@edsilv/ami.js/src/controls/controls.trackball.js

<p align="center"> <img src="https://user-images.githubusercontent.com/214063/46479857-4cd66e80-c7f0-11e8-9585-5748409c9490.png" width="60%"> </p>

/**
 * Original authors from THREEJS repo
 * @author Eberhard Graether / http://egraether.com/
 * @author Mark Lundin  / http://mark-lundin.com
 * @author Simone Manini / http://daron1337.github.io
 * @author Luca Antiga  / http://lantiga.github.io
 */

const trackball = (three = window.THREE) => {
  if (three === undefined || three.EventDispatcher === undefined) {
    return null;
  }

  const Constructor = three.EventDispatcher;
  return class extends Constructor {
    constructor(object, domElement) {
      super();

      let _this = this;
      let STATE = {
        NONE: -1,
        ROTATE: 0,
        ZOOM: 1,
        PAN: 2,
        TOUCH_ROTATE: 3,
        TOUCH_ZOOM: 4,
        TOUCH_PAN: 5,
        CUSTOM: 99,
      };

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

      // API

      this.enabled = true;

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

      this.rotateSpeed = 1.0;
      this.zoomSpeed = 1.2;
      this.panSpeed = 0.3;

      this.noRotate = false;
      this.noZoom = false;
      this.noPan = false;
      this.noCustom = false;

      this.forceState = -1;

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

      this.minDistance = 0;
      this.maxDistance = Infinity;

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

      // internals

      this.target = new three.Vector3();

      let EPS = 0.000001;

      let lastPosition = new three.Vector3();

      let _state = STATE.NONE,
        _prevState = STATE.NONE,
        _eye = new three.Vector3(),
        _movePrev = new three.Vector2(),
        _moveCurr = new three.Vector2(),
        _lastAxis = new three.Vector3(),
        _lastAngle = 0,
        _zoomStart = new three.Vector2(),
        _zoomEnd = new three.Vector2(),
        _touchZoomDistanceStart = 0,
        _touchZoomDistanceEnd = 0,
        _panStart = new three.Vector2(),
        _panEnd = new three.Vector2(),
        _customStart = new three.Vector2(),
        _customEnd = new three.Vector2();

      // for reset

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

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

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

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

          return vector;
        };
      })();

      let getMouseOnCircle = (function() {
        let vector = new three.Vector2();

        return function(pageX, pageY) {
          vector.set(
            (pageX - _this.screen.width * 0.5 - _this.screen.left) / (_this.screen.width * 0.5),
            (_this.screen.height + 2 * (_this.screen.top - pageY)) / _this.screen.width // screen.width intentional
          );

          return vector;
        };
      })();

      this.rotateCamera = (function() {
        let axis = new three.Vector3(),
          quaternion = new three.Quaternion(),
          eyeDirection = new three.Vector3(),
          objectUpDirection = new three.Vector3(),
          objectSidewaysDirection = new three.Vector3(),
          moveDirection = new three.Vector3(),
          angle;

        return function() {
          moveDirection.set(_moveCurr.x - _movePrev.x, _moveCurr.y - _movePrev.y, 0);
          angle = moveDirection.length();

          if (angle) {
            _eye.copy(_this.object.position).sub(_this.target);

            eyeDirection.copy(_eye).normalize();
            objectUpDirection.copy(_this.object.up).normalize();
            objectSidewaysDirection.crossVectors(objectUpDirection, eyeDirection).normalize();

            objectUpDirection.setLength(_moveCurr.y - _movePrev.y);
            objectSidewaysDirection.setLength(_moveCurr.x - _movePrev.x);

            moveDirection.copy(objectUpDirection.add(objectSidewaysDirection));

            axis.crossVectors(moveDirection, _eye).normalize();

            angle *= _this.rotateSpeed;
            quaternion.setFromAxisAngle(axis, angle);

            _eye.applyQuaternion(quaternion);
            _this.object.up.applyQuaternion(quaternion);

            _lastAxis.copy(axis);
            _lastAngle = angle;
          } else if (!_this.staticMoving && _lastAngle) {
            _lastAngle *= Math.sqrt(1.0 - _this.dynamicDampingFactor);
            _eye.copy(_this.object.position).sub(_this.target);
            quaternion.setFromAxisAngle(_lastAxis, _lastAngle);
            _eye.applyQuaternion(quaternion);
            _this.object.up.applyQuaternion(quaternion);
          }

          _movePrev.copy(_moveCurr);
        };
      })();

      this.zoomCamera = function() {
        let factor;

        if (_state === STATE.TOUCH_ZOOM) {
          factor = _touchZoomDistanceStart / _touchZoomDistanceEnd;
          _touchZoomDistanceStart = _touchZoomDistanceEnd;
          _eye.multiplyScalar(factor);
        } else {
          factor = 1.0 + (_zoomEnd.y - _zoomStart.y) * _this.zoomSpeed;

          if (factor !== 1.0 && factor > 0.0) {
            _eye.multiplyScalar(factor);

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

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

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

          if (mouseChange.lengthSq()) {
            mouseChange.multiplyScalar(_eye.length() * _this.panSpeed);

            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)
              );
            }
          }
        };
      })();

      this.checkDistances = function() {
        if (!_this.noZoom || !_this.noPan) {
          if (_eye.lengthSq() > _this.maxDistance * _this.maxDistance) {
            _this.object.position.addVectors(_this.target, _eye.setLength(_this.maxDistance));
          }

          if (_eye.lengthSq() < _this.minDistance * _this.minDistance) {
            _this.object.position.addVectors(_this.target, _eye.setLength(_this.minDistance));
          }
        }
      };

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

        if (!_this.noRotate) {
          _this.rotateCamera();
        }

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

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

        if (!_this.noCustom) {
          _this.custom(_customStart, _customEnd);
        }

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

        _this.checkDistances();

        _this.object.lookAt(_this.target);

        if (lastPosition.distanceToSquared(_this.object.position) > EPS) {
          _this.dispatchEvent(changeEvent);

          lastPosition.copy(_this.object.position);
        }
      };

      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.lookAt(_this.target);

        _this.dispatchEvent(changeEvent);

        lastPosition.copy(_this.object.position);
      };

      this.setState = function(targetState) {
        _this.forceState = targetState;
        _prevState = targetState;
        _state = targetState;
      };

      this.custom = function(customStart, customEnd) {};

      // 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) {
          _moveCurr.copy(getMouseOnCircle(event.pageX, event.pageY));
          _movePrev.copy(_moveCurr);
        } 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);
        } else if (_state === STATE.CUSTOM && !_this.noCustom) {
          _customStart.copy(getMouseOnScreen(event.pageX, event.pageY));
          _customEnd.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) {
          _movePrev.copy(_moveCurr);
          _moveCurr.copy(getMouseOnCircle(event.pageX, event.pageY));
        } 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));
        } else if (_state === STATE.CUSTOM && !_this.noCustom) {
          _customEnd.copy(getMouseOnScreen(event.pageX, event.pageY));
        }
      }

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

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

        if (_this.forceState === -1) {
          _state = STATE.NONE;
        }

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

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

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

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

        switch (event.deltaMode) {
          case 2:
            // Zoom in pages
            _zoomStart.y -= event.deltaY * 0.025;
            break;

          case 1:
            // Zoom in lines
            _zoomStart.y -= event.deltaY * 0.01;
            break;

          default:
            // undefined, 0, assume pixels
            _zoomStart.y -= event.deltaY * 0.00025;
            break;
        }

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

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

        if (_this.forceState === -1) {
          switch (event.touches.length) {
            case 1:
              _state = STATE.TOUCH_ROTATE;
              _moveCurr.copy(getMouseOnCircle(event.touches[0].pageX, event.touches[0].pageY));
              _movePrev.copy(_moveCurr);
              break;

            case 2:
              _state = STATE.TOUCH_ZOOM;
              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;
          }
        } else {
          // { NONE: -1, ROTATE: 0, ZOOM: 1, PAN: 2, TOUCH_ROTATE: 3, TOUCH_ZOOM_PAN: 4, CUSTOM: 99 };
          switch (_state) {
            case 0:
              // 1 or 2 fingers, smae behavior
              _state = STATE.TOUCH_ROTATE;
              _moveCurr.copy(getMouseOnCircle(event.touches[0].pageX, event.touches[0].pageY));
              _movePrev.copy(_moveCurr);
              break;

            case 1:
            case 4:
              if (event.touches.length >= 2) {
                _state = STATE.TOUCH_ZOOM;
                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);
              } else {
                _state = STATE.ZOOM;
                _zoomStart.copy(getMouseOnScreen(event.touches[0].pageX, event.touches[0].pageY));
                _zoomEnd.copy(_zoomStart);
              }
              break;

            case 2:
            case 5:
              if (event.touches.length >= 2) {
                _state = STATE.TOUCH_PAN;
                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);
              } else {
                _state = STATE.PAN;
                _panStart.copy(getMouseOnScreen(event.touches[0].pageX, event.touches[0].pageY));
                _panEnd.copy(_panStart);
              }
              break;

            case 99:
              _state = STATE.CUSTOM;
              var x = (event.touches[0].pageX + event.touches[1].pageX) / 2;
              var y = (event.touches[0].pageY + event.touches[1].pageY) / 2;
              _customStart.copy(getMouseOnScreen(x, y));
              _customEnd.copy(_customStart);
              break;

            default:
              _state = STATE.NONE;
          }
        }

        _this.dispatchEvent(startEvent);
      }

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

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

        if (_this.forceState === -1) {
          switch (event.touches.length) {
            case 1:
              _movePrev.copy(_moveCurr);
              _moveCurr.copy(getMouseOnCircle(event.touches[0].pageX, event.touches[0].pageY));
              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;
          }
        } else {
          // { NONE: -1, ROTATE: 0, ZOOM: 1, PAN: 2, TOUCH_ROTATE: 3, TOUCH_ZOOM_PAN: 4, CUSTOM: 99 };
          switch (_state) {
            case 0:
              _movePrev.copy(_moveCurr);
              _moveCurr.copy(getMouseOnCircle(event.touches[0].pageX, event.touches[0].pageY));
              break;

            case 1:
              _zoomEnd.copy(getMouseOnScreen(event.touches[0].pageX, event.touches[0].pageY));
              break;

            case 2:
              _panEnd.copy(getMouseOnScreen(event.touches[0].pageX, event.touches[0].pageY));
              break;

            case 4:
              // 2 fingers!
              // TOUCH ZOOM
              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);
              break;

            case 5:
              // 2 fingers
              // TOUCH_PAN
              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;

            case 99:
              var x = (event.touches[0].pageX + event.touches[1].pageX) / 2;
              var y = (event.touches[0].pageY + event.touches[1].pageY) / 2;
              _customEnd.copy(getMouseOnScreen(x, y));
              break;

            default:
              _state = STATE.NONE;
          }
        }
      }

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

        if (_this.forceState === -1) {
          switch (event.touches.length) {
            case 1:
              _movePrev.copy(_moveCurr);
              _moveCurr.copy(getMouseOnCircle(event.touches[0].pageX, event.touches[0].pageY));
              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;
        } else {
          switch (_state) {
            case 0:
              _movePrev.copy(_moveCurr);
              _moveCurr.copy(getMouseOnCircle(event.touches[0].pageX, event.touches[0].pageY));
              break;

            case 1:
            case 2:
              break;

            case 4:
              // TOUCH ZOOM
              _touchZoomDistanceStart = _touchZoomDistanceEnd = 0;
              _state = STATE.ZOOM;
              break;

            case 5:
              // TOUCH ZOOM
              if (event.touches.length >= 2) {
                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);
              }
              _state = STATE.PAN;
              break;

            case 99:
              var x = (event.touches[0].pageX + event.touches[1].pageX) / 2;
              var y = (event.touches[0].pageY + event.touches[1].pageY) / 2;
              _customEnd.copy(getMouseOnScreen(x, y));
              _customStart.copy(_customEnd);
              break;

            default:
              _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('wheel', mousewheel, false);

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

      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();
    }
  };
};

// export factory
export { trackball };
// default export to
export default trackball();