/// <summary>
/// Checks first coordinate in Geography to see if it contains a valid altitude
/// </summary>
/// <returns>A boolean indicating if the Shape has a valid altitude</returns>
public bool Is3D()
{
if (this is Point)
{
return((this as Point).Coordinate.Altitude.HasValue);
}
else if (this is LineString)
{
LineString l = (this as LineString);
if (l.Vertices.Count > 0)
{
return(l.Vertices[0].Altitude.HasValue);
}
return(false);
}
else if (this is Polygon)
{
Polygon p = (this as Polygon);
if (p.ExteriorRing.Count > 0)
{
return(p.ExteriorRing[0].Altitude.HasValue);
}
return(false);
}
else if (this is MultiPoint)
{
MultiPoint mp = (this as MultiPoint);
if (mp.Geometries.Count > 0)
{
return(mp.Geometries[0].Coordinate.Altitude.HasValue);
}
return(false);
}
else if (this is MultiLineString)
{
MultiLineString ml = (this as MultiLineString);
if (ml.Geometries.Count > 0 && ml.Geometries[0].Vertices.Count > 0)
{
return(ml.Geometries[0].Vertices[0].Altitude.HasValue);
}
return(false);
}
else if (this is MultiPolygon)
{
MultiPolygon mp = (this as MultiPolygon);
if (mp.Geometries.Count > 0 && mp.Geometries[0].ExteriorRing.Count > 0)
{
return(mp.Geometries[0].ExteriorRing[0].Altitude.HasValue);
}
return(false);
}
else if (this is GeometryCollection)
{
var gc = (this as GeometryCollection);
if (gc.Geometries.Count > 0)
{
return(gc.Geometries[0].Is3D());
}
return(false);
}
return(false);
}
/// <summary>
/// Returns an approximation of the given Geometry instance produced by
/// running polylines and polygons through the vertex reduction algorithm.
///
/// The following Geometries are not reduced:
/// - Point
/// - MultiPoint
/// - BoundingBox
/// </summary>
/// <param name="tolerance">
/// A tolerance is the closest distnace any two points can be
/// to each other. The tolerance must be a positive number.
/// </param>
public async Task Reduce(double tolerance)
{
if (this is LineString)
{
LineString l = this as LineString;
l.Vertices = await SpatialTools.VertexReductionAsync(l.Vertices, tolerance);
}
else if (this is Polygon)
{
Polygon p = this as Polygon;
//reduce the extrior ring
p.ExteriorRing = await SpatialTools.VertexReductionAsync(p.ExteriorRing, tolerance);
//Reduce the interior rings
for (int i = 0; i < p.InteriorRings.Count; i++)
{
p.InteriorRings[i] = await SpatialTools.VertexReductionAsync(p.InteriorRings[i], tolerance);
}
//Makes sure polygon is valid
await p.MakeValidAsync();
}
else if (this is MultiLineString)
{
MultiLineString ml = this as MultiLineString;
for (int i = 0; i < ml.Geometries.Count; i++)
{
ml.Geometries[i].Vertices = await SpatialTools.VertexReductionAsync(ml.Geometries[i].Vertices, tolerance);
}
}
else if (this is MultiPolygon)
{
MultiPolygon mp = this as MultiPolygon;
for (int i = 0; i < mp.Geometries.Count; i++)
{
//reduce the extrior ring
mp.Geometries[i].ExteriorRing = await SpatialTools.VertexReductionAsync(mp.Geometries[i].ExteriorRing, tolerance);
//Reduce the interior rings
for (int j = 0; j < mp.Geometries[i].InteriorRings.Count; j++)
{
mp.Geometries[i].InteriorRings[j] = await SpatialTools.VertexReductionAsync(mp.Geometries[i].InteriorRings[j], tolerance);
}
//Makes sure polygon is valid
await mp.Geometries[i].MakeValidAsync();
}
}
else if (this is GeometryCollection)
{
GeometryCollection gc = this as GeometryCollection;
foreach (Geometry g in gc)
{
await g.Reduce(tolerance);
}
}
}
