Writing stuff in separate files

[Xrocetoxtos]

Hi people, I'm new here (well, I have some Löve experience back in the past, but switched to Unity and revisiting Löve now)

I am working on a survival game of currently just blocks avoiding each other and I'm getting to the point of inserting some animations and graphics. To avoid my files being very large and stuff being hard to find and debug, I want graphics stuff, AI stuff, inventory stuff etc outside the main.lua if it's possible.

I know you can use the require to link to other files, but can anyone tell me how to set that up? I'm planning to have a graphics.lua file that will contain a couple of references like an image called "spritesheet" and a couple of functions to do something with that image. in main.lua, I want to access those functions and references in code, like in love.draw().

for instance:

Code: Select all

-- main.lua

graphics = require 'graphics'

-- [...]

function love.update(dt)
	graphics.doSomething(dt)
end

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-- graphics.lua

function doSomething(dt)
	-- AAA-style graphics doing mindboggling stuff
end

How should that be done?

[Andlac028]

Basically, modify your graphics.lua to return table, like:

Code: Select all

local graphics = {}

function graphics.doSomething(a, b)
    -- your logic here
end

-- maybe more functions

return graphics

Then you can just do what you have in main.lua (note that if graphics.lua is not in same directory as main.lua (for example it is in scripts/graphics.lua, you need do call require with ‘scripts.graphics’ instead of ‘graphics’ only)

[BrotSagtMist]

Well there are basically two ways of using require:
We can just use it to plain insert any file at that place so that the end result behaves as being one file.
Or we handle it as a block that returns a result that can be used, as explained above.

For private use its just a matter of if you want to ad "graphics" before every call or not.
Libs however are required to use the later format.

[Xrocetoxtos]

Thank you both. What I meant was exactly what Andlac was suggesting. I'll use it that way, except the other way is even better for my taste, so he's one more question:

We can just use it to plain insert any file at that place so that the end result behaves as being one file.

does this in practice mean that in my example the require needed to be inside the love.update? Something like this:

Code: Select all

function love.update(dt)
	graphics = require 'graphics'
	doSomething(dt)
end

Or should it be written differently? Or does it not work like that at all?

[BrotSagtMist]

Yea the thing is that require itself is a wrapper around the actual code insert and as such does a little bit more than just adding it.
Specifically it resolves and searches all possible paths for libs, inspects what the file is about and keeps track about if that file has been used already.
What you wrote there would mean to check for a file in a bunch of places 60 times per second, yea thats a bit stupid.
It also wont work because as it keeps track of what it already opened before it will simply ignore this.

You could make this work by using the dofile() function instead, which lacks the trackkeeping and place resolving.
But again, reading a file 60 times per second isnt normal.

You could read the file once and then insert it using just do, but thats just require with extra steps.

Your example would neet to look like this:

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--something.lua
function doSomething(dt)
-- stuff
end

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--main.lua
require(something)
function love.update(dt)
	doSomething(dt)
end

[Xrocetoxtos]

Ah right. I think I understand. i probably like the other way better, with graphics.doSomething(). Maybe once I'm more versed in lua and less in c#, it might feel more comfortable. Thanks anyway, I'll let my people bring you guys the karma

[Xrocetoxtos]

Hmm I think I'm still misunderstanding something, because I have this thing in my love.load now in main.lua

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objects = require 'objects'

player=objects.Player:new([... params...)

then there is objects.lua

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local objects={}

Player={}
function objects:Player:new([...params...])
...
end

If I run this, Löve tells me it can't index field 'Player' because it's nil. Now I can solve this by using the other way of referencing the file, like you suggested, BrotSagtMist, and remove the references to 'objects', but how do I use the objects....- or objects:... way?

does this question make sense?

[BrotSagtMist]

Ahh yea sweet dejavu.
We just had a thread here viewtopic.php?f=4&t=94465
The TLDR is: I am out.

[Andlac028]

Hmm I think I'm still misunderstanding something, because I have this thing in my love.load now in main.lua

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objects = require 'objects'

player=objects.Player:new([... params...)

then there is objects.lua

Code: Select all

local objects={}

Player={}
function objects:Player:new([...params...])
...
end

If I run this, Löve tells me it can't index field 'Player' because it's nil. Now I can solve this by using the other way of referencing the file, like you suggested, BrotSagtMist, and remove the references to 'objects', but how do I use the objects....- or objects:... way?

does this question make sense?

Yes, Player is undefined, because it is not in table, use something like this:

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local objects = {
    Player = {},
    more = {}
}

function object.Player.something()
end

return objects

Note that there is actually difference when using . and : and how you then can use self, but to better understand it, I recommend you manual for Lua OOP mentioned in the thread mentioned above (sorry, I am on phone and too lazy to find and copy link, just search for some Lua OOP tutorials)

[Xrocetoxtos]

I will check that out. Thank you for the help anyway.