Add support for mods to hide/disable existing data files

[johnbartholomew]

Sometimes it is desirable for mods to be able to disable data files that come in the main distribution. For example, if someone wants to provide a mod that keeps the gameplay features but changes all the models, it is necessary not just to add in new models but also to prevent the game from using the default ones.

To do this, we should look for an optional manifest file in the root of the mod. This file can specify files to disable. Later on there will be other information about the mod that could be useful, such as mod title, author, version, description, game version compatibility, and probably other things.

[fluffyfreak]

Alternatively we could actually ship the engine bare and have the Pioneer data as a mod file?

For the actual Pioneer distribution of course that mod would be there by default.

[johnbartholomew]

If the Pioneer data is just a single mod then that doesn't help. However, packaging the Pioneer data as a set of mods that can be enabled separately is a good idea.

[johnbartholomew]

Also related conversation from IRC:

<jpab> robn: Should mods be able to hide/disable files? If so, how do we do it?
<jpab> Perhaps an optional manifest file in the root of a mod zip, that can specify files to disable and later other information about the mod (title, author, description etc)?
<robn> I think the manifest file is the right way to go. we'll need it anyway for info as you say. without saying "disable this file" the mod has to provide a zero-size file or something
<robn> longer term we might like to sometime annotate certain bits of code with names, and then be able to say "disable this feature" instead of specific files
<robn> its a bit more flexible, and future proof
<robn> that's more manifest file
<robn> so its a good way to do it
<jpab> zero-size file doesn't always work with current code -- it's fine for things like scripts where you just load the empty file and it does nothing, but for other data files it can cause problems
<robn> we should probably provide some sort of manifest helper script, and/or template. though probably a mod with no manifest can just get a default of "add all the files"
<robn> jpab: that's true, good point
<robn> more plusses for manifest
<jpab> re: features, perhaps the easiest way of doing that is for more core content to be provided as built-in "mods"
<robn> ooh, interesting
<robn> I do like that.
<robn> ok, I'm going to assume that this is the direction we're working towards

[bszlrd]

Hmm, I think I might bump this.
I'm thinking about (planning actually) a total conversion mod, where it would be useful. I'm also thinking about making a barebones mode that could be loaded quite fast, to reduce loading times as far as possible. Which would make some testing stuff a bit faster. Like for checking new modes, ships, scripts even.