Babylon.js/src/Cameras/Inputs/freeCameraDeviceOrientationInput.ts

import { Nullable } from "types";
import { ICameraInput, CameraInputTypes } from "Cameras/cameraInputsManager";
import { FreeCamera } from "Cameras/freeCamera";
import { Quaternion } from "Maths/math";
import { Tools } from "Misc/tools";
    /**
     * Takes information about the orientation of the device as reported by the deviceorientation event to orient the camera.
     * Screen rotation is taken into account.
     * @see http://doc.babylonjs.com/how_to/customizing_camera_inputs
     */
    export class FreeCameraDeviceOrientationInput implements ICameraInput<FreeCamera> {
        private _camera: FreeCamera;

        private _screenOrientationAngle: number = 0;

        private _constantTranform: Quaternion;
        private _screenQuaternion: Quaternion = new Quaternion();

        private _alpha: number = 0;
        private _beta: number = 0;
        private _gamma: number = 0;

        /**
         * Instantiates a new input
         * @see http://doc.babylonjs.com/how_to/customizing_camera_inputs
         */
        constructor() {
            this._constantTranform = new Quaternion(- Math.sqrt(0.5), 0, 0, Math.sqrt(0.5));
            this._orientationChanged();
        }

        /**
         * Define the camera controlled by the input.
         */
        public get camera(): FreeCamera {
            return this._camera;
        }

        public set camera(camera: FreeCamera) {
            this._camera = camera;
            if (this._camera != null && !this._camera.rotationQuaternion) {
                this._camera.rotationQuaternion = new Quaternion();
            }
        }

        /**
         * Attach the input controls to a specific dom element to get the input from.
         * @param element Defines the element the controls should be listened from
         * @param noPreventDefault Defines whether event caught by the controls should call preventdefault() (https://developer.mozilla.org/en-US/docs/Web/API/Event/preventDefault)
         */
        public attachControl(element: HTMLElement, noPreventDefault?: boolean): void {
            window.addEventListener("orientationchange", this._orientationChanged);
            window.addEventListener("deviceorientation", this._deviceOrientation);
            //In certain cases, the attach control is called AFTER orientation was changed,
            //So this is needed.
            this._orientationChanged();
        }

        private _orientationChanged = () => {
            this._screenOrientationAngle = (<any>window.orientation !== undefined ? +<any>window.orientation : ((<any>window.screen).orientation && ((<any>window.screen).orientation)['angle'] ? ((<any>window.screen).orientation).angle : 0));
            this._screenOrientationAngle = -Tools.ToRadians(this._screenOrientationAngle / 2);
            this._screenQuaternion.copyFromFloats(0, Math.sin(this._screenOrientationAngle), 0, Math.cos(this._screenOrientationAngle));
        }

        private _deviceOrientation = (evt: DeviceOrientationEvent) => {
            this._alpha = evt.alpha !== null ? evt.alpha : 0;
            this._beta = evt.beta !== null ? evt.beta : 0;
            this._gamma = evt.gamma !== null ? evt.gamma : 0;
        }

        /**
         * Detach the current controls from the specified dom element.
         * @param element Defines the element to stop listening the inputs from
         */
        public detachControl(element: Nullable<HTMLElement>): void {
            window.removeEventListener("orientationchange", this._orientationChanged);
            window.removeEventListener("deviceorientation", this._deviceOrientation);
        }

        /**
         * Update the current camera state depending on the inputs that have been used this frame.
         * This is a dynamically created lambda to avoid the performance penalty of looping for inputs in the render loop.
         */
        public checkInputs(): void {
            //if no device orientation provided, don't update the rotation.
            //Only testing against alpha under the assumption thatnorientation will never be so exact when set.
            if (!this._alpha) { return; }
            Quaternion.RotationYawPitchRollToRef(Tools.ToRadians(this._alpha), Tools.ToRadians(this._beta), -Tools.ToRadians(this._gamma), this.camera.rotationQuaternion);
            this._camera.rotationQuaternion.multiplyInPlace(this._screenQuaternion);
            this._camera.rotationQuaternion.multiplyInPlace(this._constantTranform);
            //Mirror on XY Plane
            this._camera.rotationQuaternion.z *= -1;
            this._camera.rotationQuaternion.w *= -1;
        }

        /**
         * Gets the class name of the current intput.
         * @returns the class name
         */
        public getClassName(): string {
            return "FreeCameraDeviceOrientationInput";
        }

        /**
         * Get the friendly name associated with the input class.
         * @returns the input friendly name
         */
        public getSimpleName(): string {
            return "deviceOrientation";
        }
    }

    (<any>CameraInputTypes)["FreeCameraDeviceOrientationInput"] = FreeCameraDeviceOrientationInput;