static void google_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest );
static gboolean google_coord_to_mapcoord ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest );
static void google_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest );
static gboolean google_coord_to_mapcoord ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest );