One question that keeps popping up: "when do we release 2.0?".
NewGRF will force that at least 1.16 will be 2.0, but to not wait
for this, let's drop the "1." and be for ever done with that
conversation.
We are following in the footstep of giants here.
Currently, scripts use various heuristics to detect loaded NewGRFs that are inherently unreliable.
The list of loaded NewGRFs is easily accessible to a human player, and thus giving
scripts the same information is consistent with the current approach to not give scripts
more information than a human player.
We won't be able to make it fully self-descriptive (looking at you
MAP-chunks), but anything else can. With this framework, we can
add headers for each chunk explaining how each chunk looks like
in detail.
They also will all be tables, making it a lot easier to read in
external tooling, and opening the way to consider a database
(like SQLite) to use as savegame format.
Lastly, with the headers in the savegame, you can freely add
fields without needing a savegame version bump; older versions
of OpenTTD will simply ignore the new field. This also means
we can remove all the SLE_CONDNULL, as they are irrelevant.
The next few commits will start using this framework.
This means that during loading we can validate that what is saved
is also that what is expected. Additionally, this makes all list
types similar to how they are stored on disk:
First a gamma to indicate length, followed by the data.
The size still depends on the type.
It was rather confusing which one was for what, especially as some
SaveLoad flags were settings-only. Clean up this mess a bit by
having only Setting flags.
Basically, this changes "SaveLoad *" to either:
1) "SaveLoadTable" if a list of SaveLoads was meant
2) "SaveLoad &" if a single entry was meant
As added bonus, this removes SL_END / SLE_END / SLEG_END. This
also adds core/span.hpp, a "std::span"-lite.
This is mostly done as there are now constraints on settings.ini you might not
expected. For example, conditional settings always have to come last, as otherwise
they would influence the index.
This as during construction the sub class has not been initialized yet, and
during destruction the sub class has already been destroyed, so the overriding
virtual function would be accessing uninitialized data.