private void FindSmallestNodeData(
HashSet <TNode> keys,
Dictionary <TNode, DynamicGraphNodeData <TNode, TCost, TEdge> > lookUp,
out TNode smallestNode,
out DynamicGraphNodeData <TNode, TCost, TEdge> smallestEdge
)
{
Contract.Requires(keys != null);
Contract.Requires(keys.Count > 0);
Contract.Requires(lookUp != null);
Contract.Requires(lookUp.Count > 0);
Contract.Requires(lookUp.Count >= keys.Count);
Contract.Requires(Contract.ForAll(lookUp.Values, x => x != null));
Contract.Requires(Contract.ForAll(keys, key => key != null && lookUp.ContainsKey(key)));
Contract.Ensures(Contract.ValueAtReturn(out smallestNode) != null);
Contract.Ensures(Contract.ValueAtReturn(out smallestEdge) != null);
using (var enumerator = keys.GetEnumerator()) {
if (!enumerator.MoveNext())
{
throw new ArgumentException("keys is empty", "keys");
}
var currentNode = enumerator.Current;
//var smallest = new KeyValuePair<TNode, DynamicGraphNodeData<TNode, TCost, TEdge>>(currentNode, lookUp[currentNode]);
smallestNode = currentNode;
smallestEdge = lookUp[currentNode];
Contract.Assume(smallestEdge != null);
while (enumerator.MoveNext())
{
currentNode = enumerator.Current;
var currentData = lookUp[currentNode];
Contract.Assume(currentData != null);
if (CostComparer.Compare(smallestEdge.Cost, currentData.Cost) > 0)
{
smallestNode = currentNode;
smallestEdge = currentData;
}
}
}
if (null == smallestNode)
{
throw new ArgumentException("null keys are not allowed", "keys");
}
if (null == smallestEdge)
{
throw new ArgumentException("null edge contained in edge look-up", "lookUp");
}
}
/// <summary>
/// Finds a graph path from the <paramref name="start"/> node to the <paramref name="target"/> node.
/// </summary>
/// <param name="start">The node to begin the path search from.</param>
/// <param name="target">The target node of the search.</param>
/// <returns>The shortest path from the start node to the target node if one exists.</returns>
/// <exception cref="System.ArgumentException">Thrown if a node or edge encountered within the graph is <c>null</c>.</exception>
public ReadOnlyCollection <DynamicGraphNodeData <TNode, TCost, TEdge> > FindPath(TNode start, TNode target)
{
if (null == start)
{
throw new ArgumentNullException("start");
}
if (null == target)
{
throw new ArgumentNullException("target");
}
Contract.EndContractBlock();
// initialize the look-ups
var nodeDataCache = new Dictionary <TNode, DynamicGraphNodeData <TNode, TCost, TEdge> >(NodeComparer)
{
{ start, new DynamicGraphNodeData <TNode, TCost, TEdge>(start, default(TCost), default(TEdge)) }
};
var visitRequired = new HashSet <TNode>(NodeComparer)
{
start
}; // NOTE: in order for a node to be in this collection it must have a corresponding key in the pathData dictionary.
DynamicGraphNodeData <TNode, TCost, TEdge> nodeData;
TNode currentNode;
var bestCompleteCost = default(TCost);
var completeRouteFound = false;
// generate the dynamic path information and find the shortest path
while (visitRequired.Count != 0)
{
DynamicGraphNodeData <TNode, TCost, TEdge> currentNodeData;
Contract.Assume(nodeDataCache.Count >= visitRequired.Count);
Contract.Assume(Contract.ForAll(visitRequired, k => k != null && nodeDataCache.ContainsKey(k)));
FindSmallestNodeData(visitRequired, nodeDataCache, out currentNode, out currentNodeData);
visitRequired.Remove(currentNode);
// logic to see if we can short out of checking this node due to it being too long
if (completeRouteFound)
{
if (CostComparer.Compare(bestCompleteCost, currentNodeData.Cost) <= 0)
{
continue; // this path is larger than or equal to the best found complete path
}
if (NodeComparer.Equals(currentNode, target))
{
bestCompleteCost = currentNodeData.Cost;
}
}
else if (NodeComparer.Equals(currentNode, target))
{
bestCompleteCost = currentNodeData.Cost;
completeRouteFound = true;
}
foreach (var neighborInfo in GetNeighborInfo(currentNode, currentNodeData.Cost))
{
if (ReferenceEquals(null, neighborInfo) || ReferenceEquals(null, neighborInfo.Node))
{
continue;
}
if (nodeDataCache.TryGetValue(neighborInfo.Node, out nodeData))
{
Contract.Assume(nodeData != null);
if (CostComparer.Compare(neighborInfo.Cost, nodeData.Cost) < 0)
{
nodeData.Node = currentNode;
nodeData.Cost = neighborInfo.Cost;
nodeData.Edge = neighborInfo.Edge;
visitRequired.Add(neighborInfo.Node);
}
}
else
{
nodeDataCache.Add(
neighborInfo.Node,
new DynamicGraphNodeData <TNode, TCost, TEdge>(currentNode, neighborInfo.Cost, neighborInfo.Edge));
visitRequired.Add(neighborInfo.Node);
}
}
}
// build the final result path
if (nodeDataCache.TryGetValue(target, out nodeData))
{
Contract.Assume(nodeData != null);
var pathResult = new List <DynamicGraphNodeData <TNode, TCost, TEdge> > {
new DynamicGraphNodeData <TNode, TCost, TEdge>(target, nodeData.Cost, nodeData.Edge)
};
currentNode = nodeData.Node;
if (null == currentNode)
{
return(null);
}
while (nodeDataCache.TryGetValue(currentNode, out nodeData))
{
Contract.Assume(nodeData != null);
pathResult.Add(new DynamicGraphNodeData <TNode, TCost, TEdge>(currentNode, nodeData.Cost, nodeData.Edge));
if (Equals(currentNode, start))
{
break;
}
currentNode = nodeData.Node;
if (null == currentNode)
{
return(null);
}
}
pathResult.Reverse();
return(new ReadOnlyCollection <DynamicGraphNodeData <TNode, TCost, TEdge> >(pathResult));
}
return(null); // no path was found
}
public static void AssignTasksGreedy(List <Task> newGoals, List <CreatureAI> creatures, int maxPerGoal)
{
string trackingString = "AssignTasksGreedy(" + newGoals.Count + ")";
GamePerformance.Instance.StartTrackPerformance(trackingString);
// We are going to keep track of the unassigned goal count
// to avoid having to parse the list at the end of the loop.
int goalsUnassigned = newGoals.Count;
List <int> counts = new List <int>(goalsUnassigned);
for (int i = 0; i < goalsUnassigned; i++)
{
counts.Add(0);
}
// Randomized list changed from the CreatureAI objects themselves to an index into the
// List passed in. This is to avoid having to shift the masterCosts list around to match
// each time we randomize.
List <int> randomIndex = new List <int>(creatures.Count);
for (int i = 0; i < creatures.Count; i++)
{
randomIndex.Add(i);
}
// We create the comparer outside of the loop. It gets reused for each sort.
CostComparer toCompare = new CostComparer();
// One of the biggest issues with the old function was that it was recalculating the whole task list for
// the creature each time through the loop, using one item and then throwing it away. Nothing changed
// in how the calculation happened between each time so we will instead make a costs list for each creature
// and keep them all. This not only avoids rebuilding the list but the sheer KeyValuePair object churn there already was.
List <List <KeyValuePair <int, float> > > masterCosts = new List <List <KeyValuePair <int, float> > >(creatures.Count);
// We will set this up in the next loop rather than make it's own loop.
List <int> costsPositions = new List <int>(creatures.Count);
for (int costIndex = 0; costIndex < creatures.Count; costIndex++)
{
List <KeyValuePair <int, float> > costs = new List <KeyValuePair <int, float> >();
CreatureAI creature = creatures[costIndex];
// We already were doing an index count to be able to make the KeyValuePair for costs
// and foreach uses Enumeration which is slower.
for (int i = 0; i < newGoals.Count; i++)
{
Task task = newGoals[i];
// We are checking for tasks the creature is already assigned up here to avoid having to check
// every task in the newGoals list against every task in the newGoals list. The newGoals list
// should reasonably not contain any task duplicates.
if (creature.Tasks.Contains(task))
{
continue;
}
float cost = 0;
// We've swapped the order of the two checks to take advantage of a new ComputeCost that can act different
// if we say we've already called IsFeasible first. This allows us to skip any calculations that are repeated in both.
if (!task.IsFeasible(creature.Creature))
{
cost += 1e10f;
}
cost += task.ComputeCost(creature.Creature, true);
costs.Add(new KeyValuePair <int, float>(i, cost));
}
// The sort lambda function has been replaced by an IComparer class.
// This is faster but I mainly did it because VS can not Edit & Continue
// any function with a Lambda function in it which was slowing down dev time.
costs.Sort(toCompare);
masterCosts.Add(costs);
costsPositions.Add(0);
}
// We are going to precalculate the maximum iterations and count down
// instead of up.
int iters = goalsUnassigned * creatures.Count;
while (goalsUnassigned > 0 && iters > 0)
{
randomIndex.Shuffle();
iters--;
for (int creatureIndex = 0; creatureIndex < randomIndex.Count; creatureIndex++)
{
int randomCreature = randomIndex[creatureIndex];
CreatureAI creature = creatures[randomCreature];
List <KeyValuePair <int, float> > costs = masterCosts[randomCreature];
int costPosition = costsPositions[randomCreature];
// This loop starts with the previous spot we stopped. This avoids us having to constantly run a task we
// know we have processed.
for (int i = costPosition; i < costs.Count; i++)
{
// Incremented at the start in case we find a task and break.
costPosition++;
KeyValuePair <int, float> taskCost = costs[i];
// We've swapped the checks here. Tasks.Contains is far more expensive so being able to skip
// if it's going to fail the maxPerGoal check anyways is very good.
if (counts[taskCost.Key] < maxPerGoal)// && !creature.Tasks.Contains(newGoals[taskCost.Key]))
{
// We have to check to see if the task we are assigning is fully unassigned. If so
// we reduce the goalsUnassigned count. If it's already assigned we skip it.
if (counts[taskCost.Key] == 0)
{
goalsUnassigned--;
}
counts[taskCost.Key]++;
creature.Tasks.Add(newGoals[taskCost.Key].Clone());
break;
}
}
// We have to set the position we'll start the loop at the next time based on where we found
// our task.
costsPositions[randomCreature] = costPosition;
// The loop at the end to see if all are unassigned is gone now, replaced by a countdown
// variable: goalsUnassigned.
}
}
GamePerformance.Instance.EndTrackPerformance(trackingString);
}