Expose most of the music handler to Lua

This exposes several music functions to Lua, while also enabling modders to add their own custom tune IDs.

Music system changes

Tunes can now be added via the Music_AddTune function. A set of tune flags can be passed to the function to assign various values on creation of a tune:

• TN_LOOPING
• TN_INCLUSIVEFADE
• TN_USEMAPVOLUME
• TN_SYNCMUSIC
• TN_MUSICCRED
• TN_VAPES
• TN_NIGHTCOREABLE
• TN_CHANGEPITCH (combination of TN_VAPES and TN_NIGHTCOREABLE)

A Music_SetFadeIn function has been added to the music framework, allowing for an easy way to set a tune's fade-in.

Example

I've created a Lua file that serves as a basic test for the music functions, playing existing base-game music.

ringracers0014.webm

muschangetest.lua

Everything has been tested in a Windows build. Both the Developer and Release presets have been used.

I'm not convinced that restricting this Lua-facing API to just one tune mimicking the legacy API would be the right approach. ACS already has full access to Music_Play, Music_Remap and Music_StopAll, plus a custom fade-in/fade-out function using g_musicfade, so I don't see why we shouldn't expose at least a large chunk of music.h to Lua directly. It might also be a good idea to add some more direct control over the music manager that music.h doesn't expose, using a hook, similarly to how SRB2Kart had the MusicChange hook.

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• 3369852a - Add ``Music_AddTune``, ``Music_TuneExists``, and tune creation flags
• 6ba5ee37 - Expose almost all of ``music.h`` to lua

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• 648d4724 - Get rid of the ``"lua"`` tune

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• c394732c - Clean up leftovers of the prior implementation

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• 35fd3fb5 - Get rid of ``credit_hidden``

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• db96c6b8 - Get rid of credit hiding functions

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Do you mind cleaning up the commit history by force pushing a flatter diff? Adding and then removing significant amounts of code makes git bisect harder to manage

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• ddc89121 - Expose most of music.h to Lua

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changed title from Partially expose music to Lua to Expose most of the music handler to Lua

added Lua label

I am uncomfortable with adding anything that retrieves client-sided information about the music's state, because they can create desyncs online. The music functions already in ACS and the new tune functions are OK, because they do their function without giving you any additional information about the music's state.

See the explanation here on why: !38 (comment 61422)

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• fb448fd5 - Remove functions that retrieve client-sided information

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• 90860cc6 - Remove Lua function for ``Music_TuneExists``

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resolved all threads

added 42 commits

• 90860cc6...e4b81494 - 39 commits from branch KartKrew:master
• 72c7ee0e - Expose most of music.h to Lua
• f65d59a8 - Remove functions that retrieve client-sided information
• 3feb03ef - Remove Lua function for ``Music_TuneExists``

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mentioned in commit 61956f59

merged