/// <summary>
/// Creates a <see cref="Polygon" /> using the next token in the stream.
/// </summary>
/// <param name="tokenizer">
/// tokenizer over a stream of text in Well-known Text
/// format. The next tokens must form a MultiPolygon.
/// </param>
/// <returns>
/// a <code>MultiPolygon</code> specified by the next token in the
/// stream, or if if the coordinates used to create the <see cref="Polygon" />
/// shells and holes do not form closed linestrings.
/// </returns>
private static Polygon ReadMultiPolygonText(WktStreamTokenizer tokenizer)
{
var nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
throw new Exception("Empty MultiPolygon");
}
var polygon = ReadPolygonText(tokenizer);
var polygons = new PolygonBuilder(polygon);
var exteriorRingCcw = false;
// Need to pay attention to whether or not the first exterior ring is CW or CCW, so
// the other exterior rings match.
if (polygon.Parts.Count > 0)
{
exteriorRingCcw = Algorithms.IsCcw(polygon.Parts[0]);
}
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
polygon = ReadPolygonText(tokenizer, exteriorRingCcw, true);
polygons.AddParts(polygon.Parts);
nextToken = GetNextCloserOrComma(tokenizer);
}
return(polygons.ToGeometry());
}
private static Polygon CreateWkbMultiPolygon(BinaryReader reader, WkbByteOrder byteOrder)
{
// Get the number of Polygons.
var numPolygons = (int)ReadUInt32(reader, byteOrder);
if (numPolygons < 1)
{
throw new Exception("Could not create MultiPolygon");
}
// Read linestring header
reader.ReadByte();
ReadUInt32(reader, byteOrder);
// Create a new array for the Polygons.
var polygons = new PolygonBuilder(CreateWkbPolygon(reader, byteOrder));
// Loop on the number of polygons.
for (var i = 1; i < numPolygons; i++)
{
// read polygon header
reader.ReadByte();
ReadUInt32(reader, byteOrder);
// TODO: Validate type
polygons.AddParts(CreateWkbPolygon(reader, byteOrder).Parts);
}
//Create and return the MultiPolygon.
return(polygons.ToGeometry());
}
/// <summary>
/// The methods retrieves the outer ring(s) of the input polygon.
/// This method must be called on the MCT. Use QueuedTask.Run.
/// </summary>
/// <param name="inputPolygon">Input Polygon.</param>
/// <returns>The outer most (exterior, clockwise) ring(s) of the polygon. If the input is null or empty, a null pointer is returned.</returns>
/// <remarks>This method must be called on the MCT. Use QueuedTask.Run.</remarks>
public Polygon GetOutermostRings(Polygon inputPolygon)
{
if (inputPolygon == null || inputPolygon.IsEmpty)
{
return(null);
}
PolygonBuilder outerRings = new PolygonBuilder();
List <Polygon> internalRings = new List <Polygon>();
// explode the parts of the polygon into a list of individual geometries
var parts = MultipartToSinglePart(inputPolygon);
// get an enumeration of clockwise geometries (area > 0) ordered by the area
var clockwiseParts = parts.Where(geom => ((Polygon)geom).Area > 0).OrderByDescending(geom => ((Polygon)geom).Area);
// for each of the exterior rings
foreach (var part in clockwiseParts)
{
// add the first (the largest) ring into the internal collection
if (internalRings.Count == 0)
{
internalRings.Add(part as Polygon);
}
// use flag to indicate if current part is within the already selection polygons
bool isWithin = false;
foreach (var item in internalRings)
{
if (GeometryEngine.Within(part, item))
{
isWithin = true;
}
}
// if the current polygon is not within any polygon of the internal collection
// then it is disjoint and needs to be added to
if (isWithin == false)
{
internalRings.Add(part as Polygon);
}
}
// now assemble a new polygon geometry based on the internal polygon collection
foreach (var ring in internalRings)
{
outerRings.AddParts(ring.Parts);
}
// return the final geometry of the outer rings
return(outerRings.ToGeometry());
}
private void AddShapeLayer(List <IGeoInfo> shapeList, Layer layer)
{
foreach (ShapeGeoInfo shape in shapeList)
{
if (shape.Polygons.Values.Count == 0)
{
continue;
}
PolygonBuilder builder = new PolygonBuilder(SpatialReferences.Wgs84);
shape.Polygons.Values.ToList().ForEach(p => builder.AddParts(p.Parts));
Polygon polygon = builder.ToGeometry();
Dictionary <string, object> attr = new Dictionary <string, object>(shape.AttrList);
attr[KEY_CODE] = shape.KeyCode;
layer.GraphicsLayer.Graphics.Add(new Graphic(polygon, attr, MapShapeLayer.GetSymbol(GeoMarkerType.Fill, GeoStatus.Normal)));
_shapeList.Add(polygon.Extent);
layer.GraphicsLayer.Graphics.Add(new Graphic(polygon.Extent.GetCenter(), attr, MapShapeLayer.GetSymbol(GeoMarkerType.Point, GeoStatus.Normal)));
}
}
/// <summary>
/// The methods retrieves the outer ring(s) of the input polygon.
/// This method must be called on the MCT. Use QueuedTask.Run.
/// </summary>
/// <param name="inputPolygon">Input Polygon.</param>
/// <returns>The outer most (exterior, clockwise) ring(s) of the polygon. If the input is null or empty, a null pointer is returned.</returns>
/// <remarks>This method must be called on the MCT. Use QueuedTask.Run.</remarks>
public Polygon GetOutermostRings(Polygon inputPolygon)
{
if (inputPolygon == null || inputPolygon.IsEmpty)
return null;
PolygonBuilder outerRings = new PolygonBuilder();
List<Polygon> internalRings = new List<Polygon>();
// explode the parts of the polygon into a list of individual geometries
var parts = MultipartToSinglePart(inputPolygon);
// get an enumeration of clockwise geometries (area > 0) ordered by the area
var clockwiseParts = parts.Where(geom => ((Polygon)geom).Area > 0).OrderByDescending(geom => ((Polygon)geom).Area);
// for each of the exterior rings
foreach (var part in clockwiseParts)
{
// add the first (the largest) ring into the internal collection
if (internalRings.Count == 0)
internalRings.Add(part as Polygon);
// use flag to indicate if current part is within the already selection polygons
bool isWithin = false;
foreach (var item in internalRings)
{
if (GeometryEngine.Within(part, item))
isWithin = true;
}
// if the current polygon is not within any polygon of the internal collection
// then it is disjoint and needs to be added to
if (isWithin == false)
internalRings.Add(part as Polygon);
}
// now assemble a new polygon geometry based on the internal polygon collection
foreach (var ring in internalRings)
{
outerRings.AddParts(ring.Parts);
}
// return the final geometry of the outer rings
return outerRings.ToGeometry();
}
