# lib/controls/OrbitControls.js

    import * as THREE from 'three';

    /**
     * @classdesc Orbit Controls
     * @constructor
     * @external OrbitControls
     * @param {THREE.Object} object
     * @param {HTMLElement} domElement
     */
    function OrbitControls ( object, domElement ) {

        this.object = object;
        this.domElement = ( domElement !== undefined ) ? domElement : document;
        this.frameId = null;

        // API

        // Set to false to disable this control
        this.enabled = true;

        /*
         * "target" sets the location of focus, where the control orbits around
         * and where it pans with respect to.
         */
        this.target = new THREE.Vector3();

        // center is old, deprecated; use "target" instead
        this.center = this.target;

        /*
         * This option actually enables dollying in and out; left as "zoom" for
         * backwards compatibility
         */
        this.noZoom = false;
        this.zoomSpeed = 1.0;

        // Limits to how far you can dolly in and out ( PerspectiveCamera only )
        this.minDistance = 0;
        this.maxDistance = Infinity;

        // Limits to how far you can zoom in and out ( OrthographicCamera only )
        this.minZoom = 0;
        this.maxZoom = Infinity;

        // Set to true to disable this control
        this.noRotate = false;
        this.rotateSpeed = -0.15;

        // Set to true to disable this control
        this.noPan = true;
        this.keyPanSpeed = 7.0;	// pixels moved per arrow key push

        // Set to true to automatically rotate around the target
        this.autoRotate = false;
        this.autoRotateSpeed = 2.0; // 30 seconds per round when fps is 60

        /*
         * How far you can orbit vertically, upper and lower limits.
         * Range is 0 to Math.PI radians.
         */
        this.minPolarAngle = 0; // radians
        this.maxPolarAngle = Math.PI; // radians

        // Momentum
      	this.momentumDampingFactor = 0.90;
      	this.momentumScalingFactor = -0.005;
      	this.momentumKeydownFactor = 20;

      	// Fov
      	this.minFov = 30;
      	this.maxFov = 120;

        /*
         * How far you can orbit horizontally, upper and lower limits.
         * If set, must be a sub-interval of the interval [ - Math.PI, Math.PI ].
         */
        this.minAzimuthAngle = - Infinity; // radians
        this.maxAzimuthAngle = Infinity; // radians

        // Set to true to disable use of the keys
        this.noKeys = false;

        // The four arrow keys
        this.keys = { LEFT: 37, UP: 38, RIGHT: 39, BOTTOM: 40 };

        // Mouse buttons
        this.mouseButtons = { ORBIT: THREE.MOUSE.LEFT, ZOOM: THREE.MOUSE.MIDDLE, PAN: THREE.MOUSE.RIGHT };

        /*
         * //////////
         * internals
         */

        var scope = this;

        var EPS = 10e-8;
        var MEPS = 10e-5;

        var rotateStart = new THREE.Vector2();
        var rotateEnd = new THREE.Vector2();
        var rotateDelta = new THREE.Vector2();

        var panStart = new THREE.Vector2();
        var panEnd = new THREE.Vector2();
        var panDelta = new THREE.Vector2();
        var panOffset = new THREE.Vector3();

        var offset = new THREE.Vector3();

        var dollyStart = new THREE.Vector2();
        var dollyEnd = new THREE.Vector2();
        var dollyDelta = new THREE.Vector2();

        var theta = 0;
        var phi = 0;
        var phiDelta = 0;
        var thetaDelta = 0;
        var scale = 1;
        var pan = new THREE.Vector3();

        var lastPosition = new THREE.Vector3();
        var lastQuaternion = new THREE.Quaternion();

        var momentumLeft = 0, momentumUp = 0;
        var eventPrevious;
        var momentumOn = false;

        var keyUp, keyBottom, keyLeft, keyRight;

        var STATE = { NONE: -1, ROTATE: 0, DOLLY: 1, PAN: 2, TOUCH_ROTATE: 3, TOUCH_DOLLY: 4, TOUCH_PAN: 5 };

        var state = STATE.NONE;

        // for reset

        this.target0 = this.target.clone();
        this.position0 = this.object.position.clone();
        this.zoom0 = this.object.zoom;

        // so camera.up is the orbit axis

        var quat = new THREE.Quaternion().setFromUnitVectors( object.up, new THREE.Vector3( 0, 1, 0 ) );
        var quatInverse = quat.clone().inverse();

        // events

        var changeEvent = { type: 'change' };
        var startEvent = { type: 'start' };
        var endEvent = { type: 'end' };

        this.setLastQuaternion = function ( quaternion ) {
            lastQuaternion.copy( quaternion );
            scope.object.quaternion.copy( quaternion );
        };

        this.getLastPosition = function () {
            return lastPosition;
        };

        this.rotateLeft = function ( angle ) {

            if ( angle === undefined ) {

                angle = getAutoRotationAngle();

            }

            thetaDelta -= angle;

        };

        this.rotateUp = function ( angle ) {

            if ( angle === undefined ) {

                angle = getAutoRotationAngle();

            }

            phiDelta -= angle;

        };

        // pass in distance in world space to move left
        this.panLeft = function ( distance ) {

            var te = this.object.matrix.elements;

            // get X column of matrix
            panOffset.set( te[ 0 ], te[ 1 ], te[ 2 ] );
            panOffset.multiplyScalar( - distance );

            pan.add( panOffset );

        };

        // pass in distance in world space to move up
        this.panUp = function ( distance ) {

            var te = this.object.matrix.elements;

            // get Y column of matrix
            panOffset.set( te[ 4 ], te[ 5 ], te[ 6 ] );
            panOffset.multiplyScalar( distance );

            pan.add( panOffset );

        };

        /*
         * pass in x,y of change desired in pixel space,
         * right and down are positive
         */
        this.pan = function ( deltaX, deltaY ) {

            var element = scope.domElement === document ? scope.domElement.body : scope.domElement;

            if ( scope.object instanceof THREE.PerspectiveCamera ) {

                // perspective
                var position = scope.object.position;
                var offset = position.clone().sub( scope.target );
                var targetDistance = offset.length();

                // half of the fov is center to top of screen
                targetDistance *= Math.tan( ( scope.object.fov / 2 ) * Math.PI / 180.0 );

                // we actually don't use screenWidth, since perspective camera is fixed to screen height
                scope.panLeft( 2 * deltaX * targetDistance / element.clientHeight );
                scope.panUp( 2 * deltaY * targetDistance / element.clientHeight );

            } else if ( scope.object instanceof THREE.OrthographicCamera ) {

                // orthographic
                scope.panLeft( deltaX * (scope.object.right - scope.object.left) / element.clientWidth );
                scope.panUp( deltaY * (scope.object.top - scope.object.bottom) / element.clientHeight );

            } else {

                // camera neither orthographic or perspective
                console.warn( 'WARNING: OrbitControls.js encountered an unknown camera type - pan disabled.' );

            }

        };

        this.momentum = function(){

            if ( !momentumOn ) return;

            if ( Math.abs( momentumLeft ) < MEPS && Math.abs( momentumUp ) < MEPS ) {

                momentumOn = false;
                return;
            }

            momentumUp   *= this.momentumDampingFactor;
            momentumLeft *= this.momentumDampingFactor;

            thetaDelta -= this.momentumScalingFactor * momentumLeft;
            phiDelta   -= this.momentumScalingFactor * momentumUp;

        };

        this.dollyIn = function ( dollyScale ) {

            if ( dollyScale === undefined ) {

                dollyScale = getZoomScale();

            }

            if ( scope.object instanceof THREE.PerspectiveCamera ) {

                scale /= dollyScale;

            } else if ( scope.object instanceof THREE.OrthographicCamera ) {

                scope.object.zoom = Math.max( this.minZoom, Math.min( this.maxZoom, this.object.zoom * dollyScale ) );
                scope.object.updateProjectionMatrix();
                scope.dispatchEvent( changeEvent );

            } else {

                console.warn( 'WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.' );

            }

        };

        this.dollyOut = function ( dollyScale ) {

            if ( dollyScale === undefined ) {

                dollyScale = getZoomScale();

            }

            if ( scope.object instanceof THREE.PerspectiveCamera ) {

                scale *= dollyScale;

            } else if ( scope.object instanceof THREE.OrthographicCamera ) {

                scope.object.zoom = Math.max( this.minZoom, Math.min( this.maxZoom, this.object.zoom / dollyScale ) );
                scope.object.updateProjectionMatrix();
                scope.dispatchEvent( changeEvent );

            } else {

                console.warn( 'WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.' );

            }

        };

        this.update = function ( ignoreUpdate ) {

            var position = this.object.position;

            offset.copy( position ).sub( this.target );

            // rotate offset to "y-axis-is-up" space
            offset.applyQuaternion( quat );

            // angle from z-axis around y-axis

            theta = Math.atan2( offset.x, offset.z );

            // angle from y-axis

            phi = Math.atan2( Math.sqrt( offset.x * offset.x + offset.z * offset.z ), offset.y );

            if ( this.autoRotate && state === STATE.NONE ) {

                this.rotateLeft( getAutoRotationAngle() );

            }

            this.momentum();

            theta += thetaDelta;
            phi += phiDelta;

            // restrict theta to be between desired limits
            theta = Math.max( this.minAzimuthAngle, Math.min( this.maxAzimuthAngle, theta ) );

            // restrict phi to be between desired limits
            phi = Math.max( this.minPolarAngle, Math.min( this.maxPolarAngle, phi ) );

            // restrict phi to be betwee EPS and PI-EPS
            phi = Math.max( EPS, Math.min( Math.PI - EPS, phi ) );

            var radius = offset.length() * scale;

            // restrict radius to be between desired limits
            radius = Math.max( this.minDistance, Math.min( this.maxDistance, radius ) );

            // move target to panned location
            this.target.add( pan );

            offset.x = radius * Math.sin( phi ) * Math.sin( theta );
            offset.y = radius * Math.cos( phi );
            offset.z = radius * Math.sin( phi ) * Math.cos( theta );

            // rotate offset back to "camera-up-vector-is-up" space
            offset.applyQuaternion( quatInverse );

            position.copy( this.target ).add( offset );

            this.object.lookAt( this.target );

            thetaDelta = 0;
            phiDelta = 0;
            scale = 1;
            pan.set( 0, 0, 0 );

            /*
             * update condition is:
             * min(camera displacement, camera rotation in radians)^2 > EPS
             * using small-angle approximation cos(x/2) = 1 - x^2 / 8
             */
            if ( lastPosition.distanceToSquared( this.object.position ) > EPS
    		    || 8 * (1 - lastQuaternion.dot(this.object.quaternion)) > EPS ) {

                if ( ignoreUpdate !== true ) { this.dispatchEvent( changeEvent ); }

                lastPosition.copy( this.object.position );
                lastQuaternion.copy (this.object.quaternion );

            }

        };

        this.reset = function () {

            state = STATE.NONE;

            this.target.copy( this.target0 );
            this.object.position.copy( this.position0 );
            this.object.zoom = this.zoom0;

            this.object.updateProjectionMatrix();
            this.dispatchEvent( changeEvent );

            this.update();

        };

        this.getPolarAngle = function () {

            return phi;

        };

        this.getAzimuthalAngle = function () {

            return theta;

        };

        function getAutoRotationAngle() {

            return 2 * Math.PI / 60 / 60 * scope.autoRotateSpeed;

        }

        function getZoomScale() {

            return Math.pow( 0.95, scope.zoomSpeed );

        }

        function onMouseDown( event ) {

            momentumOn = false;

       		momentumLeft = momentumUp = 0;

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

            if ( event.button === scope.mouseButtons.ORBIT ) {
                if ( scope.noRotate === true ) return;

                state = STATE.ROTATE;

                rotateStart.set( event.clientX, event.clientY );

            } else if ( event.button === scope.mouseButtons.ZOOM ) {
                if ( scope.noZoom === true ) return;

                state = STATE.DOLLY;

                dollyStart.set( event.clientX, event.clientY );

            } else if ( event.button === scope.mouseButtons.PAN ) {
                if ( scope.noPan === true ) return;

                state = STATE.PAN;

                panStart.set( event.clientX, event.clientY );

            }

            if ( state !== STATE.NONE ) {
                document.addEventListener( 'mousemove', onMouseMove, false );
                document.addEventListener( 'mouseup', onMouseUp, false );
                scope.dispatchEvent( startEvent );
            }

            scope.update();

        }

        function onMouseMove( event ) {

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

            event.preventDefault();

            var element = scope.domElement === document ? scope.domElement.body : scope.domElement;

            if ( state === STATE.ROTATE ) {

                if ( scope.noRotate === true ) return;

                rotateEnd.set( event.clientX, event.clientY );
                rotateDelta.subVectors( rotateEnd, rotateStart );

                // rotating across whole screen goes 360 degrees around
                scope.rotateLeft( 2 * Math.PI * rotateDelta.x / element.clientWidth * scope.rotateSpeed );

                // rotating up and down along whole screen attempts to go 360, but limited to 180
                scope.rotateUp( 2 * Math.PI * rotateDelta.y / element.clientHeight * scope.rotateSpeed );

                rotateStart.copy( rotateEnd );

                if( eventPrevious ){
                    momentumLeft = event.clientX - eventPrevious.clientX;
                    momentumUp = event.clientY - eventPrevious.clientY;
                }

                eventPrevious = event;

            } else if ( state === STATE.DOLLY ) {

                if ( scope.noZoom === true ) return;

                dollyEnd.set( event.clientX, event.clientY );
                dollyDelta.subVectors( dollyEnd, dollyStart );

                if ( dollyDelta.y > 0 ) {

                    scope.dollyIn();

                } else if ( dollyDelta.y < 0 ) {

                    scope.dollyOut();

                }

                dollyStart.copy( dollyEnd );

            } else if ( state === STATE.PAN ) {

                if ( scope.noPan === true ) return;

                panEnd.set( event.clientX, event.clientY );
                panDelta.subVectors( panEnd, panStart );

                scope.pan( panDelta.x, panDelta.y );

                panStart.copy( panEnd );

            }

            if ( state !== STATE.NONE ) scope.update();

        }

        function onMouseUp( /* event */ ) {

            momentumOn = true;

            eventPrevious = undefined;

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

            document.removeEventListener( 'mousemove', onMouseMove, false );
            document.removeEventListener( 'mouseup', onMouseUp, false );
            scope.dispatchEvent( endEvent );
            state = STATE.NONE;

        }

        function onMouseWheel( event ) {

            if ( scope.enabled === false || scope.noZoom === true || state !== STATE.NONE ) return;

            event.preventDefault();
            event.stopPropagation();

            var delta = 0;

            if ( event.wheelDelta !== undefined ) { // WebKit / Opera / Explorer 9

                delta = event.wheelDelta;

            } else if ( event.detail !== undefined ) { // Firefox

                delta = - event.detail;

            }

            if ( delta > 0 ) {

                // scope.dollyOut();
                scope.object.fov = ( scope.object.fov < scope.maxFov )
                    ? scope.object.fov + 1
                    : scope.maxFov;
                scope.object.updateProjectionMatrix();

            } else if ( delta < 0 ) {

                // scope.dollyIn();
                scope.object.fov = ( scope.object.fov > scope.minFov )
                    ? scope.object.fov - 1
                    : scope.minFov;
                scope.object.updateProjectionMatrix();

            }

            scope.update();
            scope.dispatchEvent( changeEvent );
            scope.dispatchEvent( startEvent );
            scope.dispatchEvent( endEvent );

        }

        function onKeyUp ( event ) {

            switch ( event.keyCode ) {

            case scope.keys.UP:
                keyUp = false;
                break;

            case scope.keys.BOTTOM:
                keyBottom = false;
                break;

            case scope.keys.LEFT:
                keyLeft = false;
                break;

            case scope.keys.RIGHT:
                keyRight = false;
                break;

            }

        }

        function onKeyDown( event ) {

            if ( scope.enabled === false || scope.noKeys === true || scope.noRotate === true ) return;

            switch ( event.keyCode ) {

            case scope.keys.UP:
                keyUp = true;
                break;

            case scope.keys.BOTTOM:
                keyBottom = true;
                break;

            case scope.keys.LEFT:
                keyLeft = true;
                break;

            case scope.keys.RIGHT:
                keyRight = true;
                break;

            }

            if (keyUp || keyBottom || keyLeft || keyRight) {

                momentumOn = true;

                if (keyUp) momentumUp = - scope.rotateSpeed * scope.momentumKeydownFactor;
                if (keyBottom) momentumUp = scope.rotateSpeed * scope.momentumKeydownFactor;
                if (keyLeft) momentumLeft = - scope.rotateSpeed * scope.momentumKeydownFactor;
                if (keyRight) momentumLeft = scope.rotateSpeed * scope.momentumKeydownFactor;

            }

        }

        function touchstart( event ) {

            momentumOn = false;

            momentumLeft = momentumUp = 0;

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

            switch ( event.touches.length ) {

            case 1:	// one-fingered touch: rotate

                if ( scope.noRotate === true ) return;

                state = STATE.TOUCH_ROTATE;

                rotateStart.set( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY );
                break;

            case 2:	// two-fingered touch: dolly

                if ( scope.noZoom === true ) return;

                state = STATE.TOUCH_DOLLY;

                var dx = event.touches[ 0 ].pageX - event.touches[ 1 ].pageX;
                var dy = event.touches[ 0 ].pageY - event.touches[ 1 ].pageY;
                var distance = Math.sqrt( dx * dx + dy * dy );

                dollyStart.set( 0, distance );

                break;

            case 3: // three-fingered touch: pan

                if ( scope.noPan === true ) return;

                state = STATE.TOUCH_PAN;

                panStart.set( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY );
                break;

            default:

                state = STATE.NONE;

            }

            if ( state !== STATE.NONE ) scope.dispatchEvent( startEvent );

        }

        function touchmove( event ) {

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

            event.preventDefault();
            event.stopPropagation();

            var element = scope.domElement === document ? scope.domElement.body : scope.domElement;

            switch ( event.touches.length ) {

            case 1: // one-fingered touch: rotate

                if ( scope.noRotate === true ) return;
                if ( state !== STATE.TOUCH_ROTATE ) return;

                rotateEnd.set( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY );
                rotateDelta.subVectors( rotateEnd, rotateStart );

                // rotating across whole screen goes 360 degrees around
                scope.rotateLeft( 2 * Math.PI * rotateDelta.x / element.clientWidth * scope.rotateSpeed );
                // rotating up and down along whole screen attempts to go 360, but limited to 180
                scope.rotateUp( 2 * Math.PI * rotateDelta.y / element.clientHeight * scope.rotateSpeed );

                rotateStart.copy( rotateEnd );

                if( eventPrevious ){
                    momentumLeft = event.touches[ 0 ].pageX - eventPrevious.pageX;
                    momentumUp = event.touches[ 0 ].pageY - eventPrevious.pageY;
                }

                eventPrevious = {
                    pageX: event.touches[ 0 ].pageX,
                    pageY: event.touches[ 0 ].pageY,
                };

                scope.update();
                break;

            case 2: // two-fingered touch: dolly

                if ( scope.noZoom === true ) return;
                if ( state !== STATE.TOUCH_DOLLY ) return;

                var dx = event.touches[ 0 ].pageX - event.touches[ 1 ].pageX;
                var dy = event.touches[ 0 ].pageY - event.touches[ 1 ].pageY;
                var distance = Math.sqrt( dx * dx + dy * dy );

                dollyEnd.set( 0, distance );
                dollyDelta.subVectors( dollyEnd, dollyStart );

                if ( dollyDelta.y < 0 ) {

                    scope.object.fov = ( scope.object.fov < scope.maxFov )
                        ? scope.object.fov + 1
                        : scope.maxFov;
                    scope.object.updateProjectionMatrix();

                } else if ( dollyDelta.y > 0 ) {

                    scope.object.fov = ( scope.object.fov > scope.minFov )
                        ? scope.object.fov - 1
                        : scope.minFov;
                    scope.object.updateProjectionMatrix();

                }

                dollyStart.copy( dollyEnd );

                scope.update();
                scope.dispatchEvent( changeEvent );
                break;

            case 3: // three-fingered touch: pan

                if ( scope.noPan === true ) return;
                if ( state !== STATE.TOUCH_PAN ) return;

                panEnd.set( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY );
                panDelta.subVectors( panEnd, panStart );

                scope.pan( panDelta.x, panDelta.y );

                panStart.copy( panEnd );

                scope.update();
                break;

            default:

                state = STATE.NONE;

            }

        }

        function touchend( /* event */ ) {

            momentumOn = true;

            eventPrevious = undefined;

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

            scope.dispatchEvent( endEvent );
            state = STATE.NONE;

        }

        this.dispose = function() {

            this.domElement.removeEventListener( 'mousedown', onMouseDown );
            this.domElement.removeEventListener( 'mousewheel', onMouseWheel );
            this.domElement.removeEventListener( 'DOMMouseScroll', onMouseWheel );

            this.domElement.removeEventListener( 'touchstart', touchstart );
            this.domElement.removeEventListener( 'touchend', touchend );
            this.domElement.removeEventListener( 'touchmove', touchmove );

            window.removeEventListener( 'keyup', onKeyUp );
            window.removeEventListener( 'keydown', onKeyDown );

        };

        // this.domElement.addEventListener( 'contextmenu', function ( event ) { event.preventDefault(); }, false );
        this.domElement.addEventListener( 'mousedown', onMouseDown, { passive: false } );
        this.domElement.addEventListener( 'mousewheel', onMouseWheel, { passive: false } );
        this.domElement.addEventListener( 'DOMMouseScroll', onMouseWheel, { passive: false } ); // firefox

        this.domElement.addEventListener( 'touchstart', touchstart, { passive: false } );
        this.domElement.addEventListener( 'touchend', touchend, { passive: false } );
        this.domElement.addEventListener( 'touchmove', touchmove, { passive: false } );

        window.addEventListener( 'keyup', onKeyUp, { passive: false } );
        window.addEventListener( 'keydown', onKeyDown, { passive: false } );

        // force an update at start
        this.update();

    };

    OrbitControls.prototype = Object.assign( Object.create( THREE.EventDispatcher.prototype ), {

        constructor: OrbitControls

    } );

    export { OrbitControls };