public void FindPath_WhenNoPathExists_WillBeNull()
{
EdgeWeightedDigraph digraph = new EdgeWeightedDigraph(5);
digraph.AddEdge(new DirectedEdge(0, 1, 2.5));
digraph.AddEdge(new DirectedEdge(1, 2, 3.25));
digraph.AddEdge(new DirectedEdge(1, 4, 4.75));
digraph.AddEdge(new DirectedEdge(2, 3, 1.25));
digraph.AddEdge(new DirectedEdge(3, 4, 2));
IEnumerable <DirectedEdge> path = DijkstraShortestPath.FindPath(digraph, 4, 0);
Assert.IsNull(path);
}
public void FindPath_WhenMultiplePathsExistBetween0And4_WillBeShortestPath()
{
EdgeWeightedDigraph digraph = new EdgeWeightedDigraph(5);
digraph.AddEdge(new DirectedEdge(0, 1, 2.5));
digraph.AddEdge(new DirectedEdge(1, 2, 3.25));
digraph.AddEdge(new DirectedEdge(1, 4, 4.75));
digraph.AddEdge(new DirectedEdge(2, 3, 1.25));
digraph.AddEdge(new DirectedEdge(3, 4, 2));
DirectedEdge[] path = DijkstraShortestPath.FindPath(digraph, 0, 4).ToArray();
Assert.AreEqual("From: 0, To: 1, Weight: 2.5", path[0].ToString());
Assert.AreEqual("From: 1, To: 4, Weight: 4.75", path[1].ToString());
Assert.AreEqual(2, path.Length);
}
private IEnumerable <Cell> ShortestPathCells(Cell source, Cell destination)
{
IEnumerable <DirectedEdge> path = DijkstraShortestPath
.FindPath(_graph, IndexFor(source.Point), IndexFor(destination.Point));
if (path == null)
{
yield break;
}
yield return(source);
foreach (DirectedEdge edge in path)
{
yield return(CellFor(edge.To));
}
}
private IEnumerable <ITile> ShortestPathCells(ITile source, ITile destination)
{
IEnumerable <DirectedEdge> path = DijkstraShortestPath.FindPath(_graph, IndexFor(source), IndexFor(destination));
if (path == null)
{
yield return(null);
}
else
{
yield return(source);
foreach (DirectedEdge edge in path)
{
yield return(CellFor(edge.To));
}
}
}
private IEnumerable <ICell> ShortestPathCells(ICell source, ICell destination)
{
var path = DijkstraShortestPath.FindPath(_graph, IndexFor(source), IndexFor(destination));
if (path == null)
{
yield return(null);
}
else
{
yield return(source);
foreach (var edge in path)
{
yield return(CellFor(edge.To));
}
}
}
public List <Point> ShortestPathList(Point source, Point destination)
{
var list = new List <Point>();
IEnumerable <DirectedEdge> path = DijkstraShortestPath
.FindPath(_graph, IndexFor(source), IndexFor(destination));
if (path == null)
{
return(list);
}
foreach (DirectedEdge edge in path)
{
list.Add(CoordFor(edge.To));
}
return(list);
}
/// <summary>
/// Get instructions for Roomba to get to room
/// </summary>
/// <param name="room"></param>
/// <returns></returns>
public List <Instruction> GetDirections(int room)
{
_directions = new List <Instruction>();
_distance = 0;
int tempX = 0, tempY = 0; //for comparing X and Y of previous node
var instructions = new List <Instruction>();
endVertex = FindRoom(room);
if (endVertex != null)
{
var edgePath = DijkstraShortestPath.FindPath(graph, startVertex.Id, endVertex.Id);
foreach (var edge in edgePath)
{
var from = GetVertex(edge.From);
var to = GetVertex(edge.To);
//Turning from start
if (edge.From == startVertex.Id)
{
//ASSUME STARTING POSITION IS FACING NORTH (north as defined by map)
int xDiff = to.X - startVertex.X;
if (xDiff > 0)
{
//go east
//TURN RIGHT
instructions.Add(new Instruction(InstructionType.Angle, 90));
currentDirection += 90;
}
else if (xDiff < 0)
{
//go west
//TURN LEFT
instructions.Add(new Instruction(InstructionType.Angle, -90));
currentDirection -= 90;
}
else
{
int yDiff = to.Y - startVertex.Y;
if (yDiff < 0)
{
//go south
//TURN AROUND
instructions.Add(new Instruction(InstructionType.Angle, 180));
currentDirection += 180;
}
else if (yDiff > 0)
{
//go up (roomba starting should face north so no turn)
}
}
}
//Turning from a previous place
else
{
//Only turn if both X AND Y value is different
FindTurn(tempX, tempY, from.X, from.Y, to.X, to.Y);
}
//Add onto move distance (continuing in same direction)
_distance += edge.Weight;
//Check if we've reached the end and are done getting directions!
if (to.Id == endVertex.Id)
{
_directions.Add(new Instruction(InstructionType.Distance, _distance));
break;
}
//Set for next iteration of loop
tempX = from.X;
tempY = from.Y;
}
PrepareNextNavigation();
}
return(_directions);
}