James Dansereau
cc169874ce
- D318 (RESOLVED): as-authored latent race — gas bit mid-monologue derails c78's pre-aim hold into a permanent ACT_ATTACK anim pin (actor_fire_or_aim_at_target_update moves only the endframe, never re-inits; N64-identical). NOT a port bug. Port-side watchdog port/src/d318watchdog.c (hooked in lv.c after g_GlobalTimer += ) detects the pinned state and re-inits the attack on confirm; GE_D318T=1 timeline diagnostic included. random.c gains an env-gated probe (GE_RANDPROBE) for bit-exact PRNG verification. Scratch evidence (dis/seqcmp scripts, addr dumps, session handoff) parked per house practice. - D320 (OPEN): swept every level's AI scripts for the same aim-hold -> _update shape: 17 lists in 8 levels. Facility ai_19 and Control ai_9 are HIGH (non-self-healing, same as ai_22); Depot ai_12 MED-HIGH (objective bit gated behind a stop-check). Bond-combat loops likely safe (sustained fire stays inside the shoot window by design; exercised every playtest). Classified as-authored latent race(s), faithfully reproduced. Probe-verify path + generalize-the-watchdog recommendation documented in findings.md. - gfx_pc.cpp: GE_D116 debug printf used %f for uint32_t args and %d for unsigned tile fields; casts added, build warning-free. Full ntsc-final configure+compile+link PASS. Accuracy sweep write-up in docs/dev/ACCURACY-AUDIT-2026-09-20.md (PRNG bit-exact; A1/shift32/wrapv/ PORT-hygiene/Gfx-Vtx/osVirtualToPhysical sweeps all clean or already fixed).
4.8 KiB
Accuracy / code review — N64 fidelity sweep (2026-09-20)
A thorough pass over the PC port with one question: where does the port diverge from the
N64 original, and what latent failure classes of the D318 kind are still unpriced?
Method: static review against the decomp ground truth + targeted verification builds.
Findings below; new finding D320 logged in findings.md.
1. PRNG — verified bit-exact
port/src/random.c re-checked line-by-line against both src/random.s and
src/game/chrObjRandom.s. The MIPS64 dsll32/dsrl32 semantics (post-D284) are
emulated correctly: the 32-bit LFSR state advances identically, and
randomGetNext() returns the same 31-bit values in the same order. No divergence.
2. Known bug-class sweeps — all clean or already fixed
| Class | Result |
|---|---|
| A1 raw-byte/padding aliases (32→64-bit layout shift) | Remaining padding[] uses are in pointer-free structs (layout-stable) or already fixed (D115, D209, D312). No live misreads. |
| Shifts by 32 / pointer-width arithmetic in game logic | Only port-layer code (d318watchdog print, DRAM_SIZE). Game logic clean. |
| Signed-overflow UB | -fwrapv enabled in CMakeLists.txt — the whole class is neutralized to N64-wrap semantics. |
#ifdef PORT hygiene (N64 path preserved) |
307 hunks audited; 178 are pure additions (diagnostics / struct extensions). No hunk alters the non-PORT control flow. |
| §B Gfx/Vtx 16-byte records (raw byte indexing) | bg.c uses typed .words/.dma fields throughout; no remaining raw byte offsets. D312's fix pattern is the last of this class. |
osVirtualToPhysical call sites (88) |
All flow through fast3d's seg_addr() (D131 fix intact). No site assumes N64 segment RAM layout. |
| Dead code | objecthandler_2.c compiles but is not linked on PC (symbols absent from the binary). Harmless; noted for a future source-list prune. |
3. Timing layer — intentional, documented
Frame-locked virtual clock (vsync tick), GE_DETERM fixed-tick mode, and
g_GlobalTimerDelta zero-guarded at every division site. All deliberate port-layer
design, each documented in its finding. No hidden drift source found beyond the
already-fixed D204 tempo work.
4. D318-class latent softlock sweep → D320 (the main new result)
D318's mechanism is generic, not Facility-specific: actor_fire_or_aim_at_target_update
(chraction.c:4882) retargets any ACT_ATTACK chr with an AIM_ONLY/DONTTURN attacktype and
only moves the model's endframe — it never re-inits the animation. If the chr is pinned
on a pre-shoot aim-hold pose (hold endframe H < variant shoot window) and the new endframe
lands above H, the model pins forever and the timer-gated fire events never open; if the
surrounding AI script's only escape is an if_guard_has_stopped_moving gate, it can never
pass (chrHasStoppedOrPatroling is FALSE for ACT_ATTACK). Permanent softlock — on N64 too.
Swept every level's AI scripts (assets/obseg/setup/*.c): 17 lists in 8 levels contain an
aim-hold + _update pair. Risk-ranked table in the D320 entry. Headlines:
- Facility ai_19 — HIGH. Same non-self-healing shape as ai_22 (second softlock point in the same level).
- Control ai_9 — HIGH. Near-exact ai_22 mirror (pre-aim hold → timer → update → fire loop gated on the target dying from this guard's shot).
- Depot ai_12 — MED-HIGH. The kill is scripted, but the objective bit is gated behind a stop-check; pinned guard → level-complete softlock.
- Bond-combat loops (Aztec/Control/Egyptian/Depot/Streets/Bunker/Surface) — likely safe: sustained fire keeps the model inside the shoot window by design, and every playtest exercises them without freezes. Inferred, not probe-verified per list.
Classification: as-authored latent race(s), faithfully reproduced — same bucket as D318, not a port bug. Verification path (generalized timeline probe) and the generalize-the-watchdog recommendation are in D320.
5. Fixed this session
port/fast3d/gfx_pc.cpp:2417— the GE_D116 diagnostic printf used%fforuint32_targs (v->u,tex_width) and%dfor unsigned tile fields; wrong debug output only, no runtime impact. Casts added; build now warning-free on that file.
6. Verification ritual
Full ./build-pc.sh ntsc-final configure + compile + link: PASS, no warnings on
touched files. All new/changed symbols resolve exactly once (link is the sweep). D318
watchdog/timeline symbols confirmed present in the binary.
7. Deliberately not committed (release-prep WIP, separate workstream)
.github/release-notes.md, README.md, docs/index.md, docs/media/goldeneye-gh-preview.gif,
docs/dev/agentic-development.md, .gitignore (/local/ exclude), and non-D318 scratch
artifacts — left in the working tree for their owner.