static int lwcollection_calculate_gbox_cartesian(LWCOLLECTION *coll, GBOX *gbox)
{
GBOX subbox;
int i;
int result = LW_FAILURE;
int first = LW_TRUE;
assert(coll);
if ( (coll->ngeoms == 0) || !gbox)
return LW_FAILURE;
subbox.flags = coll->flags;
for ( i = 0; i < coll->ngeoms; i++ )
{
if ( lwgeom_calculate_gbox_cartesian((LWGEOM*)(coll->geoms[i]), &subbox) == LW_SUCCESS )
{
/* Keep a copy of the sub-bounding box for later
if ( coll->geoms[i]->bbox )
lwfree(coll->geoms[i]->bbox);
coll->geoms[i]->bbox = gbox_copy(&subbox); */
if ( first )
{
gbox_duplicate(&subbox, gbox);
first = LW_FALSE;
}
else
{
gbox_merge(&subbox, gbox);
}
result = LW_SUCCESS;
}
}
return result;
}
/**
* Calculate the gbox for this goemetry, a cartesian box or
* geodetic box, depending on how it is flagged.
*/
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);
}
/**
* Takes a GEOMETRY and returns a GeoJson representation
*/
char *
lwgeom_to_geojson(const LWGEOM *geom, char *srs, int precision, int has_bbox)
{
int type = geom->type;
GBOX *bbox = NULL;
GBOX tmp;
if ( precision > OUT_MAX_DOUBLE_PRECISION ) precision = OUT_MAX_DOUBLE_PRECISION;
if (has_bbox)
{
/* Whether these are geography or geometry,
the GeoJSON expects a cartesian bounding box */
lwgeom_calculate_gbox_cartesian(geom, &tmp);
bbox = &tmp;
}
switch (type)
{
case POINTTYPE:
return asgeojson_point((LWPOINT*)geom, srs, bbox, precision);
case LINETYPE:
return asgeojson_line((LWLINE*)geom, srs, bbox, precision);
case POLYGONTYPE:
return asgeojson_poly((LWPOLY*)geom, srs, bbox, precision);
case MULTIPOINTTYPE:
return asgeojson_multipoint((LWMPOINT*)geom, srs, bbox, precision);
case MULTILINETYPE:
return asgeojson_multiline((LWMLINE*)geom, srs, bbox, precision);
case MULTIPOLYGONTYPE:
return asgeojson_multipolygon((LWMPOLY*)geom, srs, bbox, precision);
case COLLECTIONTYPE:
return asgeojson_collection((LWCOLLECTION*)geom, srs, bbox, precision);
default:
lwerror("lwgeom_to_geojson: '%s' geometry type not supported",
lwtype_name(type));
}
/* Never get here */
return NULL;
}
/*
** Return a geohash string for the geometry. <http://geohash.org>
** Where the precision is non-positive, calculate a precision based on the
** bounds of the feature. Big features have loose precision.
** Small features have tight precision.
*/
char *lwgeom_geohash(const LWGEOM *lwgeom, int precision)
{
GBOX gbox;
GBOX gbox_bounds;
double lat, lon;
int result;
gbox_init(&gbox);
gbox_init(&gbox_bounds);
result = lwgeom_calculate_gbox_cartesian(lwgeom, &gbox);
if ( result == LW_FAILURE ) return NULL;
/* Return error if we are being fed something outside our working bounds */
if ( gbox.xmin < -180 || gbox.ymin < -90 || gbox.xmax > 180 || gbox.ymax > 90 )
{
lwerror("Geohash requires inputs in decimal degrees.");
return NULL;
}
/* What is the center of our geometry bounds? We'll use that to
** approximate location. */
lon = gbox.xmin + (gbox.xmax - gbox.xmin) / 2;
lat = gbox.ymin + (gbox.ymax - gbox.ymin) / 2;
if ( precision <= 0 )
{
precision = lwgeom_geohash_precision(gbox, &gbox_bounds);
}
/*
** Return the geohash of the center, with a precision determined by the
** extent of the bounds.
** Possible change: return the point at the center of the precision bounds?
*/
return geohash_point(lon, lat, precision);
}