public Tuple <List <PointF>, float, float> CalculatePathBetweenVertices(GraphVertex vertex1, GraphVertex vertex2, RouteCalculationMode mode)
{
//Реализация алгоритма Дейкстры на основе очереди с приоритетом (Heap)
int n = vertices.Count;
float[] d = new float[n];
int[] p = new int[n];
for (int i = 0; i < n; i++)
{
d[i] = float.MaxValue;
p[i] = -1;
}
d[vertex1.Id] = 0;
var queue = new SimplePriorityQueue <int, float>();
queue.Enqueue(vertex1.Id, 0);
while (queue.Count > 0)
{
int v = queue.Dequeue();
for (int i = 0; i < vertices[v].Edges.Count; i++)
{
int to = vertices[v].Edges[i].Vert2.Id;
//если нужен самый короткий путь - минимизируем длину пути.
//если нужен самый быстрый - минимизируем время (длина/скорость).
float len = (mode == RouteCalculationMode.ShortRoute) ? (vertices[v].Edges[i].Length) : (vertices[v].Edges[i].Time);
if (d[v] + len < d[to])
{
d[to] = d[v] + len;
p[to] = v;
if (!queue.TryUpdatePriority(to, d[to]))
{
queue.Enqueue(to, d[to]);
}
}
}
}
if (p[vertex2.Id] == -1)
{
//не нашли путь
throw new Exception();
}
// восстанавливаем путь
int currentPoint = vertex2.Id;
var vertPath = new List <int>();
while (currentPoint != -1)
{
vertPath.Add(currentPoint);
currentPoint = p[currentPoint];
}
vertPath.Reverse();
var edgePath = new List <GraphEdge>();
for (int i = 0; i < vertPath.Count - 1; i++)
{
var vert1 = vertices[vertPath[i]];
var vert2 = vertices[vertPath[i + 1]];
var edge = vert1.Edges.First(e => e.Vert2.Id == vert2.Id);
edgePath.Add(edge);
}
List <PointF> wktPath = edgePath.SelectMany(e => e.Shape).ToList();
float length = edgePath.Sum(edge => edge.Length);
float time = edgePath.Sum(edge => edge.Time);
return(new Tuple <List <PointF>, float, float>(wktPath, length, time));
}
public RouteCalculationCheckpointResult CalculatePathBetweenPoints(PointF startPoint, PointF finishPoint, RouteCalculationMode mode)
{
//TO-DO: Искать не ближайшую точку дороги, а наиболее удобную.
//TO-DO: Обработать кейс, когда nearStart и nearFinish окажутся одинаковыми
var nearStart = this.GetNearVertex(startPoint);
var nearFinish = this.GetNearVertex(finishPoint);
var calcResult = CalculatePathBetweenVertices(nearStart, nearFinish, mode);
if (calcResult.Item1.First() != startPoint)
{
calcResult.Item1.Insert(0, startPoint);
}
if (calcResult.Item1.Last() != finishPoint)
{
calcResult.Item1.Add(finishPoint);
}
// Length и Time маршрута учитывают только движение по дорогам
// и не учитывают время и длину маршрута до ближайшей точки дороги
var result = new RouteCalculationCheckpointResult
{
StartPoint = startPoint,
FinishPoint = finishPoint,
WKTPath = calcResult.Item1,
Length = calcResult.Item2,
Time = calcResult.Item3
};
return(result);
}
public RouteCalculationResult Calculate(PointF startPoint, List <PointF> checkpoints, RouteCalculationMode mode = RouteCalculationMode.ShortRoute)
{
var result = new RouteCalculationResult
{
Mode = mode
};
var graph = RoadGraph.getInstance();
var list = new List <List <Tuple <PointF, PointF> > >();
foreach (var checkpoint in checkpoints)
{
var localResult = graph.CalculatePathBetweenPoints(startPoint, checkpoint, mode);
result.Checkpoints.Add(localResult);
result.TotalLength += localResult.Length;
result.TotalTime += localResult.Time;
startPoint = checkpoint;
}
return(result);
}
