Commit Graph

26 Commits

Author SHA1 Message Date
nmlgc 0e96a8e578 [Research] Document why TH02 and TH03 must manually pause BGM before loading
And the fact that TH04 and TH05 do it automatically. This allows us to
share the 'm' command implementation between the cutscene system and
the upcoming decompilation of TH04's dialog system… after developing
another new piece of decompilation tech 👀

Part of P0258, funded by [Anonymous] and Blue Bolt.
2023-10-31 22:33:41 +01:00
nmlgc c22299e0c8 [Contributing] Introduce a new "ZUN landmine" label for invisible bugs
Thanks to Clerish for the naming inspiration:

	https://twitter.com/Clerish/status/1623990678937034752

Part of P0231, funded by [Anonymous].
2023-02-28 08:08:10 +01:00
nmlgc 7cae44a31f [Reverse-engineering] snd_delay_until_measure(): Corner cases
The 2022 edition of "fundamental KAJA function I haven't looked into
more deeply during all these years"…

Part of P0225, funded by Yanga, Blue Bolt, and 32th System.
2022-11-30 22:46:22 +01:00
nmlgc 8118e61c77 [Decompilation] [th03/th04/th05] Cutscenes: Script opcode interpreter
Even that part's the same in these three games… except for the 27 small
places where it isn't, 7 of which are purely coding style cosmetics.

Completes P0224, funded by Splashman and -Tom-.
2022-11-30 22:46:22 +01:00
nmlgc 753f73f5f2 [Maintenance] master.hpp: Centrally define packfile filename length
The later games need this constant for their buffers as well, and it's
not just needed for loading sound files. Might be overkill to force all
of `master.hpp` to be #included in some additional places, but the
alternative would have been to move it to a `fn_len.hpp` file.
Ultimately, this constant *is* related to master.lib.

Part of P0223, funded by Blue Bolt and rosenrose.
2022-11-30 16:58:30 +01:00
nmlgc 9432e0d2bf [Maintenance] Macros: Update to current coding standards
Less fancy token pasting, replacing them with inline functions where
possible, entirely removing unnecessary ones, and fixing smaller
issues here and there.

Part of P0186, funded by [Anonymous] and Blue Bolt.
2022-03-25 14:05:36 +01:00
nmlgc 53920309a1 [Decompilation] [th05] snd_kaja_interrupt()
Boom! Decompilable after all. And look what that made us finally point
out: In all 4 games that use this function, its return value is
undefined if BGM is inactive. (That is, if the user disabled it, or if
no FM sound board is installed.)

Part of P0148, funded by [Anonymous].
2021-07-21 00:35:03 +02:00
nmlgc cd96b039fa [Maintenance] Use a dedicated enum for snd_load()'s function parameter
It's not a kaja_func_t if it's shifted left by 8 bits. Why is it
shifted left by 8 bits to begin with, though? Why not just pass a
kaja_func_t, and assign it to AH? Arrrrgh.

Part of P0139, funded by [Anonymous].
2021-05-12 14:31:02 +02:00
nmlgc 46a1674250 [Reverse-engineering] [th02/th03/th04/th05] snd_load() buffer size
Hardcoding these *might* have been acceptable if the numbers actually
matched the sizes defined in GAME.BAT, but they don't. With PMD's
AH=22h function, there's really no excuse though.
About time I looked into this, and expressed that constant as an inline
function that can easily be replaced with a proper implementation.

Part of P0139, funded by [Anonymous].
2021-05-12 14:31:00 +02:00
nmlgc 0e11d33520 [Translation unit catch-up] [th03] snd_load()
Exhibit B for the theory that ZUN did *not* set the default calling
convention to `pascal` for TH03.

Part of P0138, funded by [Anonymous] and Blue Bolt.
2021-04-21 16:28:29 +02:00
nmlgc c85f444b07 [Decompilation] [th02/th03] Sound effect playback
Second previously undecompilable translation unit, second creative
workaround for the workaround. We can't compile snd_se_play() with -WX,
as that function needs a stack frame, and it's also illegal to disable
-WX in the middle of a translation unit. But since we only need word
alignment in front of snd_se_reset() *and* that function is identical
in all 4 games, it makes sense to move it to its own translation unit.

And then you notice that the TH02/TH03 and TH04/TH05 versions of the
other two functions are basically identical. The small differences can
easily be moved out to inline functions, leaving us with a single
implementation file for all 4 games. Nice!

Part of P0137, funded by [Anonymous].
2021-04-03 22:11:45 +02:00
nmlgc 01c92da1ac [Decompilation] [th05] snd_load()
A decompilation of ZUN-written ASM that was almost worth it, for once!
Too bad that those aren't the <string.h> intrinsics that the
Wolfenstein 3D disassembly hinted at, though.

Part of P0135, funded by [Anonymous].
2021-03-19 19:22:57 +01:00
nmlgc 84d4914a3b [Separate translation units] [th02] snd_mmd_resident() (undecompilable)
Reason: Wants to be word-aligned, and the previous version in OP.EXE,
game_exit(), is not, despite having an even length :(
Oh well, at least I'm confident enough about it by now to document it.
And out of all decompilations to be thrown away, this is a pretty
dispensable one.

Part of P0133, funded by [Anonymous].
2021-01-31 15:21:11 +01:00
nmlgc cdbd621f91 [Separate translation units] [th02] snd_determine_mode()
Perfectly decompilable with pseudo-registers. Why did I decide against
them in 2015?

Part of P0133, funded by [Anonymous].
2021-01-31 15:18:09 +01:00
nmlgc 5bbc08c3ef [Separate translation units] [th02] snd_pmd_resident()
Seemingly impossible to decompile further.

Part of P0133, funded by [Anonymous].
2021-01-31 15:18:06 +01:00
nmlgc c77a5fd8ed [Separate translation units] [th02] snd_delay_until_volume()
Part of P0133, funded by [Anonymous].
2021-01-31 15:14:55 +01:00
nmlgc f539cca15d [Decompilation] [th03/th04] snd_delay_until_measure()
Part of P0132, funded by [Anonymous].
2021-01-05 21:56:57 +01:00
nmlgc 8ef8f78cc9 [Maintenance] Add a PMD/MMD-independent wrapper for KAJA_GET_SONG_MEASURE
No pseudo-registers in the usage code! Awesome!

Part of P0132, funded by [Anonymous].
2021-01-05 20:02:28 +01:00
nmlgc b9c24cf931 [Separate translation units] [th02] snd_delay_until_measure()
How was this game even *built*, originally, if it uses *both* a common
shared set of library functions *and* obviously copy-pasted and
separately compiled versions of some of these functions?

Part of P0132, funded by [Anonymous].
2021-01-05 19:32:18 +01:00
nmlgc 0bfff60a0a [Maintenance] Define `bool` as unsigned
Wait, we can just do that, and nothing breaks?! All this time, we
could have avoided the `unsigned char` workaround???

Part of P0130, funded by Yanga.
2020-12-18 00:45:54 +01:00
nmlgc 2fde03406c [Maintenance] Move the SE reset/play/update sequence into its own function
Part of P0119, funded by [Anonymous] and -Tom-.
2020-09-21 14:59:54 +02:00
nmlgc f6757fe76a [Maintenance] Fix DEFCONV declarations, and remove them where possible
Wow, this is the first time we're about to call any of these from C
land in ≥TH03? Found no built-in way to just uppercase an identifier
in TASM, so apparently we have to spell out the names in both lower-
and uppercase.
So, let's go back to regular, non-macro PUBLIC / PROC / ENDP code
wherever we can – for all functions introduced in ≥TH03, and for
everything that takes no parameters. It's simply not worth the
trouble.

Part of P0114, funded by Lmocinemod.
2020-09-07 21:18:39 +02:00
nmlgc a75e0f8f53 [Maintenance] Compile all VRAM-accessing translation units as C++
Leading to slight complications in TH02's Music Room and shot type
selection menus. Thought about leaving those in C for a while, but I
still think it's worth it for the consistency we get with the VRAM
offset functions. Also, we'll have similar code for the main menus of
later games, and I'll surely won't be using C++ when starting out with
these.

Part of P0105, funded by Yanga.
2020-08-12 16:16:09 +02:00
nmlgc 6363a37d7a [Maintenance] Move TH02's sound functions to a separate header
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-.
2020-02-23 16:51:45 +01:00
nmlgc 83f422c61a [Decompilation] [th05] Character-independent shot type functions
Part of P0062, funded by Touhou Patch Center.
2019-12-22 15:37:36 +01:00
nmlgc db4de240e9 [Decompilation] Prepare the C side for the shot type control functions
That should make this convoluted copypasta a bit easier to read. And
sure, I could have done something about the loop as well, but
SHOT_FUNC_INIT already hides enough control flow behind a macro…

Part of P0037, funded by zorg.
2019-10-14 23:42:20 +02:00