And this is how you make code less undecompilable by improving your
pointless micro-optimizations to use more registers instead of
self-modifying code. Worth it if only to get rid of the branches in
TH04's undecompilable ASM implementation.
Part of P0133, funded by [Anonymous].
Undecompilable again. The loading functions have these *_noalpha()
variants that simply set a global variable and fall through to the
regular functions, while cdg_free() has its first `PUSH DI` instruction
after the first expression we'd be decompiling. cdg_free_all() *could*
be decompiled… but would also require _FLAGS trickery, and it's simply
not worth starting a translation unit for one such small function.
Part of P0127, funded by [Anonymous].
No need to make the function names more complicated if we already
expressed the one subtle format difference between TH03 and TH04/TH05
in the plane layout enum.
Part of P0113, funded by Lmocinemod.
Whew, time to look at every `int` variable we ever declared! The best
moment to do this would have been a year ago, but well, better late
than never. No need to communicate that in comments anymore.
These shouldn't be used for widths, heights, or sprite-space
coordinates. Maybe we'll cover that another time, this commit is
already large enough.
Part of P0111, funded by [Anonymous] and Blue Bolt.
One fewer magic number. And one more deliberate dependency on a
PC-98-specific hardware constant, to further drive home just how
unportable these games are, even once decompilation will be complete.
Part of P0105, funded by Yanga.
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-.
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.
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-.
Which *looks* like a master.lib function, but only because ZUN adapted
his own micro-optimized super_roll_put_tiny() for 32×32. Good thing we
covered that one first!
Part of P0073, funded by [Anonymous] and -Tom-.
So, master.lib has:
• super_put_tiny() for tiny-format 16×n sprites
• super_roll_put_tiny() for vertically wrapped tiny-format 16×16
sprites
• super_put_tiny_small() for tiny-format 8×n sprites
• yet *no* super_roll_put_tiny_small() function
And now we have ZUN adding micro-optimized versions of:
1) vertically-wrapped tiny-format 16×16, clearly based on master.lib's
super_roll_put_tiny(), RE'd in 35f9bd7
2) vertically-wrapped tiny-format 32×32
3) vertically-wrapped non-tiny monochrome 16×16 (TH05 only)
Conclusion: Even though 1) does duplicate a master.lib function, trying
to continue following master.lib's inconsistent naming convention only
leads to more confusion here. master.lib also already designates the _8
suffix to mean "x will be byte-aligned, ⌊x/8⌋*8"…
So let's:
• spell out both coordinates of the sprite size directly in the
function
• keep the z_ prefix to encode ZUN's optimized calling convention
(left/top coordinates in registers, ES already set to the beginning
of a VRAM plane, GRCG already on) for all of these, not just 1).
• and prefix the actual functions with _raw, since C land will want
to handle the coordinate parameter registers in a macro.
Part of P0073, funded by [Anonymous] and -Tom-.
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-.
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.
WTF. Fine, let's have separate, micro-optimized ASM implementations for
decoding and encoding inr MAIN.EXE, but still, all those minute
difference between OP.EXE and MAINE.EXE…
This is as far as anyone should reasonably go before decompilation;
things will get really ugly with the loading functions once the file
name is involved as well…
Completes P0063, funded by -Tom-.
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-.
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?
No leading underscore for functions with Pascal calling convention, but
we do have one for all variables, because it's not worth it to put
keywords in front of everything for no reason.
Seemed to have forgotten this rule in 2017?
Part of P0030, funded by zorg.
Yup, nothing interesting in here.
Except for maybe the confirmation that LS00.BB is used for the curved
bullets used by Shinki and EX-Alice?
Funded by -Tom-.
… because TH04's version of this takes the ASCII stage ID directly from
the resident structure.
So boss battles are simply triggered by setting the background tile
scroll speed to 0? That means…
Funded by zorg.
nmlgc