internal void AddNode(FreeSpaceNode node)
{
base.AddNode(node);
foreach (var nodePos in node.Value.FreeSpaces)
{
PositionToNode.Add(nodePos, node);
}
}
internal void AddFreeSpaceNodes(GraphSearchData gsData, Level level)
{
//
//All entities need to be made into walls so the only freepsace is space
//that won't block the path or be on top of other entities.
//
HashSet <Point> agentPositions = new HashSet <Point>();
foreach (var inode in Nodes)
{
if (inode is BoxConflictNode boxNode)
{
level.Walls[boxNode.Value.Ent.Pos.X, boxNode.Value.Ent.Pos.Y] = true;
if (boxNode.Value.EntType == EntityType.AGENT)
{
agentPositions.Add(boxNode.Value.Ent.Pos);
}
}
}
//
//Now go through the map and and find all empty spaces. When an empty space is found, bfs is used to
//find all connecting spaces which makes up the free space node.
//
var foundFreeSpace = new Func <(Point pos, int distance), GraphSearcher.GoalFound <Point> >(x =>
{
return(new GraphSearcher.GoalFound <Point>(x.pos, !level.IsWall(x.pos)));
});
HashSet <Point> alreadySeenSpaces = new HashSet <Point>();
List <FreeSpaceNode> freeSpaceNodes = new List <FreeSpaceNode>();
for (int y = 0; y < level.Height; y++)
{
for (int x = 0; x < level.Width; x++)
{
if (!level.Walls[x, y] && !alreadySeenSpaces.Contains(new Point(x, y)))
{
//There is an issue here.
//The list has a duplicate in it.
//It's currently handled by inserting it
//into a hashset.
var freeSpacesFound = GraphSearcher.GetReachedGoalsBFS(gsData, level, new Point(x, y), foundFreeSpace);
//A single free space can't be part of multiple nodes
alreadySeenSpaces.UnionWith(freeSpacesFound);
//Create node and add it to the graph.
//keep a list of the freespace nodes so edges can be added later
var newFreeSpaceNode = new FreeSpaceNode(new FreeSpaceNodeInfo(freeSpacesFound));
AddNode(newFreeSpaceNode);
freeSpaceNodes.Add(newFreeSpaceNode);
}
}
}
//
//Now it's time to add edges between the free spaces nodes and the rest of the graph.
//To do that the original map has to be restored as the path may block pathways from
//a freespace to any other node on the map. Agents and boxes still have to be walls
//as there is no direct path through them. This excludes goals as only goals with
//boxes on them should be walls and the boxes on top of them will makes them walls.
//Go through all free space nodes and use bfs to check which other nodes it can reach,
//then add edges to those nodes.
//
level.ResetWalls();
foreach (var inode in Nodes)
{
if (inode is BoxConflictNode boxNode && !boxNode.Value.EntType.IsGoal())
{
level.Walls[boxNode.Value.Ent.Pos.X, boxNode.Value.Ent.Pos.Y] = true;
}
}
var foundNode = new Func <(Point pos, int distance), GraphSearcher.GoalFound <INode> >(x =>
{
if (PositionToNode.TryGetValue(x.pos, out INode node))
{
return(new GraphSearcher.GoalFound <INode>(node, true));
}
return(new GraphSearcher.GoalFound <INode>(null, false));
});
foreach (var freeSpaceNode in freeSpaceNodes)
{
var nodesFound = GraphSearcher.GetReachedGoalsBFS(gsData, level, freeSpaceNode.Value.FreeSpaces.First(), foundNode);
foreach (var neighbour in nodesFound.ToHashSet())
{
//The search may find itself and such edges are not necessary
if (neighbour != freeSpaceNode)
{
//Bidirectional edges
freeSpaceNode.AddEdge(new Edge <DistanceEdgeInfo>(neighbour, new DistanceEdgeInfo()));
if (neighbour is BoxConflictNode boxNode)
{
boxNode.AddEdge(new Edge <DistanceEdgeInfo>(freeSpaceNode, new DistanceEdgeInfo()));
}
else if (neighbour is FreeSpaceNode freeNode)
{
freeNode.AddEdge(new Edge <DistanceEdgeInfo>(freeSpaceNode, new DistanceEdgeInfo()));
}
}
}
}
level.ResetWalls();
foreach (var agentPos in agentPositions)
{
foreach (var dirDelta in Direction.NONE.DirectionDeltas())
{
Point nextToAgent = agentPos + dirDelta;
if (PositionHasNode(nextToAgent))
{
INode node = GetNodeFromPosition(nextToAgent);
if (node is FreeSpaceNode freeSpaceNode)
{
freeSpaceNode.Value.FreeSpaces.Add(agentPos);
continue;
}
}
}
}
}
