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);
}
/// <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);
}
/// <summary>
/// We suppose that the holes are convex and oriented clockwis and are mutually disjoint
/// </summary>
/// <param name="listOfHoles"></param>
/// <param name="visibilityGraph"></param>
/// <param name="point">The point can belong to the boundary of one of the holes</param>
/// <param name="visibilityKind">tangent or regural visibility</param>
/// <param name="qVertex">the graph vertex corresponding to the pivot</param>
/// <returns></returns>
internal static VisibilityVertex CalculatePointVisibilityGraph(
IEnumerable <Polyline> listOfHoles,
VisibilityGraph visibilityGraph,
Point point,
VisibilityKind visibilityKind)
{
//maybe there is nothing to do
var qv = visibilityGraph.FindVertex(point);
if (qv != null)
{
return(qv);
}
var calculator = new PointVisibilityCalculator(listOfHoles, visibilityGraph, point, visibilityKind);
calculator.FillGraph();
return(calculator.QVertex);
}
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);
}