/// <summary>
/// Constructor
/// </summary>
/// <param name="width">Width in pixels</param>
/// <param name="height">Height in pixels</param>
/// <param name="g">Game Reference</param>
/// <param name="_gw">GameWorld Reference</param>
public NavMeshManager(int width, int height, Game g)
{
nodeList = new List <PolygonNode>();
PolygonNode root = new PolygonNode(new Rectangle(0, 0, width, height));
nodeList.Add(root);
game = g;
}
/// <summary>
/// Returns an array of polygons that form a path
/// between the two provided points from start to finish.
/// </summary>
/// <param name="start">Starting point</param>
/// <param name="finish">Finish</param>
/// <returns>Path</returns>
public PolygonNode[] getPath(Point start, Point finish)
{
List <PolygonNode> closedSet = new List <PolygonNode>();
List <PolygonNode> openSet = new List <PolygonNode>();
List <PolygonNode> came_from = new List <PolygonNode>();
int g_score = 0;
int h_score = getHScore(start, finish);
int f_score = 0;
PolygonNode endzone = getNodeFromPosition(finish);
openSet.Add(getNodeFromPosition(start));
PolygonNode current = openSet.ElementAt <PolygonNode>(0);
openSet.Remove(current);
closedSet.Add(current);
while (true)
{
if (current == endzone)
{
break;
}
foreach (PolygonNode pn in current.getAdjacentNodes())
{
if (closedSet.Contains(pn))
{
continue;
}
if (!openSet.Contains(pn))
{
openSet.Add(pn);
pn.parent = current;
}
}
current = getNodeWithLowestFScore(openSet, g_score, finish);
if (current == null)
{
throw new Exception("There is no spoon.");
}
openSet.Remove(current);
closedSet.Add(current);
}
List <PolygonNode> output = new List <PolygonNode>();
while (current != null)
{
output.Add(current);
current = current.parent;
}
output.Reverse();
nullParents();
return(output.ToArray());
}
/// <summary>
/// Add a new unwalkable rectangle
/// </summary>
/// <param name="rect">Rectangle to block.</param>
public void addRectangle(Rectangle rect)
{
tex = game.Content.Load <Texture2D>("White");
PolygonNode[] overlaps = getOverlappingNodes(rect);
List <PolygonNode> newNodes = new List <PolygonNode>();
List <Point> vertices = new List <Point>();
addVertex(vertices, new Point(rect.Left, rect.Top));
addVertex(vertices, new Point(rect.Left, rect.Bottom));
addVertex(vertices, new Point(rect.Right, rect.Top));
addVertex(vertices, new Point(rect.Right, rect.Bottom));
foreach (PolygonNode pn in overlaps)
{
Rectangle oldRect = pn.rectangle;
addVertex(vertices, new Point(oldRect.Left, oldRect.Top));
addVertex(vertices, new Point(oldRect.Left, oldRect.Bottom));
addVertex(vertices, new Point(oldRect.Right, oldRect.Top));
addVertex(vertices, new Point(oldRect.Right, oldRect.Bottom));
addOverlapVerts(vertices, oldRect, rect);
}
Point badPoint = new Point(-1, -1);
foreach (Point origin in vertices)
{
Point left = getClosestLeft(origin, vertices);
Point bottom = getClosestBottom(origin, vertices);
if (left.Equals(badPoint) || bottom.Equals(badPoint))
{
continue;
}
int width = left.X - origin.X;
int height = bottom.Y - origin.Y;
Rectangle newRect = new Rectangle(origin.X, origin.Y, width, height);
if (rect.Contains(newRect.Center))
{
continue;
}
if (!newRect.Equals(rect))
{
PolygonNode newPoly = new PolygonNode(newRect);
// newPoly.rectangle.Inflate(1,1);
nodeList.Add(newPoly);
newNodes.Add(newPoly);
}
}
redoAdj(overlaps, newNodes.ToArray());
foreach (PolygonNode pn in overlaps.ToArray())
{
nodeList.Remove(pn);
}
}
/// <summary>
/// Adds each node to the other's adjacency list.
/// </summary>
/// <param name="p1">First node.</param>
/// <param name="p2">Second node.</param>
public static void linkPolygons(PolygonNode p1, PolygonNode p2)
{
if (p1 == p2)
{
throw new Exception("A polygon can't be adjacent to itself.");
}
if (!p1.adjacentNodes.Contains(p2))
{
p1.addNode(p2);
}
if (!p2.adjacentNodes.Contains(p1))
{
p2.addNode(p1);
}
}
/// <summary>
/// Method for getting the node with the f_score from the given set.
/// </summary>
/// <param name="set">Nodes to check</param>
/// <param name="g_score">Current g_score</param>
/// <param name="end">Finish</param>
/// <returns></returns>
private PolygonNode getNodeWithLowestFScore(IEnumerable <PolygonNode> set, int g_score, Point end)
{
int lowest = int.MaxValue;
PolygonNode pnLowest = null;
foreach (PolygonNode pn in set)
{
int _f = getHScore(pn.rectangle.Center, end) + g_score;
if (_f < lowest)
{
lowest = _f;
pnLowest = pn;
}
}
return(pnLowest);
}
/// <summary>
/// This is not really working it should be the point
/// that one should pass through between to polygons.
/// </summary>
/// <param name="pn1">First Polygon</param>
/// <param name="pn2">Second Polygon</param>
/// <returns>the sweet spot</returns>
public static Point getConnectionPoint(PolygonNode pn1, PolygonNode pn2)
{
if (pn1 == pn2)
{
throw new Exception("A node cannot be connected to itself.");
}
if (!pn1.adjacentNodes.Contains(pn2))
{
throw new Exception("These nodes are not adjacent and therefore have no connection point.");
}
Rectangle r1 = pn1.rectangle;
Rectangle r2 = pn2.rectangle;
int x = -10;
int y = -10;
if (r1.Top == r2.Bottom)
{
y = r1.Top;
}
if (r1.Bottom == r2.Top)
{
y = r1.Bottom;
}
if (r1.Left == r2.Right)
{
x = r1.Left;
}
if (r1.Right == r2.Left)
{
x = r1.Right;
}
if (x == -10)
{
int n = (Math.Max(r1.Width, r2.Width) - Math.Abs(r1.X - r2.X));
x = n / 2 + Math.Max(r1.X, r2.X);
}
if (y == -10)
{
int n = (Math.Max(r1.Height, r2.Height) - Math.Abs(r1.Y - r2.Y));
y = n / 2 + Math.Max(r1.Y, r2.Y);
}
return(new Point(x, y));
}
/// <summary>
/// Check if two PolygonNodes are adjacent.
/// </summary>
/// <param name="p1">First Node</param>
/// <param name="p2">Second Node</param>
/// <returns>True if they are next to each other.</returns>
public static bool areTheseAdjacent(PolygonNode p1, PolygonNode p2)
{
Rectangle r1 = p1.rectangle;
Rectangle r2 = p2.rectangle;
r1.Inflate(1, 0);
if (r1.Intersects(r2))
{
return(true);
}
r1.Inflate(-1, 1);
if (r1.Intersects(r2))
{
return(true);
}
r1.Inflate(0, -1);
return(false);
}
/// <summary>
/// Redoes the adjacency's of all of the effected polygons.
/// </summary>
/// <param name="oldNodes">Nodes to be deleted</param>
/// <param name="newNodes">New nodes generated</param>
private void redoAdj(IEnumerable <PolygonNode> oldNodes, IEnumerable <PolygonNode> newNodes)
{
foreach (PolygonNode pnOld in oldNodes)
{
foreach (PolygonNode pnAdj in pnOld.getAdjacentNodes())
{
pnAdj.removeNode(pnOld);
foreach (PolygonNode pnNew in newNodes)
{
if (pnNew == pnAdj)
{
continue;
}
if (PolygonNode.areTheseAdjacent(pnNew, pnAdj))
{
PolygonNode.linkPolygons(pnNew, pnAdj);
}
}
}
}
foreach (PolygonNode pn1 in newNodes)
{
foreach (PolygonNode pn2 in newNodes)
{
if (pn1 == pn2)
{
continue;
}
if (PolygonNode.areTheseAdjacent(pn1, pn2))
{
PolygonNode.linkPolygons(pn1, pn2);
}
}
}
}
/// <summary>
/// Adds an adjacent node from this node.
/// </summary>
/// <param name="pn">Node to add</param>
/// <returns>True</returns>
public bool addNode(PolygonNode pn)
{
adjacentNodes.Add(pn);
return(true);
}
/// <summary>
/// Removes an adjacent node from this node.
/// </summary>
/// <param name="pn">Node to remove</param>
/// <returns>True if it was in the list, false otherwise.</returns>
public bool removeNode(PolygonNode pn)
{
return(adjacentNodes.Remove(pn));
}
