react-native-vision-camera/lib/hooks/useDepthOutput.js

VisionCamera is the fastest and most powerful Camera for react-native.

import { useEffect, useMemo, useRef } from 'react';
import { VisionCameraWorkletsProxy } from '../third-party/VisionCameraWorkletsProxy';
import { CommonResolutions } from '../utils/CommonResolutions';
import { VisionCamera } from '../VisionCamera';
/**
 * Use a {@linkcode CameraDepthFrameOutput} for streaming {@linkcode Depth} Frames.
 *
 * The {@linkcode UseDepthOutputProps.onDepth | onDepth(...)} callback will be
 * called for every {@linkcode Depth} Frame the Camera produces. It is a
 * synchronous JS function running on the {@linkcode CameraDepthFrameOutput}'s
 * thread - aka a "worklet".
 *
 * @note {@linkcode useDepthOutput | useDepthOutput(...)} requires
 * `react-native-vision-camera-worklets` (and
 * [react-native-worklets](https://docs.swmansion.com/react-native-worklets/docs/))
 * to be installed.
 *
 * @discussion
 * You must {@linkcode Depth.dispose | dispose} the {@linkcode Depth} Frame after
 * your callback has finished processing, otherwise subsequent Frames may be
 * dropped (see {@linkcode UseDepthOutputProps.onDepthFrameDropped | onDepthFrameDropped(...)}).
 *
 * @example
 * ```ts
 * const depthOutput = useDepthOutput({
 *   onDepth(depth) {
 *     'worklet'
 *     // some depth processing
 *     depth.dispose()
 *   }
 * })
 * ```
 */
export function useDepthOutput({ targetResolution = CommonResolutions.VGA_16_9, enableFiltering = true, onDepth, onDepthFrameDropped, dropFramesWhileBusy = true, allowDeferredStart = true, }) {
    // 1. Create depth output
    const depthOutput = useMemo(() => VisionCamera.createDepthFrameOutput({
        targetResolution: targetResolution,
        enableFiltering: enableFiltering,
        enablePhysicalBufferRotation: false,
        dropFramesWhileBusy: dropFramesWhileBusy,
        allowDeferredStart: allowDeferredStart,
    }), [
        targetResolution,
        enableFiltering,
        dropFramesWhileBusy,
        allowDeferredStart,
    ]);
    // 2. Add Frame dropped warner
    const onDepthFrameDroppedRef = useRef(onDepthFrameDropped);
    onDepthFrameDroppedRef.current = onDepthFrameDropped;
    useEffect(() => {
        depthOutput.setOnDepthFrameDroppedCallback((reason) => {
            const callback = onDepthFrameDroppedRef.current;
            if (callback != null)
                callback(reason);
            else
                console.warn(`Depth Frame Dropped! Reason: ${reason}`);
        });
    }, [depthOutput]);
    // 3. Create Worklet Runtime for NativeThread
    const runtime = useMemo(() => VisionCameraWorkletsProxy.createRuntimeForThread(depthOutput.thread), [depthOutput.thread]);
    // 4. Update onDepth() callback if it changed
    useEffect(() => {
        runtime.setOnDepthFrameCallback(depthOutput, onDepth);
    }, [runtime, depthOutput, onDepth]);
    // 5. Return :)
    return depthOutput;
}