A few facts of life:
- Guest difficulties are at this point a staple of mapping.
- People are very much used to flinging `.osu`s around (because there's
no better alternative).
- Currently there are two ways to get an `.osu` out of lazer. You can:
- Export the beatmap as "compatibility" to an `.osz`, then
transmogrify the `.osz` to a `.zip`, then extract the `.zip`, then
pluck out the `.osu`. This is the "correct" way to make sure stable
works, but is also stupidly arcane.
- Use "edit externally" to mount the beatmap files to disk, then
copy-paste out the `.osu`. This is the *wrong* way to make sure
stable works, because the mounting process exposes the raw "for
editing" format with features stable doesn't support, but it the
actual easy one.
- Reports about guest difficulties exported from lazer "working wrong on
stable" are prevalent. Probably mostly because of the preceding point.
What this PR does is introduce a *third* method to export an `.osu`,
which is designed to be both the easiest one yet *and* correct. I am
hoping this will curb the complaints until support for direct submission
of guest difficulties is added - which I still hope to see, but it will
be a significant effort *client-side* (the server side has been ready
for years now).
And yes, you will notice that much of the code added in
`LegacyBeatmapExporter` related to manipulation of the path is
copy-pasted from `LegacyExporter`. I don't care enough to invent
protected / abstract / whatever else OOP faff for something that may not
survive review and is mostly a weird semi-temporary wart.
This was another IRL request from a mapper / team member. The rationale
here is that it can be very annoying to map with break time enabled if
you have a large gap in the beatmap you are trying to fill with
hitobjects, as you are placing objects on top of a very gray area.
They will not only contract if the user chooses to have them contract
(new setting in the `View` menu) or if the game isn't wide enough to
allow full interaction with the playfield while they are expanded.
Addressess https://github.com/ppy/osu/discussions/28970.