/// <summary>
		/// Writes a multipoint.
		/// </summary>
		/// <param name="mp">The multipoint to be written.</param>
		private void WriteMultiPoint(MultiPoint mp, byte format)
		{
			//Get the number of points in this multipoint.
			int numPoints = mp.GetNumPoints();

			//Write the number of points.
			_bWriter.Write(numPoints);

			//Loop on the number of points.
			for(int i = 0; i < numPoints; i++)
			{
				//write the multipoint header
				_bWriter.Write(format);
				_bWriter.Write(4);

				_bWriter.Write(numPoints);

				//Write each point.
				WritePoint((Point)mp[i]);
			}
		}