Treesharp C# behavior tree library - where to start?

Recently I have been attempting to implement a robust behavior tree using the treesharp library posted by apoc. I have been going over iterators and interfaces in my books, but I still can't even figure out how to test let alone use this library. How the interfaces connect with eachother and how to actually perform a test/build a tree with them is confusing the heck out of me.

Usually in this situation, I wou开发者_JAVA技巧ld look for code examples and derive enlightenment from looking at other people's work, however, for this library, there does not seem to be any example code.

Could anyone help me figure out how I could start to build a behavior tree using this library? I am sorry if the question is very noobish (and I think it may be) but Enumerators and progressive interfaces within interfaces are extremely difficult for me to understand right now.

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I'm the author of TreeSharp, if you guys have any questions, feel free to shoot me an email (its contained in every source file in the header).

You'll first need to understand the concepts of behavior trees (the differences between selectors, sequences, decorators, actions, and the like). I also provide a few "vanity" composites to make things slightly easier (such as Wait).

The constructor-based API lets you define trees entirely via ctors (with the use of delegates which are evaluated at runtime to provide decisions, etc)

Unfortunately I never got around to implementing the "TreeExecutor" class, which handles executing an arbitrary behavior branch from something like a Tick() method. The easiest way (using a PrioritySelector in this example, but you can use any composite) is as follows;

    static void Start()
    {
        // Start MUST be called before you can tick the tree.
        Logic.Start(null);
        // do work to spool up a thread, or whatever to call Tick();
    }

    private static void Tick()
    {
        try
        {             
            Logic.Tick(null);
            // If the last status wasn't running, stop the tree, and restart it.
            if (Logic.LastStatus != RunStatus.Running)
            {
                Logic.Stop(null);
                Logic.Start(null);
            }
        }
        catch (Exception e)
        {
            // Restart on any exception.
            Logging.WriteException(e);
            Logic.Stop(null);
            Logic.Start(null);
            throw;
        }
    }

Unfortunately, giving "examples" of its usage really depends on what you're using it for. (Since its so generic, its difficult to give examples that will make sense for any given project. I've been using it from things to AI logic, to workflows, down to scheduling processes)

A small example which may help a bit;

    static Composite CreateFireMissile()
    {
        return new PrioritySelector(
            new Decorator(ret => CurrentShip.CurrentTarget != null,
                new Action(ret => CurrentShip.CurrentTarget.FireMissile())),

            new Decorator(ret => CurrentShip.CurrentTarget == null,
                new Decorator(ret => CurrentShip.NearbyHostiles.Count > 0,
                    new Sequence(
                        new Action(ret => CurrentShip.SetTarget(CurrentShip.NearbyHostiles[0])),
                        new Action(ret => CurrentShip.RotateTo(CurrentShip.CurrentTarget.Location))
                        )
                    )
                )       
        );
    }

Again, this really depends on your requirements. The library will let you subclass any composites for easier to re-use composites. (Eg; you can create a SetTargetAndRotate action, which eliminates the two actions within the Sequence)

Again, if you guys have questions, don't hesitate to ask.

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Jason, The library seems to implement all the ideas I've seen demonstrated in other examples of BT libraries. I'm looking into leveraging such a library for one of my own projects, so until I do, I'm only guessing on how to use this one based on a brief inspection.

Nevertheless, I think you would supply your own callback functions to instances of the Action class, and then piece together various actions into group combinations based on BT ideas (wait until something is true before acting, act until one of these actions is successful, perform all these actions unless one fails, etc).

HTH