Cesarus85--ringfall-mjolnir-vr/docs/object_matching_logs/game_engine_obj_codex_checkpoint.md

game_engine.obj Codex recovery checkpoint

Scope and provenance

• Fresh lane: jonas/game-engine-large-20260820, based on 188aca952343415a52c6034ccd148e508c4be15c.
• Recovered the independently reproducible source sequence through historical donor e311fa706078abeb2ed8cc7b556909cc1de68c51, then retained the policy-clean typed views from bf1ff5e2a70fd88cac1d53c6f516c407671b7e01 only where they reproduced on the fresh base.
• The donor worktrees and the existing game_engine_obj.md ledger were treated as read-only. No divergent configuration, parks, shared-header, or unrelated documentation changes were imported.
• The recovery itself kept shared headers unchanged. The later policy correction on jonas/game-engine-policy-fix-20260820, based on 30dc49d4, adds same-size named views to source/game/game_engine.h and source/game/players.h; the bounded consumer proof for those two header changes is recorded below.
• source/game/game_engine remains NonMatching.

Policy correction

The corrective pass removed the remaining incompatible-call and raw-layout accesses without tuning any residual function:

• Both statistic sort callbacks now use the exact qsort comparator type and read a typed postgame_statistic_entry view.
• The actual game_engine definition now owns correctly typed callback members at offsets 0x34, 0x38, 0x4C, 0x50, 0x54, 0x64, and 0x70, while preserving the unused slot at 0x60. Callers access those members directly; the unrelated-structure callback view and its cast are gone. Compile-time assertions cover those offsets plus game_variant.unknown16 and player_datum.target_hold_time.
• game_engine_update uses a union of data_iterator and object_iterator and accesses only the active typed member.
• The game-engine global team counter, the game-variant field at offset 0x16, and the player target-hold counter at offset 0x80 have named, size-preserving typed members. Their former integer-address/byte-array overlays are gone.
• Item-collection permutation access is through a typed permutation pointer, and the netgame-flag helpers now accept real_point3d const * directly.
• code_0009bdf0 now uses a naturally scoped collision_plane for the point test and a separate zero-initialized screen_flash_definition. Its manual 56-byte scratch union and byte-by-byte clear are gone. This safe form is nonexact and receives zero credit.

The pass adds no assembly, volatile access, force-inline directive, pragma, barrier, incompatible function-pointer cast, integer-address dereference, or byte-forcing construct. An additional audit advisory identified two adjacent-global pointer bounds in the custom-motion/nav rendering loops. Those bounds are byte-identical pre-existing debt from the base, not introduced by this checkpoint, so this bounded follow-up leaves them unchanged and does not invent aggregate or alias ownership to recover their relocation identity.

Strict improvement

The same target object, compiler, splitter, and strict COFF comparator were used on both sides of the checkpoint.

Measurement	Fresh base	Recovered	Gain	Target
Strict-exact functions	125	164	39	180
Exact meaningful code bytes	12,879	22,996	10,117	32,397
Exact padded code bytes	13,904	24,240	10,336	33,760
Exact semantic relocations	539	1,210	671	1,679

All 125 baseline-exact functions remain strict exact. The 39 newly exact functions are:

_code_00096850, _code_00096890, _code_00096b30, _code_00096b40, _code_00096b50, _code_00096c10, _code_00096d00, _code_00096e30, _code_00096ed0, _code_00097020, _code_00098470, _code_00098510, _code_00099b90, _code_0009a100, _code_0009a840, _code_0009a940, _code_0009b260, _code_0009b4f0, _code_0009b6a0, _code_0009b770, _code_0009baa0, _code_0009cb60, _code_0009cbe0, _code_0009cc20, _code_0009cc80, _code_0009ccf0, _code_0009e9c0, _game_engine_get_goal_position, _game_engine_player_added, _game_engine_postspawn_player_update, _game_engine_remap_equipment, _game_engine_remap_weapon, _game_engine_update, _game_show_score_extended, _game_show_score_team, _game_show_score_you_ally_enemy, _populate_statistic_buffer, _sort_statistic_buffer_ranking, and _team_has_players.

The raw whole-object SHA-256 is intentionally not used as an admission gate: compiler-generated COFF metadata varies across otherwise identical rebuilds. The strict gate fingerprints normalized bytes, padded sections, relocation semantics, symbols, and owned data instead.

Owned data

• .data: strict exact, 32/32 bytes, zero relocations, normalized SHA-256 daa87eb1c49a06849cf7cda46c7cbb445e5de697a99dcf5ebd09cea9d06dc707 on both sides.
• .bss: strict exact, 1,148/1,148 bytes, zero relocations, normalized SHA-256 509607d81ec2cc01c8776f0ef9a4adf126f8a4c2f021838d350f48d6e5a8d19d on both sides.
• Public ownership offsets reproduce exactly: _debug_player_color at .data offset 0; _global_goal at .bss offset 0; _global_variant at 1,024; _game_engine at 1,128; _global_autogenerate_list at 1,140; and _global_autogenerate_count at 1,144. The private teleporter state occupies the target-backed intervening offsets 1,132 and 1,136.

Fail-closed residual emission

Six nonexact standalone definitions are omitted, so objdiff reports no base emission for them:

• _game_engine_should_spawn_player
• _game_engine_get_place
• _code_0009a680
• _code_0009b3a0
• _game_engine_get_state_message
• _game_engine_player_killed

Ten nonexact bodies remain emitted with zero credit because removing them also removes independently exact private callees or callers:

• _code_0009b6e0 is the natural private callee required by exact _game_engine_player_added, the three exact score-display functions, _code_0009b770, _code_0009b6a0, and _code_0009a940.
• _game_engine_get_starting_location_rating and _code_0009c460 are the natural emission chain for exact _code_00097570 and _code_0009c340.
• _code_0009e670, _code_0009d140, _code_000994f0, and _code_0009a490 are the natural static cluster required to retain exact _code_00096b50.
• _game_engine_post_rasterize_post_game and _code_00096ba0 are the natural emission chain required to retain exact _code_0009cb60.
• _code_0009bdf0 is the naturally typed teleport/update body called by exact _game_engine_update; its former scratch overlay was exact but unsafe.

At the recovery checkpoint, omitting the original 15 residual bodies reduced the exact set to 154 and the retained nine-body minimum restored 165. The policy correction converts _code_0009bdf0 into one additional emitted zero-credit residual. Candidate emission remains 174/180 target functions: 164 strict exact, ten emitted residuals, and six omitted residuals.

Validation

• Forced game_engine.c XDK 3911 compile: warning-free.
• Full Halo and libcmt dependency graphs: green; the final aggregate build had no remaining work after the forced translation-unit rebuild.
• The final policy-corrected translation unit is 164/180 strict exact, with 22,996 meaningful and 24,240 padded exact code bytes. Direct callback-member access preserves every affected exact function; the sole loss is the honest safe-form withdrawal of _code_0009bdf0.
• Strict semantic report: 470 units, 3,865 functions evaluated, 3,724 semantic exact, 99 hidden exact, 61,015 hidden code bytes, 39 ordinary-only findings (38 structural and one rejected), zero unit errors, and 3,788 accepted exact.
• Progress after the clean rebuild: 375/833 complete objects, 3,777/11,060 exact functions, and 460,004/2,198,102 code bytes overall; Halo is 273/468 objects and 3,610/7,574 functions; libcmt is 102/212 objects and 167/476 functions. The second global count change is rejection of the pre-existing stale source/shell/shell_xbox:_main ordinary false positive.
• Admission audit: zero candidates, zero revocations, and only the pre-existing source/shell/shell_xbox contradiction.
• Parked-function audit: three active, zero stale, zero invalid.
• Tool tests: 179/179 pass.
• A clean 569-object corrected-header rebuild was byte-for-byte reproducible after timestamp normalization. A bounded original-header/corrected-header A/B found raw deltas only in game_engine.obj and five consumers whose local compiler-label spellings moved with header line numbers. All sections, relocations, and meaningful symbol ownership in those five consumers were identical. In particular, frozen ai_debug.obj and units.obj are unchanged by the type correction; frozen vehicles.obj, ai_script.obj, and actions.obj were normalized raw-identical across the A/B.
• A second bounded A/B for the direct callback members rebuilt all 568 non-game_engine consumers under the old and corrected declarations. 565 were timestamp-normalized raw-identical. The only raw deltas were players.obj, objects.obj, and frozen units.obj; every section, relocation, and meaningful symbol was identical in all three. The other four frozen objects were normalized raw-identical. Before the assertions, a final corrected rebuild reproduced all 569 corrected snapshot objects exactly after timestamp normalization. Adding the zero-emission offset assertions produced only compiler-local-label raw deltas in six objects (ai_debug, game_engine, players, network_game_globals, objects, and units); every section, relocation, and meaningful symbol remained identical in all six.
• Policy, house-style, scope, frozen-object, and Markdown audits pass. No frozen source or configuration file is touched, and this Codex checkpoint is the only Markdown file modified.

Disposition

This is a positive but incomplete recovery. Keep game_engine.obj active and NonMatching; the 16 residuals receive zero credit until independently proven strict exact.