Files
LuaCsForBarotraumaEP/Subsurface/Source/Characters/AI/PathFinder.cs
Regalis 7910b13120 Hulls, gaps, structures & waypoints implement ShallowRemove (= a method that's used to remove entities without severing links between them when copypasting).
Copied waypoints used to stay in the waypoint list, causing an exception to be thrown in PathFinder.GenerateNodes due to duplicate IDs.
2017-05-29 19:49:58 +03:00

388 lines
13 KiB
C#

using Microsoft.Xna.Framework;
using System.Collections.Generic;
using System.Linq;
namespace Barotrauma
{
class PathNode
{
private WayPoint wayPoint;
private int wayPointID;
public int state;
public PathNode Parent;
private Vector2 position;
public float F,G,H;
public List<PathNode> connections;
public List<float> distances;
public WayPoint Waypoint
{
get { return wayPoint; }
}
public Vector2 Position
{
get {return position;}
}
public PathNode(WayPoint wayPoint)
{
this.wayPoint = wayPoint;
this.position = wayPoint.SimPosition;
wayPointID = wayPoint.ID;
connections = new List<PathNode>();
}
public static List<PathNode> GenerateNodes(List<WayPoint> wayPoints)
{
var nodes = new Dictionary<int, PathNode>();
foreach (WayPoint wayPoint in wayPoints)
{
if (wayPoint == null) continue;
if (nodes.ContainsKey(wayPoint.ID))
{
DebugConsole.ThrowError("Error in PathFinder.GenerateNodes (duplicate ID \"" + wayPoint.ID + "\")");
continue;
}
nodes.Add(wayPoint.ID, new PathNode(wayPoint));
}
foreach (KeyValuePair<int,PathNode> node in nodes)
{
foreach (MapEntity linked in node.Value.wayPoint.linkedTo)
{
PathNode connectedNode = null;
nodes.TryGetValue(linked.ID, out connectedNode);
if (connectedNode == null) continue;
node.Value.connections.Add(connectedNode);
}
}
var nodeList = nodes.Values.ToList();
nodeList.RemoveAll(n => n.connections.Count == 0);
foreach (PathNode node in nodeList)
{
node.distances = new List<float>();
for (int i = 0; i< node.connections.Count; i++)
{
node.distances.Add(Vector2.Distance(node.position, node.connections[i].position));
}
}
return nodeList;
}
}
class PathFinder
{
public delegate float? GetNodePenaltyHandler(PathNode node, PathNode prevNode);
public GetNodePenaltyHandler GetNodePenalty;
private List<PathNode> nodes;
private bool insideSubmarine;
public PathFinder(List<WayPoint> wayPoints, bool insideSubmarine = false)
{
nodes = PathNode.GenerateNodes(wayPoints.FindAll(w => w.MoveWithLevel != insideSubmarine));
foreach (WayPoint wp in wayPoints)
{
wp.linkedTo.CollectionChanged += WaypointLinksChanged;
}
this.insideSubmarine = insideSubmarine;
}
void WaypointLinksChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
if (Submarine.Unloading) return;
var waypoints = sender as IEnumerable<MapEntity>;
foreach (MapEntity me in waypoints)
{
WayPoint wp = me as WayPoint;
if (me == null) continue;
var node = nodes.Find(n => n.Waypoint == wp);
if (node == null) return;
if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Remove)
{
for (int i = node.connections.Count - 1; i >= 0; i--)
{
//remove connection if the waypoint isn't connected anymore
if (wp.linkedTo.FirstOrDefault(l => l == node.connections[i].Waypoint) == null)
{
node.connections.RemoveAt(i);
node.distances.RemoveAt(i);
}
}
}
else if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add)
{
for (int i = 0; i < wp.linkedTo.Count; i++)
{
WayPoint connected = wp.linkedTo[i] as WayPoint;
if (connected == null) continue;
//already connected, continue
if (node.connections.Any(n => n.Waypoint == connected)) continue;
var matchingNode = nodes.Find(n => n.Waypoint == connected);
if (matchingNode == null)
{
#if DEBUG
DebugConsole.ThrowError("Waypoint connections were changed, no matching path node found in PathFinder");
#endif
return;
}
node.connections.Add(matchingNode);
node.distances.Add(Vector2.Distance(node.Position, matchingNode.Position));
}
}
}
}
public SteeringPath FindPath(Vector2 start, Vector2 end)
{
System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
sw.Start();
float closestDist = 0.0f;
PathNode startNode = null;
foreach (PathNode node in nodes)
{
Vector2 nodePos = node.Position;
float dist = System.Math.Abs(start.X - nodePos.X) +
System.Math.Abs(start.Y - nodePos.Y) * 10.0f; //higher cost for vertical movement
//prefer nodes that are closer to the end position
dist += Vector2.Distance(end, nodePos) / 10.0f;
if (dist<closestDist || startNode==null)
{
//if searching for a path inside the sub, make sure the waypoint is visible
if (insideSubmarine)
{
var body = Submarine.PickBody(
start, node.Waypoint.SimPosition, null,
Physics.CollisionWall | Physics.CollisionLevel | Physics.CollisionStairs | Physics.CollisionPlatform);
if (body != null)
{
if (body.UserData is Structure && !((Structure)body.UserData).IsPlatform) continue;
if (body.UserData is Item && body.FixtureList[0].CollisionCategories.HasFlag(Physics.CollisionWall)) continue;
}
}
closestDist = dist;
startNode = node;
}
}
if (startNode == null)
{
DebugConsole.NewMessage("Pathfinding error, couldn't find a start node", Color.DarkRed);
return new SteeringPath();
}
closestDist = 0.0f;
PathNode endNode = null;
foreach (PathNode node in nodes)
{
Vector2 nodePos = node.Position;
float dist = Vector2.Distance(end, nodePos);
if (dist < closestDist || endNode == null)
{
//if searching for a path inside the sub, make sure the waypoint is visible
if (insideSubmarine)
{
var body = Submarine.CheckVisibility(end, node.Waypoint.SimPosition);
if (body != null && body.UserData is Structure) continue;
}
closestDist = dist;
endNode = node;
}
}
if (endNode == null)
{
DebugConsole.NewMessage("Pathfinding error, couldn't find an end node", Color.DarkRed);
return new SteeringPath();
}
var path = FindPath(startNode,endNode);
sw.Stop();
System.Diagnostics.Debug.WriteLine("findpath: " + sw.ElapsedMilliseconds+" ms");
return path;
}
public SteeringPath FindPath(WayPoint start, WayPoint end)
{
PathNode startNode=null, endNode=null;
foreach (PathNode node in nodes)
{
if (node.Waypoint == start)
{
startNode = node;
if (endNode != null) break;
}
if (node.Waypoint == end)
{
endNode = node;
if (startNode != null) break;
}
}
if (startNode == null || endNode == null)
{
DebugConsole.NewMessage("Pathfinding error, couldn't find matching pathnodes to waypoints", Color.DarkRed);
return new SteeringPath();
}
return FindPath(startNode, endNode);
}
private SteeringPath FindPath(PathNode start, PathNode end)
{
if (start == end)
{
var path1 = new SteeringPath();
path1.AddNode(start.Waypoint);
return path1;
}
foreach (PathNode node in nodes)
{
node.state = 0;
node.F = 0.0f;
node.G = 0.0f;
node.H = 0.0f;
}
start.state = 1;
while (true)
{
PathNode currNode = null;
float dist = 10000.0f;
foreach (PathNode node in nodes)
{
if (node.state != 1) continue;
if (node.F < dist)
{
dist = node.F;
currNode = node;
}
}
if (currNode == null || currNode == end) break;
currNode.state = 2;
for (int i = 0; i < currNode.connections.Count; i++)
{
PathNode nextNode = currNode.connections[i];
//a node that hasn't been searched yet
if (nextNode.state==0)
{
nextNode.H = Vector2.Distance(nextNode.Position,end.Position);
if (GetNodePenalty != null)
{
float? nodePenalty =GetNodePenalty(currNode, nextNode);
if (nodePenalty == null)
{
nextNode.state = -1;
continue;
}
nextNode.H += (float)nodePenalty;
}
nextNode.G = currNode.G + currNode.distances[i];
nextNode.F = nextNode.G + nextNode.H;
nextNode.Parent = currNode;
nextNode.state = 1;
}
//node that has been searched
else if (nextNode.state==1)
{
float tempG = currNode.G + currNode.distances[i];
//only use if this new route is better than the
//route the node was a part of
if (tempG < nextNode.G)
{
nextNode.G = tempG;
nextNode.F = nextNode.G + nextNode.H;
nextNode.Parent = currNode;
}
}
}
}
if (end.state == 0 || end.Parent == null)
{
//path not found
return new SteeringPath(true);
}
SteeringPath path = new SteeringPath();
List<WayPoint> finalPath = new List<WayPoint>();
PathNode pathNode = end;
while (pathNode != start && pathNode != null)
{
finalPath.Add(pathNode.Waypoint);
//there was one bug report that seems to have been caused by this loop never terminating:
//couldn't reproduce or figure out what caused it, but here's a workaround that prevents the game from crashing in case it happens again
if (finalPath.Count > nodes.Count)
{
DebugConsole.ThrowError("Pathfinding error: constructing final path failed");
return new SteeringPath(true);
}
path.Cost += pathNode.F;
pathNode = pathNode.Parent;
}
finalPath.Add(start.Waypoint);
finalPath.Reverse();
foreach (WayPoint wayPoint in finalPath)
{
path.AddNode(wayPoint);
}
return path;
}
}
}