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

Tools to more easily create VR and AR experiences with Threlte

import { useTask, useThrelte } from '@threlte/core';
import { useHand } from './useHand.svelte.js';
import { isPresenting } from '../internal/state.svelte.js';
import { runeToCurrentReadable } from './currentReadable.svelte.js';
import { fromStore } from 'svelte/store';
/**
 * Provides a reference to a requested hand joint, once available.
 */
export const useHandJoint = (handedness, joint) => {
    const { invalidate } = useThrelte();
    const hand = fromStore(useHand(handedness));
    let jointSpace = $state.raw();
    useTask(() => {
        const space = hand.current?.hand.joints[joint];
        // The joint radius is a good indicator that the joint is ready.
        // Re-check each frame so we pick up reconnects and clear on disconnect.
        if (space?.jointRadius !== undefined) {
            if (jointSpace !== space) {
                jointSpace = space;
                invalidate();
            }
        }
        else if (jointSpace !== undefined) {
            jointSpace = undefined;
            invalidate();
        }
    }, { running: () => isPresenting.current });
    return runeToCurrentReadable(() => jointSpace);
};