TLpath, A* pathfinding for Love

[Taehl]

I hope this will be handy. TLpath is a fast, efficient pathfinder which I've built to be as flexible as possible. But despite my best efforts, pathfinding isn't a simple thing, so this isn't completely a fire-and-forget solution. To implement it in a given game, you'll need to add path nodes and (likely) give it an appropriate g-function. But other than that, it should be pretty easy to get along with. It even does its work in a separate thread, so your game can continue working as normal while it finds paths for you. It comes with a simple demo showing off how fast it is and how to use it. So let's see some AI in your games!

Download: Here
Documentation/wiki: TLpath

Comments? Critique? Accolades? Need help using it? This is the place for it.

[Robin]

Looks interesting.

Accolades?

{, }

[kikito]

[vrld]

The demo doesn't work for me:

Code: Select all

Error: [string "main.lua"]:174: attempt to index field '?' (a nil value)

Also set[GH]function feel akward. You can serialize functions (without upvalues) using string.dump:

Code: Select all

function foo() print('bar') return 'baz' end
serialized = string.dump(foo) --> function bytecode
magic = loadstring(serialized)
print( magic() )

Edit: Wait, it worked. Then it failed on line 143 (attempt to index local 'b').
Sometimes love locks completely (deadlock somewhere?)

[Taehl]

I have a .zip instead of a .love file to make it that much easier to open up and get the files from - it's not a game in and of itself.

I have no idea what your problems are from, vrld. I don't experience those. I've updated the download, which may help. set[GH]function are for convenience. If you don't want to use them, you can go rewrite the gScore and hScore functions in TLpath.lua (lines 78 and 80).

[vrld]

I've updated the download, which may help.

That fixed it.

set[GH]function are for convenience.

They would be more convenient if I could pass true lua functions instead of strings, possibly alongside with some custom data:

Code: Select all

TLpath.setGfunction(function(a,b, my_data)
    local function reachable() ... stuff with my_data ... end
    return reachable() and math.abs(b.x - a.x) + math.abs(b.y - a.y)
end, walls)

That would feel less hackish to me and allow the editor to highlight the code

[Lap]

Straight into my game whenever vrld's suggestion gets added. Well done.

[ishkabible]

can you make a Dijkstra's path finding option? i have an un-encapsulated implementation if you want to look at it. it names nodes by string and lets you build your network. with a bit of modification to the NewNode function it could store whatever data it needed(like coordinates). the benefit of Dijkstra's algorithm here is you don't need a uniform plane for it to work. say you want to put a few rocks in the way, no biggy you simply wont put a node there.

[Taehl]

They would be more convenient if I could pass true lua functions instead of strings, possibly alongside with some custom data:

I'd love to offer that, but you can only send strings and numbers (and maybe bools?) to threads, and the resulting functions would have to have the right name or else it wouldn't work. The best I can do is send code as a string and execute it on the other side.

it names nodes by string and lets you build your network. with a bit of modification to the NewNode function it could store whatever data it needed(like coordinates). the benefit of Dijkstra's algorithm here is you don't need a uniform plane for it to work. say you want to put a few rocks in the way, no biggy you simply wont put a node there.

I don't see why you can't do that in A*? My demo only uses a grid for half of the maps just to show it can be done. Technically you don't even need to place and g-score nodes by coordinates, if you have a different method.

[vrld]

I'd love to offer that, but you can only send strings and numbers (and maybe bools?) to threads, and the resulting functions would have to have the right name or else it wouldn't work.

You can serialize functions (without upvalues) using string.dump:

Code: Select all

function foo() print('bar') return 'baz' end
serialized = string.dump(foo) --> function bytecode
magic = loadstring(serialized)
print( magic() )