[SOLVED] Jumper exception thrown not expected

[nyenye]

First of all I've created a new thread, because Jumper's thread isn't active since 2009...

Now the exception that I get is as follows

Screenshot from 2016-12-25 18-27-55.png (27.08 KiB) Viewed 5524 times

and at line 330 we find:

Screenshot from 2016-12-25 18-29-11.png (144.02 KiB) Viewed 5524 times

The thing is that the map that I pass on is correctly formated. See map.txt

map.txt

(1.93 KiB) Downloaded 121 times

[nyenye]

Sorry about repost, but couldn't attach game.love on the same entry, dunno why though.

[Zeliarden]

math.floor or ceil the input coordinates will fix the problem

Code: Select all

assert(startNode, ('Invalid location [%d, %d]'):format(startX, startY))

outputs the integer (12,12) value of startX, startY instead of the real value (12.5, 12.5 or something like that)

[raidho36]

Doesn't that generates strings every time this functions is called? Because all (assert) function arguments are evaluated before it is called. That's hugely wasteful.

[Positive07]

Yes it does, assert is a really inefficient function since the string is evaluated regardless of being valid or not... I usually use simple checks

Code: Select all

if not startNode then
   error(('Invalid location [%d, %d]'):format(startX, startY), 1)
end

Which also lets you specify the start depth of the stack traceback

[nyenye]

Thanks for the tips, I'll give it a shot. About the performance problem, I thought that Jumper was the standard library for pathfinding in Lua/Love2D. Do you have any other recomendation? Or do you make your own implementation?

[raidho36]

There's no "standard" anything in Lua, because it's a "there are many ways to do this" kind of language. But sure enough, generating strings in asserts will slow things down substantially for no reason. Not only creating an unique string is not a fast operation, but also the result is immediately discarded and becomes garbage thus contributing to runtime overhead, and all of that on top of never needing to do any of it in the first place.

[nyenye]

There's no "standard" anything in Lua...

Thanks for the info. Then do you have any "better" or different implementation for Pathfinding? Or maybe just change the code of the library to do what Positive07 said?

[raidho36]

I don't have anything in my sights, so yes you could just replace wasteful asserts with less intensive checks, or even remove them altogether since they serve no practical function and only exist to assist debugging.