public Vector2 Parse( string s )
{
// the format is "Vector2(x, y)"
if ( !s.StartsWith( "Vector2(" ) )
throw new FormatException();
string[] values = s.Substring( 8 ).TrimEnd( '}' ).Split( ',' );
return new Vector2( Real.Parse( values[ 0 ], CultureInfo.InvariantCulture ),
Real.Parse( values[ 1 ], CultureInfo.InvariantCulture ) );
}