// Computes a (hopefully) efficient connection from one Platform start to Platform end
private List <Waypoint> ComputeConnection(NavGraphNode start, NavGraphNode end)
{
List <Waypoint> res = new List <Waypoint>();
Collidable startC = start.Platform;
Collidable endC = end.Platform;
// Position of the transition waypoints between the two nodes
Vector2 fst, snd;
foreach (Tuple <NavGraphNode, Vector2, Vector2> t in start.ReachableNodes)
{
if (t.Item1 == end)
{
fst = t.Item2; // waypoint on start
snd = t.Item3; // waypoint on end
// if different platforms (but roughly on same height): ensure, that the waypoint clearly
// lies on the target platform
if (end.Platform != start.Platform && Math.Abs(fst.Y - snd.Y) <= AiConfig.DISTANCE_JUMP_VERT &&
Math.Abs(fst.X - snd.X) > AiConfig.DISTANCE_JUMP_MIN_HOR)
{
if (fst.X < snd.X)
{
snd.X += AiConfig.DISTANCE_OVERSHOOT_HOR;
}
else if (fst.X > snd.X)
{
snd.X -= AiConfig.DISTANCE_OVERSHOOT_HOR;
}
}
// If target-waypoint is higher up (and only reachable by climbing): ensure that the
// AI climbs high enough and doesn't get stuck at the top
if (fst.Y > snd.Y && Math.Abs(fst.Y - snd.Y) > AiConfig.DISTANCE_JUMP_VERT)
{
fst.Y -= AiConfig.DISTANCE_OVERSHOOT_UP;
snd.Y -= 0.8f * AiConfig.DISTANCE_OVERSHOOT_UP;
}
else if (fst.Y < snd.Y && Math.Abs(fst.Y - snd.Y) > AiConfig.DISTANCE_JUMP_VERT)
{
fst.Y -= AiConfig.DISTANCE_OVERSHOOT_UP;
}
// Add in the correct order
res.Add(new Waypoint(new Vector3(fst.X, fst.Y, 0), startC));
res.Add(new Waypoint(new Vector3(snd.X, snd.Y, 0), endC));
return(res);
}
}
return(res);
}
// Compute waypoints from start to target via the paths defined with the pathMap<next, previous>
private List <Waypoint> BacktrackPath(Dictionary <NavGraphNode, NavGraphNode> pathMap, NavGraphNode start, NavGraphNode target)
{
List <Waypoint> res = new List <Waypoint>();
NavGraphNode current = target;
while (current != start)
{
NavGraphNode next = pathMap[current];
// Compute path from previous (next) to the current one (<- reverse order)
res.InsertRange(0, ComputeConnection(next, current));
current = next;
}
return(res);
}
public NavGraph(Scene scene)
{
this.scene = scene;
NavGraphNodes = new NavGraphNode[scene.WalkableCollidables.Count];
CurrClimbGroup = new List <ClimbGroup>();
//Init a NavGraphNode for each walkable platform in the scene
for (var i = 0; i < NavGraphNodes.Length; i++)
{
NavGraphNodes[i] = new NavGraphNode(scene.WalkableCollidables[i]);
}
InitClimbGroups();
InitClimbReachableNodes();
InitCloseReachableNodes();
scene.NavigationGraph = this;
}
private List <Waypoint> ComputePath(Collidable currP, Collidable tgtP)
{
List <Waypoint> res = new List <Waypoint>();
// Map to remember last step of fastest connection to <key>
Dictionary <NavGraphNode, NavGraphNode> pathMap = new Dictionary <NavGraphNode, NavGraphNode>();
NavGraphNode start = scene.NavigationGraph.findNode(currP);
NavGraphNode target = null;
// Do breadth-first-search on NavGraph (start by adding all neighboring nodes of the start node to "to visit")
// <which new node to visit, last platform before this new one>
List <Tuple <NavGraphNode, NavGraphNode> > toVisit = new List <Tuple <NavGraphNode, NavGraphNode> >();
foreach (Tuple <NavGraphNode, Vector2, Vector2> t in start.ReachableNodes)
{
if (!pathMap.ContainsKey(t.Item1))
{
pathMap.Add(t.Item1, start);
toVisit.Add(new Tuple <NavGraphNode, NavGraphNode>(t.Item1, start));
}
}
while (toVisit.Count > 0)
{
Tuple <NavGraphNode, NavGraphNode> t = toVisit.First();
NavGraphNode next = t.Item1;
toVisit.RemoveAt(0);
// Check if the currently visited node is the target platform
if (next.Platform == tgtP)
{
// Found our target platform
if (!pathMap.ContainsKey(next))
{
pathMap.Add(next, t.Item2);
}
target = t.Item1;
break;
}
// Not yet reached our target, check connections to other platforms (which not have been visited yet)
foreach (Tuple <NavGraphNode, Vector2, Vector2> newConn in next.ReachableNodes)
{
if (!pathMap.ContainsKey(newConn.Item1))
{
// Not yet visited
if (!pathMap.ContainsKey(newConn.Item1))
{
pathMap.Add(newConn.Item1, next);
toVisit.Add(new Tuple <NavGraphNode, NavGraphNode>(newConn.Item1, next));
}
}
}
}
// Check if target platform has been found
if (target != null)
{
// Compute final path
res = BacktrackPath(pathMap, start, target);
}
return(res);
}
private void InitCloseReachableNodes()
{
for (int i = 0; i < NavGraphNodes.Length; i++)
{
NavGraphNode n = NavGraphNodes[i];
for (int j = i; j < NavGraphNodes.Length; j++)
{
NavGraphNode o = NavGraphNodes[j];
// Check if vertically close enough
if (Math.Abs(n.Platform.MinHeight - o.Platform.MinHeight) <= AiConfig.DISTANCE_JUMP_VERT)
{
// Check horizontal displacement
Vector2 nMm = n.Platform.WalkableMinMax;
Vector2 oMm = o.Platform.WalkableMinMax;
float leftDis = nMm.X - oMm.Y;
float rightDis = oMm.X - nMm.Y;
if (leftDis <= AiConfig.DISTANCE_JUMP_MAX_HOR && leftDis >= -AiConfig.DISTANCE_VALID_OVERLAP)
{
// Horizontally reachable (both ways) on the left side of n
Vector2 wpN = new Vector2(nMm.X + AiConfig.DISTANCE_OFFS_DROP_HOR, n.Platform.MinHeight - AiConfig.DISTANCE_OFFS_DROP_HOR);
Vector2 wpO = new Vector2(oMm.Y - AiConfig.DISTANCE_OFFS_DROP_HOR, o.Platform.MinHeight - AiConfig.DISTANCE_OFFS_DROP_HOR);
Vector2 diff = wpN - wpO;
if (!IsWithinPlatform(wpN - 0.3f * diff) && !IsWithinPlatform(wpO + 0.3f * diff) &&
!IsWithinPlatform(wpN) && !IsWithinPlatform(wpO))
{
n.ReachableNodes.Add(new Tuple <NavGraphNode, Vector2, Vector2>(o, wpN, wpO));
o.ReachableNodes.Add(new Tuple <NavGraphNode, Vector2, Vector2>(n, wpO, wpN));
}
}
else if (rightDis <= AiConfig.DISTANCE_JUMP_MAX_HOR && rightDis >= -AiConfig.DISTANCE_VALID_OVERLAP)
{
// Horizontally reachable (both ways) on the right side of n
Vector2 wpN = new Vector2(nMm.Y - AiConfig.DISTANCE_OFFS_DROP_HOR, n.Platform.MinHeight - AiConfig.DISTANCE_OFFS_DROP_HOR);
Vector2 wpO = new Vector2(oMm.X + AiConfig.DISTANCE_OFFS_DROP_HOR, o.Platform.MinHeight - AiConfig.DISTANCE_OFFS_DROP_HOR);
Vector2 diff = wpN - wpO;
if (!IsWithinPlatform(wpN - 0.3f * diff) && !IsWithinPlatform(wpO + 0.3f * diff) &&
!IsWithinPlatform(wpN) && !IsWithinPlatform(wpO))
{
n.ReachableNodes.Add(new Tuple <NavGraphNode, Vector2, Vector2>(o, wpN, wpO));
o.ReachableNodes.Add(new Tuple <NavGraphNode, Vector2, Vector2>(n, wpO, wpN));
}
}
}
else
{
NavGraphNode above, below;
if (n.Platform.MinHeight < o.Platform.MinHeight)
{
// N is higher then O
above = n;
below = o;
}
else
{
// O is higher then N
above = o;
below = n;
}
// Check horizontal overlap of the platforms
Vector2 abMm = above.Platform.WalkableMinMax;
Vector2 belMm = above.Platform.WalkableMinMax;
if (abMm.X >= belMm.X)
{
// Can drop from platform above to below (left side)
Vector2 wpAbove = new Vector2(abMm.X - AiConfig.DISTANCE_OFFS_DROP_COLL, above.Platform.MinHeight - AiConfig.DISTANCE_OFFS_DROP_COLL_VERT);
Vector2 wpBelow = new Vector2(abMm.X - AiConfig.DISTANCE_OFFS_DROP_COLL, below.Platform.MinHeight - 5);
if (!IntersectsWithCollidable(wpAbove, wpBelow - wpAbove))
{
wpAbove += new Vector2(-AiConfig.DISTANCE_OFFS_DROP_HOR, AiConfig.DISTANCE_OFFS_DROP_COLL_VERT - AiConfig.DISTANCE_OFFS_DROP_HOR);
wpBelow += new Vector2(-AiConfig.DISTANCE_OFFS_DROP_HOR, 0);
above.ReachableNodes.Add(new Tuple <NavGraphNode, Vector2, Vector2>(below, wpAbove, wpBelow));
}
}
else if (abMm.Y <= belMm.Y)
{
// Can drop from platform above to below (right side)
Vector2 wpAbove = new Vector2(abMm.X + AiConfig.DISTANCE_OFFS_DROP_COLL, above.Platform.MinHeight - AiConfig.DISTANCE_OFFS_DROP_COLL_VERT);
Vector2 wpBelow = new Vector2(abMm.X + AiConfig.DISTANCE_OFFS_DROP_COLL, below.Platform.MinHeight - 5);
if (!IntersectsWithCollidable(wpAbove, wpBelow - wpAbove))
{
wpAbove += new Vector2(AiConfig.DISTANCE_OFFS_DROP_HOR, AiConfig.DISTANCE_OFFS_DROP_COLL_VERT - AiConfig.DISTANCE_OFFS_DROP_HOR);
wpBelow += new Vector2(AiConfig.DISTANCE_OFFS_DROP_HOR, 0);
above.ReachableNodes.Add(new Tuple <NavGraphNode, Vector2, Vector2>(below, wpAbove, wpBelow));
}
}
}
}
}
}
