static internal VisibilityEdge AddEdge(VisibilityVertex source, VisibilityVertex target)
{
VisibilityEdge visEdge;
if (source.TryGetEdge(target, out visEdge))
{
return(visEdge);
}
Debug.Assert(source != target, "Self-edges are not allowed");
var edge = new VisibilityEdge(source, target);
source.OutEdges.Insert(edge);
target.InEdges.Add(edge);
return(edge);
}
/// <summary>
///
/// </summary>
/// <param name="pathStart"></param>
/// <param name="pathEnd"></param>
/// <param name="obstacles"></param>
/// <param name="sourceVertex">graph vertex corresponding to the source</param>
/// <param name="targetVertex">graph vertex corresponding to the target</param>
/// <returns></returns>
internal static VisibilityGraph GetVisibilityGraphForShortestPath(Point pathStart, Point pathEnd,
IEnumerable <Polyline> obstacles,
out VisibilityVertex sourceVertex,
out VisibilityVertex targetVertex)
{
var holes = new List <Polyline>(OrientHolesClockwise(obstacles));
var visibilityGraph = CalculateGraphOfBoundaries(holes);
var polygons = holes.Select(hole => new Polygon(hole)).ToList();
TangentVisibilityGraphCalculator.AddTangentVisibilityEdgesToGraph(polygons, visibilityGraph);
PointVisibilityCalculator.CalculatePointVisibilityGraph(holes, visibilityGraph, pathStart,
VisibilityKind.Tangent, out sourceVertex);
PointVisibilityCalculator.CalculatePointVisibilityGraph(holes, visibilityGraph, pathEnd,
VisibilityKind.Tangent, out targetVertex);
return(visibilityGraph);
}
static internal VisibilityEdge AddEdge(VisibilityVertex source, VisibilityVertex target)
{
VisibilityEdge visEdge;
if (source.TryGetEdge(target, out visEdge))
{
return(visEdge);
}
if (source == target)
{
Debug.Assert(false, "Self-edges are not allowed");
throw new InvalidOperationException("Self-edges are not allowed");
}
var edge = new VisibilityEdge(source, target);
source.OutEdges.Insert(edge);
target.InEdges.Add(edge);
return(edge);
}
internal bool TryGetEdge(VisibilityVertex target, out VisibilityEdge visEdge)
{
var node = FindFirst(OutEdges, target.Point);// OutEdges.FindFirst(e => e.TargetPoint >= target.Point);
if (node != null)
{
if (node.Item.Target == target)
{
visEdge = node.Item;
return(true);
}
}
node = FindFirst(target.OutEdges, Point);// target.OutEdges.FindFirst(e => e.TargetPoint >= Point);
if (node != null)
{
if (node.Item.Target == this)
{
visEdge = node.Item;
return(true);
}
}
visEdge = null;
return(false);
}
internal static void CalculatePointVisibilityGraph(IEnumerable <Polyline> listOfHoles,
VisibilityGraph visibilityGraph, Point point,
VisibilityKind visibilityKind, out VisibilityVertex qVertex)
{
//maybe there is nothing to do
var qv = visibilityGraph.FindVertex(point);
if (qv != null)
{
qVertex = qv;
return;
}
var calculator = new PointVisibilityCalculator(listOfHoles, visibilityGraph, point, visibilityKind);
calculator.FillGraph();
qVertex = calculator.QVertex;
Debug.Assert(qVertex != null);
}
internal void SetPreviousEdge(VisibilityVertex v, VisibilityEdge e)
{
Debug.Assert(v == e.Source || v == e.Target);
_prevEdgesDictionary[v] = e;
}
internal void ShrinkLengthOfPrevEdge(VisibilityVertex v, double lengthMultiplier)
{
_prevEdgesDictionary[v].LengthMultiplier = lengthMultiplier;
}
internal void AddVertex(VisibilityVertex vertex)
{
Debug.Assert(!PointToVertexMap.ContainsKey(vertex.Point), "A vertex already exists at this location");
PointToVertexMap[vertex.Point] = vertex;
}
internal VisibilityEdge(VisibilityVertex source, VisibilityVertex target) : this(source, target, 1.0)
{
}
internal void RemoveEdge(VisibilityVertex v1, VisibilityVertex v2)
{
RemoveEdge(v1.Point, v2.Point);
}
