lwgeom.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 (C) 2001-2006 Refractions Research Inc.
 * Copyright (C) 2017-2018 Daniel Baston <dbaston@gmail.com>
 *
 **********************************************************************/
 
 
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
 
#include "liblwgeom_internal.h"
#include "lwgeom_log.h"
 
 
void
lwgeom_force_clockwise(LWGEOM *lwgeom)
{
        LWCOLLECTION *coll;
        uint32_t i;
 
        switch (lwgeom->type)
        {
        case POLYGONTYPE:
                lwpoly_force_clockwise((LWPOLY *)lwgeom);
                return;
 
        case TRIANGLETYPE:
                lwtriangle_force_clockwise((LWTRIANGLE *)lwgeom);
                return;
 
                /* Not handle POLYHEDRALSURFACE and TIN
                   as they are supposed to be well oriented */
        case MULTIPOLYGONTYPE:
        case COLLECTIONTYPE:
                coll = (LWCOLLECTION *)lwgeom;
                for (i=0; i<coll->ngeoms; i++)
                        lwgeom_force_clockwise(coll->geoms[i]);
                return;
        }
}
 
int
lwgeom_is_clockwise(LWGEOM *lwgeom)
{
        switch (lwgeom->type)
        {
                case POLYGONTYPE:
                        return lwpoly_is_clockwise((LWPOLY *)lwgeom);
 
                case TRIANGLETYPE:
                        return lwtriangle_is_clockwise((LWTRIANGLE *)lwgeom);
 
                case MULTIPOLYGONTYPE:
                case COLLECTIONTYPE:
                {
                        uint32_t i;
                        LWCOLLECTION* coll = (LWCOLLECTION *)lwgeom;
 
                        for (i=0; i < coll->ngeoms; i++)
                                if (!lwgeom_is_clockwise(coll->geoms[i]))
                                        return LW_FALSE;
                        return LW_TRUE;
                }
                default:
                        return LW_TRUE;
                return LW_FALSE;
        }
}
 
LWGEOM *
lwgeom_reverse(const LWGEOM *geom)
{
        LWGEOM *geomout = lwgeom_clone_deep(geom);
        lwgeom_reverse_in_place(geomout);
        return geomout;
}
 
void
lwgeom_reverse_in_place(LWGEOM *geom)
{
        uint32_t i;
        LWCOLLECTION *col;
        if (!geom)
                return;
 
        switch (geom->type)
        {
                case MULTIPOINTTYPE:
                case POINTTYPE:
                {
                        return;
                }
                case TRIANGLETYPE:
                case CIRCSTRINGTYPE:
                case LINETYPE:
                {
                        LWLINE *line = (LWLINE *)(geom);
                        ptarray_reverse_in_place(line->points);
                        return;
                }
                case POLYGONTYPE:
                {
                        LWPOLY *poly = (LWPOLY *)(geom);
                        if (!poly->rings)
                                return;
                        uint32_t r;
                        for (r = 0; r < poly->nrings; r++)
                                ptarray_reverse_in_place(poly->rings[r]);
                        return;
                }
                case MULTICURVETYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case MULTISURFACETYPE:
                case POLYHEDRALSURFACETYPE:
                case TINTYPE:
                case COLLECTIONTYPE:
                case COMPOUNDTYPE:
                case CURVEPOLYTYPE:
                {
                        col = (LWCOLLECTION *)(geom);
                        if (!col->geoms)
                                return;
                        for (i=0; i<col->ngeoms; i++)
                                lwgeom_reverse_in_place(col->geoms[i]);
                        return;
                }
                default:
                {
                        lwerror("%s: Unknown geometry type: %s", __func__, lwtype_name(geom->type));
                        return;
                }
 
        }
}
 
LWLINE *
lwgeom_as_lwline(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == LINETYPE )
                return (LWLINE *)lwgeom;
        else return NULL;
}
 
LWCIRCSTRING *
lwgeom_as_lwcircstring(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == CIRCSTRINGTYPE )
                return (LWCIRCSTRING *)lwgeom;
        else return NULL;
}
 
LWCOMPOUND *
lwgeom_as_lwcompound(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == COMPOUNDTYPE )
                return (LWCOMPOUND *)lwgeom;
        else return NULL;
}
 
LWCURVEPOLY *
lwgeom_as_lwcurvepoly(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == CURVEPOLYTYPE )
                return (LWCURVEPOLY *)lwgeom;
        else return NULL;
}
 
LWPOLY *
lwgeom_as_lwpoly(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == POLYGONTYPE )
                return (LWPOLY *)lwgeom;
        else return NULL;
}
 
LWTRIANGLE *
lwgeom_as_lwtriangle(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == TRIANGLETYPE )
                return (LWTRIANGLE *)lwgeom;
        else return NULL;
}
 
LWCOLLECTION *
lwgeom_as_lwcollection(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom_is_collection(lwgeom) )
                return (LWCOLLECTION*)lwgeom;
        else return NULL;
}
 
LWMPOINT *
lwgeom_as_lwmpoint(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == MULTIPOINTTYPE )
                return (LWMPOINT *)lwgeom;
        else return NULL;
}
 
LWMLINE *
lwgeom_as_lwmline(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == MULTILINETYPE )
                return (LWMLINE *)lwgeom;
        else return NULL;
}
 
LWMPOLY *
lwgeom_as_lwmpoly(const LWGEOM *lwgeom)
{
        if ( lwgeom == NULL ) return NULL;
        if ( lwgeom->type == MULTIPOLYGONTYPE )
                return (LWMPOLY *)lwgeom;
        else return NULL;
}
 
LWPSURFACE *
lwgeom_as_lwpsurface(const LWGEOM *lwgeom)
{
        if ( lwgeom->type == POLYHEDRALSURFACETYPE )
                return (LWPSURFACE *)lwgeom;
        else return NULL;
}
 
LWTIN *
lwgeom_as_lwtin(const LWGEOM *lwgeom)
{
        if ( lwgeom->type == TINTYPE )
                return (LWTIN *)lwgeom;
        else return NULL;
}
 
LWGEOM *lwtin_as_lwgeom(const LWTIN *obj)
{
        return (LWGEOM *)obj;
}
 
LWGEOM *lwpsurface_as_lwgeom(const LWPSURFACE *obj)
{
        return (LWGEOM *)obj;
}
 
LWGEOM *lwmpoly_as_lwgeom(const LWMPOLY *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwmline_as_lwgeom(const LWMLINE *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwmpoint_as_lwgeom(const LWMPOINT *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwcollection_as_lwgeom(const LWCOLLECTION *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwcircstring_as_lwgeom(const LWCIRCSTRING *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwcurvepoly_as_lwgeom(const LWCURVEPOLY *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwcompound_as_lwgeom(const LWCOMPOUND *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwpoly_as_lwgeom(const LWPOLY *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwtriangle_as_lwgeom(const LWTRIANGLE *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwline_as_lwgeom(const LWLINE *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
LWGEOM *lwpoint_as_lwgeom(const LWPOINT *obj)
{
        if ( obj == NULL ) return NULL;
        return (LWGEOM *)obj;
}
 
 
uint8_t MULTITYPE[NUMTYPES] =
{
        0,
        MULTIPOINTTYPE,        /*  1 */
        MULTILINETYPE,         /*  2 */
        MULTIPOLYGONTYPE,      /*  3 */
        0,0,0,0,
        MULTICURVETYPE,        /*  8 */
        MULTICURVETYPE,        /*  9 */
        MULTISURFACETYPE,      /* 10 */
        POLYHEDRALSURFACETYPE, /* 11 */
        0, 0,
        TINTYPE,               /* 14 */
        0
};
 
uint8_t lwtype_multitype(uint8_t type)
{
        if (type > 15) return 0;
        return MULTITYPE[type];
}
 
LWGEOM *
lwgeom_as_multi(const LWGEOM *lwgeom)
{
        LWGEOM **ogeoms;
        LWGEOM *ogeom = NULL;
        GBOX *box = NULL;
        int type;
 
        type = lwgeom->type;
 
        if ( ! MULTITYPE[type] ) return lwgeom_clone(lwgeom);
 
        if( lwgeom_is_empty(lwgeom) )
        {
                ogeom = (LWGEOM *)lwcollection_construct_empty(
                        MULTITYPE[type],
                        lwgeom->srid,
                        FLAGS_GET_Z(lwgeom->flags),
                        FLAGS_GET_M(lwgeom->flags)
                );
        }
        else
        {
                ogeoms = lwalloc(sizeof(LWGEOM*));
                ogeoms[0] = lwgeom_clone(lwgeom);
 
                /* Sub-geometries are not allowed to have bboxes or SRIDs, move the bbox to the collection */
                box = ogeoms[0]->bbox;
                ogeoms[0]->bbox = NULL;
                ogeoms[0]->srid = SRID_UNKNOWN;
 
                ogeom = (LWGEOM *)lwcollection_construct(MULTITYPE[type], lwgeom->srid, box, 1, ogeoms);
        }
 
        return ogeom;
}
 
LWGEOM *
lwgeom_as_curve(const LWGEOM *lwgeom)
{
        LWGEOM *ogeom;
        int type = lwgeom->type;
        /*
        int hasz = FLAGS_GET_Z(lwgeom->flags);
        int hasm = FLAGS_GET_M(lwgeom->flags);
        int32_t srid = lwgeom->srid;
        */
 
        switch(type)
        {
                case LINETYPE:
                        /* turn to COMPOUNDCURVE */
                        ogeom = (LWGEOM*)lwcompound_construct_from_lwline((LWLINE*)lwgeom);
                        break;
                case POLYGONTYPE:
                        ogeom = (LWGEOM*)lwcurvepoly_construct_from_lwpoly(lwgeom_as_lwpoly(lwgeom));
                        break;
                case MULTILINETYPE:
                        /* turn to MULTICURVE */
                        ogeom = lwgeom_clone(lwgeom);
                        ogeom->type = MULTICURVETYPE;
                        break;
                case MULTIPOLYGONTYPE:
                        /* turn to MULTISURFACE */
                        ogeom = lwgeom_clone(lwgeom);
                        ogeom->type = MULTISURFACETYPE;
                        break;
                case COLLECTIONTYPE:
                default:
                        ogeom = lwgeom_clone(lwgeom);
                        break;
        }
 
        /* TODO: copy bbox from input geom ? */
 
        return ogeom;
}
 
 
void
lwgeom_release(LWGEOM *lwgeom)
{
        if ( ! lwgeom )
                lwerror("lwgeom_release: someone called on 0x0");
 
        LWDEBUGF(3, "releasing type %s", lwtype_name(lwgeom->type));
 
        /* Drop bounding box (always a copy) */
        if ( lwgeom->bbox )
        {
                LWDEBUGF(3, "lwgeom_release: releasing bbox. %p", lwgeom->bbox);
                lwfree(lwgeom->bbox);
        }
        lwfree(lwgeom);
 
}
 
 
/* @brief Clone LWGEOM object. Serialized point lists are not copied.
 *
 * @see ptarray_clone
 */
LWGEOM *
lwgeom_clone(const LWGEOM *lwgeom)
{
        LWDEBUGF(2, "lwgeom_clone called with %p, %s",
                 lwgeom, lwtype_name(lwgeom->type));
 
        switch (lwgeom->type)
        {
        case POINTTYPE:
                return (LWGEOM *)lwpoint_clone((LWPOINT *)lwgeom);
        case LINETYPE:
                return (LWGEOM *)lwline_clone((LWLINE *)lwgeom);
        case CIRCSTRINGTYPE:
                return (LWGEOM *)lwcircstring_clone((LWCIRCSTRING *)lwgeom);
        case POLYGONTYPE:
                return (LWGEOM *)lwpoly_clone((LWPOLY *)lwgeom);
        case TRIANGLETYPE:
                return (LWGEOM *)lwtriangle_clone((LWTRIANGLE *)lwgeom);
        case COMPOUNDTYPE:
        case CURVEPOLYTYPE:
        case MULTICURVETYPE:
        case MULTISURFACETYPE:
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case MULTIPOLYGONTYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
        case COLLECTIONTYPE:
                return (LWGEOM *)lwcollection_clone((LWCOLLECTION *)lwgeom);
        default:
                lwerror("lwgeom_clone: Unknown geometry type: %s", lwtype_name(lwgeom->type));
                return NULL;
        }
}
 
LWGEOM *
lwgeom_clone_deep(const LWGEOM *lwgeom)
{
        LWDEBUGF(2, "lwgeom_clone called with %p, %s",
                 lwgeom, lwtype_name(lwgeom->type));
 
        switch (lwgeom->type)
        {
        case POINTTYPE:
        case LINETYPE:
        case CIRCSTRINGTYPE:
        case TRIANGLETYPE:
                return (LWGEOM *)lwline_clone_deep((LWLINE *)lwgeom);
        case POLYGONTYPE:
                return (LWGEOM *)lwpoly_clone_deep((LWPOLY *)lwgeom);
        case COMPOUNDTYPE:
        case CURVEPOLYTYPE:
        case MULTICURVETYPE:
        case MULTISURFACETYPE:
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case MULTIPOLYGONTYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
        case COLLECTIONTYPE:
                return (LWGEOM *)lwcollection_clone_deep((LWCOLLECTION *)lwgeom);
        default:
                lwerror("lwgeom_clone_deep: Unknown geometry type: %s", lwtype_name(lwgeom->type));
                return NULL;
        }
}
 
 
char*
lwgeom_to_ewkt(const LWGEOM *lwgeom)
{
        char* wkt = NULL;
        size_t wkt_size = 0;
 
        wkt = lwgeom_to_wkt(lwgeom, WKT_EXTENDED, 12, &wkt_size);
 
        if ( ! wkt )
        {
                lwerror("Error writing geom %p to WKT", lwgeom);
        }
 
        return wkt;
}
 
char
lwgeom_same(const LWGEOM *lwgeom1, const LWGEOM *lwgeom2)
{
        LWDEBUGF(2, "lwgeom_same(%s, %s) called",
                 lwtype_name(lwgeom1->type),
                 lwtype_name(lwgeom2->type));
 
        if ( lwgeom1->type != lwgeom2->type )
        {
                LWDEBUG(3, " type differ");
 
                return LW_FALSE;
        }
 
        if ( FLAGS_GET_ZM(lwgeom1->flags) != FLAGS_GET_ZM(lwgeom2->flags) )
        {
                LWDEBUG(3, " ZM flags differ");
 
                return LW_FALSE;
        }
 
        /* Check boxes if both already computed  */
        if ( lwgeom1->bbox && lwgeom2->bbox )
        {
                /*lwnotice("bbox1:%p, bbox2:%p", lwgeom1->bbox, lwgeom2->bbox);*/
                if ( ! gbox_same(lwgeom1->bbox, lwgeom2->bbox) )
                {
                        LWDEBUG(3, " bounding boxes differ");
 
                        return LW_FALSE;
                }
        }
 
        /* geoms have same type, invoke type-specific function */
        switch (lwgeom1->type)
        {
        case POINTTYPE:
                return lwpoint_same((LWPOINT *)lwgeom1,
                                    (LWPOINT *)lwgeom2);
        case LINETYPE:
                return lwline_same((LWLINE *)lwgeom1,
                                   (LWLINE *)lwgeom2);
        case POLYGONTYPE:
                return lwpoly_same((LWPOLY *)lwgeom1,
                                   (LWPOLY *)lwgeom2);
        case TRIANGLETYPE:
                return lwtriangle_same((LWTRIANGLE *)lwgeom1,
                                       (LWTRIANGLE *)lwgeom2);
        case CIRCSTRINGTYPE:
                return lwcircstring_same((LWCIRCSTRING *)lwgeom1,
                                         (LWCIRCSTRING *)lwgeom2);
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case MULTIPOLYGONTYPE:
        case MULTICURVETYPE:
        case MULTISURFACETYPE:
        case COMPOUNDTYPE:
        case CURVEPOLYTYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
        case COLLECTIONTYPE:
                return lwcollection_same((LWCOLLECTION *)lwgeom1,
                                         (LWCOLLECTION *)lwgeom2);
        default:
                lwerror("lwgeom_same: unsupported geometry type: %s",
                        lwtype_name(lwgeom1->type));
                return LW_FALSE;
        }
 
}
 
int
lwpoint_inside_circle(const LWPOINT *p, double cx, double cy, double rad)
{
        const POINT2D *pt;
        POINT2D center;
 
        if ( ! p || ! p->point )
                return LW_FALSE;
 
        pt = getPoint2d_cp(p->point, 0);
 
        center.x = cx;
        center.y = cy;
 
        if ( distance2d_pt_pt(pt, &center) < rad )
                return LW_TRUE;
 
        return LW_FALSE;
}
 
void
lwgeom_drop_bbox(LWGEOM *lwgeom)
{
        if ( lwgeom->bbox ) lwfree(lwgeom->bbox);
        lwgeom->bbox = NULL;
        FLAGS_SET_BBOX(lwgeom->flags, 0);
}
 
void
lwgeom_add_bbox(LWGEOM *lwgeom)
{
        /* an empty LWGEOM has no bbox */
        if ( lwgeom_is_empty(lwgeom) ) return;
 
        if ( lwgeom->bbox ) return;
        FLAGS_SET_BBOX(lwgeom->flags, 1);
        lwgeom->bbox = gbox_new(lwgeom->flags);
        lwgeom_calculate_gbox(lwgeom, lwgeom->bbox);
}
 
void
lwgeom_refresh_bbox(LWGEOM *lwgeom)
{
        lwgeom_drop_bbox(lwgeom);
        lwgeom_add_bbox(lwgeom);
}
 
void
lwgeom_add_bbox_deep(LWGEOM *lwgeom, GBOX *gbox)
{
        if ( lwgeom_is_empty(lwgeom) ) return;
 
        FLAGS_SET_BBOX(lwgeom->flags, 1);
 
        if ( ! ( gbox || lwgeom->bbox ) )
        {
                lwgeom->bbox = gbox_new(lwgeom->flags);
                lwgeom_calculate_gbox(lwgeom, lwgeom->bbox);
        }
        else if ( gbox && ! lwgeom->bbox )
        {
                lwgeom->bbox = gbox_clone(gbox);
        }
 
        if ( lwgeom_is_collection(lwgeom) )
        {
                uint32_t i;
                LWCOLLECTION *lwcol = (LWCOLLECTION*)lwgeom;
 
                for ( i = 0; i < lwcol->ngeoms; i++ )
                {
                        lwgeom_add_bbox_deep(lwcol->geoms[i], lwgeom->bbox);
                }
        }
}
 
const GBOX *
lwgeom_get_bbox(const LWGEOM *lwg)
{
        /* add it if not already there */
        lwgeom_add_bbox((LWGEOM *)lwg);
        return lwg->bbox;
}
 
 
int lwgeom_calculate_gbox(const LWGEOM *lwgeom, GBOX *gbox)
{
        gbox->flags = lwgeom->flags;
        if( FLAGS_GET_GEODETIC(lwgeom->flags) )
                return lwgeom_calculate_gbox_geodetic(lwgeom, gbox);
        else
                return lwgeom_calculate_gbox_cartesian(lwgeom, gbox);
}
 
void
lwgeom_drop_srid(LWGEOM *lwgeom)
{
        lwgeom->srid = SRID_UNKNOWN;    /* TODO: To be changed to SRID_UNKNOWN */
}
 
LWGEOM *
lwgeom_segmentize2d(const LWGEOM *lwgeom, double dist)
{
        switch (lwgeom->type)
        {
        case LINETYPE:
                return (LWGEOM *)lwline_segmentize2d((LWLINE *)lwgeom,
                                                     dist);
        case POLYGONTYPE:
                return (LWGEOM *)lwpoly_segmentize2d((LWPOLY *)lwgeom,
                                                     dist);
        case MULTILINETYPE:
        case MULTIPOLYGONTYPE:
        case COLLECTIONTYPE:
                return (LWGEOM *)lwcollection_segmentize2d(
                           (LWCOLLECTION *)lwgeom, dist);
 
        default:
                return lwgeom_clone(lwgeom);
        }
}
 
LWGEOM*
lwgeom_force_2d(const LWGEOM *geom)
{
        return lwgeom_force_dims(geom, 0, 0);
}
 
LWGEOM*
lwgeom_force_3dz(const LWGEOM *geom)
{
        return lwgeom_force_dims(geom, 1, 0);
}
 
LWGEOM*
lwgeom_force_3dm(const LWGEOM *geom)
{
        return lwgeom_force_dims(geom, 0, 1);
}
 
LWGEOM*
lwgeom_force_4d(const LWGEOM *geom)
{
        return lwgeom_force_dims(geom, 1, 1);
}
 
LWGEOM*
lwgeom_force_dims(const LWGEOM *geom, int hasz, int hasm)
{
        if (!geom)
                return NULL;
        switch(geom->type)
        {
                case POINTTYPE:
                        return lwpoint_as_lwgeom(lwpoint_force_dims((LWPOINT*)geom, hasz, hasm));
                case CIRCSTRINGTYPE:
                case LINETYPE:
                case TRIANGLETYPE:
                        return lwline_as_lwgeom(lwline_force_dims((LWLINE*)geom, hasz, hasm));
                case POLYGONTYPE:
                        return lwpoly_as_lwgeom(lwpoly_force_dims((LWPOLY*)geom, hasz, hasm));
                case COMPOUNDTYPE:
                case CURVEPOLYTYPE:
                case MULTICURVETYPE:
                case MULTISURFACETYPE:
                case MULTIPOINTTYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case POLYHEDRALSURFACETYPE:
                case TINTYPE:
                case COLLECTIONTYPE:
                        return lwcollection_as_lwgeom(lwcollection_force_dims((LWCOLLECTION*)geom, hasz, hasm));
                default:
                        lwerror("lwgeom_force_2d: unsupported geom type: %s", lwtype_name(geom->type));
                        return NULL;
        }
}
 
LWGEOM*
lwgeom_force_sfs(LWGEOM *geom, int version)
{
        LWCOLLECTION *col;
        uint32_t i;
        LWGEOM *g;
 
        /* SFS 1.2 version */
        if (version == 120)
        {
                switch(geom->type)
                {
                        /* SQL/MM types */
                        case CIRCSTRINGTYPE:
                        case COMPOUNDTYPE:
                        case CURVEPOLYTYPE:
                        case MULTICURVETYPE:
                        case MULTISURFACETYPE:
                                return lwgeom_stroke(geom, 32);
 
                        case COLLECTIONTYPE:
                                col = (LWCOLLECTION*)geom;
                                for ( i = 0; i < col->ngeoms; i++ )
                                        col->geoms[i] = lwgeom_force_sfs((LWGEOM*)col->geoms[i], version);
 
                                return lwcollection_as_lwgeom((LWCOLLECTION*)geom);
 
                        default:
                                return (LWGEOM *)geom;
                }
        }
 
 
        /* SFS 1.1 version */
        switch(geom->type)
        {
                /* SQL/MM types */
                case CIRCSTRINGTYPE:
                case COMPOUNDTYPE:
                case CURVEPOLYTYPE:
                case MULTICURVETYPE:
                case MULTISURFACETYPE:
                        return lwgeom_stroke(geom, 32);
 
                /* SFS 1.2 types */
                case TRIANGLETYPE:
                        g = lwpoly_as_lwgeom(lwpoly_from_lwlines((LWLINE*)geom, 0, NULL));
                        lwgeom_free(geom);
                        return g;
 
                case TINTYPE:
                        col = (LWCOLLECTION*) geom;
                        for ( i = 0; i < col->ngeoms; i++ )
                        {
                                g = lwpoly_as_lwgeom(lwpoly_from_lwlines((LWLINE*)col->geoms[i], 0, NULL));
                                lwgeom_free(col->geoms[i]);
                                col->geoms[i] = g;
                        }
                        col->type = COLLECTIONTYPE;
                        return lwmpoly_as_lwgeom((LWMPOLY*)geom);
 
                case POLYHEDRALSURFACETYPE:
                        geom->type = COLLECTIONTYPE;
                        return (LWGEOM *)geom;
 
                /* Collection */
                case COLLECTIONTYPE:
                        col = (LWCOLLECTION*)geom;
                        for ( i = 0; i < col->ngeoms; i++ )
                                col->geoms[i] = lwgeom_force_sfs((LWGEOM*)col->geoms[i], version);
 
                        return lwcollection_as_lwgeom((LWCOLLECTION*)geom);
 
                default:
                        return (LWGEOM *)geom;
        }
}
 
int32_t
lwgeom_get_srid(const LWGEOM *geom)
{
        if ( ! geom ) return SRID_UNKNOWN;
        return geom->srid;
}
 
int
lwgeom_has_z(const LWGEOM *geom)
{
        if ( ! geom ) return LW_FALSE;
        return FLAGS_GET_Z(geom->flags);
}
 
int
lwgeom_has_m(const LWGEOM *geom)
{
        if ( ! geom ) return LW_FALSE;
        return FLAGS_GET_M(geom->flags);
}
 
int
lwgeom_is_solid(const LWGEOM *geom)
{
        if ( ! geom ) return LW_FALSE;
        return FLAGS_GET_GEODETIC(geom->flags);
}
 
int
lwgeom_ndims(const LWGEOM *geom)
{
        if ( ! geom ) return 0;
        return FLAGS_NDIMS(geom->flags);
}
 
 
 
void
lwgeom_set_geodetic(LWGEOM *geom, int value)
{
        LWPOINT *pt;
        LWLINE *ln;
        LWPOLY *ply;
        LWCOLLECTION *col;
        uint32_t i;
 
        FLAGS_SET_GEODETIC(geom->flags, value);
        if ( geom->bbox )
                FLAGS_SET_GEODETIC(geom->bbox->flags, value);
 
        switch(geom->type)
        {
                case POINTTYPE:
                        pt = (LWPOINT*)geom;
                        if ( pt->point )
                                FLAGS_SET_GEODETIC(pt->point->flags, value);
                        break;
                case LINETYPE:
                        ln = (LWLINE*)geom;
                        if ( ln->points )
                                FLAGS_SET_GEODETIC(ln->points->flags, value);
                        break;
                case POLYGONTYPE:
                        ply = (LWPOLY*)geom;
                        for ( i = 0; i < ply->nrings; i++ )
                                FLAGS_SET_GEODETIC(ply->rings[i]->flags, value);
                        break;
                case MULTIPOINTTYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case COLLECTIONTYPE:
                        col = (LWCOLLECTION*)geom;
                        for ( i = 0; i < col->ngeoms; i++ )
                                lwgeom_set_geodetic(col->geoms[i], value);
                        break;
                default:
                        lwerror("lwgeom_set_geodetic: unsupported geom type: %s", lwtype_name(geom->type));
                        return;
        }
}
 
void
lwgeom_longitude_shift(LWGEOM *lwgeom)
{
        uint32_t i;
        switch (lwgeom->type)
        {
                LWPOINT *point;
                LWLINE *line;
                LWPOLY *poly;
                LWTRIANGLE *triangle;
                LWCOLLECTION *coll;
 
        case POINTTYPE:
                point = (LWPOINT *)lwgeom;
                ptarray_longitude_shift(point->point);
                return;
        case LINETYPE:
                line = (LWLINE *)lwgeom;
                ptarray_longitude_shift(line->points);
                return;
        case POLYGONTYPE:
                poly = (LWPOLY *)lwgeom;
                for (i=0; i<poly->nrings; i++)
                        ptarray_longitude_shift(poly->rings[i]);
                return;
        case TRIANGLETYPE:
                triangle = (LWTRIANGLE *)lwgeom;
                ptarray_longitude_shift(triangle->points);
                return;
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case MULTIPOLYGONTYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
        case COLLECTIONTYPE:
                coll = (LWCOLLECTION *)lwgeom;
                for (i=0; i<coll->ngeoms; i++)
                        lwgeom_longitude_shift(coll->geoms[i]);
                return;
        default:
                lwerror("lwgeom_longitude_shift: unsupported geom type: %s",
                        lwtype_name(lwgeom->type));
        }
}
 
int
lwgeom_is_closed(const LWGEOM *geom)
{
        int type = geom->type;
 
        if( lwgeom_is_empty(geom) )
                return LW_FALSE;
 
        /* Test linear types for closure */
        switch (type)
        {
        case LINETYPE:
                return lwline_is_closed((LWLINE*)geom);
        case POLYGONTYPE:
                return lwpoly_is_closed((LWPOLY*)geom);
        case CIRCSTRINGTYPE:
                return lwcircstring_is_closed((LWCIRCSTRING*)geom);
        case COMPOUNDTYPE:
                return lwcompound_is_closed((LWCOMPOUND*)geom);
        case TINTYPE:
                return lwtin_is_closed((LWTIN*)geom);
        case POLYHEDRALSURFACETYPE:
                return lwpsurface_is_closed((LWPSURFACE*)geom);
        }
 
        /* Recurse into collections and see if anything is not closed */
        if ( lwgeom_is_collection(geom) )
        {
                LWCOLLECTION *col = lwgeom_as_lwcollection(geom);
                uint32_t i;
                int closed;
                for ( i = 0; i < col->ngeoms; i++ )
                {
                        closed = lwgeom_is_closed(col->geoms[i]);
                        if ( ! closed )
                                return LW_FALSE;
                }
                return LW_TRUE;
        }
 
        /* All non-linear non-collection types we will call closed */
        return LW_TRUE;
}
 
int
lwgeom_is_collection(const LWGEOM *geom)
{
        if( ! geom ) return LW_FALSE;
        return lwtype_is_collection(geom->type);
}
 
int
lwtype_is_collection(uint8_t type)
{
 
        switch (type)
        {
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case MULTIPOLYGONTYPE:
        case COLLECTIONTYPE:
        case CURVEPOLYTYPE:
        case COMPOUNDTYPE:
        case MULTICURVETYPE:
        case MULTISURFACETYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
                return LW_TRUE;
                break;
 
        default:
                return LW_FALSE;
        }
}
 
uint32_t
lwtype_get_collectiontype(uint8_t type)
{
        switch (type)
        {
                case POINTTYPE:
                        return MULTIPOINTTYPE;
                case LINETYPE:
                        return MULTILINETYPE;
                case POLYGONTYPE:
                        return MULTIPOLYGONTYPE;
                case CIRCSTRINGTYPE:
                        return MULTICURVETYPE;
                case COMPOUNDTYPE:
                        return MULTICURVETYPE;
                case CURVEPOLYTYPE:
                        return MULTISURFACETYPE;
                case TRIANGLETYPE:
                        return TINTYPE;
                default:
                        return COLLECTIONTYPE;
        }
}
 
 
void lwgeom_free(LWGEOM *lwgeom)
{
 
        /* There's nothing here to free... */
        if( ! lwgeom ) return;
 
        LWDEBUGF(5,"freeing a %s",lwtype_name(lwgeom->type));
 
        switch (lwgeom->type)
        {
        case POINTTYPE:
                lwpoint_free((LWPOINT *)lwgeom);
                break;
        case LINETYPE:
                lwline_free((LWLINE *)lwgeom);
                break;
        case POLYGONTYPE:
                lwpoly_free((LWPOLY *)lwgeom);
                break;
        case CIRCSTRINGTYPE:
                lwcircstring_free((LWCIRCSTRING *)lwgeom);
                break;
        case TRIANGLETYPE:
                lwtriangle_free((LWTRIANGLE *)lwgeom);
                break;
        case MULTIPOINTTYPE:
                lwmpoint_free((LWMPOINT *)lwgeom);
                break;
        case MULTILINETYPE:
                lwmline_free((LWMLINE *)lwgeom);
                break;
        case MULTIPOLYGONTYPE:
                lwmpoly_free((LWMPOLY *)lwgeom);
                break;
        case POLYHEDRALSURFACETYPE:
                lwpsurface_free((LWPSURFACE *)lwgeom);
                break;
        case TINTYPE:
                lwtin_free((LWTIN *)lwgeom);
                break;
        case CURVEPOLYTYPE:
        case COMPOUNDTYPE:
        case MULTICURVETYPE:
        case MULTISURFACETYPE:
        case COLLECTIONTYPE:
                lwcollection_free((LWCOLLECTION *)lwgeom);
                break;
        default:
                lwerror("lwgeom_free called with unknown type (%d) %s", lwgeom->type, lwtype_name(lwgeom->type));
        }
        return;
}
 
int lwgeom_needs_bbox(const LWGEOM *geom)
{
        assert(geom);
        if ( geom->type == POINTTYPE )
        {
                return LW_FALSE;
        }
        else if ( geom->type == LINETYPE )
        {
                if ( lwgeom_count_vertices(geom) <= 2 )
                        return LW_FALSE;
                else
                        return LW_TRUE;
        }
        else if ( geom->type == MULTIPOINTTYPE )
        {
                if ( ((LWCOLLECTION*)geom)->ngeoms == 1 )
                        return LW_FALSE;
                else
                        return LW_TRUE;
        }
        else if ( geom->type == MULTILINETYPE )
        {
                if ( ((LWCOLLECTION*)geom)->ngeoms == 1 && lwgeom_count_vertices(geom) <= 2 )
                        return LW_FALSE;
                else
                        return LW_TRUE;
        }
        else
        {
                return LW_TRUE;
        }
}
 
uint32_t lwgeom_count_vertices(const LWGEOM *geom)
{
        int result = 0;
 
        /* Null? Zero. */
        if( ! geom ) return 0;
 
        LWDEBUGF(4, "lwgeom_count_vertices got type %s",
                 lwtype_name(geom->type));
 
        /* Empty? Zero. */
        if( lwgeom_is_empty(geom) ) return 0;
 
        switch (geom->type)
        {
        case POINTTYPE:
                result = 1;
                break;
        case TRIANGLETYPE:
        case CIRCSTRINGTYPE:
        case LINETYPE:
                result = lwline_count_vertices((LWLINE *)geom);
                break;
        case POLYGONTYPE:
                result = lwpoly_count_vertices((LWPOLY *)geom);
                break;
        case COMPOUNDTYPE:
        case CURVEPOLYTYPE:
        case MULTICURVETYPE:
        case MULTISURFACETYPE:
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case MULTIPOLYGONTYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
        case COLLECTIONTYPE:
                result = lwcollection_count_vertices((LWCOLLECTION *)geom);
                break;
        default:
                lwerror("%s: unsupported input geometry type: %s",
                        __func__, lwtype_name(geom->type));
                break;
        }
        LWDEBUGF(3, "counted %d vertices", result);
        return result;
}
 
int lwgeom_dimension(const LWGEOM *geom)
{
 
        /* Null? Zero. */
        if( ! geom ) return -1;
 
        LWDEBUGF(4, "lwgeom_dimension got type %s",
                 lwtype_name(geom->type));
 
        /* Empty? Zero. */
        /* if( lwgeom_is_empty(geom) ) return 0; */
 
        switch (geom->type)
        {
        case POINTTYPE:
        case MULTIPOINTTYPE:
                return 0;
        case CIRCSTRINGTYPE:
        case LINETYPE:
        case COMPOUNDTYPE:
        case MULTICURVETYPE:
        case MULTILINETYPE:
                return 1;
        case TRIANGLETYPE:
        case POLYGONTYPE:
        case CURVEPOLYTYPE:
        case MULTISURFACETYPE:
        case MULTIPOLYGONTYPE:
        case TINTYPE:
                return 2;
        case POLYHEDRALSURFACETYPE:
        {
                /* A closed polyhedral surface contains a volume. */
                int closed = lwpsurface_is_closed((LWPSURFACE*)geom);
                return ( closed ? 3 : 2 );
        }
        case COLLECTIONTYPE:
        {
                int maxdim = 0;
                uint32_t i;
                LWCOLLECTION *col = (LWCOLLECTION*)geom;
                for( i = 0; i < col->ngeoms; i++ )
                {
                        int dim = lwgeom_dimension(col->geoms[i]);
                        maxdim = ( dim > maxdim ? dim : maxdim );
                }
                return maxdim;
        }
        default:
                lwerror("%s: unsupported input geometry type: %s",
                        __func__, lwtype_name(geom->type));
        }
        return -1;
}
 
uint32_t lwgeom_count_rings(const LWGEOM *geom)
{
        int result = 0;
 
        /* Null? Empty? Zero. */
        if( ! geom || lwgeom_is_empty(geom) )
                return 0;
 
        switch (geom->type)
        {
        case POINTTYPE:
        case CIRCSTRINGTYPE:
        case COMPOUNDTYPE:
        case MULTICURVETYPE:
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case LINETYPE:
                result = 0;
                break;
        case TRIANGLETYPE:
                result = 1;
                break;
        case POLYGONTYPE:
                result = ((LWPOLY *)geom)->nrings;
                break;
        case CURVEPOLYTYPE:
                result = ((LWCURVEPOLY *)geom)->nrings;
                break;
        case MULTISURFACETYPE:
        case MULTIPOLYGONTYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
        case COLLECTIONTYPE:
        {
                LWCOLLECTION *col = (LWCOLLECTION*)geom;
                uint32_t i = 0;
                for( i = 0; i < col->ngeoms; i++ )
                        result += lwgeom_count_rings(col->geoms[i]);
                break;
        }
        default:
                lwerror("lwgeom_count_rings: unsupported input geometry type: %s", lwtype_name(geom->type));
                break;
        }
        LWDEBUGF(3, "counted %d rings", result);
        return result;
}
 
int lwgeom_has_srid(const LWGEOM *geom)
{
        if ( geom->srid != SRID_UNKNOWN )
                return LW_TRUE;
 
        return LW_FALSE;
}
 
 
static int lwcollection_dimensionality(const LWCOLLECTION *col)
{
        uint32_t i;
        int dimensionality = 0;
        for ( i = 0; i < col->ngeoms; i++ )
        {
                int d = lwgeom_dimensionality(col->geoms[i]);
                if ( d > dimensionality )
                        dimensionality = d;
        }
        return dimensionality;
}
 
extern int lwgeom_dimensionality(const LWGEOM *geom)
{
        int dim;
 
        LWDEBUGF(3, "lwgeom_dimensionality got type %s",
                 lwtype_name(geom->type));
 
        switch (geom->type)
        {
        case POINTTYPE:
        case MULTIPOINTTYPE:
                return 0;
                break;
        case LINETYPE:
        case CIRCSTRINGTYPE:
        case MULTILINETYPE:
        case COMPOUNDTYPE:
        case MULTICURVETYPE:
                return 1;
                break;
        case POLYGONTYPE:
        case TRIANGLETYPE:
        case CURVEPOLYTYPE:
        case MULTIPOLYGONTYPE:
        case MULTISURFACETYPE:
                return 2;
                break;
 
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
                dim = lwgeom_is_closed(geom)?3:2;
                return dim;
                break;
 
        case COLLECTIONTYPE:
                return lwcollection_dimensionality((const LWCOLLECTION *)geom);
                break;
        default:
                lwerror("lwgeom_dimensionality: unsupported input geometry type: %s",
                        lwtype_name(geom->type));
                break;
        }
        return 0;
}
 
extern LWGEOM* lwgeom_remove_repeated_points(const LWGEOM *in, double tolerance)
{
        LWGEOM *out = lwgeom_clone_deep(in);
        lwgeom_remove_repeated_points_in_place(out, tolerance);
        return out;
}
 
void lwgeom_swap_ordinates(LWGEOM *in, LWORD o1, LWORD o2)
{
        LWCOLLECTION *col;
        LWPOLY *poly;
        uint32_t i;
 
        if ( (!in) || lwgeom_is_empty(in) ) return;
 
  /* TODO: check for lwgeom NOT having the specified dimension ? */
 
        LWDEBUGF(4, "lwgeom_flip_coordinates, got type: %s",
                 lwtype_name(in->type));
 
        switch (in->type)
        {
        case POINTTYPE:
                ptarray_swap_ordinates(lwgeom_as_lwpoint(in)->point, o1, o2);
                break;
 
        case LINETYPE:
                ptarray_swap_ordinates(lwgeom_as_lwline(in)->points, o1, o2);
                break;
 
        case CIRCSTRINGTYPE:
                ptarray_swap_ordinates(lwgeom_as_lwcircstring(in)->points, o1, o2);
                break;
 
        case POLYGONTYPE:
                poly = (LWPOLY *) in;
                for (i=0; i<poly->nrings; i++)
                {
                        ptarray_swap_ordinates(poly->rings[i], o1, o2);
                }
                break;
 
        case TRIANGLETYPE:
                ptarray_swap_ordinates(lwgeom_as_lwtriangle(in)->points, o1, o2);
                break;
 
        case MULTIPOINTTYPE:
        case MULTILINETYPE:
        case MULTIPOLYGONTYPE:
        case COLLECTIONTYPE:
        case COMPOUNDTYPE:
        case CURVEPOLYTYPE:
        case MULTISURFACETYPE:
        case MULTICURVETYPE:
        case POLYHEDRALSURFACETYPE:
        case TINTYPE:
                col = (LWCOLLECTION *) in;
                for (i=0; i<col->ngeoms; i++)
                {
                        lwgeom_swap_ordinates(col->geoms[i], o1, o2);
                }
                break;
 
        default:
                lwerror("lwgeom_swap_ordinates: unsupported geometry type: %s",
                        lwtype_name(in->type));
                return;
        }
 
        /* only refresh bbox if X or Y changed */
        if ( in->bbox && (o1 < 2 || o2 < 2) )
        {
                lwgeom_refresh_bbox(in);
        }
}
 
void lwgeom_set_srid(LWGEOM *geom, int32_t srid)
{
        uint32_t i;
 
        LWDEBUGF(4,"entered with srid=%d",srid);
 
        geom->srid = srid;
 
        if ( lwgeom_is_collection(geom) )
        {
                /* All the children are set to the same SRID value */
                LWCOLLECTION *col = lwgeom_as_lwcollection(geom);
                for ( i = 0; i < col->ngeoms; i++ )
                {
                        lwgeom_set_srid(col->geoms[i], srid);
                }
        }
}
 
 
/**************************************************************/
 
 
int
lwgeom_remove_repeated_points_in_place(LWGEOM *geom, double tolerance)
{
        int geometry_modified = LW_FALSE;
        switch (geom->type)
        {
                /* No-op! Cannot remote points */
                case POINTTYPE:
                case TRIANGLETYPE:
                        return geometry_modified;
                case LINETYPE:
                {
                        LWLINE *g = (LWLINE*)(geom);
                        POINTARRAY *pa = g->points;
                        uint32_t npoints = pa->npoints;
                        ptarray_remove_repeated_points_in_place(pa, tolerance, 2);
                        geometry_modified = npoints != pa->npoints;
                        /* Invalid output */
                        if (pa->npoints == 1 && pa->maxpoints > 1)
                        {
                                /* Use first point as last point */
                                pa->npoints = 2;
                                ptarray_copy_point(pa, 0, 1);
                        }
                        break;
                }
                case POLYGONTYPE:
                {
                        uint32_t i, j = 0;
                        LWPOLY *g = (LWPOLY*)(geom);
                        for (i = 0; i < g->nrings; i++)
                        {
                                POINTARRAY *pa = g->rings[i];
                                int minpoints = 4;
                                uint32_t npoints = 0;
                                /* Skip zero'ed out rings */
                                if(!pa)
                                        continue;
                                npoints = pa->npoints;
                                ptarray_remove_repeated_points_in_place(pa, tolerance, minpoints);
                                geometry_modified |= npoints != pa->npoints;
                                /* Drop collapsed rings */
                                if(pa->npoints < 4)
                                {
                                        geometry_modified = LW_TRUE;
                                        ptarray_free(pa);
                                        continue;
                                }
                                g->rings[j++] = pa;
                        }
                        /* Update ring count */
                        g->nrings = j;
                        break;
                }
                case MULTIPOINTTYPE:
                {
                        static uint32_t out_stack_size = 32;
                        double tolsq = tolerance*tolerance;
                        uint32_t i, j, n = 0;
                        LWMPOINT *mpt = (LWMPOINT *)(geom);
                        LWPOINT **out;
                        LWPOINT *out_stack[out_stack_size];
                        int use_heap = (mpt->ngeoms > out_stack_size);
 
                        /* No-op on empty */
                        if (mpt->ngeoms < 2)
                                return geometry_modified;
 
                        /* We cannot write directly back to the multipoint */
                        /* geoms array because we're reading out of it still */
                        /* so we use a side array */
                        if (use_heap)
                                out = lwalloc(sizeof(LWMPOINT *) * mpt->ngeoms);
                        else
                                out = out_stack;
 
                        /* Inefficient O(n^2) implementation */
                        for (i = 0; i < mpt->ngeoms; i++)
                        {
                                int seen = 0;
                                LWPOINT *p1 = mpt->geoms[i];
                                const POINT2D *pt1 = getPoint2d_cp(p1->point, 0);
                                for (j = 0; j < n; j++)
                                {
                                        LWPOINT *p2 = out[j];
                                        const POINT2D *pt2 = getPoint2d_cp(p2->point, 0);
                                        if (distance2d_sqr_pt_pt(pt1, pt2) <= tolsq)
                                        {
                                                seen = 1;
                                                break;
                                        }
                                }
                                if (seen)
                                {
                                        lwpoint_free(p1);
                                        continue;
                                }
                                out[n++] = p1;
                        }
 
                        /* Copy remaining points back into the input */
                        /* array */
                        memcpy(mpt->geoms, out, sizeof(LWPOINT *) * n);
                        geometry_modified = mpt->ngeoms != n;
                        mpt->ngeoms = n;
                        if (use_heap) lwfree(out);
                        break;
                }
 
                case CIRCSTRINGTYPE:
                        /* Dunno how to handle these, will return untouched */
                        return geometry_modified;
 
                /* Can process most multi* types as generic collection */
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case TINTYPE:
                case COLLECTIONTYPE:
                /* Curve types we mostly ignore, but allow the linear */
                /* portions to be processed by recursing into them */
                case MULTICURVETYPE:
                case CURVEPOLYTYPE:
                case MULTISURFACETYPE:
                case COMPOUNDTYPE:
                {
                        uint32_t i, j = 0;
                        LWCOLLECTION *col = (LWCOLLECTION*)(geom);
                        for (i = 0; i < col->ngeoms; i++)
                        {
                                LWGEOM *g = col->geoms[i];
                                if (!g) continue;
                                geometry_modified |= lwgeom_remove_repeated_points_in_place(g, tolerance);
                                /* Drop zero'ed out geometries */
                                if(lwgeom_is_empty(g))
                                {
                                        lwgeom_free(g);
                                        continue;
                                }
                                col->geoms[j++] = g;
                        }
                        /* Update geometry count */
                        col->ngeoms = j;
                        break;
                }
                default:
                {
                        lwerror("%s: unsupported geometry type: %s", __func__, lwtype_name(geom->type));
                        break;
                }
        }
 
        if (geometry_modified)
        {
                lwgeom_drop_bbox(geom);
        }
        return geometry_modified;
}
 
 
/**************************************************************/
 
int
lwgeom_simplify_in_place(LWGEOM *geom, double epsilon, int preserve_collapsed)
{
        int modified = LW_FALSE;
        switch (geom->type)
        {
                /* No-op! Cannot simplify points or triangles */
                case POINTTYPE:
                        return modified;
                case TRIANGLETYPE:
                {
                        if (preserve_collapsed)
                                return modified;
                        LWTRIANGLE *t = lwgeom_as_lwtriangle(geom);
                        POINTARRAY *pa = t->points;
                        ptarray_simplify_in_place(pa, epsilon, 0);
                        if (pa->npoints < 3)
                        {
                                pa->npoints = 0;
                                modified = LW_TRUE;
                        }
                        break;
                }
                case LINETYPE:
                {
                        LWLINE *g = (LWLINE*)(geom);
                        POINTARRAY *pa = g->points;
                        uint32_t in_npoints = pa->npoints;
                        ptarray_simplify_in_place(pa, epsilon, 2);
                        modified = in_npoints != pa->npoints;
                        /* Invalid output */
                        if (pa->npoints == 1 && pa->maxpoints > 1)
                        {
                                /* Use first point as last point */
                                if (preserve_collapsed)
                                {
                                        pa->npoints = 2;
                                        ptarray_copy_point(pa, 0, 1);
                                }
                                /* Finish the collapse process */
                                else
                                {
                                        pa->npoints = 0;
                                }
                        }
                        /* Duped output, force collapse */
                        if (pa->npoints == 2 && !preserve_collapsed)
                        {
                                if (p2d_same(getPoint2d_cp(pa, 0), getPoint2d_cp(pa, 1)))
                                        pa->npoints = 0;
                        }
                        break;
                }
                case POLYGONTYPE:
                {
                        uint32_t i, j = 0;
                        LWPOLY *g = (LWPOLY*)(geom);
                        for (i = 0; i < g->nrings; i++)
                        {
                                POINTARRAY *pa = g->rings[i];
                                /* Only stop collapse on first ring */
                                int minpoints = (preserve_collapsed && i == 0) ? 4 : 0;
                                /* Skip zero'ed out rings */
                                if(!pa)
                                        continue;
                                uint32_t in_npoints = pa->npoints;
                                ptarray_simplify_in_place(pa, epsilon, minpoints);
                                modified |= in_npoints != pa->npoints;
                                /* Drop collapsed rings */
                                if(pa->npoints < 4)
                                {
                                        if (i == 0)
                                        {
                                                /* If the outter ring is dropped, all can be dropped */
                                                for (i = 0; i < g->nrings; i++)
                                                {
                                                        pa = g->rings[i];
                                                        ptarray_free(pa);
                                                }
                                                break;
                                        }
                                        else
                                        {
                                                /* Drop this inner ring only */
                                                ptarray_free(pa);
                                                continue;
                                        }
                                }
                                g->rings[j++] = pa;
                        }
                        /* Update ring count */
                        g->nrings = j;
                        break;
                }
                /* Can process all multi* types as generic collection */
                case MULTIPOINTTYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case TINTYPE:
                case COLLECTIONTYPE:
                {
                        uint32_t i, j = 0;
                        LWCOLLECTION *col = (LWCOLLECTION*)geom;
                        for (i = 0; i < col->ngeoms; i++)
                        {
                                LWGEOM *g = col->geoms[i];
                                if (!g) continue;
                                modified |= lwgeom_simplify_in_place(g, epsilon, preserve_collapsed);
                                /* Drop zero'ed out geometries */
                                if(lwgeom_is_empty(g))
                                {
                                        lwgeom_free(g);
                                        continue;
                                }
                                col->geoms[j++] = g;
                        }
                        /* Update geometry count */
                        col->ngeoms = j;
                        break;
                }
                default:
                {
                        lwerror("%s: unsupported geometry type: %s", __func__, lwtype_name(geom->type));
                        break;
                }
        }
 
        if (modified)
        {
                lwgeom_drop_bbox(geom);
        }
        return modified;
}
 
LWGEOM* lwgeom_simplify(const LWGEOM *igeom, double dist, int preserve_collapsed)
{
        LWGEOM *lwgeom_out = lwgeom_clone_deep(igeom);
        lwgeom_simplify_in_place(lwgeom_out, dist, preserve_collapsed);
        if (lwgeom_is_empty(lwgeom_out))
        {
                lwgeom_free(lwgeom_out);
                return NULL;
        }
        return lwgeom_out;
}
 
/**************************************************************/
 
 
double lwgeom_area(const LWGEOM *geom)
{
        int type = geom->type;
 
        if ( type == POLYGONTYPE )
                return lwpoly_area((LWPOLY*)geom);
        else if ( type == CURVEPOLYTYPE )
                return lwcurvepoly_area((LWCURVEPOLY*)geom);
        else if (type ==  TRIANGLETYPE )
                return lwtriangle_area((LWTRIANGLE*)geom);
        else if ( lwgeom_is_collection(geom) )
        {
                double area = 0.0;
                uint32_t i;
                LWCOLLECTION *col = (LWCOLLECTION*)geom;
                for ( i = 0; i < col->ngeoms; i++ )
                        area += lwgeom_area(col->geoms[i]);
                return area;
        }
        else
                return 0.0;
}
 
double lwgeom_perimeter(const LWGEOM *geom)
{
        int type = geom->type;
        if ( type == POLYGONTYPE )
                return lwpoly_perimeter((LWPOLY*)geom);
        else if ( type == CURVEPOLYTYPE )
                return lwcurvepoly_perimeter((LWCURVEPOLY*)geom);
        else if ( type == TRIANGLETYPE )
                return lwtriangle_perimeter((LWTRIANGLE*)geom);
        else if ( lwgeom_is_collection(geom) )
        {
                double perimeter = 0.0;
                uint32_t i;
                LWCOLLECTION *col = (LWCOLLECTION*)geom;
                for ( i = 0; i < col->ngeoms; i++ )
                        perimeter += lwgeom_perimeter(col->geoms[i]);
                return perimeter;
        }
        else
                return 0.0;
}
 
double lwgeom_perimeter_2d(const LWGEOM *geom)
{
        int type = geom->type;
        if ( type == POLYGONTYPE )
                return lwpoly_perimeter_2d((LWPOLY*)geom);
        else if ( type == CURVEPOLYTYPE )
                return lwcurvepoly_perimeter_2d((LWCURVEPOLY*)geom);
        else if ( type == TRIANGLETYPE )
                return lwtriangle_perimeter_2d((LWTRIANGLE*)geom);
        else if ( lwgeom_is_collection(geom) )
        {
                double perimeter = 0.0;
                uint32_t i;
                LWCOLLECTION *col = (LWCOLLECTION*)geom;
                for ( i = 0; i < col->ngeoms; i++ )
                        perimeter += lwgeom_perimeter_2d(col->geoms[i]);
                return perimeter;
        }
        else
                return 0.0;
}
 
double lwgeom_length(const LWGEOM *geom)
{
        int type = geom->type;
        if ( type == LINETYPE )
                return lwline_length((LWLINE*)geom);
        else if ( type == CIRCSTRINGTYPE )
                return lwcircstring_length((LWCIRCSTRING*)geom);
        else if ( type == COMPOUNDTYPE )
                return lwcompound_length((LWCOMPOUND*)geom);
        else if ( lwgeom_is_collection(geom) )
        {
                double length = 0.0;
                uint32_t i;
                LWCOLLECTION *col = (LWCOLLECTION*)geom;
                for ( i = 0; i < col->ngeoms; i++ )
                        length += lwgeom_length(col->geoms[i]);
                return length;
        }
        else
                return 0.0;
}
 
double lwgeom_length_2d(const LWGEOM *geom)
{
        int type = geom->type;
        if ( type == LINETYPE )
                return lwline_length_2d((LWLINE*)geom);
        else if ( type == CIRCSTRINGTYPE )
                return lwcircstring_length_2d((LWCIRCSTRING*)geom);
        else if ( type == COMPOUNDTYPE )
                return lwcompound_length_2d((LWCOMPOUND*)geom);
        else if ( lwgeom_is_collection(geom) )
        {
                double length = 0.0;
                uint32_t i;
                LWCOLLECTION *col = (LWCOLLECTION*)geom;
                for ( i = 0; i < col->ngeoms; i++ )
                        length += lwgeom_length_2d(col->geoms[i]);
                return length;
        }
        else
                return 0.0;
}
 
void
lwgeom_affine(LWGEOM *geom, const AFFINE *affine)
{
        int type = geom->type;
        uint32_t i;
 
        switch(type)
        {
                /* Take advantage of fact tht pt/ln/circ/tri have same memory structure */
                case POINTTYPE:
                case LINETYPE:
                case CIRCSTRINGTYPE:
                case TRIANGLETYPE:
                {
                        LWLINE *l = (LWLINE*)geom;
                        ptarray_affine(l->points, affine);
                        break;
                }
                case POLYGONTYPE:
                {
                        LWPOLY *p = (LWPOLY*)geom;
                        for( i = 0; i < p->nrings; i++ )
                                ptarray_affine(p->rings[i], affine);
                        break;
                }
                case CURVEPOLYTYPE:
                {
                        LWCURVEPOLY *c = (LWCURVEPOLY*)geom;
                        for( i = 0; i < c->nrings; i++ )
                                lwgeom_affine(c->rings[i], affine);
                        break;
                }
                default:
                {
                        if( lwgeom_is_collection(geom) )
                        {
                                LWCOLLECTION *c = (LWCOLLECTION*)geom;
                                for( i = 0; i < c->ngeoms; i++ )
                                {
                                        lwgeom_affine(c->geoms[i], affine);
                                }
                        }
                        else
                        {
                                lwerror("lwgeom_affine: unable to handle type '%s'", lwtype_name(type));
                        }
                }
        }
 
        /* Recompute bbox if needed */
        if (geom->bbox)
                lwgeom_refresh_bbox(geom);
}
 
void
lwgeom_scale(LWGEOM *geom, const POINT4D *factor)
{
        int type = geom->type;
        uint32_t i;
 
        switch(type)
        {
                /* Take advantage of fact tht pt/ln/circ/tri have same memory structure */
                case POINTTYPE:
                case LINETYPE:
                case CIRCSTRINGTYPE:
                case TRIANGLETYPE:
                {
                        LWLINE *l = (LWLINE*)geom;
                        ptarray_scale(l->points, factor);
                        break;
                }
                case POLYGONTYPE:
                {
                        LWPOLY *p = (LWPOLY*)geom;
                        for( i = 0; i < p->nrings; i++ )
                                ptarray_scale(p->rings[i], factor);
                        break;
                }
                case CURVEPOLYTYPE:
                {
                        LWCURVEPOLY *c = (LWCURVEPOLY*)geom;
                        for( i = 0; i < c->nrings; i++ )
                                lwgeom_scale(c->rings[i], factor);
                        break;
                }
                default:
                {
                        if( lwgeom_is_collection(geom) )
                        {
                                LWCOLLECTION *c = (LWCOLLECTION*)geom;
                                for( i = 0; i < c->ngeoms; i++ )
                                {
                                        lwgeom_scale(c->geoms[i], factor);
                                }
                        }
                        else
                        {
                                lwerror("lwgeom_scale: unable to handle type '%s'", lwtype_name(type));
                        }
                }
        }
 
        /* Recompute bbox if needed */
        if (geom->bbox)
                lwgeom_refresh_bbox(geom);
}
 
LWGEOM *
lwgeom_construct_empty(uint8_t type, int32_t srid, char hasz, char hasm)
{
        switch(type)
        {
                case POINTTYPE:
                        return lwpoint_as_lwgeom(lwpoint_construct_empty(srid, hasz, hasm));
                case LINETYPE:
                        return lwline_as_lwgeom(lwline_construct_empty(srid, hasz, hasm));
                case POLYGONTYPE:
                        return lwpoly_as_lwgeom(lwpoly_construct_empty(srid, hasz, hasm));
                case CURVEPOLYTYPE:
                        return lwcurvepoly_as_lwgeom(lwcurvepoly_construct_empty(srid, hasz, hasm));
                case CIRCSTRINGTYPE:
                        return lwcircstring_as_lwgeom(lwcircstring_construct_empty(srid, hasz, hasm));
                case TRIANGLETYPE:
                        return lwtriangle_as_lwgeom(lwtriangle_construct_empty(srid, hasz, hasm));
                case COMPOUNDTYPE:
                case MULTIPOINTTYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case COLLECTIONTYPE:
                        return lwcollection_as_lwgeom(lwcollection_construct_empty(type, srid, hasz, hasm));
                default:
                        lwerror("lwgeom_construct_empty: unsupported geometry type: %s",
                                lwtype_name(type));
                        return NULL;
        }
}
 
int
lwgeom_startpoint(const LWGEOM *lwgeom, POINT4D *pt)
{
        if ( ! lwgeom )
                return LW_FAILURE;
 
        switch( lwgeom->type )
        {
                case POINTTYPE:
                        return ptarray_startpoint(((LWPOINT*)lwgeom)->point, pt);
                case TRIANGLETYPE:
                case CIRCSTRINGTYPE:
                case LINETYPE:
                        return ptarray_startpoint(((LWLINE*)lwgeom)->points, pt);
                case POLYGONTYPE:
                        return lwpoly_startpoint((LWPOLY*)lwgeom, pt);
                case TINTYPE:
                case CURVEPOLYTYPE:
                case COMPOUNDTYPE:
                case MULTIPOINTTYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case COLLECTIONTYPE:
                case POLYHEDRALSURFACETYPE:
                        return lwcollection_startpoint((LWCOLLECTION*)lwgeom, pt);
                default:
                        lwerror("lwgeom_startpoint: unsupported geometry type: %s", lwtype_name(lwgeom->type));
                        return LW_FAILURE;
        }
}
 
void
lwgeom_grid_in_place(LWGEOM *geom, const gridspec *grid)
{
        if (!geom) return;
        if (lwgeom_is_empty(geom)) return;
        switch ( geom->type )
        {
                case POINTTYPE:
                {
                        LWPOINT *pt = (LWPOINT*)(geom);
                        ptarray_grid_in_place(pt->point, grid);
                        return;
                }
                case CIRCSTRINGTYPE:
                case TRIANGLETYPE:
                case LINETYPE:
                {
                        LWLINE *ln = (LWLINE*)(geom);
                        ptarray_grid_in_place(ln->points, grid);
                        /* For invalid line, return an EMPTY */
                        if (ln->points->npoints < 2)
                                ln->points->npoints = 0;
                        return;
                }
                case POLYGONTYPE:
                {
                        LWPOLY *ply = (LWPOLY*)(geom);
                        if (!ply->rings) return;
 
                        /* Check first the external ring */
                        uint32_t i = 0;
                        POINTARRAY *pa = ply->rings[0];
                        ptarray_grid_in_place(pa, grid);
                        if (pa->npoints < 4)
                        {
                                /* External ring collapsed: free everything */
                                for (i = 0; i < ply->nrings; i++)
                                {
                                        ptarray_free(ply->rings[i]);
                                }
                                ply->nrings = 0;
                                return;
                        }
 
                        /* Check the other rings */
                        uint32_t j = 1;
                        for (i = 1; i < ply->nrings; i++)
                        {
                                POINTARRAY *pa = ply->rings[i];
                                ptarray_grid_in_place(pa, grid);
 
                                /* Skip bad rings */
                                if (pa->npoints >= 4)
                                {
                                        ply->rings[j++] = pa;
                                }
                                else
                                {
                                        ptarray_free(pa);
                                }
                        }
                        /* Adjust ring count appropriately */
                        ply->nrings = j;
                        return;
                }
                case MULTIPOINTTYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case TINTYPE:
                case COLLECTIONTYPE:
                case COMPOUNDTYPE:
                {
                        LWCOLLECTION *col = (LWCOLLECTION*)(geom);
                        uint32_t i, j = 0;
                        if (!col->geoms) return;
                        for (i = 0; i < col->ngeoms; i++)
                        {
                                LWGEOM *g = col->geoms[i];
                                lwgeom_grid_in_place(g, grid);
                                /* Empty geoms need to be freed */
                                /* before we move on */
                                if (lwgeom_is_empty(g))
                                {
                                        lwgeom_free(g);
                                        continue;
                                }
                                col->geoms[j++] = g;
                        }
                        col->ngeoms = j;
                        return;
                }
                default:
                {
                        lwerror("%s: Unsupported geometry type: %s", __func__,
                                lwtype_name(geom->type));
                        return;
                }
        }
}
 
 
LWGEOM *
lwgeom_grid(const LWGEOM *lwgeom, const gridspec *grid)
{
        LWGEOM *lwgeom_out = lwgeom_clone_deep(lwgeom);
        lwgeom_grid_in_place(lwgeom_out, grid);
        return lwgeom_out;
}
 
 
/* Prototype for recursion */
static void lwgeom_subdivide_recursive(const LWGEOM *geom,
                                       uint8_t dimension,
                                       uint32_t maxvertices,
                                       uint32_t depth,
                                       LWCOLLECTION *col);
 
static void
lwgeom_subdivide_recursive(const LWGEOM *geom,
                           uint8_t dimension,
                           uint32_t maxvertices,
                           uint32_t depth,
                           LWCOLLECTION *col)
{
        const uint32_t maxdepth = 50;
 
        if (!geom)
                return;
 
        const GBOX *box_in = lwgeom_get_bbox(geom);
        if (!box_in)
                return;
 
        GBOX clip;
        gbox_duplicate(box_in, &clip);
        double width = clip.xmax - clip.xmin;
        double height = clip.ymax - clip.ymin;
 
        if ( geom->type == POLYHEDRALSURFACETYPE || geom->type == TINTYPE )
                lwerror("%s: unsupported geometry type '%s'", __func__, lwtype_name(geom->type));
 
        if ( width == 0.0 && height == 0.0 )
        {
                if ( geom->type == POINTTYPE && dimension == 0)
                        lwcollection_add_lwgeom(col, lwgeom_clone_deep(geom));
                return;
        }
 
        if (width == 0.0)
        {
                clip.xmax += FP_TOLERANCE;
                clip.xmin -= FP_TOLERANCE;
                width = 2 * FP_TOLERANCE;
        }
        if (height == 0.0)
        {
                clip.ymax += FP_TOLERANCE;
                clip.ymin -= FP_TOLERANCE;
                height = 2 * FP_TOLERANCE;
        }
 
        /* Always just recurse into collections */
        if ( lwgeom_is_collection(geom) && geom->type != MULTIPOINTTYPE )
        {
                LWCOLLECTION *incol = (LWCOLLECTION*)geom;
                /* Don't increment depth yet, since we aren't actually
                 * subdividing geometries yet */
                for (uint32_t i = 0; i < incol->ngeoms; i++ )
                        lwgeom_subdivide_recursive(incol->geoms[i], dimension, maxvertices, depth, col);
                return;
        }
 
        if (lwgeom_dimension(geom) < dimension)
        {
                /* We've hit a lower dimension object produced by clipping at
                 * a shallower recursion level. Ignore it. */
                return;
        }
 
        /* But don't go too far. 2^50 ~= 10^15, that's enough subdivision */
        /* Just add what's left */
        if ( depth > maxdepth )
        {
                lwcollection_add_lwgeom(col, lwgeom_clone_deep(geom));
                return;
        }
 
        uint32_t nvertices = lwgeom_count_vertices(geom);
 
        /* Skip empties entirely */
        if (nvertices == 0)
                return;
 
        /* If it is under the vertex tolerance, just add it, we're done */
        if (nvertices <= maxvertices)
        {
                lwcollection_add_lwgeom(col, lwgeom_clone_deep(geom));
                return;
        }
 
        uint8_t split_ordinate = (width > height) ? 0 : 1;
        double center = (split_ordinate == 0) ? (clip.xmin + clip.xmax) / 2 : (clip.ymin + clip.ymax) / 2;
        double pivot = DBL_MAX;
        if (geom->type == POLYGONTYPE)
        {
                uint32_t ring_to_trim = 0;
                double ring_area = 0;
                double pivot_eps = DBL_MAX;
                double pt_eps = DBL_MAX;
                POINTARRAY *pa;
                LWPOLY *lwpoly = (LWPOLY *)geom;
 
                /* if there are more points in holes than in outer ring */
                if (nvertices >= 2 * lwpoly->rings[0]->npoints)
                {
                        /* trim holes starting from biggest */
                        for (uint32_t i = 1; i < lwpoly->nrings; i++)
                        {
                                double current_ring_area = fabs(ptarray_signed_area(lwpoly->rings[i]));
                                if (current_ring_area >= ring_area)
                                {
                                        ring_area = current_ring_area;
                                        ring_to_trim = i;
                                }
                        }
                }
 
                pa = lwpoly->rings[ring_to_trim];
 
                /* find most central point in chosen ring */
                for (uint32_t i = 0; i < pa->npoints; i++)
                {
                        double pt;
                        if (split_ordinate == 0)
                                pt = getPoint2d_cp(pa, i)->x;
                        else
                                pt = getPoint2d_cp(pa, i)->y;
                        pt_eps = fabs(pt - center);
                        if (pivot_eps > pt_eps)
                        {
                                pivot = pt;
                                pivot_eps = pt_eps;
                        }
                }
        }
        GBOX subbox1, subbox2;
        gbox_duplicate(&clip, &subbox1);
        gbox_duplicate(&clip, &subbox2);
 
        if (pivot == DBL_MAX)
                pivot = center;
 
        if (split_ordinate == 0)
        {
                if (FP_NEQUALS(subbox1.xmax, pivot) && FP_NEQUALS(subbox1.xmin, pivot))
                        subbox1.xmax = subbox2.xmin = pivot;
                else
                        subbox1.xmax = subbox2.xmin = center;
        }
        else
        {
                if (FP_NEQUALS(subbox1.ymax, pivot) && FP_NEQUALS(subbox1.ymin, pivot))
                        subbox1.ymax = subbox2.ymin = pivot;
                else
                        subbox1.ymax = subbox2.ymin = center;
        }
 
        ++depth;
 
        {
                LWGEOM *subbox = (LWGEOM *)lwpoly_construct_envelope(
                    geom->srid, subbox1.xmin, subbox1.ymin, subbox1.xmax, subbox1.ymax);
                LWGEOM *clipped = lwgeom_intersection(geom, subbox);
                lwgeom_simplify_in_place(clipped, 0.0, LW_TRUE);
                lwgeom_free(subbox);
                if (clipped && !lwgeom_is_empty(clipped))
                {
                        lwgeom_subdivide_recursive(clipped, dimension, maxvertices, depth, col);
                        lwgeom_free(clipped);
                }
        }
        {
                LWGEOM *subbox = (LWGEOM *)lwpoly_construct_envelope(
                    geom->srid, subbox2.xmin, subbox2.ymin, subbox2.xmax, subbox2.ymax);
                LWGEOM *clipped = lwgeom_intersection(geom, subbox);
                lwgeom_simplify_in_place(clipped, 0.0, LW_TRUE);
                lwgeom_free(subbox);
                if (clipped && !lwgeom_is_empty(clipped))
                {
                        lwgeom_subdivide_recursive(clipped, dimension, maxvertices, depth, col);
                        lwgeom_free(clipped);
                }
        }
}
 
LWCOLLECTION *
lwgeom_subdivide(const LWGEOM *geom, uint32_t maxvertices)
{
        static uint32_t startdepth = 0;
        static uint32_t minmaxvertices = 5;
        LWCOLLECTION *col;
 
        col = lwcollection_construct_empty(COLLECTIONTYPE, geom->srid, lwgeom_has_z(geom), lwgeom_has_m(geom));
 
        if ( lwgeom_is_empty(geom) )
                return col;
 
        if ( maxvertices < minmaxvertices )
        {
                lwcollection_free(col);
                lwerror("%s: cannot subdivide to fewer than %d vertices per output", __func__, minmaxvertices);
        }
 
        lwgeom_subdivide_recursive(geom, lwgeom_dimension(geom), maxvertices, startdepth, col);
        lwgeom_set_srid((LWGEOM*)col, geom->srid);
        return col;
}
 
int
lwgeom_is_trajectory(const LWGEOM *geom)
{
        int type = geom->type;
 
        if( type != LINETYPE )
        {
                lwnotice("Geometry is not a LINESTRING");
                return LW_FALSE;
        }
        return lwline_is_trajectory((LWLINE*)geom);
}
 
static uint8_t
bits_for_precision(int32_t significant_digits)
{
        int32_t bits_needed = ceil(significant_digits / log10(2));
 
        if (bits_needed > 52)
        {
                return 52;
        }
        else if (bits_needed < 1)
        {
                return 1;
        }
 
        return bits_needed;
}
 
static double trim_preserve_decimal_digits(double d, int32_t decimal_digits)
{
        if (d == 0)
                return 0;
 
        int digits_left_of_decimal = (int) (1 + log10(fabs(d)));
        uint8_t bits_needed = bits_for_precision(decimal_digits + digits_left_of_decimal);
        uint64_t mask = 0xffffffffffffffffULL << (52 - bits_needed);
        uint64_t dint = 0;
        size_t dsz = sizeof(d) < sizeof(dint) ? sizeof(d) : sizeof(dint);
 
        memcpy(&dint, &d, dsz);
        dint &= mask;
        memcpy(&d, &dint, dsz);
        return d;
}
 
void lwgeom_trim_bits_in_place(LWGEOM* geom, int32_t prec_x, int32_t prec_y, int32_t prec_z, int32_t prec_m)
{
        LWPOINTITERATOR* it = lwpointiterator_create_rw(geom);
        POINT4D p;
 
        while (lwpointiterator_has_next(it))
        {
                lwpointiterator_peek(it, &p);
                p.x = trim_preserve_decimal_digits(p.x, prec_x);
                p.y = trim_preserve_decimal_digits(p.y, prec_y);
                if (lwgeom_has_z(geom))
                        p.z = trim_preserve_decimal_digits(p.z, prec_z);
                if (lwgeom_has_m(geom))
                        p.m = trim_preserve_decimal_digits(p.m, prec_m);
                lwpointiterator_modify_next(it, &p);
        }
 
        lwpointiterator_destroy(it);
}
 
int
lwgeom_isfinite(const LWGEOM *lwgeom)
{
        LWPOINTITERATOR* it = lwpointiterator_create(lwgeom);
        int hasz = lwgeom_has_z(lwgeom);
        int hasm = lwgeom_has_m(lwgeom);
 
        while (lwpointiterator_has_next(it))
        {
                POINT4D p;
                lwpointiterator_next(it, &p);
                int finite = isfinite(p.x) &&
                        isfinite(p.y) &&
                        (hasz ? isfinite(p.z) : 1) &&
                        (hasm ? isfinite(p.m) : 1);
 
                if (!finite)
                {
                        lwpointiterator_destroy(it);
                        return LW_FALSE;
                }
        }
        lwpointiterator_destroy(it);
        return LW_TRUE;
}