ami.js/src/controls/controls.trackballortho.js

<p align="center"> <img src="https://cloud.githubusercontent.com/assets/214063/23213764/78ade038-f90c-11e6-8208-4fcade5f3832.png" width="60%"> </p>

/**
 * @author Eberhard Graether / http://egraether.com/
 * @author Mark Lundin  / http://mark-lundin.com
 * @author Patrick Fuller / http://patrick-fuller.com
 * @author Max Smolens / https://github.com/msmolens
 */

import {EventDispatcher, Vector2, Vector3} from 'three';

export default class Trackballortho extends EventDispatcher {
  constructor(object, domElement, state = {NONE: -1, ROTATE: 1, ZOOM: 2, PAN: 0, SCROLL: 4, TOUCH_ROTATE: 4, TOUCH_ZOOM_PAN: 5}) {
    super();

    let _this = this;
    let STATE = state;

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

    // API

    this.enabled = true;

    this.screen = {left: 0, top: 0, width: 0, height: 0};

    this.radius = 0;

    this.zoomSpeed = 1.2;

    this.noZoom = false;
    this.noPan = false;

    this.staticMoving = false;
    this.dynamicDampingFactor = 0.2;

    this.keys = [65 /* A*/, 83 /* S*/, 68];

    // internals

    this.target = new Vector3();

    let EPS = 0.000001;

    let _changed = true;

    let _state = STATE.NONE,
    _prevState = STATE.NONE,

    _eye = new Vector3(),

    _zoomStart = new Vector2(),
    _zoomEnd = new Vector2(),

    _touchZoomDistanceStart = 0,
    _touchZoomDistanceEnd = 0,

    _panStart = new Vector2(),
    _panEnd = new Vector2();

    // window level fire after...

    // for reset

    this.target0 = this.target.clone();
    this.position0 = this.object.position.clone();
    this.up0 = this.object.up.clone();

    this.left0 = this.object.left;
    this.right0 = this.object.right;
    this.top0 = this.object.top;
    this.bottom0 = this.object.bottom;

    // events

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

    // methods

    this.handleResize = function() {
      if (this.domElement === document) {
        this.screen.left = 0;
        this.screen.top = 0;
        this.screen.width = window.innerWidth;
        this.screen.height = window.innerHeight;
      } else {
        let box = this.domElement.getBoundingClientRect();
        // adjustments come from similar code in the jquery offset() function
        let d = this.domElement.ownerDocument.documentElement;
        this.screen.left = box.left + window.pageXOffset - d.clientLeft;
        this.screen.top = box.top + window.pageYOffset - d.clientTop;
        this.screen.width = box.width;
        this.screen.height = box.height;
      }

      this.radius = 0.5 * Math.min(this.screen.width, this.screen.height);

      this.left0 = this.object.left;
      this.right0 = this.object.right;
      this.top0 = this.object.top;
      this.bottom0 = this.object.bottom;
    };

    this.handleEvent = function(event) {
      if (typeof this[event.type] == 'function') {
        this[event.type](event);
      }
    };

    let getMouseOnScreen = (function() {
      let vector = new Vector2();

      return function getMouseOnScreen(pageX, pageY) {
        vector.set(
          (pageX - _this.screen.left) / _this.screen.width,
          (pageY - _this.screen.top) / _this.screen.height
        );

        return vector;
      };
    }());

    this.zoomCamera = function() {
      if (_state === STATE.TOUCH_ZOOM_PAN) {
        var factor = _touchZoomDistanceEnd / _touchZoomDistanceStart;
        _touchZoomDistanceStart = _touchZoomDistanceEnd;

        _this.object.zoom *= factor;

        _changed = true;
      } else {
        var factor = 1.0 + (_zoomEnd.y - _zoomStart.y) * _this.zoomSpeed;

        if (Math.abs(factor - 1.0) > EPS && factor > 0.0) {
          _this.object.zoom /= factor;

          if (_this.staticMoving) {
            _zoomStart.copy(_zoomEnd);
          } else {
            _zoomStart.y += (_zoomEnd.y - _zoomStart.y) * this.dynamicDampingFactor;
          }

          _changed = true;
        }
      }
    };

    this.panCamera = (function() {
      let mouseChange = new Vector2(),
        objectUp = new Vector3(),
        pan = new Vector3();

      return function panCamera() {
        mouseChange.copy(_panEnd).sub(_panStart);

        if (mouseChange.lengthSq()) {
          // Scale movement to keep clicked/dragged position under cursor
          let scale_x = (_this.object.right - _this.object.left) / _this.object.zoom;
          let scale_y = (_this.object.top - _this.object.bottom) / _this.object.zoom;
          mouseChange.x *= scale_x;
          mouseChange.y *= scale_y;

          pan.copy(_eye).cross(_this.object.up).setLength(mouseChange.x);
          pan.add(objectUp.copy(_this.object.up).setLength(mouseChange.y));

          _this.object.position.add(pan);
          _this.target.add(pan);

          if (_this.staticMoving) {
            _panStart.copy(_panEnd);
          } else {
            _panStart.add(mouseChange.subVectors(_panEnd, _panStart).multiplyScalar(_this.dynamicDampingFactor));
          }

          _changed = true;
        }
      };
    }());

    this.update = function() {
      _eye.subVectors(_this.object.position, _this.target);

      if (!_this.noZoom) {
        _this.zoomCamera();

        if (_changed) {
          _this.object.updateProjectionMatrix();
        }
      }

      if (!_this.noPan) {
        _this.panCamera();
      }

      _this.object.position.addVectors(_this.target, _eye);

      _this.object.lookAt(_this.target);

      if (_changed) {
        _this.dispatchEvent(changeEvent);

        _changed = false;
      }
    };

    this.reset = function() {
      _state = STATE.NONE;
      _prevState = STATE.NONE;

      _this.target.copy(_this.target0);
      _this.object.position.copy(_this.position0);
      _this.object.up.copy(_this.up0);

      _eye.subVectors(_this.object.position, _this.target);

      _this.object.left = _this.left0;
      _this.object.right = _this.right0;
      _this.object.top = _this.top0;
      _this.object.bottom = _this.bottom0;

      _this.object.lookAt(_this.target);

      _this.dispatchEvent(changeEvent);

      _changed = false;
    };

    // listeners

    function keydown(event) {
      if (_this.enabled === false) return;

      window.removeEventListener('keydown', keydown);

      _prevState = _state;

      if (_state !== STATE.NONE) {
        return;
      } else if (event.keyCode === _this.keys[STATE.ROTATE] && !_this.noRotate) {
        _state = STATE.ROTATE;
      } else if (event.keyCode === _this.keys[STATE.ZOOM] && !_this.noZoom) {
        _state = STATE.ZOOM;
      } else if (event.keyCode === _this.keys[STATE.PAN] && !_this.noPan) {
        _state = STATE.PAN;
      }
    }

    function keyup(event) {
      if (_this.enabled === false) return;

      _state = _prevState;

      window.addEventListener('keydown', keydown, false);
    }

    function mousedown(event) {
      if (_this.enabled === false) return;

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

      if (_state === STATE.NONE) {
        _state = event.button;
      }

      if (_state === STATE.ROTATE && !_this.noRotate) {

      } else if (_state === STATE.ZOOM && !_this.noZoom) {
        _zoomStart.copy(getMouseOnScreen(event.pageX, event.pageY));
        _zoomEnd.copy(_zoomStart);
      } else if (_state === STATE.PAN && !_this.noPan) {
        _panStart.copy(getMouseOnScreen(event.pageX, event.pageY));
        _panEnd.copy(_panStart);
      }

      document.addEventListener('mousemove', mousemove, false);
      document.addEventListener('mouseup', mouseup, false);

      _this.dispatchEvent(startEvent);
    }

    function mousemove(event) {
      if (_this.enabled === false) return;

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

      if (_state === STATE.ROTATE && !_this.noRotate) {

      } else if (_state === STATE.ZOOM && !_this.noZoom) {
        _zoomEnd.copy(getMouseOnScreen(event.pageX, event.pageY));
      } else if (_state === STATE.PAN && !_this.noPan) {
        _panEnd.copy(getMouseOnScreen(event.pageX, event.pageY));
      }
    }

    function mouseup(event) {
      if (_this.enabled === false) return;

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

      _state = STATE.NONE;

      document.removeEventListener('mousemove', mousemove);
      document.removeEventListener('mouseup', mouseup);
      _this.dispatchEvent(endEvent);
    }

    function mousewheel(event) {
      if (_this.enabled === false) return;

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

      let delta = 0;

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

        delta = event.wheelDelta / 40;
      } else if (event.detail) {
        // Firefox

        delta = -event.detail / 3;
      }

      // FIRE SCROLL EVENT

      _this.dispatchEvent({
        type: 'OnScroll',
        delta: delta,
      });

      // _zoomStart.y += delta * 0.01;
      _this.dispatchEvent(startEvent);
      _this.dispatchEvent(endEvent);
    }

    function touchstart(event) {
      if (_this.enabled === false) return;

      switch (event.touches.length) {
        case 1:
          _state = STATE.TOUCH_ROTATE;

          break;

        case 2:
          _state = STATE.TOUCH_ZOOM_PAN;
          var dx = event.touches[0].pageX - event.touches[1].pageX;
          var dy = event.touches[0].pageY - event.touches[1].pageY;
          _touchZoomDistanceEnd = _touchZoomDistanceStart = Math.sqrt(dx * dx + dy * dy);

          var x = (event.touches[0].pageX + event.touches[1].pageX) / 2;
          var y = (event.touches[0].pageY + event.touches[1].pageY) / 2;
          _panStart.copy(getMouseOnScreen(x, y));
          _panEnd.copy(_panStart);
          break;

        default:
          _state = STATE.NONE;
      }
      _this.dispatchEvent(startEvent);
    }

    function touchmove(event) {
      if (_this.enabled === false) return;

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

      switch (event.touches.length) {
        case 1:

          break;

        case 2:
          var dx = event.touches[0].pageX - event.touches[1].pageX;
          var dy = event.touches[0].pageY - event.touches[1].pageY;
          _touchZoomDistanceEnd = Math.sqrt(dx * dx + dy * dy);

          var x = (event.touches[0].pageX + event.touches[1].pageX) / 2;
          var y = (event.touches[0].pageY + event.touches[1].pageY) / 2;
          _panEnd.copy(getMouseOnScreen(x, y));
          break;

        default:
          _state = STATE.NONE;
      }
    }

    function touchend(event) {
      if (_this.enabled === false) return;

      switch (event.touches.length) {
        case 1:

          break;

        case 2:
          _touchZoomDistanceStart = _touchZoomDistanceEnd = 0;

          var x = (event.touches[0].pageX + event.touches[1].pageX) / 2;
          var y = (event.touches[0].pageY + event.touches[1].pageY) / 2;
          _panEnd.copy(getMouseOnScreen(x, y));
          _panStart.copy(_panEnd);
          break;
      }

      _state = STATE.NONE;
      _this.dispatchEvent(endEvent);
    }

    function contextmenu(event) {
      event.preventDefault();
    }

    this.dispose = function() {
      this.domElement.removeEventListener('contextmenu', contextmenu, false);
      this.domElement.removeEventListener('mousedown', mousedown, false);
      this.domElement.removeEventListener('mousewheel', mousewheel, false);
      this.domElement.removeEventListener('MozMousePixelScroll', mousewheel, false); // firefox

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

      document.removeEventListener('mousemove', mousemove, false);
      document.removeEventListener('mouseup', mouseup, false);

      window.removeEventListener('keydown', keydown, false);
      window.removeEventListener('keyup', keyup, false);
    };

    this.domElement.addEventListener('contextmenu', contextmenu, false);
    this.domElement.addEventListener('mousedown', mousedown, false);
    this.domElement.addEventListener('mousewheel', mousewheel, false);
    this.domElement.addEventListener('MozMousePixelScroll', mousewheel, false); // firefox

    this.domElement.addEventListener('touchstart', touchstart, false);
    this.domElement.addEventListener('touchend', touchend, false);
    this.domElement.addEventListener('touchmove', touchmove, false);

    window.addEventListener('keydown', keydown, false);
    window.addEventListener('keyup', keyup, false);

    this.handleResize();

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