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Developer Harmony IL2CPP

Patch style, performance rules, and IL2CPP pitfalls. (Oxide equivalent: “Publicizer” + “Using Decompiler” + “Best Practices”, adapted to Unity 6000 IL2CPP.)

Patch style

Section titled “Patch style”
  • One task per patch class, deriving from SafePatch; explicit PatchAll (never blanket-apply surprises).
  • try/catch inside every patch; true/false prefix semantics (return false skips the original — use deliberately).
  • Small defensive Prefix/Postfix pairs; emit events (greg.RACK.*, greg.SYSTEM.ButtonCheckOut, …) instead of duplicating logic.
  • Never hand-roll method lookup: gregCore.Core.Mods.GregPatches.TryPatchPrefix/TryPatchPostfix(harmony, type, name, holder, patch, logTag) warns + returns false when the target is missing (game update) instead of throwing.
  • Representative classes (src/gregCore.Patches/): HardwareIdPersistencePatch, IncompatibleModGuard, RackPatch, SaveSystemPatch, SaveManagerPatch, NetworkMapPatch, CablePositionsPatch, TimePatch, LoadingScreenPatch, PlayerPatch, ShopPatch, ServerPatch, KeybindPatches, SettingsUiBridgePatch, InputControllerPatch, RackPlacementPatch.

Performance rules (measured, not stylistic)

Section titled “Performance rules (measured, not stylistic)”
  • No per-frame reflection. Cache Type.GetType / MethodInfo once.
  • No FindObjectsOfType in OnUpdate. Cache holders; throttle scans (tiers: 0.1 s / 1 s / 2 s / 30 s).
  • Event-state, not polling where possible (PortSpeedMemory pattern); visual animators (RgbAnimator) track slots instead of rescanning.
  • Route bursts through GregOperationQueue; background budgets via GregPerformanceGovernor / GregResourceMonitor / GregPerformancePatches (incl. WorldCanvasCuller, technician/footstep/indicator throttles).

IL2CPP pitfalls

Section titled “IL2CPP pitfalls”
  • Il2CppReferenceArray: always copy/extend properly (shop rows, dropdown items via Il2CppSystem.Collections.Generic.List<string>).
  • Nullable<Color> needs explicit handling; renderer.materials clones — mutate the clone.
  • Never cache Il2Cpp objects long-term (GC moves them); re-resolve via inventory UIDs.
  • Inactive DontDestroyOnLoad holders for state you must keep; DelegateSupport.ConvertDelegate for managed→Il2Cpp callbacks.
  • OnGUI is stripped and there is no EventSystem — UIToolkit + GregClickRouter only (Developer UI Panels HUD).

After a game update

Section titled “After a game update”
  1. Run the game once with MelonLoader; re-copy Il2CppAssemblies + net6 into references/.
  2. tools/GameApiGenerator/regenerate.sh → re-check src/gregCore.GameApi/Generated/.
  3. scripts/Generate-GregHooksFromIl2CppDump.ps1 → review game_hooks.json → curate framework/greg_hooks.json.
  4. scripts/validate_contracts.py + scripts/check-coverage.sh + full dotnet test.
  5. Vanilla-first test: no mods → game loads → enable yours.