horizon-mods/native/zoom

Zoom (Horizon native mod)

Horizon's official Zoom: hold a key (Z by default) to zoom in, and turn the mouse wheel while you hold it to zoom further in or out. Its settings page (Options > Mods > Zoom > Settings) has the key and three options: the starting zoom (2x to 10x), smooth zoom (eased like the spyglass) and slower turning while zoomed.

It is a horizon-mixins bundle (mixins/zoom/) that the Horizon launcher builds into the game. It keeps the settings of earlier versions: the same files (horizon-mods/.horizon-mod-data/zoom/level, smooth, sensitivity) and the same key line (key.zoom.zoom:… in horizon-mods.txt).

Install

In the Horizon launcher: Mods → Zoom → Install, then Build on the same page (once built, switch it on or off in the game under Options → Mods). The launcher downloads its own Rust and builds the game with your native mods; see Horizon's native mods.

Made on the hook points

The bundle hooks only Horizon's native hook points (crates/horizon-client/src/game/native_hooks.rs), which keep their names and signatures across releases. compatibility.json names the version it needs ("hooks": 1), so the launcher builds Zoom on any Horizon with that version or a later one, the player's own game by default, together with any other mod. horizon_revision is only the commit it was last tested on.

File	What it is
mixins/zoom/horizon-mixin.toml	The bundle: one module and the HEAD hooks
mixins/zoom/runtime.rs	The mod's logic and state, added to the game as game::official_zoom; also this crate's library, for its tests
mixins/zoom/*.rs	One small helper per hook
../tools/native.py	Shared by the native mods: apply on Horizon (from GitHub, by commit), check, build, package the .hnmod, run the proof
proof.py (with ../tools/game.py)	The proof: the built game driven with horizon-ctl --offscreen on fresh, temporary data

Build and prove

(cd native/zoom && cargo test)                    # the logic
python3 native/tools/native.py check zoom          # apply on the tested Horizon and cargo check the game
python3 native/tools/native.py check zoom --horizon latest  # ... on the newest Nightly
python3 native/tools/native.py check all           # with the other native mods, as a player's set
python3 native/tools/native.py package zoom        # native/target/zoom-<version>.hnmod for the registry
python3 native/tools/native.py proof zoom --resources /path/to/.local/horizon-client/26.3

The proof needs resources prepared from your own Minecraft 26.3 (horizon-prepare); none are in this repository. It seeds an earlier version's settings (8x, no smoothing, key C) in a temporary game folder, then checks that Options > Mods shows them, that Z does nothing and C zooms, that the wheel zooms instead of moving the hotbar while C is held, and that the page's buttons write the same files. CI runs cargo test, packages the .hnmod and checks the game on the tested commit, and every Monday on the newest Nightly.

License: MIT.