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📝 Posted:
🚚 Summary of:
P0076, P0077
Commits:
222fc99...9ae9754, 9ae9754...f4eb7a8
💰 Funded by:
[Anonymous], -Tom-, Splashman
🏷 Tags:
rec98+ th02+ th03+ th04+ th05+ resident- gaiji+ tcc+

Well, that took twice as long as I thought, with the two pushes containing a lot more maintenance than actual new research. Spending some time improving both field names and types in 32th System's TH03 resident structure finally gives us all of those structures. Which means that we can now cover all the remaining decompilable ZUN.COM parts at once…

Oh wait, their main() functions have stayed largely identical since TH02? Time to clean up and separate that first, then… and combine two recent code generation observations into the solution to a decompilation puzzle from 4½ years ago. Alright, time to decomp-

Oh wait, we'd kinda like to properly RE all the code in TH03-TH05 that deals with loading and saving .CFG files. Almost every outside contributor wanted to grab this supposedly low-hanging fruit a lot earlier, but (of course) always just for a single game, while missing how the format evolved.

So, ZUN.COM. For some reason, people seem to consider it particularly important, even though it contains neither any game logic nor any code specific to PC-98 hardware… All that this decompilable part does is to initialize a game's .CFG file, allocate an empty resident structure using master.lib functions, release it after you quit the game, error-check all that, and print some playful messages~ (OK, TH05's also directly fills the resident structure with all data from MIKO.CFG, which all the other games do in OP.EXE.) At least modders can now freely change and extend all the resident structures, as well as the .CFG files? And translators can translate those messages that you won't see on a decently fast emulator anyway? Have fun, I guess 🤷‍

And you can in fact do this right now – even for TH04 and TH05, whose ZUN.COM currently isn't rebuilt by ReC98. There is actually a rather involved reason for this:

  • One of the missing files is TH05's GJINIT.COM.
  • Which contains all of TH05's gaiji characters in hardcoded 1bpp form, together with a bit of ASM for writing them to the PC-98's hardware gaiji RAM
  • Which means we'd ideally first like to have a sprite compiler, for all the hardcoded 1bpp sprites
  • Which must compile to an ASM slice in the meantime, but should also output directly to an OMF .OBJ file (for performance now), as well as to C code (for portability later)
  • The custom build system I've been using since mid-August has some declarations for OMF .OBJ files, but it needs maybe 1 or 2 more weeks of polish to be shipped
  • Which I won't put in as long as the backlog contains actual progress to drive up the percentages on the front page.

So yeah, no meaningful RE and PI progress at any of these levels. Heck, even as a modder, you can just replace the zun zun_res (TH02), zun -5 (TH03), or zun -s (TH04/TH05) calls in GAME.BAT with a direct call to your modified *RES*.COM. And with the alternative being "manually typing 0 and 1 bits into a text file", editing the sprites in TH05's GJINIT.COM is way more comfortable in a binary sprite editor anyway.

For me though, the best part in all of this was that it finally made sense to throw out the old Borland C++ run-time assembly slices 🗑 This giant waste of time became obvious 5 years ago, but any ASM dump of a .COM file would have needed rather ugly workarounds without those slices. Now that all .COM binaries that were originally written in C are compiled from C, we can all enjoy slightly faster grepping over the entire repository, which now has 229 fewer files. Productivity will skyrocket! :tannedcirno:

Next up: Three weeks of almost full-time ReC98 work! Two more PI-focused pushes to finish this TH05 stretch first, before switching priorities to TH01 again.

📝 Posted:
🚚 Summary of:
P0065
Commits:
9faa29a...042b780
💰 Funded by:
Touhou Patch Center
🏷 Tags:
rec98+ th03+ th04+ th05+ resident-

A~nd resident structures ended up being exactly the right thing to start off the new year with. WindowsTiger and spaztron64 have already been pushing for them with their own reverse-engineering, and together with my own recent GENSOU.SCR RE work, we've clarified just enough context around the harder-to-explain values to make both TH04's and TH05's structures fit nicely into the typical time frame of a single push.

With all the apparently obvious and seemingly just duplicated values, it has always been easy to do a superficial job for most of the structure, then lose motivation for the last few unknown fields. Pretty glad to got this finally covered; I've heard that people are going to write trainer tools now?

Also, where better to slot in a push that, in terms of figures, seems to deliver 0% RE and only miniscule PI progress, than at the end of Touhou Patch Center's 5-push order that already had multiple pushes yielding above-average progress? :onricdennat: As usual, we'll be reaping the rewards of this work in the next few TH04/TH05 pushes…

…whenever they get funded, that is, as for January, the backers have shifted the priorities towards TH01 and TH03. TH01 especially is something I'm quite excited about, as we're finally going to see just how fast this bloated game is really going to progress. Are you excited?