@inweb/viewer-three/src/Viewer/controls/OrbitControls.js

JavaScript library for rendering CAD and BIM files in a browser using Three.js

import { EventDispatcher, MOUSE, Quaternion, Spherical, TOUCH, Vector2, Vector3 } from "three";

// OrbitControls performs orbiting, dollying (zooming), and panning.
// Unlike TrackballControls, it maintains the "up" direction object.up (+Y by default).
//
//    Orbit - left mouse / touch: one-finger move
//    Zoom - middle mouse, or mousewheel / touch: two-finger spread or squish
//    Pan - right mouse, or left mouse + ctrl/meta/shiftKey, or arrow keys / touch: two-finger move

const _changeEvent = { type: "change" };
const _startEvent = { type: "start" };
const _endEvent = { type: "end" };

const STATE = {
  NONE: -1,
  ROTATE: 0,
  DOLLY: 1,
  PAN: 2,
  TOUCH_ROTATE: 3,
  TOUCH_PAN: 4,
  TOUCH_DOLLY_PAN: 5,
  TOUCH_DOLLY_ROTATE: 6,
};

class OrbitControls extends EventDispatcher {
  constructor(object, domElement) {
    super();

    this.object = object;
    this.domElement = domElement;
    this.domElement.style.touchAction = "none"; // disable touch scroll

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

    // "target" sets the location of focus, where the object orbits around
    this.target = new Vector3();

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

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

    // 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

    // How far you can orbit horizontally, upper and lower limits.
    // If set, the interval [ min, max ] must be a sub-interval of [ - 2 PI, 2 PI ], with ( max - min < 2 PI )
    this.minAzimuthAngle = -Infinity; // radians
    this.maxAzimuthAngle = Infinity; // radians

    // Set to true to enable damping (inertia)
    // If damping is enabled, you must call controls.update() in your animation loop
    this.enableDamping = false;
    this.dampingFactor = 0.05;

    // This option actually enables dollying in and out; left as "zoom" for backwards compatibility.
    // Set to false to disable zooming
    this.enableZoom = true;
    this.zoomSpeed = 1.0;

    // Set to false to disable rotating
    this.enableRotate = true;
    this.rotateSpeed = 1.0;

    // Set to false to disable panning
    this.enablePan = true;
    this.panSpeed = 1.0;
    this.screenSpacePanning = true; // if false, pan orthogonal to world-space direction camera.up
    this.keyPanSpeed = 7.0; // pixels moved per arrow key push

    // Set to true to automatically rotate around the target
    // If auto-rotate is enabled, you must call controls.update() in your animation loop
    this.autoRotate = false;
    this.autoRotateSpeed = 2.0; // 30 seconds per orbit when fps is 60

    // The four arrow keys
    this.keys = { LEFT: "ArrowLeft", UP: "ArrowUp", RIGHT: "ArrowRight", BOTTOM: "ArrowDown" };

    // Mouse buttons
    this.mouseButtons = { LEFT: MOUSE.ROTATE, MIDDLE: MOUSE.DOLLY, RIGHT: MOUSE.PAN };

    // Touch fingers
    this.touches = { ONE: TOUCH.ROTATE, TWO: TOUCH.DOLLY_PAN };

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

    // the target DOM element for key events
    this._domElementKeyEvents = null;

    //
    // public methods
    //

    this.getPolarAngle = function () {
      return spherical.phi;
    };

    this.getAzimuthalAngle = function () {
      return spherical.theta;
    };

    this.getDistance = function () {
      return this.object.position.distanceTo(this.target);
    };

    this.listenToKeyEvents = function (domElement) {
      domElement.addEventListener("keydown", onKeyDown);
      this._domElementKeyEvents = domElement;
    };

    this.stopListenToKeyEvents = function () {
      this._domElementKeyEvents.removeEventListener("keydown", onKeyDown);
      this._domElementKeyEvents = null;
    };

    this.saveState = function () {
      scope.target0.copy(scope.target);
      scope.position0.copy(scope.object.position);
      scope.zoom0 = scope.object.zoom;
    };

    this.reset = function () {
      scope.target.copy(scope.target0);
      scope.object.position.copy(scope.position0);
      scope.object.zoom = scope.zoom0;

      scope.object.updateProjectionMatrix();
      scope.dispatchEvent(_changeEvent);

      scope.update();

      scope.state = STATE.NONE;
    };

    // this method is exposed, but perhaps it would be better if we can make it private...
    this.update = (function () {
      const offset = new Vector3();

      // so camera.up is the orbit axis
      const quat = new Quaternion().setFromUnitVectors(object.up, new Vector3(0, 1, 0));
      const quatInverse = quat.clone().invert();

      const lastPosition = new Vector3();
      const lastQuaternion = new Quaternion();
      const lastTargetPosition = new Vector3();

      const twoPI = 2 * Math.PI;

      return function update() {
        const position = scope.object.position;

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

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

        // angle from z-axis around y-axis
        spherical.setFromVector3(offset);

        if (scope.autoRotate && scope.state === STATE.NONE) {
          rotateLeft(getAutoRotationAngle());
        }

        if (scope.enableDamping) {
          spherical.theta += sphericalDelta.theta * scope.dampingFactor;
          spherical.phi += sphericalDelta.phi * scope.dampingFactor;
        } else {
          spherical.theta += sphericalDelta.theta;
          spherical.phi += sphericalDelta.phi;
        }

        // restrict theta to be between desired limits

        let min = scope.minAzimuthAngle;
        let max = scope.maxAzimuthAngle;

        if (isFinite(min) && isFinite(max)) {
          if (min < -Math.PI) min += twoPI;
          else if (min > Math.PI) min -= twoPI;

          if (max < -Math.PI) max += twoPI;
          else if (max > Math.PI) max -= twoPI;

          if (min <= max) {
            spherical.theta = Math.max(min, Math.min(max, spherical.theta));
          } else {
            spherical.theta =
              spherical.theta > (min + max) / 2 ? Math.max(min, spherical.theta) : Math.min(max, spherical.theta);
          }
        }

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

        spherical.makeSafe();

        spherical.radius *= scope.scale;

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

        // move target to panned location

        if (scope.enableDamping === true) {
          scope.target.addScaledVector(scope.panOffset, scope.dampingFactor);
        } else {
          scope.target.add(scope.panOffset);
        }

        offset.setFromSpherical(spherical);

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

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

        scope.object.lookAt(scope.target);

        if (scope.enableDamping === true) {
          sphericalDelta.theta *= 1 - scope.dampingFactor;
          sphericalDelta.phi *= 1 - scope.dampingFactor;

          scope.panOffset.multiplyScalar(1 - scope.dampingFactor);
        } else {
          sphericalDelta.set(0, 0, 0);

          scope.panOffset.set(0, 0, 0);
        }

        scope.scale = 1;

        // update condition is:
        // min(camera displacement, camera rotation in radians)^2 > EPS
        // using small-angle approximation cos(x/2) = 1 - x^2 / 8

        if (
          scope.zoomChanged ||
          lastPosition.distanceToSquared(scope.object.position) > EPS ||
          8 * (1 - lastQuaternion.dot(scope.object.quaternion)) > EPS ||
          lastTargetPosition.distanceToSquared(scope.target) > 0
        ) {
          scope.dispatchEvent(_changeEvent);

          lastPosition.copy(scope.object.position);
          lastQuaternion.copy(scope.object.quaternion);
          lastTargetPosition.copy(scope.target);

          scope.zoomChanged = false;

          return true;
        }

        return false;
      };
    })();

    this.dispose = function () {
      scope.domElement.removeEventListener("contextmenu", onContextMenu);

      scope.domElement.removeEventListener("pointerdown", onPointerDown);
      scope.domElement.removeEventListener("pointercancel", onPointerUp);
      scope.domElement.removeEventListener("wheel", onMouseWheel);

      scope.domElement.removeEventListener("pointermove", onPointerMove);
      scope.domElement.removeEventListener("pointerup", onPointerUp);

      if (scope._domElementKeyEvents !== null) {
        scope._domElementKeyEvents.removeEventListener("keydown", onKeyDown);
        scope._domElementKeyEvents = null;
      }

      //scope.dispatchEvent( { type: 'dispose' } ); // should this be added here?
    };

    //
    // internals
    //

    const scope = this;

    scope.state = STATE.NONE;

    const EPS = 0.000001;

    // current position in spherical coordinates
    const spherical = new Spherical();
    const sphericalDelta = new Spherical();

    scope.scale = 1;
    scope.panOffset = new Vector3();
    scope.zoomChanged = false;

    scope.rotateStart = new Vector2();
    scope.rotateEnd = new Vector2();
    scope.rotateDelta = new Vector2();

    scope.panStart = new Vector2();
    scope.panEnd = new Vector2();
    scope.panDelta = new Vector2();

    scope.dollyStart = new Vector2();
    scope.dollyEnd = new Vector2();
    scope.dollyDelta = new Vector2();
    scope.dollyScale = 0;

    scope.pointers = [];
    scope.pointerPositions = {};

    function getAutoRotationAngle() {
      return ((2 * Math.PI) / 60 / 60) * scope.autoRotateSpeed;
    }

    function getZoomScale() {
      return Math.pow(0.95, scope.zoomSpeed);
    }

    function rotateLeft(angle) {
      sphericalDelta.theta -= angle;
    }

    function rotateUp(angle) {
      sphericalDelta.phi -= angle;
    }

    const panLeft = (function () {
      const v = new Vector3();

      return function panLeft(distance, objectMatrix) {
        v.setFromMatrixColumn(objectMatrix, 0); // get X column of objectMatrix
        v.multiplyScalar(-distance);

        scope.panOffset.add(v);
      };
    })();

    const panUp = (function () {
      const v = new Vector3();

      return function panUp(distance, objectMatrix) {
        if (scope.screenSpacePanning === true) {
          v.setFromMatrixColumn(objectMatrix, 1);
        } else {
          v.setFromMatrixColumn(objectMatrix, 0);
          v.crossVectors(scope.object.up, v);
        }

        v.multiplyScalar(distance);

        scope.panOffset.add(v);
      };
    })();

    // deltaX and deltaY are in pixels; right and down are positive
    const pan = (function () {
      const offset = new Vector3();

      return function pan(deltaX, deltaY) {
        const element = scope.domElement;

        if (scope.object.isPerspectiveCamera) {
          // perspective
          const position = scope.object.position;
          offset.copy(position).sub(scope.target);
          let 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 use only clientHeight here so aspect ratio does not distort speed
          panLeft((2 * deltaX * targetDistance) / element.clientHeight, scope.object.matrix);
          panUp((2 * deltaY * targetDistance) / element.clientHeight, scope.object.matrix);
        } else if (scope.object.isOrthographicCamera) {
          // orthographic
          panLeft(
            (deltaX * (scope.object.right - scope.object.left)) / scope.object.zoom / element.clientWidth,
            scope.object.matrix
          );
          panUp(
            (deltaY * (scope.object.top - scope.object.bottom)) / scope.object.zoom / element.clientHeight,
            scope.object.matrix
          );
        } else {
          // camera neither orthographic nor perspective
          console.warn("WARNING: OrbitControls.js encountered an unknown camera type - pan disabled.");
          scope.enablePan = false;
        }
      };
    })();

    function dollyOut(dollyScale) {
      if (scope.object.isPerspectiveCamera) {
        scope.scale /= dollyScale;
      } else if (scope.object.isOrthographicCamera) {
        scope.object.zoom = Math.max(scope.minZoom, Math.min(scope.maxZoom, scope.object.zoom * dollyScale));
        scope.object.updateProjectionMatrix();
        scope.zoomChanged = true;
      } else {
        console.warn("WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.");
        scope.enableZoom = false;
      }
    }

    function dollyIn(dollyScale) {
      if (scope.object.isPerspectiveCamera) {
        scope.scale *= dollyScale;
      } else if (scope.object.isOrthographicCamera) {
        scope.object.zoom = Math.max(scope.minZoom, Math.min(scope.maxZoom, scope.object.zoom / dollyScale));
        scope.object.updateProjectionMatrix();
        scope.zoomChanged = true;
      } else {
        console.warn("WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.");
        scope.enableZoom = false;
      }
    }

    //
    // event callbacks - update the object state
    //

    function handleMouseDownRotate(event) {
      scope.rotateStart.set(event.clientX, event.clientY);
    }

    function handleMouseDownDolly(event) {
      scope.dollyStart.set(event.clientX, event.clientY);
    }

    function handleMouseDownPan(event) {
      scope.panStart.set(event.clientX, event.clientY);
    }

    function handleMouseMoveRotate(event) {
      scope.rotateEnd.set(event.clientX, event.clientY);

      scope.rotateDelta.subVectors(scope.rotateEnd, scope.rotateStart).multiplyScalar(scope.rotateSpeed);

      const element = scope.domElement;

      rotateLeft((2 * Math.PI * scope.rotateDelta.x) / element.clientHeight); // yes, height

      rotateUp((2 * Math.PI * scope.rotateDelta.y) / element.clientHeight);

      scope.rotateStart.copy(scope.rotateEnd);

      scope.update();
    }

    function handleMouseMoveDolly(event) {
      scope.dollyEnd.set(event.clientX, event.clientY);

      scope.dollyDelta.subVectors(scope.dollyEnd, scope.dollyStart);

      if (scope.dollyDelta.y < 0) {
        scope.dollyScale = 1 / getZoomScale();
        dollyOut(getZoomScale());
      } else if (scope.dollyDelta.y > 0) {
        scope.dollyScale = getZoomScale();
        dollyIn(getZoomScale());
      }

      scope.dollyStart.copy(scope.dollyEnd);

      scope.update();
    }

    function handleMouseMovePan(event) {
      scope.panEnd.set(event.clientX, event.clientY);

      scope.panDelta.subVectors(scope.panEnd, scope.panStart).multiplyScalar(scope.panSpeed);

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

      scope.panStart.copy(scope.panEnd);

      scope.update();
    }

    function handleMouseWheel(event) {
      scope.dollyEnd.set(scope.domElement.clientWidth / 2, scope.domElement.clientHeight / 2);

      scope.dollyDelta.set(event.deltaX, event.deltaY);

      if (event.deltaY < 0) {
        scope.dollyScale = 1 / getZoomScale();
        dollyIn(getZoomScale());
      } else if (event.deltaY > 0) {
        scope.dollyScale = getZoomScale();
        dollyOut(getZoomScale());
      }

      scope.dollyStart.copy(scope.dollyEnd);

      scope.update();

      if (event.deltaY !== 0) {
        scope.state = STATE.DOLLY;
        scope.dispatchEvent(_changeEvent);
        scope.state = STATE.NONE;
      }
    }

    function handleKeyDown(event) {
      let needsUpdate = false;

      switch (event.code) {
        case scope.keys.UP:
          if (event.ctrlKey || event.metaKey || event.shiftKey) {
            rotateUp((2 * Math.PI * scope.rotateSpeed) / scope.domElement.clientHeight);
          } else {
            pan(0, scope.keyPanSpeed);
          }

          needsUpdate = true;
          break;

        case scope.keys.BOTTOM:
          if (event.ctrlKey || event.metaKey || event.shiftKey) {
            rotateUp((-2 * Math.PI * scope.rotateSpeed) / scope.domElement.clientHeight);
          } else {
            pan(0, -scope.keyPanSpeed);
          }

          needsUpdate = true;
          break;

        case scope.keys.LEFT:
          if (event.ctrlKey || event.metaKey || event.shiftKey) {
            rotateLeft((2 * Math.PI * scope.rotateSpeed) / scope.domElement.clientHeight);
          } else {
            pan(scope.keyPanSpeed, 0);
          }

          needsUpdate = true;
          break;

        case scope.keys.RIGHT:
          if (event.ctrlKey || event.metaKey || event.shiftKey) {
            rotateLeft((-2 * Math.PI * scope.rotateSpeed) / scope.domElement.clientHeight);
          } else {
            pan(-scope.keyPanSpeed, 0);
          }

          needsUpdate = true;
          break;
      }

      if (needsUpdate) {
        // prevent the browser from scrolling on cursor keys
        event.preventDefault();

        scope.update();
      }
    }

    function handleTouchStartRotate() {
      if (scope.pointers.length === 1) {
        scope.rotateStart.set(scope.pointers[0].pageX, scope.pointers[0].pageY);
      } else {
        const x = 0.5 * (scope.pointers[0].pageX + scope.pointers[1].pageX);
        const y = 0.5 * (scope.pointers[0].pageY + scope.pointers[1].pageY);

        scope.rotateStart.set(x, y);
      }
    }

    function handleTouchStartPan() {
      if (scope.pointers.length === 1) {
        scope.panStart.set(scope.pointers[0].pageX, scope.pointers[0].pageY);
      } else {
        const x = 0.5 * (scope.pointers[0].pageX + scope.pointers[1].pageX);
        const y = 0.5 * (scope.pointers[0].pageY + scope.pointers[1].pageY);

        scope.panStart.set(x, y);
      }
    }

    function handleTouchStartDolly() {
      const dx = scope.pointers[0].pageX - scope.pointers[1].pageX;
      const dy = scope.pointers[0].pageY - scope.pointers[1].pageY;

      const distance = Math.sqrt(dx * dx + dy * dy);

      scope.dollyStart.set(0, distance);
    }

    function handleTouchStartDollyPan() {
      if (scope.enableZoom) handleTouchStartDolly();

      if (scope.enablePan) handleTouchStartPan();
    }

    function handleTouchStartDollyRotate() {
      if (scope.enableZoom) handleTouchStartDolly();

      if (scope.enableRotate) handleTouchStartRotate();
    }

    function handleTouchMoveRotate(event) {
      if (scope.pointers.length == 1) {
        scope.rotateEnd.set(event.pageX, event.pageY);
      } else {
        const position = getSecondPointerPosition(event);

        const x = 0.5 * (event.pageX + position.x);
        const y = 0.5 * (event.pageY + position.y);

        scope.rotateEnd.set(x, y);
      }

      scope.rotateDelta.subVectors(scope.rotateEnd, scope.rotateStart).multiplyScalar(scope.rotateSpeed);

      const element = scope.domElement;

      rotateLeft((2 * Math.PI * scope.rotateDelta.x) / element.clientHeight); // yes, height

      rotateUp((2 * Math.PI * scope.rotateDelta.y) / element.clientHeight);

      scope.rotateStart.copy(scope.rotateEnd);
    }

    function handleTouchMovePan(event) {
      if (scope.pointers.length === 1) {
        scope.panEnd.set(event.pageX, event.pageY);
      } else {
        const position = getSecondPointerPosition(event);

        const x = 0.5 * (event.pageX + position.x);
        const y = 0.5 * (event.pageY + position.y);

        scope.panEnd.set(x, y);
      }

      scope.panDelta.subVectors(scope.panEnd, scope.panStart).multiplyScalar(scope.panSpeed);

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

      scope.panStart.copy(scope.panEnd);
    }

    function handleTouchMoveDolly(event) {
      const position = getSecondPointerPosition(event);

      const dx = event.pageX - position.x;
      const dy = event.pageY - position.y;

      const distance = Math.sqrt(dx * dx + dy * dy);

      scope.dollyEnd.set(0, distance);

      scope.dollyDelta.set(0, Math.pow(scope.dollyEnd.y / scope.dollyStart.y, scope.zoomSpeed));

      dollyOut(scope.dollyDelta.y);

      scope.dollyStart.copy(scope.dollyEnd);
    }

    function handleTouchMoveDollyPan(event) {
      if (scope.enableZoom) handleTouchMoveDolly(event);

      if (scope.enablePan) handleTouchMovePan(event);
    }

    function handleTouchMoveDollyRotate(event) {
      if (scope.enableZoom) handleTouchMoveDolly(event);

      if (scope.enableRotate) handleTouchMoveRotate(event);
    }

    //
    // event handlers - FSM: listen for events and reset state
    //

    function onPointerDown(event) {
      if (scope.enabled === false) return;

      if (scope.pointers.length === 0) {
        scope.domElement.setPointerCapture(event.pointerId);

        scope.domElement.addEventListener("pointermove", onPointerMove);
        scope.domElement.addEventListener("pointerup", onPointerUp);
      }

      //

      addPointer(event);

      if (event.pointerType === "touch") {
        onTouchStart(event);
      } else {
        onMouseDown(event);
      }
    }

    function onPointerMove(event) {
      if (scope.enabled === false) return;

      if (event.pointerType === "touch") {
        onTouchMove(event);
      } else {
        onMouseMove(event);
      }
    }

    function onPointerUp(event) {
      removePointer(event);

      if (scope.pointers.length === 0) {
        scope.domElement.releasePointerCapture(event.pointerId);

        scope.domElement.removeEventListener("pointermove", onPointerMove);
        scope.domElement.removeEventListener("pointerup", onPointerUp);
      }

      scope.dispatchEvent(_endEvent);

      scope.state = STATE.NONE;
    }

    function onMouseDown(event) {
      let mouseAction;

      switch (event.button) {
        case 0:
          mouseAction = scope.mouseButtons.LEFT;
          break;

        case 1:
          mouseAction = scope.mouseButtons.MIDDLE;
          break;

        case 2:
          mouseAction = scope.mouseButtons.RIGHT;
          break;

        default:
          mouseAction = -1;
      }

      switch (mouseAction) {
        case MOUSE.DOLLY:
          if (scope.enableZoom === false) return;

          handleMouseDownDolly(event);

          scope.state = STATE.DOLLY;

          break;

        case MOUSE.ROTATE:
          if (event.ctrlKey || event.metaKey || event.shiftKey) {
            if (scope.enablePan === false) return;

            handleMouseDownPan(event);

            scope.state = STATE.PAN;
          } else {
            if (scope.enableRotate === false) return;

            handleMouseDownRotate(event);

            scope.state = STATE.ROTATE;
          }

          break;

        case MOUSE.PAN:
          if (event.ctrlKey || event.metaKey || event.shiftKey) {
            if (scope.enableRotate === false) return;

            handleMouseDownRotate(event);

            scope.state = STATE.ROTATE;
          } else {
            if (scope.enablePan === false) return;

            handleMouseDownPan(event);

            scope.state = STATE.PAN;
          }

          break;

        default:
          scope.state = STATE.NONE;
      }

      if (scope.state !== STATE.NONE) {
        scope.dispatchEvent(_startEvent);
      }
    }

    function onMouseMove(event) {
      switch (scope.state) {
        case STATE.ROTATE:
          if (scope.enableRotate === false) return;

          handleMouseMoveRotate(event);

          break;

        case STATE.DOLLY:
          if (scope.enableZoom === false) return;

          handleMouseMoveDolly(event);

          break;

        case STATE.PAN:
          if (scope.enablePan === false) return;

          handleMouseMovePan(event);

          break;
      }
    }

    function onMouseWheel(event) {
      if (scope.enabled === false || scope.enableZoom === false || scope.state !== STATE.NONE) return;

      event.preventDefault();

      scope.dispatchEvent(_startEvent);

      handleMouseWheel(event);

      scope.dispatchEvent(_endEvent);
    }

    function onKeyDown(event) {
      if (scope.enabled === false || scope.enablePan === false) return;

      handleKeyDown(event);
    }

    function onTouchStart(event) {
      trackPointer(event);

      switch (scope.pointers.length) {
        case 1:
          switch (scope.touches.ONE) {
            case TOUCH.ROTATE:
              if (scope.enableRotate === false) return;

              handleTouchStartRotate();

              scope.state = STATE.TOUCH_ROTATE;

              break;

            case TOUCH.PAN:
              if (scope.enablePan === false) return;

              handleTouchStartPan();

              scope.state = STATE.TOUCH_PAN;

              break;

            default:
              scope.state = STATE.NONE;
          }

          break;

        case 2:
          switch (scope.touches.TWO) {
            case TOUCH.DOLLY_PAN:
              if (scope.enableZoom === false && scope.enablePan === false) return;

              handleTouchStartDollyPan();

              scope.state = STATE.TOUCH_DOLLY_PAN;

              break;

            case TOUCH.DOLLY_ROTATE:
              if (scope.enableZoom === false && scope.enableRotate === false) return;

              handleTouchStartDollyRotate();

              scope.state = STATE.TOUCH_DOLLY_ROTATE;

              break;

            default:
              scope.state = STATE.NONE;
          }

          break;

        default:
          scope.state = STATE.NONE;
      }

      if (scope.state !== STATE.NONE) {
        scope.dispatchEvent(_startEvent);
      }
    }

    function onTouchMove(event) {
      trackPointer(event);

      switch (scope.state) {
        case STATE.TOUCH_ROTATE:
          if (scope.enableRotate === false) return;

          handleTouchMoveRotate(event);

          scope.update();

          break;

        case STATE.TOUCH_PAN:
          if (scope.enablePan === false) return;

          handleTouchMovePan(event);

          scope.update();

          break;

        case STATE.TOUCH_DOLLY_PAN:
          if (scope.enableZoom === false && scope.enablePan === false) return;

          handleTouchMoveDollyPan(event);

          scope.update();

          break;

        case STATE.TOUCH_DOLLY_ROTATE:
          if (scope.enableZoom === false && scope.enableRotate === false) return;

          handleTouchMoveDollyRotate(event);

          scope.update();

          break;

        default:
          scope.state = STATE.NONE;
      }
    }

    function onContextMenu(event) {
      if (scope.enabled === false) return;

      event.preventDefault();
    }

    function addPointer(event) {
      scope.pointers.push(event);
    }

    function removePointer(event) {
      delete scope.pointerPositions[event.pointerId];

      for (let i = 0; i < scope.pointers.length; i++) {
        if (scope.pointers[i].pointerId == event.pointerId) {
          scope.pointers.splice(i, 1);
          return;
        }
      }
    }

    function trackPointer(event) {
      let position = scope.pointerPositions[event.pointerId];

      if (position === undefined) {
        position = new Vector2();
        scope.pointerPositions[event.pointerId] = position;
      }

      position.set(event.pageX, event.pageY);
    }

    function getSecondPointerPosition(event) {
      const pointer = event.pointerId === scope.pointers[0].pointerId ? scope.pointers[1] : scope.pointers[0];

      return scope.pointerPositions[pointer.pointerId];
    }

    //

    scope.domElement.addEventListener("contextmenu", onContextMenu);

    scope.domElement.addEventListener("pointerdown", onPointerDown);
    scope.domElement.addEventListener("pointercancel", onPointerUp);
    scope.domElement.addEventListener("wheel", onMouseWheel, { passive: false });

    // force an update at start

    this.update();
  }
}

export { OrbitControls, STATE };