Expansion catalogue and implementation

The March 1995 expansion is now included in the inspection browsers. Select Expansion in the model browser to find Apocalypse, Diablo, Headhunter, Wasteland and Ruins scenery, the landing craft and bunker, and the revised original HERCs. The original versions remain available alongside them.

Resources and viewers

Mission text includes 310 effective English, French and German resources across the original and expansion missions. The mission browser has a language selector. The short mission summaries are editorial descriptions of the supplied briefings. S2_RCN03 has source and briefing resources but is absent from the single-mission selector; it is labelled as a retained variant.

The floppy expansion contains no unique VOL member bytes relative to this CD. Its simulator is a different build. The April patch replaces the simulator only. The three executable revisions remain separate in Simulator versions.

Original-code checks

HERC assembly uses the expansion's original model loader and profile binding routine, including every stored LOD. The nineteen chassis all pass. The native mission launch path prepares counters, consumes its RNG and writes SCRIPT.DAT, PLAYER.MEC and MISSION.VAR before the original simulator constructs actors. Browser scenes use those captured placements and equipment. All 37 render without missing model resources, invalid vertex references or JavaScript exceptions. Inactive groups remain visible for inspection; the scene is the starting state, not a running simulation.

The nine cockpit exports compare all four views, bitmap selections, mirroring, 425 instrument words and palette copies against original code. The expansion copies sixteen cockpit colours to indices 32-47 and one selected highlight to 64. It leaves 65-79 from the world palette. The base game copies a second full sixteen-colour bank there, so reusing its palette rule gives incorrect colours.

Every exported DFL delta is compared with PLAYFLIC's original decoder. That executable is byte-identical on the original and expansion CDs. The expansion shell calls its integrated movie player at 67 ms/frame for MI_INT1 and MECHVIC3; localized original cinematics retain the ESCD launcher's 83 ms/frame. Header rates differ and are recorded separately. MI_INT1 starts audio at frame 14; its synchronized audition includes the corresponding leading silence.

FR_INTRO contains two overlong copies, on frames 100 and 360. Each writes two bytes beyond the 64,000 visible pixels. Extraction keeps a bounded guard word, compares it with the original decoder and exports only the visible image.

Expansion tapes use a sixteen-byte input packet, followed by mouse-event and command counts, fourteen-byte mouse events and a separate sixteen-bit command queue. The original version has a fourteen-byte packet and no command queue. All expansion packets and queued events were checked against DBSIM 0x51f84, stopping after the recorded state is copied at 0x5233f. Starting worlds were also constructed by the original loader. The C++ game now runs all four recordings to completion. Comparison of every subsequent world state with the original remains separate from packet decoding.

Remaining uncertainties

The catalogue preserves existing uncertainties rather than assigning new meanings to unchanged data. Two archive copies of CFG/TEST.DAT are identical to the base release's unclassified test resource. Legacy HOVTANK.DMG and retained mission layout exceptions remain identified. Module BND fields and some profile/table words have no established semantic consumer. The coverage inspector distinguishes those records from fully named layouts.

C++ integration

The native launcher now offers the March CD expansion alongside the original edition. Archive precedence, Battleset 2, career transfer, nine service-bay HERCs, expanded weapons, combat, cockpit rules, deployment pods, terrain, music and cinematics are connected. Saves use a separate expansion directory by default.

The executable comparisons add:

• 16 complete career constructors, eight transfers, 2,200 technology checks and 32 mission-return transactions. The returns compare career/history bytes, hangars, inventory, repair costs, debrief values and RNG for both battlesets.
• 108 bullet traces with 4,794 updates, 56 beam cases, and 160 radial shield cases. Expansion ordinary hits do not use the base difficulty multiplier; plasma area damage has its own multiplier. Recorded demos enable projectile falloff independently of preference 17.
• 3,240 landing-craft controller frames and 506 launches, including damaged weapon banks. Eleven structure types have 2,112 collision and 1,628 lifecycle comparisons.
• 192 deployment-point searches and 24 complete pod sequences. Modes 2/3 arrive in pods; modes 4/5 place a group directly. A pod warns on approach, lands with radial damage, opens and releases its group only if its landing was unobstructed. It leaves a crater. These paths retain the original separate clocks for falling and opening.
• 432 complete pixel, palette and visual RNG comparisons across all 36 environments, including cockpit masks and smaller offset viewports. The expansion clips the projected ground polygon before generating texture spans; it also changes sky-band edges and cloud placement. The two extra WLD words specify cloud altitude and ground texture scale. Wasteland/Ruins use lower clouds and a shorter texture repeat.
• All 74 captured launches construct, advance and render in C++. All four expansion recordings run through with cockpit commands, audio and drawing. These integration runs do not establish full original replay equivalence.

See the native repository's docs/EXPANSION.md for its regression coverage. The March CD engine is the implemented ruleset. The floppy engine and April patch remain separately characterised builds, not selectable C++ modes. Remaining work is broader consecutive gameplay comparison and playtesting, plus the unidentified data fields listed above. No complete expansion campaign playthrough is claimed by the component tests.

Rebuilding

Generators write to work/research; only curated findings and viewer assets are copied to analysis. Raw handoffs, original-code probes and individual film frames stay in the working directory.

Run these with the project virtual environment, in order:

python tools/build_expansion_catalogue.py
python tools/build_expansion_links.py
python tools/build_expansion_worlds.py
python tools/build_expansion_missions.py
python tools/complete_expansion_models.py
python tools/build_expansion_text.py
python tools/build_expansion_interface.py
python tools/build_expansion_tables.py
python tools/build_expansion_shell_catalogue.py
python tools/build_expansion_cockpits.py
python tools/build_expansion_fonts.py
python tools/build_expansion_music.py
python tools/build_expansion_movies.py
python tools/build_expansion_environment.py
python tools/build_expansion_tapes.py
python tools/build_expansion_inventory.py
python tools/render_model_thumbnails.py --edition expansion
python tools/check_expansion_browsers.py
python tools/publish_analysis.py

The film and environment exporters reuse completed checked captures. To replace a capture after changing its decoder, remove only that capture's cached report and outputs first. The publication manifest controls which results are shared.