/// <summary>
/// Encapsulates the actual unioning of two polygonal geometries.
/// </summary>
/// <param name="g0">A geometry to union</param>
/// <param name="g1">A geometry to union</param>
/// <param name="unionStrategy">A </param>
/// <returns>The union of the inputs</returns>
private static Geometry UnionActual(Geometry g0, Geometry g1, UnionStrategy unionStrategy)
{
var union = unionStrategy.Union(g0, g1);
var unionPoly = RestrictToPolygons(union);
return(unionPoly);
}
/// <summary>
/// Creates a new instance to union
/// the given collection of <see cref="Geometry"/>s.
/// </summary>
/// <param name="polys">A collection of <see cref="IPolygonal"/> <see cref="Geometry"/>s</param>
/// <param name="unionStrategy"></param>
public CascadedPolygonUnion(ICollection <Geometry> polys, UnionStrategy unionStrategy)
{
_inputPolys = polys;
_unionStrategy = unionStrategy;
// guard against null input
if (_inputPolys == null)
{
_inputPolys = new List <Geometry>();
}
_countInput = _inputPolys.Count;
_countRemainder = _countInput;
}
/// <summary>
/// Creates a new instance for unioning the given geometries.
/// </summary>
/// <param name="g0">A geometry to union</param>
/// <param name="g1">A geometry to union</param>
/// <param name="unionFun">Function to union two geometries</param>
public OverlapUnion(Geometry g0, Geometry g1, UnionStrategy unionFun)
{
if (g0 == null)
{
throw new ArgumentNullException(nameof(g0));
}
_g0 = g0;
_g1 = g1;
_geomFactory = g0.Factory;
_unionFun = unionFun;
}
/// <summary>
/// Computes the union of
/// a collection of <see cref="Geometry"/>s.
/// </summary>
/// <param name="polys">A collection of <see cref="IPolygonal"/> <see cref="Geometry"/>s.</param>
/// <param name="unionStrategy">A strategy to perform the unioning.</param>
/// <returns>The union of the <paramref name="polys"/></returns>
public static Geometry Union(ICollection <Geometry> polys, UnionStrategy unionStrategy)
{
var op = new CascadedPolygonUnion(polys, unionStrategy);
return(op.Union());
}
/// <summary>
/// Union a pair of geometries,
/// using the more performant overlap union algorithm if possible.
/// </summary>
/// <param name="g0">A geometry to union</param>
/// <param name="g1">A geometry to union</param>
/// <param name="unionFun">Function to union two geometries</param>
/// <returns>The union of the inputs</returns>
public static Geometry Union(Geometry g0, Geometry g1, UnionStrategy unionFun)
{
var union = new OverlapUnion(g0, g1, unionFun);
return(union.Union());
}