LHDF Core

# LHDF Core

LHDF Core is the framework the other mods of the Lost Hope Dynamic Framework (LHDF) build on. It adds no gameplay of its own.

Each LHDF mod registers with Core when it is loaded. Core loads the mod's settings from JSON files on the server, sends the values clients need, stores the mod's data inside the vanilla save, and adds the mod's attributes and placeables to the Game Master editor.

## Features

- Settings for every LHDF mod in one JSON file per mod. The file only needs the keys you change; the server never overwrites it.
- A reference of every key with its default, range and description, written on every start.
- Live changes by a Game Master: settings marked as live appear as checkboxes and sliders in the mod's attribute tab, apply at once and are kept in `<Key>.live.json`. Delete that file to go back to the owner's settings.
- Saved data of LHDF mods (per player and per world) is part of the vanilla save. Data of a mod that is not loaded is kept.
- Returning players get their saved character back when vanilla would spawn them fresh after a restart.
- Game Master editor: one attribute tab per LHDF mod, LHDF placeables in the Game Master content browser, plain-text search ("LHDF" or a mod name). Only Game Masters in unlimited edit mode and admins can read or change these attributes.
- Admin rights for LHDF features: logged-in and listed server admins, and players named in the start parameter `-lhdfAdmins "<identity id>,<identity id>"`.
- Shared world index of buildings and named map locations, built once and cached.
- Work queue that spreads long jobs of LHDF mods over many frames.
- Performance log and a warning when LHDF work in one frame takes too long.

## Required on server and clients

Core replicates settings to clients and adds Game Master attributes, so it must be loaded on the server and on every client. It is normally pulled in as a dependency of the other LHDF mods.

## Dependencies

- Arma Reforger

## Configuration

Settings live in `$profile:LHDF/<namespace>/Core.json`. The namespace is taken from the scenario's mission header file name unless the scenario sets one. On every start the server writes every key with its default to `_defaults/Core.md` and `_defaults/Core.json` in the same folder; copy the lines you need into `Core.json`. The same applies to every other LHDF mod, with its own key (for example `Server.json`, `VehicleLock.json`).

Main keys of `Core.json`:

- `debug` (default `[]`): mods whose debug lines are logged, by key, or `"*"` for all.
- `perfLog` (default false): log a performance summary of LHDF work. The start parameter `-lhdfPerf` switches it on for one run.
- `perfIntervalSeconds` (default 60, 10 to 3600): seconds between summaries.
- `frameWarnMs` (default 25, 5 to 1000): warn when LHDF work in one frame takes longer.
- `workBudgetMs` (default 2, 1 to 8): milliseconds per frame for long LHDF jobs.
- `writeDefaults` (default true): write the `_defaults` reference on every start.

Start parameters:

- `-lhdfAdmins "<identity id>,<identity id>"`: LHDF admin rights (for example `#save` and `#message` of LHDF Server Tools) for servers without listed admins. Vanilla admin features still need `#login`.
- `-lhdfUnverifiedIdentity`: name-based player ids for local test servers without backend. Anyone using the same name gets the same data. Never use it on a public server.

## Known limitations

- Without a persistence system (for example Workbench play), LHDF mods run but nothing is saved.

Beta (0.9.0): feedback welcome on the Lost Hope Survival Discord: https://discord.gg/uDzYTTdsM6