PG_GETARG_FLOAT8(2);
        y2 = PG_GETARG_FLOAT8(3);
        if (PG_NARGS() > 4)
        {
                srid = PG_GETARG_INT32(4);
        }
 
        poly = lwpoly_construct_envelope(srid, x1, y1, x2, y2);
 
        result = geometry_serialize(lwpoly_as_lwgeom(poly));
        lwpoly_free(poly);
 
        PG_RETURN_POINTER(result);
}
 
 
PG_FUNCTION_INFO_V1(ST_TileEnvelope);
Datum ST_TileEnvelope(PG_FUNCTION_ARGS)
{
        GSERIALIZED *bounds;
        uint32_t zoomu;
        int32_t x, y, zoom;
        uint32_t worldTileSize;
        double tileGeoSizeX, tileGeoSizeY;
        double boundsWidth, boundsHeight;
        double x1, y1, x2, y2;
        double margin;
        /* This is broken, since 3857 doesn't mean "web mercator", it means
           the contents of the row in spatial_ref_sys with srid = 3857.
           For practical purposes this will work, but in good implementation
           we should de-reference in spatial ref sys to confirm that the
           srid of the object is EPSG:3857. */
        int32_t srid;
        GBOX bbox;
        LWGEOM *g = NULL;
 
        POSTGIS_DEBUG(2, "ST_TileEnvelope called");
 
        zoom = PG_GETARG_INT32(0);
        x = PG_GETARG_INT32(1);
        y = PG_GETARG_INT32(2);
 
        bounds = PG_GETARG_GSERIALIZED_P(3);
        /*
         * We deserialize the geometry and recalculate the bounding box here to get
         * 64b floating point precision. The serialized bbox has 32b float is not
         * precise enough with big numbers such as the ones used in the default
         * parameters, e.g: -20037508.3427892 is transformed into -20037510
         */
        g = lwgeom_from_gserialized(bounds);
        if (lwgeom_calculate_gbox(g, &bbox) != LW_SUCCESS)
                elog(ERROR, "%s: Unable to compute bbox", __func__);
        srid = g->srid;
        lwgeom_free(g);
 
        /* Avoid crashing with old signature (old sql code with 3 args, new C code with 4) */
        margin = PG_NARGS() < 4 ? 0 : PG_GETARG_FLOAT8(4);
        /* shrinking by more than 50% would eliminate the tile outright */
        if (margin < -0.5)
                elog(ERROR, "%s: Margin must not be less than -50%%, margin=%f", __func__, margin);
 
        boundsWidth  = bbox.xmax - bbox.xmin;
        boundsHeight = bbox.ymax - bbox.ymin;
        if (boundsWidth <= 0 || boundsHeight <= 0)
                elog(ERROR, "%s: Geometric bounds are too small", __func__);
 
        if (zoom < 0 || zoom >= 32)
                elog(ERROR, "%s: Invalid tile zoom value, %d", __func__, zoom);
 
        zoomu = (uint32_t)zoom;
        worldTileSize = 0x01u << (zoomu > 31 ? 31 : zoomu);
 
        if (x < 0 || (uint32_t)x >= worldTileSize)
                elog(ERROR, "%s: Invalid tile x value, %d", __func__, x);
        if (y < 0 || (uint32_t)y >= worldTileSize)
                elog(ERROR, "%s: Invalid tile y value, %d", __func__, y);
 
        tileGeoSizeX = boundsWidth / worldTileSize;
        tileGeoSizeY = boundsHeight / worldTileSize;
 
        /*
         * 1 margin (100%) is the same as a single tile width
         * if the size of the tile with margins span more than the total number of tiles,
         * reset x1/x2 to the bounds
         */
        if ((1 + margin * 2) > worldTileSize)
        {
                x1 = bbox.xmin;
                x2 = bbox.xmax;
        }
        else
        {
                x1 = bbox.xmin + tileGeoSizeX * (x - margin);
                x2 = bbox.xmin + tileGeoSizeX * (x + 1 + margin);
        }
 
        y1 = bbox.ymax - tileGeoSizeY * (y + 1 + margin);
        y2 = bbox.ymax - tileGeoSizeY * (y - margin);
 
        /* Clip the final tile bounds to the bounds of the tile plane */
        if (y1 < bbox.ymin) y1 = bbox.ymin;
        if (y2 > bbox.ymax) y2 = bbox.ymax;
        if (x1 < bbox.xmin) x1 = bbox.xmin;
        if (x2 > bbox.xmax) x2 = bbox.xmax;
 
        PG_RETURN_POINTER(
                geometry_serialize(
                lwpoly_as_lwgeom(
                lwpoly_construct_envelope(
                        srid, x1, y1, x2, y2))));
}
 
 
PG_FUNCTION_INFO_V1(ST_IsCollection);
Datum ST_IsCollection(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_HEADER(0);
        uint32_t lwtype = gserialized_get_type(geom);
        PG_RETURN_BOOL(!lwtype_is_unitary(lwtype));
}
 
PG_FUNCTION_INFO_V1(LWGEOM_makepoint);
Datum LWGEOM_makepoint(PG_FUNCTION_ARGS)
{
        double x, y, z, m;
        LWPOINT *point;
        GSERIALIZED *result;
 
        POSTGIS_DEBUG(2, "LWGEOM_makepoint called");
 
        x = PG_GETARG_FLOAT8(0);
        y = PG_GETARG_FLOAT8(1);
 
        if (PG_NARGS() == 2)
                point = lwpoint_make2d(SRID_UNKNOWN, x, y);
        else if (PG_NARGS() == 3)
        {
                z = PG_GETARG_FLOAT8(2);
                point = lwpoint_make3dz(SRID_UNKNOWN, x, y, z);
        }
        else if (PG_NARGS() == 4)
        {
                z = PG_GETARG_FLOAT8(2);
                m = PG_GETARG_FLOAT8(3);
                point = lwpoint_make4d(SRID_UNKNOWN, x, y, z, m);
        }
        else
        {
                elog(ERROR, "LWGEOM_makepoint: unsupported number of args: %d", PG_NARGS());
                PG_RETURN_NULL();
        }
 
        result = geometry_serialize((LWGEOM *)point);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(ST_Point);
Datum ST_Point(PG_FUNCTION_ARGS)
{
        double x = PG_GETARG_FLOAT8(0);
        double y = PG_GETARG_FLOAT8(1);
        int srid = PG_GETARG_INT32(2);
        LWPOINT *point = lwpoint_make2d(srid, x, y);
        GSERIALIZED *result = geometry_serialize((LWGEOM *)point);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(ST_PointZ);
Datum ST_PointZ(PG_FUNCTION_ARGS)
{
        double x = PG_GETARG_FLOAT8(0);
        double y = PG_GETARG_FLOAT8(1);
        double z = PG_GETARG_FLOAT8(2);
        int srid = PG_GETARG_INT32(3);
        LWPOINT *point = lwpoint_make3dz(srid, x, y, z);
        GSERIALIZED *result = geometry_serialize((LWGEOM *)point);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(ST_PointM);
Datum ST_PointM(PG_FUNCTION_ARGS)
{
        double x = PG_GETARG_FLOAT8(0);
        double y = PG_GETARG_FLOAT8(1);
        double m = PG_GETARG_FLOAT8(2);
        int srid = PG_GETARG_INT32(3);
        LWPOINT *point = lwpoint_make3dm(srid, x, y, m);
        GSERIALIZED *result = geometry_serialize((LWGEOM *)point);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(ST_PointZM);
Datum ST_PointZM(PG_FUNCTION_ARGS)
{
        double x = PG_GETARG_FLOAT8(0);
        double y = PG_GETARG_FLOAT8(1);
        double z = PG_GETARG_FLOAT8(2);
        double m = PG_GETARG_FLOAT8(3);
        int srid = PG_GETARG_INT32(4);
        LWPOINT *point = lwpoint_make4d(srid, x, y, z, m);
        GSERIALIZED *result = geometry_serialize((LWGEOM *)point);
        PG_RETURN_POINTER(result);
}
 
 
PG_FUNCTION_INFO_V1(LWGEOM_makepoint3dm);
Datum LWGEOM_makepoint3dm(PG_FUNCTION_ARGS)
{
        double x, y, m;
        LWPOINT *point;
        GSERIALIZED *result;
 
        POSTGIS_DEBUG(2, "LWGEOM_makepoint3dm called.");
 
        x = PG_GETARG_FLOAT8(0);
        y = PG_GETARG_FLOAT8(1);
        m = PG_GETARG_FLOAT8(2);
 
        point = lwpoint_make3dm(SRID_UNKNOWN, x, y, m);
        result = geometry_serialize((LWGEOM *)point);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_addpoint);
Datum LWGEOM_addpoint(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pglwg1, *pglwg2, *result;
        LWPOINT *point;
        LWLINE *line, *linecopy;
        uint32_t uwhere = 0;
 
        POSTGIS_DEBUGF(2, "%s called.", __func__);
 
        pglwg1 = PG_GETARG_GSERIALIZED_P(0);
        pglwg2 = PG_GETARG_GSERIALIZED_P(1);
 
        if (gserialized_get_type(pglwg1) != LINETYPE)
        {
                elog(ERROR, "First argument must be a LINESTRING");
                PG_RETURN_NULL();
        }
 
        if (gserialized_get_type(pglwg2) != POINTTYPE)
        {
                elog(ERROR, "Second argument must be a POINT");
                PG_RETURN_NULL();
        }
 
        if (gserialized_is_empty(pglwg2))
        {
                PG_RETURN_POINTER(pglwg1);
        }
 
        line = lwgeom_as_lwline(lwgeom_from_gserialized(pglwg1));
 
        if (PG_NARGS() <= 2)
        {
                uwhere = line->points->npoints;
        }
        else
        {
                int32 where = PG_GETARG_INT32(2);
                if (where == -1)
                {
                        uwhere = line->points->npoints;
                }
                else if (where < 0 || where > (int32)line->points->npoints)
                {
                        elog(ERROR, "%s: Invalid offset", __func__);
                        PG_RETURN_NULL();
                }
                else
                {
                        uwhere = where;
                }
        }
 
        point = lwgeom_as_lwpoint(lwgeom_from_gserialized(pglwg2));
        linecopy = lwgeom_as_lwline(lwgeom_clone_deep(lwline_as_lwgeom(line)));
        lwline_free(line);
 
        if (lwline_add_lwpoint(linecopy, point, uwhere) == LW_FAILURE)
        {
                elog(ERROR, "Point insert failed");
                PG_RETURN_NULL();
        }
 
        result = geometry_serialize(lwline_as_lwgeom(linecopy));
 
        /* Release memory */
        PG_FREE_IF_COPY(pglwg1, 0);
        PG_FREE_IF_COPY(pglwg2, 1);
        lwpoint_free(point);
 
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_removepoint);
Datum LWGEOM_removepoint(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pglwg1, *result;
        LWLINE *line, *outline;
        int32 which;
 
        POSTGIS_DEBUG(2, "LWGEOM_removepoint called.");
 
        pglwg1 = PG_GETARG_GSERIALIZED_P(0);
        which = PG_GETARG_INT32(1);
 
        if (gserialized_get_type(pglwg1) != LINETYPE)
        {
                elog(ERROR, "First argument must be a LINESTRING");
                PG_RETURN_NULL();
        }
 
        line = lwgeom_as_lwline(lwgeom_from_gserialized(pglwg1));
 
        if (which < 0 || (uint32_t)which > line->points->npoints - 1)
        {
                elog(ERROR, "Point index out of range (%u..%u)", 0, line->points->npoints - 1);
                PG_RETURN_NULL();
        }
 
        if (line->points->npoints < 3)
        {
                elog(ERROR, "Can't remove points from a single segment line");
                PG_RETURN_NULL();
        }
 
        outline = lwline_removepoint(line, (uint32_t)which);
        /* Release memory */
        lwline_free(line);
 
        result = geometry_serialize((LWGEOM *)outline);
        lwline_free(outline);
 
        PG_FREE_IF_COPY(pglwg1, 0);
        PG_RETURN_POINTER(result);
}
 
PG_FUNCTION_INFO_V1(LWGEOM_setpoint_linestring);
Datum LWGEOM_setpoint_linestring(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pglwg1, *pglwg2, *result;
        LWGEOM *lwg;
        LWLINE *line;
        LWPOINT *lwpoint;
        POINT4D newpoint;
        int64_t which;
 
        POSTGIS_DEBUG(2, "LWGEOM_setpoint_linestring called.");
 
        /* we copy input as we're going to modify it */
        pglwg1 = PG_GETARG_GSERIALIZED_P_COPY(0);
 
        which = PG_GETARG_INT32(1);
        pglwg2 = PG_GETARG_GSERIALIZED_P(2);
 
        /* Extract a POINT4D from the point */
        lwg = lwgeom_from_gserialized(pglwg2);
        lwpoint = lwgeom_as_lwpoint(lwg);
        if (!lwpoint)
        {
                elog(ERROR, "Third argument must be a POINT");
                PG_RETURN_NULL();
        }
        getPoint4d_p(lwpoint->point, 0, &newpoint);
        lwpoint_free(lwpoint);
        PG_FREE_IF_COPY(pglwg2, 2);
 
        lwg = lwgeom_from_gserialized(pglwg1);
        line = lwgeom_as_lwline(lwg);
 
        if (!line)
        {
                elog(ERROR, "First argument must be a LINESTRING");
                PG_RETURN_NULL();
        }
 
        if ( line->points->npoints < 1 )        {
                elog(ERROR, "Line has no points");
                PG_RETURN_NULL();
        }
 
        if (which < 0)
        {
                /* Use backward indexing for negative values */
                which += (int64_t)line->points->npoints;
        }
        if ((uint32_t)which > line->points->npoints - 1)
        {
                elog(ERROR, "abs(Point index) out of range (-)(%u..%u)", 0, line->points->npoints - 1);
                PG_RETURN_NULL();
        }
 
        /*
         * This will change pointarray of the serialized pglwg1,
         */
        lwline_setPoint4d(line, (uint32_t)which, &newpoint);
        result = geometry_serialize((LWGEOM *)line);
 
        /* Release memory */
        lwline_free(line);
        pfree(pglwg1); /* we forced copy, POINARRAY is released now */
 
        PG_RETURN_POINTER(result);
}
 
/* convert LWGEOM to ewkt (in TEXT format) */
PG_FUNCTION_INFO_V1(LWGEOM_asEWKT);
Datum LWGEOM_asEWKT(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
 
        int precision = OUT_DEFAULT_DECIMAL_DIGITS;
        if (PG_NARGS() > 1)
                precision = PG_GETARG_INT32(1);
 
        PG_RETURN_TEXT_P(lwgeom_to_wkt_varlena(lwgeom, WKT_EXTENDED, precision));
}
 
PG_FUNCTION_INFO_V1(LWGEOM_azimuth);
Datum LWGEOM_azimuth(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWPOINT *lwpoint;
        POINT2D p1, p2;
        double result;
        int32_t srid;
 
        /* Extract first point */
        geom = PG_GETARG_GSERIALIZED_P(0);
        lwpoint = lwgeom_as_lwpoint(lwgeom_from_gserialized(geom));
        if (!lwpoint)
        {
                PG_FREE_IF_COPY(geom, 0);
                lwpgerror("Argument must be POINT geometries");
                PG_RETURN_NULL();
        }
        srid = lwpoint->srid;
        if (!getPoint2d_p(lwpoint->point, 0, &p1))
        {
                PG_FREE_IF_COPY(geom, 0);
                lwpgerror("Error extracting point");
                PG_RETURN_NULL();
        }
        lwpoint_free(lwpoint);
        PG_FREE_IF_COPY(geom, 0);
 
        /* Extract second point */
        geom = PG_GETARG_GSERIALIZED_P(1);
        lwpoint = lwgeom_as_lwpoint(lwgeom_from_gserialized(geom));
        if (!lwpoint)
        {
                PG_FREE_IF_COPY(geom, 1);
                lwpgerror("Argument must be POINT geometries");
                PG_RETURN_NULL();
        }
        if (lwpoint->srid != srid)
        {
                PG_FREE_IF_COPY(geom, 1);
                lwpgerror("Operation on mixed SRID geometries");
                PG_RETURN_NULL();
        }
        if (!getPoint2d_p(lwpoint->point, 0, &p2))
        {
                PG_FREE_IF_COPY(geom, 1);
                lwpgerror("Error extracting point");
                PG_RETURN_NULL();
        }
        lwpoint_free(lwpoint);
        PG_FREE_IF_COPY(geom, 1);
 
        /* Standard return value for equality case */
        if ((p1.x == p2.x) && (p1.y == p2.y))
        {
                PG_RETURN_NULL();
        }
 
        /* Compute azimuth */
        if (!azimuth_pt_pt(&p1, &p2, &result))
        {
                PG_RETURN_NULL();
        }
 
        PG_RETURN_FLOAT8(result);
}
 
 
PG_FUNCTION_INFO_V1(geometry_project_direction);
Datum geometry_project_direction(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom1, *geom2;
        LWPOINT *lwpoint1, *lwpoint2;
        LWGEOM *lwgeom1, *lwgeom2;
        double distance, azimuth;
 
        geom1 = PG_GETARG_GSERIALIZED_P(0);
        distance = PG_GETARG_FLOAT8(1);
        azimuth = PG_GETARG_FLOAT8(2);
        lwgeom1 = lwgeom_from_gserialized(geom1);
        lwpoint1 = lwgeom_as_lwpoint(lwgeom1);
 
        if (!lwpoint1)
                lwpgerror("Argument must be POINT geometry");
 
        if (lwgeom_is_empty(lwgeom1))
                PG_RETURN_NULL();
 
        lwpoint2 = lwpoint_project(lwpoint1, distance, azimuth);
        lwgeom2 = lwpoint_as_lwgeom(lwpoint2);
        geom2 = geometry_serialize(lwgeom2);
        PG_RETURN_POINTER(geom2);
}
 
 
PG_FUNCTION_INFO_V1(geometry_project_geometry);
Datum geometry_project_geometry(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom1, *geom2, *geom3;
        LWPOINT *lwpoint1, *lwpoint2, *lwpoint3;
        LWGEOM *lwgeom1, *lwgeom2, *lwgeom3;
        double distance;
 
        geom1 = PG_GETARG_GSERIALIZED_P(0);
        geom2 = PG_GETARG_GSERIALIZED_P(1);
        distance = PG_GETARG_FLOAT8(2);
 
        lwgeom1 = lwgeom_from_gserialized(geom1);
        lwpoint1 = lwgeom_as_lwpoint(lwgeom1);
        lwgeom2 = lwgeom_from_gserialized(geom2);
        lwpoint2 = lwgeom_as_lwpoint(lwgeom2);
 
        if (!(lwpoint1 && lwpoint2))
                lwpgerror("Arguments must be POINT geometries");
 
        if (lwgeom_is_empty(lwgeom1) || lwgeom_is_empty(lwgeom2))
                PG_RETURN_NULL();
 
        if (lwpoint_same2d(lwpoint1, lwpoint2))
                PG_RETURN_POINTER(geom2);
 
        lwpoint3 = lwpoint_project_lwpoint(lwpoint1, lwpoint2, distance);
        lwgeom3 = lwpoint_as_lwgeom(lwpoint3);
        geom3 = geometry_serialize(lwgeom3);
 
        PG_RETURN_POINTER(geom3);
}
 
 
 
PG_FUNCTION_INFO_V1(geometry_line_extend);
Datum geometry_line_extend(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom1, *geom2;
        LWLINE *lwline1, *lwline2;
        LWGEOM *lwgeom1, *lwgeom2;
        double distance_forward, distance_backward;
 
        geom1 = PG_GETARG_GSERIALIZED_P(0);
        distance_forward = PG_GETARG_FLOAT8(1);
        distance_backward = PG_GETARG_FLOAT8(2);
 
        lwgeom1 = lwgeom_from_gserialized(geom1);
        lwline1 = lwgeom_as_lwline(lwgeom1);
        if (!lwline1)
                lwpgerror("Argument must be LINESTRING geometry");
 
        if (lwline_is_empty(lwline1))
                PG_RETURN_NULL();
 
        if (lwline_length_2d(lwline1) <= 0.0)
                PG_RETURN_POINTER(geom1);
 
        lwline2 = lwline_extend(lwline1, distance_forward, distance_backward);
        lwgeom2 = lwline_as_lwgeom(lwline2);
        geom2 = geometry_serialize(lwgeom2);
 
        PG_RETURN_POINTER(geom2);
}
 
 
 
PG_FUNCTION_INFO_V1(LWGEOM_angle);
Datum LWGEOM_angle(PG_FUNCTION_ARGS)
{
        GSERIALIZED *seri_geoms[4];
        LWGEOM *geom_unser;
        LWPOINT *lwpoint;
        POINT2D points[4];
        double az1, az2;
        double result;
        int32_t srids[4];
        int i = 0;
        int j = 0;
        int err_code = 0;
        int n_args = PG_NARGS();
 
        /* no deserialize, checking for common error first*/
        for (i = 0; i < n_args; i++)
        {
                seri_geoms[i] = PG_GETARG_GSERIALIZED_P(i);
                if (gserialized_is_empty(seri_geoms[i]))
                { /* empty geom */
                        if (i == 3)
                        {
                                n_args = 3;
                        }
                        else
                        {
                                err_code = 1;
                                break;
                        }
                }
                else
                {
                        if (gserialized_get_type(seri_geoms[i]) != POINTTYPE)
                        { /* geom type */
                                err_code = 2;
                                break;
                        }
                        else
                        {
                                srids[i] = gserialized_get_srid(seri_geoms[i]);
                                if (srids[0] != srids[i])
                                { /* error on srid*/
                                        err_code = 3;
                                        break;
                                }
                        }
                }
        }
        if (err_code > 0)
                switch (err_code)
                {
                default: /*always executed*/
                        for (j = 0; j <= i; j++)
                                PG_FREE_IF_COPY(seri_geoms[j], j);
                /*FALLTHROUGH*/
                case 1:
                        lwpgerror("Empty geometry");
                        PG_RETURN_NULL();
                        break;
 
                case 2:
                        lwpgerror("Argument must be POINT geometries");
                        PG_RETURN_NULL();
                        break;
 
                case 3:
                        lwpgerror("Operation on mixed SRID geometries");
                        PG_RETURN_NULL();
                        break;
                }
        /* extract points */
        for (i = 0; i < n_args; i++)
        {
                geom_unser = lwgeom_from_gserialized(seri_geoms[i]);
                lwpoint = lwgeom_as_lwpoint(geom_unser);
                if (!lwpoint)
                {
                        for (j = 0; j < n_args; j++)
                                PG_FREE_IF_COPY(seri_geoms[j], j);
                        lwpgerror("Error unserializing geometry");
                        PG_RETURN_NULL();
                }
 
                if (!getPoint2d_p(lwpoint->point, 0, &points[i]))
                {
                        /* // can't free serialized geom, it might be needed by lw
                        for (j=0;j<n_args;j++)
                                PG_FREE_IF_COPY(seri_geoms[j], j); */
                        lwpgerror("Error extracting point");
                        PG_RETURN_NULL();
                }
                /* lwfree(geom_unser);don't do, lw may rely on this memory
                lwpoint_free(lwpoint); dont do , this memory is needed ! */
        }
        /* // can't free serialized geom, it might be needed by lw
        for (j=0;j<n_args;j++)
                PG_FREE_IF_COPY(seri_geoms[j], j); */
 
        /* compute azimuth for the 2 pairs of points
         * note that angle is not defined identically for 3 points or 4 points*/
        if (n_args == 3)
        { /* we rely on azimuth to complain if points are identical */
                if (!azimuth_pt_pt(&points[0], &points[1], &az1))
                        PG_RETURN_NULL();
                if (!azimuth_pt_pt(&points[2], &points[1], &az2))
                        PG_RETURN_NULL();
        }
        else
        {
                if (!azimuth_pt_pt(&points[0], &points[1], &az1))
                        PG_RETURN_NULL();
                if (!azimuth_pt_pt(&points[2], &points[3], &az2))
                        PG_RETURN_NULL();
        }
        result = az2 - az1;
        result += (result < 0) * 2 * M_PI; /* we dont want negative angle*/
        PG_RETURN_FLOAT8(result);
}
 
/*
 * optimistic_overlap(Polygon P1, Multipolygon MP2, double dist)
 * returns true if P1 overlaps MP2
 *   method: bbox check -
 *   is separation < dist?  no - return false (quick)
 *                          yes  - return distance(P1,MP2) < dist
 */
PG_FUNCTION_INFO_V1(optimistic_overlap);
Datum optimistic_overlap(PG_FUNCTION_ARGS)
{
        GSERIALIZED *pg_geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *pg_geom2 = PG_GETARG_GSERIALIZED_P(1);
        double dist = PG_GETARG_FLOAT8(2);
        GBOX g1_bvol;
        double calc_dist;
        LWGEOM *geom1 = lwgeom_from_gserialized(pg_geom1);
        LWGEOM *geom2 = lwgeom_from_gserialized(pg_geom2);
        gserialized_error_if_srid_mismatch(pg_geom1, pg_geom2, __func__);
 
        if (geom1->type != POLYGONTYPE)
        {
                elog(ERROR, "optimistic_overlap: first arg isn't a polygon\n");
                PG_RETURN_NULL();
        }
 
        if (geom2->type != POLYGONTYPE && geom2->type != MULTIPOLYGONTYPE)
        {
                elog(ERROR, "optimistic_overlap: 2nd arg isn't a [multi-]polygon\n");
                PG_RETURN_NULL();
        }
 
        /*bbox check */
        gserialized_get_gbox_p(pg_geom1, &g1_bvol);
 
        g1_bvol.xmin = g1_bvol.xmin - dist;
        g1_bvol.ymin = g1_bvol.ymin - dist;
        g1_bvol.xmax = g1_bvol.xmax + dist;
        g1_bvol.ymax = g1_bvol.ymax + dist;
 
        if ((g1_bvol.xmin > geom2->bbox->xmax) || (g1_bvol.xmax < geom2->bbox->xmin) ||
            (g1_bvol.ymin > geom2->bbox->ymax) || (g1_bvol.ymax < geom2->bbox->ymin))
        {
                PG_RETURN_BOOL(false); /*bbox not overlap */
        }
 
        /*
         * compute distances
         * should be a fast calc if they actually do intersect
         */
        calc_dist =
            DatumGetFloat8(DirectFunctionCall2(ST_Distance, PointerGetDatum(pg_geom1), PointerGetDatum(pg_geom2)));
 
        PG_RETURN_BOOL(calc_dist < dist);
}
 
/*affine transform geometry */
PG_FUNCTION_INFO_V1(LWGEOM_affine);
Datum LWGEOM_affine(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P_COPY(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        GSERIALIZED *ret;
        AFFINE affine;
 
        affine.afac = PG_GETARG_FLOAT8(1);
        affine.bfac = PG_GETARG_FLOAT8(2);
        affine.cfac = PG_GETARG_FLOAT8(3);
        affine.dfac = PG_GETARG_FLOAT8(4);
        affine.efac = PG_GETARG_FLOAT8(5);
        affine.ffac = PG_GETARG_FLOAT8(6);
        affine.gfac = PG_GETARG_FLOAT8(7);
        affine.hfac = PG_GETARG_FLOAT8(8);
        affine.ifac = PG_GETARG_FLOAT8(9);
        affine.xoff = PG_GETARG_FLOAT8(10);
        affine.yoff = PG_GETARG_FLOAT8(11);
        affine.zoff = PG_GETARG_FLOAT8(12);
 
        POSTGIS_DEBUG(2, "LWGEOM_affine called.");
 
        lwgeom_affine(lwgeom, &affine);
 
        /* COMPUTE_BBOX TAINTING */
        if (lwgeom->bbox)
        {
                lwgeom_refresh_bbox(lwgeom);
        }
        ret = geometry_serialize(lwgeom);
 
        /* Release memory */
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(geom, 0);
 
        PG_RETURN_POINTER(ret);
}
 
PG_FUNCTION_INFO_V1(ST_GeoHash);
Datum ST_GeoHash(PG_FUNCTION_ARGS)
{
 
        GSERIALIZED *geom = NULL;
        int precision = 0;
        lwvarlena_t *geohash = NULL;
 
        if (PG_ARGISNULL(0))
        {
                PG_RETURN_NULL();
        }
 
        geom = PG_GETARG_GSERIALIZED_P(0);
 
        if (!PG_ARGISNULL(1))
        {
                precision = PG_GETARG_INT32(1);
        }
 
        geohash = lwgeom_geohash((LWGEOM *)(lwgeom_from_gserialized(geom)), precision);
        if (geohash)
                PG_RETURN_TEXT_P(geohash);
        PG_RETURN_NULL();
}
 
PG_FUNCTION_INFO_V1(_ST_SortableHash);
Datum _ST_SortableHash(PG_FUNCTION_ARGS)
{
        if (PG_ARGISNULL(0))
                PG_RETURN_NULL();
        PG_RETURN_INT64(gserialized_get_sortable_hash(PG_GETARG_GSERIALIZED_P(0)));
}
 
PG_FUNCTION_INFO_V1(ST_CollectionExtract);
Datum ST_CollectionExtract(PG_FUNCTION_ARGS)
{
        GSERIALIZED *gser_in, *gser_out;
        LWGEOM *lwg_in = NULL;
        LWGEOM *lwg_out = NULL;
        int extype = 0;
 
        if (PG_NARGS() > 1)
                extype = PG_GETARG_INT32(1);
 
        /* Ensure the right type was input */
        if (!(extype == 0 || extype == POINTTYPE || extype == LINETYPE || extype == POLYGONTYPE))
        {
                elog(ERROR, "ST_CollectionExtract: only point, linestring and polygon may be extracted");
                PG_RETURN_NULL();
        }
 
        gser_in = PG_GETARG_GSERIALIZED_P(0);
        lwg_in = lwgeom_from_gserialized(gser_in);
 
        /* Mirror non-collections right back */
        if (!lwgeom_is_collection(lwg_in))
        {
                /* Non-collections of the matching type go back */
                if (lwg_in->type == extype || !extype)
                {
                        lwgeom_free(lwg_in);
                        PG_RETURN_POINTER(gser_in);
                }
                /* Others go back as EMPTY */
                else
                {
                        lwg_out = lwgeom_construct_empty(extype, lwg_in->srid, lwgeom_has_z(lwg_in), lwgeom_has_m(lwg_in));
                        PG_RETURN_POINTER(geometry_serialize(lwg_out));
                }
        }
 
        lwg_out = (LWGEOM*)lwcollection_extract((LWCOLLECTION*)lwg_in, extype);
 
        gser_out = geometry_serialize(lwg_out);
        lwgeom_free(lwg_in);
        lwgeom_free(lwg_out);
        PG_RETURN_POINTER(gser_out);
}
 
PG_FUNCTION_INFO_V1(ST_CollectionHomogenize);
Datum ST_CollectionHomogenize(PG_FUNCTION_ARGS)
{
        GSERIALIZED *input = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *output;
        LWGEOM *lwgeom = lwgeom_from_gserialized(input);
        LWGEOM *lwoutput = NULL;
 
        lwoutput = lwgeom_homogenize(lwgeom);
        lwgeom_free(lwgeom);
 
        if (!lwoutput)
        {
                PG_FREE_IF_COPY(input, 0);
                PG_RETURN_NULL();
        }
 
        output = geometry_serialize(lwoutput);
        lwgeom_free(lwoutput);
 
        PG_FREE_IF_COPY(input, 0);
        PG_RETURN_POINTER(output);
}
 
Datum ST_RemoveRepeatedPoints(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(ST_RemoveRepeatedPoints);
Datum ST_RemoveRepeatedPoints(PG_FUNCTION_ARGS)
{
        GSERIALIZED *g_in = PG_GETARG_GSERIALIZED_P_COPY(0);
        uint32_t type = gserialized_get_type(g_in);
        GSERIALIZED *g_out;
        LWGEOM *lwgeom_in = NULL;
        double tolerance = 0.0;
        int modified = LW_FALSE;
 
        /* Don't even start to think about points */
        if (type == POINTTYPE)
                PG_RETURN_POINTER(g_in);
 
        if (PG_NARGS() > 1 && !PG_ARGISNULL(1))
                tolerance = PG_GETARG_FLOAT8(1);
 
        lwgeom_in = lwgeom_from_gserialized(g_in);
        modified = lwgeom_remove_repeated_points_in_place(lwgeom_in, tolerance);
        if (!modified)
        {
                /* Since there were no changes, we can return the input to avoid the serialization */
                PG_RETURN_POINTER(g_in);
        }
 
        g_out = geometry_serialize(lwgeom_in);
 
        pfree(g_in);
        PG_RETURN_POINTER(g_out);
}
 
Datum ST_FlipCoordinates(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(ST_FlipCoordinates);
Datum ST_FlipCoordinates(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in = PG_GETARG_GSERIALIZED_P_COPY(0);
        GSERIALIZED *out;
        LWGEOM *lwgeom = lwgeom_from_gserialized(in);
 
        lwgeom_swap_ordinates(lwgeom, LWORD_X, LWORD_Y);
        out = geometry_serialize(lwgeom);
 
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(in, 0);
 
        PG_RETURN_POINTER(out);
}
 
static LWORD
ordname2ordval(char n)
{
        if (n == 'x' || n == 'X')
                return LWORD_X;
        if (n == 'y' || n == 'Y')
                return LWORD_Y;
        if (n == 'z' || n == 'Z')
                return LWORD_Z;
        if (n == 'm' || n == 'M')
                return LWORD_M;
        lwpgerror("Invalid ordinate name '%c'. Expected x,y,z or m", n);
        return (LWORD)-1;
}
 
Datum ST_SwapOrdinates(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(ST_SwapOrdinates);
Datum ST_SwapOrdinates(PG_FUNCTION_ARGS)
{
        GSERIALIZED *in;
        GSERIALIZED *out;
        LWGEOM *lwgeom;
        const char *ospec;
        LWORD o1, o2;
 
        ospec = PG_GETARG_CSTRING(1);
        if (strlen(ospec) != 2)
        {
                lwpgerror(
                    "Invalid ordinate specification. "
                    "Need two letters from the set (x,y,z,m). "
                    "Got '%s'",
                    ospec);
                PG_RETURN_NULL();
        }
        o1 = ordname2ordval(ospec[0]);
        o2 = ordname2ordval(ospec[1]);
 
        in = PG_GETARG_GSERIALIZED_P_COPY(0);
 
        /* Check presence of given ordinates */
        if ((o1 == LWORD_M || o2 == LWORD_M) && !gserialized_has_m(in))
        {
                lwpgerror("Geometry does not have an M ordinate");
                PG_RETURN_NULL();
        }
        if ((o1 == LWORD_Z || o2 == LWORD_Z) && !gserialized_has_z(in))
        {
                lwpgerror("Geometry does not have a Z ordinate");
                PG_RETURN_NULL();
        }
 
        /* Nothing to do if swapping the same ordinate, pity for the copy... */
        if (o1 == o2)
                PG_RETURN_POINTER(in);
 
        lwgeom = lwgeom_from_gserialized(in);
        lwgeom_swap_ordinates(lwgeom, o1, o2);
        out = geometry_serialize(lwgeom);
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(in, 0);
        PG_RETURN_POINTER(out);
}
 
/*
 * ST_BoundingDiagonal(inp geometry, fits boolean)
 */
Datum ST_BoundingDiagonal(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(ST_BoundingDiagonal);
Datum ST_BoundingDiagonal(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom_out;
        bool fits = PG_GETARG_BOOL(1);
        LWGEOM *lwgeom_out = NULL;
 
        GBOX gbox = {0};
        int hasz;
        int hasm;
        int32_t srid;
 
        POINT4D pt;
        POINTARRAY *pa;
 
        if (fits)
        {
                GSERIALIZED *geom_in = PG_GETARG_GSERIALIZED_P(0);
                LWGEOM *lwgeom_in = lwgeom_from_gserialized(geom_in);
                lwgeom_calculate_gbox(lwgeom_in, &gbox);
                hasz = FLAGS_GET_Z(lwgeom_in->flags);
                hasm = FLAGS_GET_M(lwgeom_in->flags);
                srid = lwgeom_in->srid;
        }
        else
        {
                uint8_t type;
                lwflags_t flags;
                int res = gserialized_datum_get_internals_p(PG_GETARG_DATUM(0), &gbox, &flags, &type, &srid);
                hasz = FLAGS_GET_Z(flags);
                hasm = FLAGS_GET_M(flags);
                if (res == LW_FAILURE)
                {
                        lwgeom_out = lwgeom_construct_empty(LINETYPE, srid, hasz, hasm);
                }
        }
 
        if (!lwgeom_out)
        {
                pa = ptarray_construct_empty(hasz, hasm, 2);
                pt.x = gbox.xmin;
                pt.y = gbox.ymin;
                pt.z = gbox.zmin;
                pt.m = gbox.mmin;
                ptarray_append_point(pa, &pt, LW_TRUE);
                pt.x = gbox.xmax;
                pt.y = gbox.ymax;
                pt.z = gbox.zmax;
                pt.m = gbox.mmax;
                ptarray_append_point(pa, &pt, LW_TRUE);
                lwgeom_out = lwline_as_lwgeom(lwline_construct(srid, NULL, pa));
        }
 
        geom_out = geometry_serialize(lwgeom_out);
        lwgeom_free(lwgeom_out);
 
        PG_RETURN_POINTER(geom_out);
}
 
Datum ST_Scale(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(ST_Scale);
Datum ST_Scale(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        GSERIALIZED *geom_scale = PG_GETARG_GSERIALIZED_P(1);
        GSERIALIZED *geom_origin = NULL;
        LWGEOM *lwg, *lwg_scale, *lwg_origin;
        LWPOINT *lwpt_scale, *lwpt_origin;
        POINT4D origin;
        POINT4D factors;
        bool translate = false;
        GSERIALIZED *ret;
        AFFINE aff;
 
        /* Make sure we have a valid scale input */
        lwg_scale = lwgeom_from_gserialized(geom_scale);
        lwpt_scale = lwgeom_as_lwpoint(lwg_scale);
        if (!lwpt_scale)
        {
                lwgeom_free(lwg_scale);
                PG_FREE_IF_COPY(geom_scale, 1);
                lwpgerror("Scale factor geometry parameter must be a point");
                PG_RETURN_NULL();
        }
 
        /* Geom Will be modified in place, so take a copy */
        geom = PG_GETARG_GSERIALIZED_P_COPY(0);
        lwg = lwgeom_from_gserialized(geom);
 
        /* Empty point, return input untouched */
        if (lwgeom_is_empty(lwg))
        {
                lwgeom_free(lwg_scale);
                lwgeom_free(lwg);
                PG_FREE_IF_COPY(geom_scale, 1);
                PG_RETURN_POINTER(geom);
        }
 
        /* Once we read the scale data into local static point, we can */
        /* free the lwgeom */
        lwpoint_getPoint4d_p(lwpt_scale, &factors);
        if (!lwgeom_has_z(lwg_scale))
                factors.z = 1.0;
        if (!lwgeom_has_m(lwg_scale))
                factors.m = 1.0;
        lwgeom_free(lwg_scale);
 
        /* Do we have the optional false origin? */
        if (PG_NARGS() > 2 && !PG_ARGISNULL(2))
        {
                geom_origin = PG_GETARG_GSERIALIZED_P(2);
                lwg_origin = lwgeom_from_gserialized(geom_origin);
                lwpt_origin = lwgeom_as_lwpoint(lwg_origin);
                if (lwpt_origin)
                {
                        lwpoint_getPoint4d_p(lwpt_origin, &origin);
                        translate = true;
                }
                /* Free the false origin inputs */
                lwgeom_free(lwg_origin);
                PG_FREE_IF_COPY(geom_origin, 2);
        }
 
        /* If we have false origin, translate to it before scaling */
        if (translate)
        {
                /* Initialize affine */
                memset(&aff, 0, sizeof(AFFINE));
                /* Set rotation/scale/sheer matrix to no-op */
                aff.afac = aff.efac = aff.ifac = 1.0;
                /* Strip false origin from all coordinates */
                aff.xoff = -1 * origin.x;
                aff.yoff = -1 * origin.y;
                aff.zoff = -1 * origin.z;
                lwgeom_affine(lwg, &aff);
        }
 
        lwgeom_scale(lwg, &factors);
 
        /* Return to original origin after scaling */
        if (translate)
        {
                aff.xoff *= -1;
                aff.yoff *= -1;
                aff.zoff *= -1;
                lwgeom_affine(lwg, &aff);
        }
 
        /* Cleanup and return */
        ret = geometry_serialize(lwg);
        lwgeom_free(lwg);
        PG_FREE_IF_COPY(geom, 0);
        PG_FREE_IF_COPY(geom_scale, 1);
        PG_RETURN_POINTER(ret);
}
 
Datum ST_Points(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(ST_Points);
Datum ST_Points(PG_FUNCTION_ARGS)
{
        if (PG_ARGISNULL(0))
        {
                PG_RETURN_NULL();
        }
        else
        {
                GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
                GSERIALIZED *ret;
                LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
                LWMPOINT *result = lwmpoint_from_lwgeom(lwgeom);
 
                lwgeom_free(lwgeom);
 
                ret = geometry_serialize(lwmpoint_as_lwgeom(result));
                lwmpoint_free(result);
                PG_RETURN_POINTER(ret);
        }
}
 
PG_FUNCTION_INFO_V1(ST_QuantizeCoordinates);
Datum ST_QuantizeCoordinates(PG_FUNCTION_ARGS)
{
        GSERIALIZED *input;
        GSERIALIZED *result;
        LWGEOM *g;
        int32_t prec_x;
        int32_t prec_y;
        int32_t prec_z;
        int32_t prec_m;
 
        if (PG_ARGISNULL(0))
                PG_RETURN_NULL();
        if (PG_ARGISNULL(1))
        {
                lwpgerror("Must specify precision");
                PG_RETURN_NULL();
        }
        else
        {
                prec_x = PG_GETARG_INT32(1);
        }
        prec_y = PG_ARGISNULL(2) ? prec_x : PG_GETARG_INT32(2);
        prec_z = PG_ARGISNULL(3) ? prec_x : PG_GETARG_INT32(3);
        prec_m = PG_ARGISNULL(4) ? prec_x : PG_GETARG_INT32(4);
 
        input = PG_GETARG_GSERIALIZED_P_COPY(0);
 
        g = lwgeom_from_gserialized(input);
 
        lwgeom_trim_bits_in_place(g, prec_x, prec_y, prec_z, prec_m);
 
        result = geometry_serialize(g);
        lwgeom_free(g);
        PG_FREE_IF_COPY(input, 0);
        PG_RETURN_POINTER(result);
}
 
/*
 * ST_FilterByM(in geometry, val double precision)
 */
PG_FUNCTION_INFO_V1(LWGEOM_FilterByM);
Datum LWGEOM_FilterByM(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom_in;
        GSERIALIZED *geom_out;
        LWGEOM *lwgeom_in;
        LWGEOM *lwgeom_out;
        double min, max;
        int returnm;
        int hasm;
 
        if (PG_NARGS() > 0 && !PG_ARGISNULL(0))
        {
                geom_in = PG_GETARG_GSERIALIZED_P(0);
        }
        else
        {
                PG_RETURN_NULL();
        }
 
        if (PG_NARGS() > 1 && !PG_ARGISNULL(1))
                min = PG_GETARG_FLOAT8(1);
        else
        {
                min = DBL_MIN;
        }
        if (PG_NARGS() > 2 && !PG_ARGISNULL(2))
                max = PG_GETARG_FLOAT8(2);
        else
        {
                max = DBL_MAX;
        }
        if (PG_NARGS() > 3 && !PG_ARGISNULL(3) && PG_GETARG_BOOL(3))
                returnm = 1;
        else
        {
                returnm = 0;
        }
 
        if (min > max)
        {
                elog(ERROR, "Min-value cannot be larger than Max value\n");
                PG_RETURN_NULL();
        }
 
        lwgeom_in = lwgeom_from_gserialized(geom_in);
 
        hasm = lwgeom_has_m(lwgeom_in);
 
        if (!hasm)
        {
                elog(NOTICE, "No M-value, No vertex removed\n");
                PG_RETURN_POINTER(geom_in);
        }
 
        lwgeom_out = lwgeom_filter_m(lwgeom_in, min, max, returnm);
 
        geom_out = geometry_serialize(lwgeom_out);
        lwgeom_free(lwgeom_out);
        PG_RETURN_POINTER(geom_out);
}
 
PG_FUNCTION_INFO_V1(boundary);
Datum boundary(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom1;
        GSERIALIZED *result;
        LWGEOM *lwgeom, *lwresult;
 
        geom1 = PG_GETARG_GSERIALIZED_P(0);
 
        /* Empty.Boundary() == Empty, but of other dimension, so can't shortcut */
 
        lwgeom = lwgeom_from_gserialized(geom1);
        lwresult = lwgeom_boundary(lwgeom);
        if (!lwresult)
        {
                lwgeom_free(lwgeom);
                PG_RETURN_NULL();
        }
 
        result = geometry_serialize(lwresult);
 
        lwgeom_free(lwgeom);
        lwgeom_free(lwresult);
 
        PG_RETURN_POINTER(result);
}