@openhps/web-sensors/src/legacy/SensorSourceNode.ts

Open Hybrid Positioning System - Web Sensors API

import {
    Acceleration,
    AngularVelocity,
    DataFrame,
    Orientation,
    SensorSourceOptions,
    SourceNode,
    AbsoluteOrientationSensor as AbsoluteOrientationSensorObject,
    Gyroscope as GyroscopeObject,
    Accelerometer as AccelerometerObject,
    DataObject,
    AccelerationUnit,
    AngularVelocityUnit,
} from '@openhps/core';
import { SensorSourceNodeInterface } from '../SensorSourceNodeInterface';

/**
 * IMU source using the HTML5 browser API for device motion and device orientation.
 * @category Source node
 */
export class SensorSourceNode extends SourceNode<DataFrame> implements SensorSourceNodeInterface {
    protected options: SensorSourceOptions;

    constructor(options?: SensorSourceOptions) {
        super(options);
        this.options.source = this.options.source ?? new DataObject(this.uid);
        if (this.options.autoStart) {
            this.once('build', this.start.bind(this));
        }
        this.once('destroy', this.stop.bind(this));
    }

    requestPermission(): Promise<void> {
        return Promise.resolve();
    }

    start(): Promise<void> {
        return new Promise((resolve) => {
            const sensorUID = this.source ? this.source.uid : this.uid;
            window.addEventListener(
                'devicemotion',
                (event) => {
                    // Create a new data frame for the orientation change
                    const dataFrame = new DataFrame();
                    const frequency = 1000 / event.interval;
                    dataFrame.addSensor(
                        new AccelerometerObject(
                            sensorUID + '_accl',
                            new Acceleration(
                                event.accelerationIncludingGravity.x,
                                event.accelerationIncludingGravity.y,
                                event.accelerationIncludingGravity.z,
                                AccelerationUnit.METER_PER_SECOND_SQUARE,
                            ),
                            frequency,
                        ),
                    );
                    dataFrame.addSensor(
                        new GyroscopeObject(
                            sensorUID + '_gyro',
                            new AngularVelocity(
                                event.rotationRate.beta,
                                event.rotationRate.gamma,
                                event.rotationRate.alpha,
                                AngularVelocityUnit.RADIAN_PER_SECOND,
                            ),
                            frequency,
                        ),
                    );
                    dataFrame.addSensor(
                        new AccelerometerObject(
                            sensorUID + '_linearaccl',
                            new Acceleration(
                                event.acceleration.x,
                                event.acceleration.y,
                                event.acceleration.z,
                                AccelerationUnit.METER_PER_SECOND_SQUARE,
                            ),
                            frequency,
                        ),
                    );

                    const source = this.source;
                    source.getPosition().angularVelocity = dataFrame.getSensor(GyroscopeObject).value;
                    dataFrame.addSensor(
                        new AbsoluteOrientationSensorObject(
                            sensorUID + '_orientation',
                            source.getPosition().orientation,
                        ),
                    );
                    dataFrame.source = source;

                    this.push(dataFrame);
                },
                true,
            );

            window.addEventListener('deviceorientation', (event) => {
                const source = this.source;
                source.getPosition().orientation = Orientation.fromEuler([event.beta, event.gamma, event.alpha]);
            });

            this.logger('debug', 'Browser orientation and motion events registered!');
            resolve();
        });
    }

    stop(): Promise<void> {
        return Promise.resolve();
    }

    public onPull(): Promise<DataFrame> {
        return new Promise<DataFrame>((resolve) => {
            resolve(undefined);
        });
    }
}