Branch: jrpm ｜ Version: jrpm-0.1.0 (tagged, 2026-08-14) Build output: openttd-jrpm (executable name)

Version Relationship

                        jgrpp-0.73.1 (common ancestor)
                        /                 \
        jgrpp branch (63 commits)          pulsexlb px-patch (152 commits)
        ├ tracerestrict and other recent updates  ├ jgrpp-decouple (train decoupling)
        ├ my 5 features (d4c45740)                └ jgrpp-multitile-airport (modular airports)
        └ version renamed jrpm-0.1.0 (425e7207)
                        \                 /
                        jrpm branch (merge 71fe214c + compatibility cb9848b)

Merge Contents

1. pulsexlb/OpenTTD-patches (px-patch full 152 commits) → Merged

Feature	Description	Main Files
Train Decoupling (decouple)	Train decouple/couple: decouple orders, path signal transfer, coupling length/speed limits, dual-head, NewGRF coupling, coupling pathfinding (YAPF/NPF), independent scheduling after decoupling	train_cmd.cpp, order_cmd.cpp, order_gui.cpp, train.h, yapf/npf
Modular Airports (multitile-airport)	Multitile airport system overhaul: air type system (air.h/air_type.h/newgrf_airtype.), PBS air traffic control (pbs_air.), YAPF air pathfinding, station.allow_modify_airports (modify airport layout), gui.default_air_type, multitile airport sprites	air., pbs_air., aircraft_cmd.cpp (3600-line refactor), airport_cmd/gui, station_cmd

Conflict resolution: Only 2 header file conflicts (aircraft.h / airport.h) — pulsexlb's aviation refactor removed unreferenced dead types from the workspace (VehicleAirFlags bitset, AirportMovingDataFlag), took pulsexlb's deletion side, confirmed no other files reference them.

2. Openttd-Cluster (User's Rust Cluster Project) → Selective Reference

Patch	Handling	Description
0006 vanilla-native-server (multi-version client compatibility)	✅ Merged (cb9848b7)	jrpm server simultaneously accepts jrpm / original jgrpp (jgrpp-) / pulsexlb (pxp) clients; NewGRF version still strictly validated
0001 revision-handshake / 0005 version-metadata	✅ Concept adopted	jrpm uses an independent tagged revision string jrpm-0.1.0, multiplayer handshake isolated from jgrpp/pxp, achieving "new version for easy multiplayer"
0007 parallel-download (HTTP thread pool + Range chunked download, 30KB)	📝 Reference, not merged	Same topic as this project's F1 "file-level parallelism + multi-mirror" and modifies the same files; 0007's transport layer thread pool/chunked download recorded as a future enhancement direction for F1
0002-0004 snapshot/command/FFI bridge	📝 Architecture reference	Depends on the entire otc-engine Rust runtime (FFI statically linked), belongs to "long-term overall integration" rather than patch-level merge; jrpm currently maintains a pure C++ single binary

3. jrpm Exclusive (Previous 5 Features, d4c45740) → Already in jrpm Branch

Parallel download (multi-mirror + 4 concurrent sessions), auto-grouping, build tooltip, whole-game-aware AI (ScriptGlobal + GlobalAI), mirror/content server settings.

Multiplayer Strategy ("New Version for Easy Multiplayer")

• jrpm is a tagged version: IsNetworkCompatibleVersion requires exact revision string match → jrpm clients only connect to jrpm servers, fully isolated from jgrpp 0.73.x / pxp;
• Server relaxed: jrpm server additionally accepts jgrpp-* and pxp* clients (IsJgrppNativeNetworkRevision / IsPxpNetworkRevision, NewGRF version must match);
• Therefore: jrpm server host = only accepts jrpm players (default); when needing compatibility with old clients, it can accept jgrpp/pxp players without configuration changes.

Build and Verification (User's Local Machine Execution)

# First time (requires CMake + dependencies, see COMPILING.md)
cmake -B build ..
cmake --build build -j
# Output: build/openttd-jrpm.exe

Verification priority:

1. openttd-jrpm -v shows jrpm-0.1.0;
2. Single-player run for 1-2 game years (merge involves major train/airport changes + save version may be bumped due to allow_modify_airports, etc.);
3. After hosting: jrpm client connects ✓; original jgrpp 0.73.x client tries to connect (expected to join, if NewGRF matches);
4. Train decoupling: add decouple/couple orders to trains, verify independent scheduling after decoupling; modular airports: enable station.allow_modify_airports and modify airport layout;
5. Previous 5 features regression (parallel download, auto-grouping, build tooltip, GlobalAI).

Known Risks

• Not compiled/verified: The merged+modified code has not been compiled on a local machine (no toolchain); first real compilation may reveal interface changes that were missed (especially the three major overhauls: aircraft/airport/train);
• Save version: px-patch may have bumped SLV (M9 mentioned savegame version gate), jrpm saves may not be readable by jgrpp 0.73.x saves (same jgrpp convention, downward compatible with trunk saves);
• Merge brings in pulsexlb's full history; use git log --oneline pulsexlb/px-patch to trace feature ownership.

---

Merge log: 2026-09-28 (jgrpp-0.73.3 + px-patch 2609.x)

Merge commits: jgrpp 94 commits (up to jgrpp-0.73.3, 48e8d51c6c) + px-patch 113 commits (up to past pxp-2609.10, ec1a3d4fb3).

New upstream content

Source	Content	Notes
pulsexlb	Road vehicle transport (RoRo)	Trains/ships/aircraft refit to carry road vehicles; dedicated VEHC cargo; see Features → Road Vehicle Transport
pulsexlb	128 cargo types	NUM_CARGO 64→128, CargoTypes now a Uint128 bitset; savegames gated via XSLFI_CARGO_TYPES_128
pulsexlb	Decouple/couple fix batch	Coupled claim state persistence (CPLM chunk / XSLFI_COUPLE_CLAIM_STATE), propulsion/label/platform-command fixes and more
pulsexlb	Schedule enhancements	Post-decouple schedule execution opens a window, schedule menu conflict fix, no-engine train panel
jgrpp	Order drag & drop + double click	Orders can be dragged; stop location / RV direction need a double click (0.73.3)
jgrpp	Double-ended ships	NewGRF double-ended ships can reverse without turning (SLV_DOUBLE_ENDED_SHIPS / XSLFI_DOUBLE_ENDED_SHIPS)
jgrpp	Routine fixes	Departures column spacing, order tag dropdown, ByteReader overflow, Robin Hood label hashing, etc.

Key conflict handling

• Saveload layer: pulsexlb is based on the old SLE_ macro system while jrpm/jgrpp 0.73.3 uses VarFileType/VarMemType + the VarTypes struct. All saveload/ and sl/ conflicts were rewritten in the modern system, with U128 support added (VarFileType::U128=13, VarMemType::U128, SLE_UINT128, SlSaveLoadConv128 converted to modern enums);
• jrpm-occupied version numbers: SLV_MULTITILE_AIRPORTS(367)/SLV_ORDER_DECOUPLE(368) kept; upstream's SLV_LABEL_ORIENTATION_UNIFICATION/SLV_DOUBLE_ENDED_SHIPS shift to 369/370 (NSL alias enum comments note the upstream numbers); upstream savegame compat still goes through the XSLFI_UPSTREAM_VERSION sub-chunk;
• order_gui.cpp: jgrpp's drag fields (drag_start_pt/drag_start_time_us) merged into jrpm's order-list refactor; drag-drop callbacks use target-mode accessors (NumOrders/OrderAt) so order-list windows are safe; the upstream double-click semantics adopted;
• train_cmd.cpp: jrpm's couple-on-contact logic kept (ValidateCoupleCandidate), crash resolution switched to the upstream TrainsCrashed helper; the enable_decouple gate kept;
• Language files: jrpm-specific airport strings kept, shared strings taken from upstream ({WHITE} prefix dropped); pulsexlb's RV_TRANSPORT error strings translated into Simplified Chinese;
• Misc: CargoLabel 4-char literals converted to string construction (CT_VEHICLES); integer grfid switch converted to GrfID byte-string comparison (OpenGFX+ Airports conversion table); console_cmds keeps both autogroup and the RORO_DEBUG_COMMANDS debug block.

Post-merge status

• Build: MinGW ninja passes, artifact build/openttd-jrpm.exe;
• Run: new-game smoke test passed (see build verification).

---

Merge log: 2026-10-07 (jgrpp 0.73.3+89 + px-patch 2610.3)

Merge commits: jgrpp 23 commits (after jgrpp-0.73.3, up to 6318727b02) + px-patch 55 commits (up to pxp-2610.3, 4a4d0724b5).

What's new upstream

Source	Content	Notes
pulsexlb	Train ferry	Ships can be refitted to carry whole trains (dedicated RAIL cargo, CT_RAILVEHICLES); loading is per-wagons, so the whole train no longer has to sit in one cargo hold
pulsexlb	Rain system	New weather.cpp simulation: random rainy periods, gradual world darkening, rain-drop overlay (scales with zoom, randomised jitter); difficulty option difficulty.rain; a sandbox cheat forces auto/rain/sun; weather state is saved with the game (WTHR chunk / XSLFI_WEATHER)
pulsexlb	Same-direction decouple exit	When decoupling you can let one part wait for the other to leave and then exit in the same direction; includes a fix so a partner that has not fully left the station is no longer treated as blocking
pulsexlb	Capacity display	The ship info window shows the capacity of each cargo hold; the train info window shows the capacity of each wagon
pulsexlb	RoRo option improvements	The road-sign picker in transport options now offers train and road-vehicle signs; trains load road vehicles per wagon; the status bar no longer lists carried vehicles
pulsexlb	Coupling pathfinding performance	Removed the coupling pathfinding stutter: cargo validation is now a pre-check with failure back-off instead of a full scan every throttle tick
pulsexlb	Android build	New Android build script and CI; APKs are published alongside releases
jgrpp	StringID strong typing	StringID is now a strong type (and no longer used as a template parameter); Label only accepts string / byte-array construction
jgrpp	Duplicate company names	Duplicate company names are now properly rejected; president name generation refactored to avoid gotos
jgrpp	Widget preferred size	Widgets can compute a preferred size from a given size
jgrpp	Assorted refactors and fixes	Order list expressions, NewGRF GEF ID checks, GetSlopePixelZOnEdge returning a tuple, a crash when exporting all order lists from non-group vehicle list windows

Key conflict handling

• Save layer: pulsexlb's new WTHR weather chunk still uses the old SLEG_VAR/SLE_ macros, which remain available through the alias set in sl/saveload_common.h; only the outdated chunk-type enum CH_TABLE had to become the refactored ChunkType::Table;
• Label / StringID strong typing (the main compile obstacle this round): every 4-character literal label in jrpm's own code was switched to string construction (CT_RAILVEHICLES{"RAIL"}); the road and tram type label comparisons in afterload.cpp became RoadTypeLabel{"ROAD"} form; the empty AirTypeInfo string fields in airport.cpp now use STR_NULL; the STR_CHEAT_RAIN switch branches in cheat_gui.cpp use .base() (matching the existing STR_CHEAT_CHANGE_COMPANY.base() style);
• cheat_gui.cpp cheat table: jrpm's VarMemType field type and the InflationCheat sentinel are preserved, and pulsexlb's new rain cheat row is merged in (SLE_VAR_U8 + ClickRainCheat);
• jrpm_watch_gui.cpp: SetStringTip(SPR_GOTO_LOCATION, …) became SetSpriteTip (upstream split the sprite/string tooltip interfaces);
• Savegame version pin: SL_UPSTREAM_VERSION is still pinned to 368 (upstream DoubleEndedShips) and the static_assert guard in src/saveload/engine_sl.cpp passes; jrpm's reserved 367/368 are unchanged and the newer upstream versions shift to 369/370;
• train_cmd.cpp: the decouple check keeps jrpm's enable_decouple gate and desync debug output, while adopting upstream's depot fix that only triggers a reverse when the front of the train passes the waypoint (if (v->IsMovingFront())); the same-direction exit flags after want_decouple come from upstream;
• aircraft_cmd.cpp / window.cpp: includes from both sides are kept (jrpm's pathfinder/pbs/roadveh_transport alongside upstream's checksum/script_event/widgets);
• order_cmd.cpp: DrivingBackwards adopts upstream's new TCF_NO_DRIVING_CAB semantics and jrpm's DecouplePart variable is retained; the language string becomes "Driving backwards at reduced speed" accordingly;
• deploy-docs.yml: jrpm's VitePress build and GitHub Pages deployment are kept (pulsexlb's Typst variant only serves its own pxp-docs directory);
• README / .gitignore / .ottdrev-vc: jrpm branding and local entries are preserved, with pulsexlb's Android build ignore entries and the pxp-2610.3 version record merged in.

State after the merge

• Build: passes with MinGW ninja (-j3), artifact build/openttd-jrpm.exe;
• Run: -D dedicated server smoke test passes — new map generation → save → load → save again → exit completes with no assertion failure and no SetupEngines crash; upstream chunk version gating behaves correctly.