Reverse-engineered the post-opening bg/sprite drift end-to-end:
- Root cause: stubbed 0x215 (native gfx-object query) collapses draws to slot 0.
- Unlocked static analysis of the unpacked engine (dump_engine.py + capstone;
AGE.EXE unpacks in-place at 0x400000; SYS4AB = XOR-0xFF(AGE.EXE) dead end).
- Live capture verdict: the real opening uses zero CG object-records => the drift
is a STATE-DIVERGENCE artifact of the unseeded headless VM, not a missing op.
Fix = Phase B state/choices flow. Native gfx-op modeling deferred (dump in hand).
No engine-code changes (RE tooling + docs only); engine 11/11 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
tools-reference: dump_engine/probe_handlers/capture_gfx_objects + SYS4AB note.
phase-a-slice-plan: post-opening drift RESOLVED as a state-divergence artifact
(fix = Phase B state flow, not a native-op subsystem). PROJECT-STRUCTURE:
build/{textures,engine-dump}, engine/, tools/frida/.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Live capture (esi=engine ctx via operand-fetch, poll object-record array
[esi+0x53d64] stride 120). KEY FINDING: through the full real opening, the record
array holds only 3 persistent UI objects — NO CG objects. The real game does NOT
draw opening CGs via the 0x212-0x21a positioned-object path our headless VM uses;
with state it takes a different (direct) branch. So the bg/sprite drift is a
STATE-DIVERGENCE artifact of the unseeded headless VM, not a missing native op —
the fix is the Phase B state/choices flow (makes label_12649 take the if-branch).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
operand-fetch (call 0x41b940) fires ~8500/sec => the VM interpreter executes
from the in-place unpacked module at 0x400000 (NOT the heap copy) => handlers are
hookable by dump address. gfx-family(0x212-0x215)=0 at the title (no CG commands
until a scene runs).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Dump validated: AGE.EXE is unpacked in-place at 0x400000 in memory (AGF-decoder
landmark @0x474f1f reads real code with the 'BM' 0x4D42 check). Kelebek handler
VAs map directly (VA-0x400000 = file offset). Handler ABI: thiscall (esi=engine
context), operands fetched via call 0x41b940, per-object command-type table at
[esi+idx*120+0x53d88]. 0x215 is part of a native gfx command-buffer manager.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Both on-disk engine images are the same packed binary, so native handler code
exists only unpacked in memory. dump_engine attaches, enumerates ranges, and
dumps the AGE.EXE module + large r-x heap regions (chunked) to build/engine-dump/
for offline disassembly (locate 0x215 @ VA 0x421160 via the dispatch table).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Decrypted SYS4AB: 0x2c header (S4AB magic + 0x10E000 size + 8-byte key) then
XOR-0xFF payload == AGE.EXE byte-for-byte. Not a patched/unpacked VM. Real
handler code exists only unpacked in the runtime heap (0x62411000). Corrects the
'likely the patched VM' assumption.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Investigation upgrade: 0x215 queries the native object manager by element
handle-id (0x62455[idx]) and returns the object's slot/status; sign-tested to
drive label_12649's slot-select. Stubbing it collapses all draws onto slot 0 →
the anchor-preserve geometry reads foreign textures → cumulative bg/sprite
drift. Keystone for the graphics object-manager; exact return via unicorn
(handler @0x421160).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Opening event-CG sequence now renders correctly. 0x208 get-texture-size
implemented as a real VM op; faithful 800x600 immediate-mode blit compositor;
gfx + --shot diagnostics. Post-opening background/sprite anchor drift is
characterized and deferred to the anchor-record subsystem (next chunk).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Godot host: source images kept per slot with dims read from the BMP header on
the VM thread (synchronous, so the bytecode's geometry math sees real sizes);
draw-texture blits src rect -> dst into one 800x600 canvas in execution order,
shown by a single TextureRect. Selftest byte-parity preserved.
Slot 0 = primary/screen surface: seed its dims to 800x600 (the boot-time
create-texture the single-scene harness skips) and record create-texture(w,h),
so the first CG's anchor-preserve math stays an identity instead of corrupting
the persistent base globals. Fixes the grey-first-CG opening. Verified: SC0000
pages 1/3 composite the opening event CG at (0,0) with dialogue over it.
Also adds a --shot <png> [--shot-page N] dev capture to Main (page-gated on a
VM-thread counter) for headless visual verification.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
BmpHeader.ReadDims reads texture dims from the pre-converted BMP header (VM-
thread-safe, no pixel decode) — the data source for GetTextureSize. `Age.Cli gfx
<SCENE>` runs a scene and dumps set-texture/get-texture-size/draw-texture in
order with resolved file + computed geometry, mirroring the `audio` diagnostic.
Confirms 0x208 now yields real dims (800x600/800x800/800x227) and sane UI
geometry; surfaces the first-load anchor edge (unseeded state, Phase B).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Promote 0x208 from stub to a real VM op that writes the loaded texture's
width/height into its two output globals, via new IHost.GetTextureSize. This is
the single native primitive the CG-load subroutine (SC0000 label_12649) needs;
all downstream centering/anchor geometry is already computed in bytecode.
Non-Godot hosts return (0,0) so trace/selftest parity holds (engine 9/9 incl.
TraceDiffTests). Godot host gets a temporary (0,0) stub; real impl in the
compositor task.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Recon of SC0000 label_12649 shows sprite/background geometry is computed in
bytecode; the only missing native primitive is 0x208 get-texture-size. Spec:
implement 0x208 (host returns real image dims) + a faithful 800x600 blit
compositor; defer fades/chromakey/multi-surface. Headless `gfx` diagnostic as
numeric oracle; --selftest/trace parity preserved.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Wire audio end-to-end (OGG plays natively in Godot; no Frida, no decode):
- IHost.PlayBgm/PlayVoice + VM dispatch for play-bgm(0xbf)/play-voice(0xc4).
Non-Godot hosts no-op them so --selftest + engine 8/8 stay byte-identical.
- GodotAdvHost resolves id->OGG; Main plays via two AudioStreamPlayer nodes
(BGM looping; voice interrupt-on-new).
Key finding (by-ear, systematic-debugging): the two audio ops use DIFFERENT
addressing — the earlier "unified manifest" assumption was wrong for BGM.
- play-voice -> per-scene manifest files[base+id] (offset 0, same as textures).
Confirmed by ear; upgraded med->HIGH.
- play-bgm -> DIRECT LITERAL NAME BGM{id:03d}.OGG, NOT the manifest.
Real game: play-bgm 5->BGM005, 8->BGM008 (manifest gave +1). Proven by
play-bgm 0x23->BGM035 (real standalone track; BGM set skips 030-034) that the
manifest mis-resolved to a graphics entry. Fix is BGM-only:
ResourceMap.BgmPathById; voices/textures unchanged.
Also: Lily's silence root-caused as correct form-gating (G[0xa57/0xa58/0xa59]),
left unseeded by choice (no dummy state). Added diagnostic
`Age.Cli audio <SCENE.BIN> [0xADDR=VAL ...]`. Corrected opcodes.toml (play-bgm
direct-name, play-voice HIGH) + docs/memory (dropped the bogus unified-manifest
/ Frida-BGM006 claims).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Runtime finding: SC0000's bg is a slot-0 full-screen slideshow (res 0x23 first), not the
static-path res 0x21. Target corrected to 0x23. CaptureHost/CountHost no-op the new methods.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
C# VM is byte-identical to vm0.py across all 297 SC/SP scenes (offsets+halt+steps);
RECOVER passes; SC0000 = 27994 steps / 186 lines matching the Python prototype.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Reverse-engineering + open reimplementation workspace for Eushully's AGE/SYS4
engine (first target: Himegari). The repo root is age-reimpl/; the original game
install and the extracted ALF data are siblings outside the repo and are never
tracked. build/ (derived corpora) is gitignored and regenerated by the tools.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
