@threlte/xr/dist/hooks/currentReadable.svelte.js

Tools to more easily create VR and AR experiences with Threlte

import { untrack } from 'svelte';
import { toStore } from 'svelte/store';
/**
 * ### `runeToCurrentReadable`
 *
 * Bridges a Svelte 5 `$state` or `$derived` rune into the `CurrentReadable`
 * interface, allowing rune-backed reactive values to be consumed as read-only
 * stores by legacy or store-aware code.
 *
 * Pass the getter of a `$state` or `$derived` variable:
 *
 * ```ts
 * let count = $state(0)
 * const doubled = $derived(count * 2)
 *
 * const store = runeToCurrentReadable(() => doubled)
 *
 * store.subscribe((v) => console.log(v)) // reacts to rune changes
 * console.log(store.current)             // synchronous read, no overhead
 * ```
 *
 * Use this over `runeToCurrentWritable` when the value is derived or when
 * external writes should not be allowed — for example, renderer settings
 * that are owned by `<Canvas>` props.
 *
 * The `.current` property reads the rune directly and is always in sync.
 * `.subscribe` is powered by `toStore`, which tracks the getter reactively
 * via `$effect`.
 */
export const runeToCurrentReadable = (get) => {
    const { subscribe } = toStore(get);
    return {
        subscribe,
        get current() {
            return untrack(get);
        }
    };
};