A future sprite converter (documented in #8) could then convert these
to C or ASM arrays.
(Except for the piano sprites for TH05's Music Room, which are stored
and used in such a compressed way that it defeats the purpose of
storing them as bitmaps.
Which works in both Borland C++, Open Watcom, and Visual C++.
Not that we're about to port any of the games to these compilers, just
something I noticed while evaluating 32-bit compilers for ReC98's own
32-bit pipeline tools. Modders might want to look into that though,
since 100% position independence also makes it easier to change
compilers.
So even TH01 wasn't 100% C++ after all. Turns out that this function
was the only instance in all of REIIDEN.EXE where ReC98 previously had
different encodings for identical x86 instructions.
Part of P0096, funded by Ember2528.
tiles_invalidate_around() must have had the hardest function signature
to figure out in all of PC-98 Touhou… because it seems impossible to
handle all three ways of passing parameters. No way around separately
declaring it in every translation unit then, with the parameter list
expected by that segment's code generation.
Part of P0089, funded by [Anonymous] and Blue Bolt.
Last one of the shared entity types! The TH05 version of the .STD enemy
VM would now be ready for decompilation in one single future push.
Completes P0088, funded by -Tom-.
Adding op/, main/, and end/ directories does nicely cover a great
majority of the "not really further classifiable slices" implied in
d56bd45.
Part of P0086, funded by [Anonymous] and Blue Bolt.
Again, 11 necessary workarounds, vs. forcing byte aligment in at least
18 places, and that number would have significantly grown in the
future.
Part of P0085, funded by -Tom-.
5 enums where code generation wants an `int`, vs. 11 cases where using
the minimum size is exactly the right default. So it's way more
idiomatic to force those 5 to 16 bits via a dummy element… except that
we can't give it a single, consistent name, because you can't redeclare
the same element in a different enum later.
Oh well, let's have this ugly naming convention instead, which makes it
totally clear that the force element not, in fact, a valid value of
that enum.
Part of P0085, funded by -Tom-.
… which allows a split into first rendering the top part of every
pellet, then the bottom part. This way, the game only needs two
grcg_setcolor() calls for any number of pellets.
Part of P0085, funded by -Tom-.
Ideally, the future sprite compiler should automatically pre-shift such
sprites, and correctly place the shifted variants in memory, by merely
parsing the C header. On disk, you'd then only have a .BMP with each
individual cel at x=0.
And that's why we need macros and consistent naming: To express these
semantics, without having to duplicate the sprite declaration in some
other format. sSPARKS[8][8][8] wouldn't help anyone 😛
Now, we could go even further there by defining a separate type
(`preshifted_dots8_t`), and maybe get rid of the _W macro by replacing
it with a method on that type. However,
• that would be inconsistent, since we'll need the _H macro anyway, for
both the actual rendering code and the sprite compiler
• we couldn't directly call such a method on a 2D or 3D array, and have
to go down to a single element to do so (`sSPARKS[0][0][0].w()`)
• making it a static method instead duplicates the type all over the
code
• and any variables of that type would no longer be scalar-type values
that can be stored in registers, requiring weird workarounds in those
places. As we've already seen with subpixels.
Part of P0085, funded by -Tom-.
I tried `brge` for the latter, but that had *the* most horrible
ergonomics, and I misspelled it as `bgre` 100% of the times I typed it
manually. Turns out that `dots` is also consistent with master.lib's
naming scheme, leaving `planar` to *actually* refer to types storing
multiple planes worth of pixels. These types are showing up more and
more, and deserve something better than their previous long-winded and
misleading name.
Part of P0081, funded by Ember2528.
And with all possible .COM executables decompiled, this set of changes
reaches an acceptable scope, allowing us to *finally*…
Part of P0077, funded by Splashman and -Tom-.
And of course, TH05 ruins the consistency once again. Sure, the added
file error handling is nice, but we also have changes in the playful
messages (lol), and now need a third distinct optimization barrier
(🤦)… But as it turns out, inlined calls to empty functions work as
well. They also seem closer to what ZUN might have actually written
there, given that their function body could have been removed by the
preprocessor, similar to the logging functions in the Windows Touhou
games. (With the difference that the latter infamously *aren't*
inlined…)
Part of P0077, funded by Splashman and -Tom-.
Huh, C++ wants its `char`s to be unsigned in order to *not* sign-extend
them to 16 bits for comparison against ASCII literals?!
Anyway, that completes TH03's ZUN.COM, with bascially no new C code.
Part of P0077, funded by Splashman and -Tom-.
The supposedly low-hanging fruit that almost every outside contributor
wanted to grab a lot earlier, but (of course) always just for a single
game… Comprehensively covering all of them has only started to make
sense recently 😛
Also, yes, the variable with the uppercase .CFG filename has itself a
lowercase name and vice versa…
Part of P0077, funded by Splashman and -Tom-.
Oh wow, caff4fe introduced wrong bytes into RES_KSO.COM by confusing
[cfg_bombs] with [credit_lives] -.- Which I didn't find out back then
because all the RES_*.COM binaries still had some different instruction
encodings anyway and I just didn't care enough to base my diff of those
files on the wrong encoding versions to notice the bug…
Whoops.
Part of P0077, funded by Splashman and -Tom-.
4½ years after aa56a7c, it turns out that the correct decompilation
involves… no-ops generated by assigning variables that just happen to
be in registers to themselves?! Which does get optimized out, but only
after TCC folded identical tail code in all branches of a function,
thus effectively functioning as an optimization barrier.
The initial attempt used register pseudovariables, but this definitely
is the best possible way this could work – portable, and doesn't
unnecessarily shred the code into tiny inlined functions pieces. The
mindblowing thing here is that ZUN could have actually written this to
have additional, albeit unnecessary, lines to place breakpoints on. But
that means he must have chosen those two local variables in SI and DI
completely by chance… 🤯
The best thing though? ~#pragma inline is gone~
Part of P0076, funded by [Anonymous] and -Tom-.
Necessary to make string literals from the first one end up at their
correct positions in the data segment even after the upcoming
deduplication…
Part of P0076, funded by [Anonymous] and -Tom-.
Oh hey, guarding declarations with complicated types via #ifdef limits
the header files we additionally have to #include!
Part of P0076, funded by [Anonymous] and -Tom-.
Since they're determined by the order of sprites in a .BFT file,
they're best auto-generated by an enum as much as possible.
Part of P0074, funded by Myles.
Which finally allows us to use the PLANE_SIZE macro in ASM land. Yeah,
(ROW_SIZE * RES_Y) has finally got old.
Part of P0073, funded by [Anonymous] and -Tom-.
Templates would have been nicer, but as soon as you add just one
non-immediate parameter, Turbo C++ generates a useless store to a new
local variable, ruining the generated code.
Part of P0069, funded by [Anonymous] and Yanga.
I did consider not doing this, because "well, can't anyone who's
*actually* interested just diff the TH01 and TH02 implementations to
figure out the differences themselves", but that duplication ended up
feeling too filthy after all.
And hey, it's a nice excuse to update TH02's version to current naming
standards! 😛
Part of P0068, funded by Yanga.
The TH04/TH05 BGM/SE mode setup is a good example for code where
different structure field offsets will vanish completely upon reverse-
engineering. If we continued to use the per-game ID string as the
variable name, we'd only have another game-specific "difference" there.
Part of P0065, funded by Touhou Patch Center.
Funny how the actual scores are stored as little-endian gaiji strings
in the bold font, yet never actually used as such.
Part of P0063, funded by -Tom-.
So many things named `score_*`, so many things named `hiscore_*`…
Let's go with `scoredat_*`, which clearly indicates that this stuff is
saved into a file, while still being only 8 characters.
Part of P0063, funded by -Tom-.
At least wherever Turbo C++ and master.lib want us to use a
non-pointer, since both use uint16_t for segment values throughout
their APIs instead of the more sensible void __seg*. Maybe, integer
arithmetic on segment values was widely considered more important than
dereferencing?
*Finally*. We already used `(unsigned) int` in quite a few places where
we actually want a 16-bit value, which was bound to annoy future port
developers.
nmlgc