/// <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="polygon"/> to a corresponding instance of <seealso cref="IPolygon"/>.
/// </summary>
/// <param name="polygon">The polygon to be converted.</param>
/// <returns>An instance of <see cref="IPolygon"/>.</returns>
/// <exception cref="ArgumentNullException"><paramref name="polygon"/> is <c>null</c>.</exception>
public static IPolygon ToPolygon(WktPolygon polygon)
{
if (polygon == null)
{
throw new ArgumentNullException(nameof(polygon));
}
var outer = polygon.Outer.Select(ToPoint);
var inner = polygon.Inner.Select(x => x.Select(ToPoint)).ToArray();
return(new Polygon(outer, inner));
}
/// <summary>
/// Returns the area of the specified <paramref name="polygon"/> measured in sqaure metres.
/// </summary>
/// <param name="polygon">The polygon.</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="polygon"/> is <c>null</c>.</exception>
public static double GetArea(WktPolygon polygon)
{
if (polygon == null)
{
throw new ArgumentNullException(nameof(polygon));
}
// Get the overall area from the outer points
double area = MapsUtils.GetArea(polygon.Outer.Select(x => new Point(x.Y, x.X)));
// Substract the area of the inner points
foreach (WktPoint[] inner in polygon.Inner)
{
area -= MapsUtils.GetArea(inner.Select(x => new Point(x.Y, x.X)));
}
return(area);
}
/// <summary>
/// Returns the <strong>Well Known Text</strong> string representation of the specified <paramref name="polygon"/>.
/// </summary>
/// <param name="polygon">The polygon to be converted.</param>
/// <param name="formatting">The formatting to be used.</param>
/// <param name="indentation">The indendatation to be used.</param>
/// <returns>The polygon formatted as a <strong>Well Known Text</strong> string.</returns>
protected string ToString(WktPolygon polygon, WktFormatting formatting, int indentation)
{
if (formatting == WktFormatting.Indented)
{
throw new NotImplementedException("Indented formatting is currently not supported");
}
List <string> temp = new List <string>();
temp.Add(ToString(polygon.Outer, formatting, indentation));
foreach (WktPoint[] array in polygon.Inner)
{
temp.Add(ToString(array, formatting, indentation));
}
return("(" + string.Join(formatting == WktFormatting.Minified ? "," : ", ", temp) + ")");
}
