/// <summary>
/// Parses the specified <paramref name="input"/> string into an instance of <see cref="WktGeometry"/>.
/// </summary>
/// <param name="input">The input string to parse.</param>
/// <returns>An instance of <see cref="WktGeometry"/>.</returns>
/// <exception cref="ArgumentNullException"><paramref name="input"/> is <c>null</c>.</exception>
/// <exception cref="WktInvalidFormatException"><paramref name="input"/> is not in a known format.</exception>
/// <exception cref="WktUnsupportedTypeException">type of <paramref name="input"/> is not supported.</exception>
public static WktGeometry Parse(string input)
{
if (string.IsNullOrWhiteSpace(input))
{
throw new ArgumentNullException(nameof(input));
}
string type = input.Split('(')[0].ToUpper().Trim();
if (string.IsNullOrWhiteSpace(type))
{
throw new WktInvalidFormatException(input);
}
switch (type)
{
case "POINT": return(WktPoint.Parse(input));
case "POLYGON": return(WktPolygon.Parse(input));
case "LINESTRING": return(WktLineString.Parse(input));
case "MULTIPOINT": return(WktMultiPoint.Parse(input));
case "MULTILINESTRING": return(WktMultiLineString.Parse(input));
case "MULTIPOLYGON": return(WktMultiPolygon.Parse(input));
default: throw new WktUnsupportedTypeException(type);
}
}
/// <summary>
/// Converts the specified <paramref name="multiPolygon"/> to a corresponding instance of <seealso cref="IMultiPolygon"/>.
/// </summary>
/// <param name="multiPolygon">The multi polygon to be converted.</param>
/// <returns>An instance of <see cref="IMultiPolygon"/>.</returns>
/// <exception cref="ArgumentNullException"><paramref name="multiPolygon"/> is <c>null</c>.</exception>
public static IMultiPolygon ToMultiPolygon(WktMultiPolygon multiPolygon)
{
if (multiPolygon == null)
{
throw new ArgumentNullException(nameof(multiPolygon));
}
return(new MultiPolygon(multiPolygon.Select(ToPolygon)));
}
/// <summary>
/// Returns the area of the specified <paramref name="multiPolygon"/> shape measured in sqaure metres.
/// </summary>
/// <param name="multiPolygon">The collection of polygons.</param>
/// <returns>A <see cref="double"/> representing the area in square metres.</returns>
/// <remarks>For this method to work, it is assumed that coordinates are specified using the
/// <strong>WGS 84</strong> coordinate system (eg. used by the Global Positioning System).</remarks>
/// <see>
/// <cref>https://en.wikipedia.org/wiki/World_Geodetic_System#WGS84</cref>
/// </see>
/// <see>
/// <cref>https://en.wikipedia.org/wiki/Global_Positioning_System</cref>
/// </see>
/// <exception cref="ArgumentNullException"><paramref name="multiPolygon"/> is <c>null</c>.</exception>
public static double GetArea(WktMultiPolygon multiPolygon)
{
if (multiPolygon == null)
{
throw new ArgumentNullException(nameof(multiPolygon));
}
return(multiPolygon.Count == 0 ? 0 : multiPolygon.Sum(GetArea));
}
