activityLink/src/utils/TrackballControls.js

import * as THREE from 'three';

// 创建 TrackballControls 类并导出
export class TrackballControls extends THREE.EventDispatcher {
    constructor(object, domElement) {
        super(); // 调用父类构造函数
        
        var _this = this;
        var STATE = { NONE: -1, ROTATE: 0, ZOOM: 1, PAN: 2, TOUCH_ROTATE: 3, TOUCH_ZOOM_PAN: 4 };

        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.staticMoving = false;
        this.dynamicDampingFactor = 0.2;
        this.minDistance = 0;
        this.maxDistance = Infinity;
        this.keys = [65 /*A*/, 83 /*S*/, 68 /*D*/];

        // internals
        this.target = new THREE.Vector3();
        
        var EPS = 0.000001;

        var lastPosition = new THREE.Vector3();

        var _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();

        // for reset

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

        // events

        var changeEvent = { type: "change" };
        var startEvent = { type: "start" };
        var 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 {
            var box = this.domElement.getBoundingClientRect();
            // adjustments come from similar code in the jquery offset() function
            var 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;
          }
        };

        var getMouseOnScreen = (function () {
          var vector = new THREE.Vector2();

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

            return vector;
          };
        })();

        var getMouseOnCircle = (function () {
          var vector = new THREE.Vector2();

          return function getMouseOnCircle(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 () {
          var 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 rotateCamera() {
            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 () {
          var factor;

          if (_state === STATE.TOUCH_ZOOM_PAN) {
            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 () {
          var mouseChange = new THREE.Vector2(),
            objectUp = new THREE.Vector3(),
            pan = new THREE.Vector3();

          return function panCamera() {
            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)
              );
              _zoomStart.copy(_zoomEnd);
            }

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

        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();
          }

          _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);
        };

        // 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;
          }

          // 阻止浏览器的默认行为
          return;

          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);
          }

          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));
          }
        }

        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;

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

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

          // return;

          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;
          }

          _this.dispatchEvent(startEvent);
          _this.dispatchEvent(endEvent);
        }

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

          event.preventDefault();

          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;

            default: // 2 or more
              _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;
          }

          _this.dispatchEvent(startEvent);
        }

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

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

          switch (event.touches.length) {
            case 1:
              _movePrev.copy(_moveCurr);
              _moveCurr.copy(
                getMouseOnCircle(event.touches[0].pageX, event.touches[0].pageY)
              );
              break;

            default: // 2 or more
              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;
          }
        }

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

          switch (event.touches.length) {
            case 0:
              _state = STATE.NONE;
              break;

            case 1:
              _state = STATE.TOUCH_ROTATE;
              _moveCurr.copy(
                getMouseOnCircle(event.touches[0].pageX, event.touches[0].pageY)
              );
              _movePrev.copy(_moveCurr);
              break;
          }

          _this.dispatchEvent(endEvent);
        }

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

          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);

          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("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();
    }
}