text: import {
  	EventDispatcher,
  	Matrix4,
  	Plane,
  	Raycaster,
  	Vector2,
  	Vector3
  } from '../../../build/three.module.js';
  
  const _plane = new Plane();
  const _raycaster = new Raycaster();
  
  const _pointer = new Vector2();
  const _offset = new Vector3();
  const _intersection = new Vector3();
  const _worldPosition = new Vector3();
  const _inverseMatrix = new Matrix4();
  
  class DragControls extends EventDispatcher {
  
  	constructor( _objects, _camera, _domElement ) {
  
  		super();
  
  		_domElement.style.touchAction = 'none'; // disable touch scroll
  
  		let _selected = null, _hovered = null;
  
  		const _intersections = [];
  
  		//
  
  		const scope = this;
  
  		function activate() {
  
  			_domElement.addEventListener( 'pointermove', onPointerMove );
  			_domElement.addEventListener( 'pointerdown', onPointerDown );
  			_domElement.addEventListener( 'pointerup', onPointerCancel );
  			_domElement.addEventListener( 'pointerleave', onPointerCancel );
  
  		}
  
  		function deactivate() {
  
  			_domElement.removeEventListener( 'pointermove', onPointerMove );
  			_domElement.removeEventListener( 'pointerdown', onPointerDown );
  			_domElement.removeEventListener( 'pointerup', onPointerCancel );
  			_domElement.removeEventListener( 'pointerleave', onPointerCancel );
  
  			_domElement.style.cursor = '';
  
  		}
  
  		function dispose() {
  
  			deactivate();
  
  		}
  
  		function getObjects() {
  
  			return _objects;
  
  		}
  
  		function onPointerMove( event ) {
  
  			if ( scope.enabled === false ) return;
  
  			updatePointer( event );
  
  			_raycaster.setFromCamera( _pointer, _camera );
  
  			if ( _selected ) {
  
  				if ( _raycaster.ray.intersectPlane( _plane, _intersection ) ) {
  
  					_selected.position.copy( _intersection.sub( _offset ).applyMatrix4( _inverseMatrix ) );
  
  				}
  
  				scope.dispatchEvent( { type: 'drag', object: _selected } );
  
  				return;
  
  			}
  
  			// hover support
  
  			if ( event.pointerType === 'mouse' || event.pointerType === 'pen' ) {
  
  				_intersections.length = 0;
  
  				_raycaster.setFromCamera( _pointer, _camera );
  				_raycaster.intersectObjects( _objects, true, _intersections );
  
  				if ( _intersections.length > 0 ) {
  
  					const object = _intersections[ 0 ].object;
  
  					_plane.setFromNormalAndCoplanarPoint( _camera.getWorldDirection( _plane.normal ), _worldPosition.setFromMatrixPosition( object.matrixWorld ) );
  
  					if ( _hovered !== object && _hovered !== null ) {
  
  						scope.dispatchEvent( { type: 'hoveroff', object: _hovered } );
  
  						_domElement.style.cursor = 'auto';
  						_hovered = null;
  
  					}
  
  					if ( _hovered !== object ) {
  
  						scope.dispatchEvent( { type: 'hoveron', object: object } );
  
  						_domElement.style.cursor = 'pointer';
  						_hovered = object;
  
  					}
  
  				} else {
  
  					if ( _hovered !== null ) {
  
  						scope.dispatchEvent( { type: 'hoveroff', object: _hovered } );
  
  						_domElement.style.cursor = 'auto';
  						_hovered = null;
  
  					}
  
  				}
  
  			}
  
  		}
  
  		function onPointerDown() {
  
  			if ( scope.enabled === false ) return;
  
  			updatePointer( event );
  
  			_intersections.length = 0;
  
  			_raycaster.setFromCamera( _pointer, _camera );
  			_raycaster.intersectObjects( _objects, true, _intersections );
  
  			if ( _intersections.length > 0 ) {
  
  				_selected = ( scope.transformGroup === true ) ? _objects[ 0 ] : _intersections[ 0 ].object;
  
  				_plane.setFromNormalAndCoplanarPoint( _camera.getWorldDirection( _plane.normal ), _worldPosition.setFromMatrixPosition( _selected.matrixWorld ) );
  
  				if ( _raycaster.ray.intersectPlane( _plane, _intersection ) ) {
  
  					_inverseMatrix.copy( _selected.parent.matrixWorld ).invert();
  					_offset.copy( _intersection ).sub( _worldPosition.setFromMatrixPosition( _selected.matrixWorld ) );
  
  				}
  
  				_domElement.style.cursor = 'move';
  
  				scope.dispatchEvent( { type: 'dragstart', object: _selected } );
  
  			}
  
  
  		}
  
  		function onPointerCancel() {
  
  			if ( scope.enabled === false ) return;
  
  			if ( _selected ) {
  
  				scope.dispatchEvent( { type: 'dragend', object: _selected } );
  
  				_selected = null;
  
  			}
  
  			_domElement.style.cursor = _hovered ? 'pointer' : 'auto';
  
  		}
  
  		function updatePointer( event ) {
  
  			const rect = _domElement.getBoundingClientRect();
  
  			_pointer.x = ( event.clientX - rect.left ) / rect.width * 2 - 1;
  			_pointer.y = - ( event.clientY - rect.top ) / rect.height * 2 + 1;
  
  		}
  
  		activate();
  
  		// API
  
  		this.enabled = true;
  		this.transformGroup = false;
  
  		this.activate = activate;
  		this.deactivate = deactivate;
  		this.dispose = dispose;
  		this.getObjects = getObjects;
  
  	}
  
  }
  
  export { DragControls };
  