DeviceOrientationControls.js

/**
 * @author richt / http://richt.me
 * @author WestLangley / http://github.com/WestLangley
 *
 * W3C Device Orientation control (http://w3c.github.io/deviceorientation/spec-source-orientation.html)
 */

THREE.DeviceOrientationControls = function( object ) {

    var scope = this;

    this.object = object;
    this.object.rotation.reorder( "YXZ" );

    this.enabled = true;

    this.deviceOrientation = {};
    this.screenOrientation = 0;

    this.alpha = 0;
    this.alphaOffsetAngle = 0;


    var onDeviceOrientationChangeEvent = function( event ) {

        scope.deviceOrientation = event;

        scope.enabled = window.orientation != null;

    };

    var onScreenOrientationChangeEvent = function() {

        scope.screenOrientation = window.orientation || 0;

        scope.enabled = window.orientation != null;

    };

    // The angles alpha, beta and gamma form a set of intrinsic Tait-Bryan angles of type Z-X'-Y''

    var setObjectQuaternion = function() {

        var zee = new THREE.Vector3( 0, 0, 1 );

        var euler = new THREE.Euler();

        var q0 = new THREE.Quaternion();

        var q1 = new THREE.Quaternion( - Math.sqrt( 0.5 ), 0, 0, Math.sqrt( 0.5 ) ); // - PI/2 around the x-axis

        return function( quaternion, alpha, beta, gamma, orient ) {

            euler.set( beta, alpha, - gamma, 'YXZ' ); // 'ZXY' for the device, but 'YXZ' for us

            quaternion.setFromEuler( euler ); // orient the device

            quaternion.multiply( q1 ); // camera looks out the back of the device, not the top

            quaternion.multiply( q0.setFromAxisAngle( zee, - orient ) ); // adjust for screen orientation

        }

    }();

    this.connect = function() {

        onScreenOrientationChangeEvent(); // run once on load

        window.addEventListener( 'orientationchange', onScreenOrientationChangeEvent, false );
        window.addEventListener( 'deviceorientation', onDeviceOrientationChangeEvent, false );

    };

    this.disconnect = function() {

        window.removeEventListener( 'orientationchange', onScreenOrientationChangeEvent, false );
        window.removeEventListener( 'deviceorientation', onDeviceOrientationChangeEvent, false );

        scope.enabled = false;

    };

    this.update = function() {

        if ( scope.enabled === false ) return;

        var alpha = scope.deviceOrientation.alpha ? THREE.Math.degToRad( scope.deviceOrientation.alpha ) + this.alphaOffsetAngle : 0; // Z
        var beta = scope.deviceOrientation.beta ? THREE.Math.degToRad( scope.deviceOrientation.beta ) : 0; // X'
        var gamma = scope.deviceOrientation.gamma ? THREE.Math.degToRad( scope.deviceOrientation.gamma ) : 0; // Y''
        var orient = scope.screenOrientation ? THREE.Math.degToRad( scope.screenOrientation ) : 0; // O

        setObjectQuaternion( scope.object.quaternion, alpha, beta, gamma, orient );
        this.alpha = alpha;

    };

    this.updateAlphaOffsetAngle = function( angle ) {

        this.alphaOffsetAngle = angle;
        this.update();

    };

    this.dispose = function() {

        this.disconnect();

    };

    this.connect();

};