public void CoordinateAngleTest()
{
// test case 1: 90°
Coordinate origin = new Coordinate(0, 0);
Coordinate first = new Coordinate(1, 0);
Coordinate second = new Coordinate(0, 1);
Assert.AreEqual(Math.PI / 2, Coordinate.Angle(origin, first, second), 0.00001);
// test case 2: 180°
origin = new Coordinate(0, 0);
first = new Coordinate(1, 0);
second = new Coordinate(-1, 0);
Assert.AreEqual(Math.PI, Coordinate.Angle(origin, first, second), 0.00001);
// test case 3: -180°
origin = new Coordinate(0, 0);
first = new Coordinate(-1, 0);
second = new Coordinate(1, 0);
Assert.AreEqual(Math.PI, Coordinate.Angle(origin, first, second), 0.00001);
// test case 4: 45°
origin = new Coordinate(0, 0);
first = new Coordinate(1, 0);
second = new Coordinate(1, 1);
Assert.AreEqual(Math.PI / 4, Coordinate.Angle(origin, first, second), 0.00001);
// test case 5: 60°
origin = new Coordinate(0, 0);
first = new Coordinate(1, 0);
second = new Coordinate(1, Math.Sqrt(3));
Assert.AreEqual(Math.PI / 3, Coordinate.Angle(origin, first, second), 0.00001);
}
public void CoordinateAngleTest()
{
// 90°
Coordinate origin = new Coordinate(0, 0);
Coordinate first = new Coordinate(1, 0);
Coordinate second = new Coordinate(0, 1);
Coordinate.Angle(origin, first, second).ShouldBe(Math.PI / 2, 0.00001);
// 180°
origin = new Coordinate(0, 0);
first = new Coordinate(1, 0);
second = new Coordinate(-1, 0);
Coordinate.Angle(origin, first, second).ShouldBe(Math.PI, 0.00001);
// -180°
origin = new Coordinate(0, 0);
first = new Coordinate(-1, 0);
second = new Coordinate(1, 0);
Coordinate.Angle(origin, first, second).ShouldBe(Math.PI, 0.00001);
// 45°
origin = new Coordinate(0, 0);
first = new Coordinate(1, 0);
second = new Coordinate(1, 1);
Coordinate.Angle(origin, first, second).ShouldBe(Math.PI / 4, 0.00001);
// 60°
origin = new Coordinate(0, 0);
first = new Coordinate(1, 0);
second = new Coordinate(1, Math.Sqrt(3));
Coordinate.Angle(origin, first, second).ShouldBe(Math.PI / 3, 0.00001);
}
static public float MapAngleBetween(Coordinate a, Coordinate b)
{
return(a.Angle(b));;
}
/// <summary>
/// Computes the result of the operation.
/// </summary>
protected override void ComputeResult()
{
switch (_dimension)
{
case 0:
foreach (IGraphVertex vertex in Source.Vertices)
{
_points.Add(_factory.CreatePoint(vertex.Coordinate, _metadataPreservation ? vertex.Metadata : null));
}
break;
case 1:
foreach (IGraphVertex vertex in Source.Vertices)
{
_points.Add(_factory.CreatePoint(vertex.Coordinate, _metadataPreservation ? vertex.Metadata : null));
}
foreach (IGraphVertex vertex in Source.Vertices)
{
foreach (IGraphEdge edge in Source.OutEdges(vertex))
{
if (edge.Source.Coordinate.Equals(edge.Target.Coordinate))
{
continue;
}
_points.Remove(_factory.CreatePoint(edge.Source.Coordinate));
_points.Remove(_factory.CreatePoint(edge.Target.Coordinate));
_lines.Add(_factory.CreateLine(edge.Source.Coordinate, edge.Target.Coordinate, _metadataPreservation ? edge.Metadata : null));
}
}
break;
case 2:
// source: Jiang, X. Y., Bunke, H.: An optimal algorithm for extracting the regions of a plane graph (1993)
List <Coordinate> coordinates = new List <Coordinate>();
// find all wedges
List <AngularEdge> edges = new List <AngularEdge>();
foreach (IGraphVertex vertex in Source.Vertices)
{
Coordinate sourceCoordinate = vertex.Coordinate;
Coordinate baseCoordinate = vertex.Coordinate - new CoordinateVector(1, 0);
IEnumerable <IGraphEdge> outEdges = Source.OutEdges(vertex);
if (outEdges.Count() == 0)
{
coordinates.Add(vertex.Coordinate);
continue;
}
foreach (IGraphEdge edge in outEdges)
{
Coordinate target = edge.Target.Coordinate;
edges.Add(new AngularEdge(sourceCoordinate, target,
Coordinate.Orientation(sourceCoordinate, baseCoordinate, target) == Orientation.CounterClockwise ?
Coordinate.Angle(sourceCoordinate, baseCoordinate, target) :
Math.PI - Coordinate.Angle(sourceCoordinate, baseCoordinate, target)));
}
}
edges.Sort(new AngularEdgeComparer());
IEnumerable <IGrouping <Coordinate, AngularEdge> > groups = edges.GroupBy(angularEdge => angularEdge.Source);
List <Wedge> wedges = new List <Wedge>();
foreach (IGrouping <Coordinate, AngularEdge> group in groups)
{
AngularEdge[] groupEdges = group.ToArray();
for (Int32 i = 0; i < groupEdges.Length - 1; i++)
{
wedges.Add(new Wedge(groupEdges[i + 1].Target, groupEdges[i].Source, groupEdges[i].Target));
}
wedges.Add(new Wedge(groupEdges[0].Target, groupEdges[0].Source, groupEdges[groupEdges.Length - 1].Target));
}
// grouping wedges to regions
List <List <Wedge> > faces = new List <List <Wedge> >();
List <List <Wedge> > leftOverEdges = new List <List <Wedge> >();
for (Int32 i = 0; i < wedges.Count; i++)
{
List <Wedge> wedgeSeries = new List <Wedge>();
Wedge currentWedge = wedges[i];
do
{
wedges.Remove(currentWedge);
wedgeSeries.Add(currentWedge);
currentWedge = wedges.FirstOrDefault(wedge => wedge.First.Equals(currentWedge.Second) && wedge.Second.Equals(currentWedge.Third));
}while (currentWedge != null);
if (wedgeSeries[0].First.Equals(wedgeSeries[wedgeSeries.Count - 1].Second) && wedgeSeries[0].Second.Equals(wedgeSeries[wedgeSeries.Count - 1].Third))
{
faces.Add(wedgeSeries);
}
else
{
leftOverEdges.Add(wedgeSeries);
}
}
for (Int32 i = 0; i < faces.Count; i++)
{
List <Coordinate> shell = faces[i].Select(wedge => wedge.First).ToList();
shell.Add(shell[0]);
if (PolygonAlgorithms.Orientation(shell) == Orientation.CounterClockwise)
{
Dictionary <String, Object> metadata = null;
if (_metadataPreservation)
{
metadata = new Dictionary <String, Object>();
foreach (IMetadataCollection collection in shell.Select(coordinate => Source.GetVertex(coordinate).Metadata))
{
foreach (String key in collection.Keys)
{
metadata[key] = collection[key];
}
}
}
_polygons.Add(_factory.CreatePolygon(shell, metadata));
}
}
for (Int32 i = 0; i < leftOverEdges.Count; i++)
{
for (Int32 j = 0; j < leftOverEdges[i].Count; j++)
{
_lines.Add(_factory.CreateLine(leftOverEdges[i][j].First,
leftOverEdges[i][j].Second,
_metadataPreservation ? Source.GetEdge(leftOverEdges[i][j].First, leftOverEdges[i][j].Second).Metadata : null));
}
}
foreach (Coordinate coordinate in coordinates)
{
_points.Add(_factory.CreatePoint(coordinate,
_metadataPreservation ? Source.GetVertex(coordinate).Metadata : null));
}
break;
}
}
