/// <summary>
/// Find all Systems within range of the specified system.
/// </summary>
/// <param name="origin">The reference system.</param>
/// <param name="range">The range to include.</param>
/// <returns>A list of all Systems that are within range of the origin.</returns>
public IEnumerable <KeyValuePair <string, EDSystem> > FindInRange(EDSystem origin, double range)
{
// We only need to consider systems within the same box as the origin, and neighbouring boxes up to the jump range away.
// One possible optimisation here is to calculate the boxes within the spherical range, but I suspect that for all but the
// longest routes, the constant circle-maths would cost more than it gains. Something to try out sometime.
// Find out how many boxes away from the origin we need to inspect.
var boxRange = ((int)range / BoxSize) + 1;
// Build up a list of boxes that might contain reachable systems. These are the boxes we'll be searching later, so the smaller
// we can make this list the better, and the fewer the number of systems in the boxes the better too.
var boxes = new List <BoxKey>();
for (int x = origin.box.X - boxRange; x <= origin.box.X + boxRange; x++)
{
for (int z = origin.box.Z - boxRange; z <= origin.box.Z + boxRange; z++)
{
var key = new BoxKey(x, z);
if (_BoxedList.ContainsKey(key))
{
boxes.Add(key);
}
}
}
// Spin through every box in our search-space, and add any systems that are actually within range to the result list.
// This can be done concurrently, because each system is independent.
var systems = new ConcurrentDictionary <string, EDSystem>();
Parallel.ForEach(boxes, (box) =>
{
// We're doing a faster box-based range check first, so we don't have to do an expensive √((x2-x1)² + (y2-y1)² + (z2-z1)²) calculation.
foreach (var system in _BoxedList[box].Where(x => x.Value != origin && Math.Abs(x.Value.x - origin.x) <= range && Math.Abs(x.Value.y - origin.y) <= range && Math.Abs(x.Value.z - origin.z) <= range).ToList())
{
// Now we have a list of systems that have their X/Y/Z coordinates all within ±jump of the origin, find out which really are in range.
// (Because the corners of the cube will be further from the centre than 1 jump-range)
if (Astrogation.Distance(origin, system.Value) <= range)
{
systems[system.Key] = system.Value;
}
}
});
// We now should have a simple list of Systems within the specified range of the provided origin system.
return(systems);
}
public List <EDSystem> Route(EDSystem start, EDSystem end)
{
if (JumpRange == 0)
{
throw new InvalidOperationException("Jump range has not been set.");
}
var key = new CacheKey()
{
JumpRange = JumpRange, Start = start.key, End = end.key
};
if (_routeCache.ContainsKey(key))
{
Console.WriteLine($"Found a cached route from {start.name} to {end.name} in {JumpRange:n2} Ly jumps.");
LastResultWasFromCache = true;
return(_routeCache[key]);
}
else
{
LastResultWasFromCache = false;
}
var swTotal = new Stopwatch();
var swSort = new Stopwatch();
var swPriority = new Stopwatch();
var swNeighbours = new Stopwatch();
swTotal.Start();
var edsm = EDSystemManager.Instance;
_frontier = new SimplePriorityQueue <EDSystem>();
_cameFrom = new Dictionary <string, RouteNode>();
_costSoFar = new Dictionary <string, RouteNode>();
_frontier.Enqueue(start, 0);
_costSoFar.Add(start.key, new RouteNode()
{
System = start, Distance = 0, Priority = 0
});
var routeFound = false;
while (_frontier.Count > 0)
{
var current = _frontier.Dequeue();
if (current == end)
{
routeFound = true;
break;
}
swNeighbours.Start();
var neighbours = edsm.FindInRange(current, JumpRange).ToList();
swNeighbours.Stop();
// sort neighbours to put those closest to the target first
swSort.Start();
neighbours.OrderBy(x => Astrogation.Distance(x.Value, end));
swSort.Stop();
foreach (var kvNext in neighbours)
{
var next = kvNext.Value;
var new_cost = _costSoFar[current.key].Priority + 1;
if (_costSoFar.ContainsKey(next.key) == false || new_cost < _costSoFar[next.key].Priority)
{
if (_costSoFar.ContainsKey(next.key))
{
var cost = _costSoFar[next.key];
cost.Priority = new_cost;
}
else
{
_costSoFar.Add(next.key, new RouteNode()
{
System = next, Priority = new_cost
});
}
var node = new RouteNode()
{
System = current, Distance = Astrogation.Distance(current, next)
};
swPriority.Start();
var priority = new_cost + Astrogation.Distance(next, end);
swPriority.Stop();
_frontier.Enqueue(next, priority);
_cameFrom[next.key] = node;
}
}
}
if (DebugDumpRouteGraphs)
{
DumpSearchSpaceGraph(start, end, _cameFrom, _costSoFar);
}
var path = new List <EDSystem>();
if (routeFound || AcceptPartialRoutes)
{
var c = end;
while (c != start)
{
path.Add(c);
if (_cameFrom.ContainsKey(c.key) == false)
{
// This should only happen if there is no route to the requested destination.
break;
}
c = _cameFrom[c.key].System;
}
path.Reverse();
}
_routeCache.Add(key, path);
swTotal.Stop();
// Console.WriteLine($"total:{swTotal.ElapsedMilliseconds}, sort:{swSort.ElapsedMilliseconds}, priority:{swPriority.ElapsedMilliseconds}, neigh:{swNeighbours.ElapsedMilliseconds}");
return(path);
}
