Differential Capture Sessions (Condensed)¶

This log tracks original-vs-rewrite differential work by capture SHA. When the capture SHA is unchanged, append updates to the same session.

Session Template¶

• Title: Session <N> (YYYY-MM-DD)
• Legacy IDs: <optional old IDs>
• Capture: <path>
• Capture SHA256: <sha256 or n/a>
• Baseline verifier command: <exact command>
• First mismatch: tick <n> (<fields>)

Key Findings¶

• <highest-signal findings only>

Landed Changes¶

• <important code/tooling/doc changes only>

Outcome / Next Probe¶

• <what remains, and where to probe next>

Capture Policy (Current)¶

• Default to full-detail gameplay_diff_capture_v2 captures (no focus window, no sample limits).
• Keep artifacts/frida/share/gameplay_diff_capture_v2.jsonl as the canonical artifact and always log SHA256.
• Use --run-summary or --run-summary-short in divergence reports.
• If any env knobs throttle capture volume, log exact knob/value.
• If capture SHA is unchanged, update the existing session; do not create a new one.

Session 1 (2026-02-08)¶

• Legacy IDs: 2026-02-08-a .. 2026-02-08-e
• Capture: artifacts/frida/share/gameplay_diff_capture_v2.jsonl
• Capture SHA256: a40e7fed4ea7b4658d420bc31f6101307864c8de1b06f926d9ddf7c0010ac2ee
• Baseline verifier command: uv run python scripts/original_capture_divergence_report.py artifacts/frida/share/gameplay_diff_capture_v2.jsonl --float-abs-tol 1e-3 --window 24 --lead-lookback 1024 --run-summary-short --run-summary-short-max-rows 20 --json-out
• First mismatch: tick 1794 (players[0].experience, score_xp)

Key Findings¶

• Rewrite awarded a rewrite-only kill at tick 1794 (+41 XP), tied to secondary projectile behavior.
• Pre-divergence RNG drift existed in AI7 timer paths, but disabling that behavior caused earlier regressions (not root fix).
• Capture coverage was initially insufficient for direct geometry/hit-resolution comparison at divergence ticks.

Landed Changes¶

• Added divergence tooling upgrades:
• --run-summary and later --run-summary-short outputs.
• rewrite RNG-call inference and stage-attribution diagnostics.
• sample-coverage/blocker reporting in divergence output.
• Added v2 capture telemetry:
• secondary projectile spawn hooks and secondary sample capture.
• Landed gameplay parity patch in src/crimson/projectiles.py for native-like secondary homing target semantics (active + hitbox sentinel behavior).

Outcome / Next Probe¶

• Session closed when a new recording moved divergence to a later and different profile (tick 3504 on next SHA), indicating this capture family had been exhausted.

Session 2 (2026-02-08)¶

• Legacy IDs: 2026-02-08-f .. 2026-02-08-o
• Capture: artifacts/frida/share/gameplay_diff_capture_v2.jsonl
• Capture SHA256: 251b2ef83c9ac247197fbce5f621e1a8e3e47acb7d709cb3869a7123ae651cd6
• Baseline verifier command: uv run python scripts/original_capture_divergence_report.py artifacts/frida/share/gameplay_diff_capture_v2.jsonl --float-abs-tol 1e-3 --window 24 --lead-lookback 1024 --run-summary-short --run-summary-short-max-rows 30 --json-out
• First mismatch: tick 3504 (players[0].experience, score_xp)

Key Findings¶

• Primary signal moved earlier than the XP mismatch:
• first major pre-focus RNG shortfall at tick 3453 (expected 353, rewrite 268, missing 85).
• RNG values matched perfectly for rewrite’s prefix (prefix_match=268), with a native-only tail.
• This indicates a missing branch sequence, not wrong RNG values in shared branches.
• Caller-gap diagnostics isolated one missing hit-equivalent presentation loop at tick 3453 (Fire-Bullets/Gauss path).
• Narrow float32/trig movement experiments changed geometry margins but did not move first mismatch (3504) or shortfall tick (3453).

Landed Changes¶

• Added major investigation tooling:
• scripts/original_capture_focus_trace.py (callsite RNG, collision near-miss, indexed sample diffs).
• RNG value-alignment and native-only tail diagnostics.
• caller-gap and loop-parity summaries.
• scripts/original_capture_creature_trajectory.py enhancements for long-horizon slot drift.
• Added v2 telemetry for projectile-hit resolution (projectile_find_hit, corpse-hit markers).
• Added shared parity helpers and precision-boundary cleanup groundwork:
• src/crimson/math_parity.py
• targeted updates in src/crimson/creatures/ai.py and src/crimson/creatures/runtime.py
• corresponding tests.

Outcome / Next Probe¶

• Unresolved at end of SHA family: missing hit-resolution branch(es) around projectile_update remained.
• Next required probe: branch-order parity in projectile hit/corpse-hit handling, not broader float cleanup.

Session 3 (2026-02-09)¶

• Legacy IDs: 2026-02-09-p
• Capture: n/a (tooling-only session)
• Capture SHA256: n/a
• First mismatch: n/a

Key Findings¶

• Absolute ticks are weak cross-session anchors once chronology diverges.
• RNG-order anchors (seq, per-tick call index, seed epoch) are required for reliable cross-run alignment.

Landed Changes¶

• Upgraded scripts/frida/gameplay_diff_capture_v2.js RNG diagnostics:
• per-roll sequence metadata, between-tick carry, optional full roll log, CRT mirror integrity counters.
• Extended scripts/original_capture_divergence_report.py to surface sequence/epoch anchors and mirror totals.
• Updated docs/frida/gameplay-diff-capture-v2.md with full RNG trace profile guidance.

Outcome / Next Probe¶

• Prepared instrumentation for the next capture family; no gameplay parity fix in this session.

Session 4 (2026-02-09)¶

• Legacy IDs: 2026-02-09-q
• Capture: artifacts/frida/share/gameplay_diff_capture_v2.jsonl
• Capture SHA256: 28b8db6eb6b679455dad7376ef76149d26fdd7339dea246518685938cdb48662
• Baseline verifier command: uv run python scripts/original_capture_divergence_report.py artifacts/frida/share/gameplay_diff_capture_v2.jsonl --float-abs-tol 1e-3 --window 24 --lead-lookback 2048 --run-summary-short --run-summary-short-max-rows 40 --json-out
• First mismatch progression:
• initial: tick 1069 (players[0].ammo)
• after replay/input + movement fixes: tick 3882 (players[0].experience, score_xp)
• after capture-RNG map + timer/reload parity fixes: tick 4421 (players[0].ammo, players[0].weapon_id)
• after hit/collision + AI float32 parity fixes: tick 7466 (players[0].experience, score_xp)

Key Findings¶

• Early divergence (tick 1069) was driven by replay input reconstruction mismatch (rewrite firing where native did not).
• tick 3624 “missing perk RNG” was a tooling false-positive: those draws happened in replay events, outside world-step RNG marks.
• Per-tick rng.outside_before_calls replay must special-case tick 0 (bootstrap draws already baked into inferred seed).
• Native bonus_update clamps double_xp/freeze to 0.0 when timer <= 0.0; missing this caused -8ms carry and tick 4311 timer drift.
• Reload timing is float-boundary sensitive: using float32-style reload math plus native preload ordering moved ammo parity to native at tick 4396.
• Strict float32 sequencing in creature AI distance/orbit paths fixed a corpse-hit timing miss at tick 6958 and moved the frontier to tick 7466.
• The current tick 7466 XP divergence is downstream of RNG stream drift:
• first clear native-only RNG tail is at tick 7336 (perk_select_random shortfall 2 draws),
• by tick 7440 RNG values are already offset at the first draw in player_fire_weapon,
• rewrite then resolves a kill at tick 7466 that native does not.
• Local diagnostic replay with +2 synthetic draws before tick 7337 moves first mismatch to tick 8593, confirming the 7336 missing-tail branch as the dominant blocker.
• Existing capture lacks explicit perk-apply IDs, so we cannot faithfully replay native perk selections for this SHA family.

Landed Changes¶

• fix(gameplay): mirror float32 movement store boundaries (da0a12de)
• fix(replay): align v2 capture input and perk reconstruction (d9f6815e)
• improved fire fallback semantics
• frame-dt precision preference
• inferred perk menu/pending event reconstruction
• fix(creatures): round ai7 timer dt_ms to native boundary (bb88cfa8)
• Added event-phase RNG checkpoint marks and event-aware divergence accounting in replay runners/reporting.
• Extended focus-trace RNG interception to cached pool RNG hooks (particles._rand, sprite_effects._rand).
• Added v2 parser support for rng.outside_before_calls and wired per-tick outside-draw replay.
• Patched bonus_update timer clamp semantics for double_experience and freeze.
• Patched reload timing semantics in player_update (native preload ordering + float32-style reload timer arithmetic + anxious-loader tail behavior).
• Added strict float32 AI distance/orbit intermediates in src/crimson/creatures/ai.py.
• Added v2 perk-apply capture telemetry (perk_apply, perk_apply_outside_before) and replay-side event support (orig_capture_perk_apply_v1) so future captures can replay explicit perk picks.
• docs(frida): renumber sessions and fold same-sha updates (90f5637e)

Validation¶

• uv run pytest tests/test_player_update.py tests/test_original_capture_conversion.py tests/test_replay_perk_menu_open_event.py tests/test_creature_runtime.py
• uv run python scripts/original_capture_focus_trace.py artifacts/frida/share/gameplay_diff_capture_v2.jsonl --tick 3624 --near-miss-threshold 0.35 --json-out
• uv run python scripts/original_capture_focus_trace.py artifacts/frida/share/gameplay_diff_capture_v2.jsonl --tick 7336 --near-miss-threshold 0.35 --json-out
• uv run python scripts/original_capture_divergence_report.py artifacts/frida/share/gameplay_diff_capture_v2.jsonl --float-abs-tol 1e-3 --window 24 --lead-lookback 2048 --run-summary-short --run-summary-short-max-rows 40 --json-out (expected non-zero exit while diverged)

Outcome / Next Probe¶

• Blocked on missing perk-selection identity in this capture: the replay can observe pending/menu transitions but cannot know which perk native applied at each menu close.
• Re-record this same SHA with updated v2 script (perk-apply telemetry enabled by default), then verify that replayed orig_capture_perk_apply_v1 events remove the tick 7336 RNG tail and push first mismatch beyond tick 7466.