Esempio n. 1
0
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;
}
Esempio n. 2
0
/**
* 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);	
}
Esempio n. 3
0
/**
 * 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;
}
Esempio n. 4
0
/*
** 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);
}