@polygonjs/polygonjs/src/modules/core/controls/OrbitControls.js

node-based WebGL 3D engine https://polygonjs.com

import {
	EventDispatcher,
	MOUSE,
	Quaternion,
	Spherical,
	TOUCH,
	Vector2,
	Vector3,
	Plane,
	Ray,
	MathUtils,
	Box3,
} 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 _ray = new Ray();
const _plane = new Plane();
const TILT_LIMIT = Math.cos(70 * MathUtils.DEG2RAD);

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
		this.zoomToCursor = false;
		this.clampPosition = false;
		this.positionBounds = new Box3(
			new Vector3(-Infinity, -Infinity, -Infinity),
			new Vector3(+Infinity, +Infinity, +Infinity)
		);
		// this.targetBounds = new Box3(
		// 	new Vector3(-Infinity, -Infinity, -Infinity),
		// 	new Vector3(+Infinity, +Infinity, +Infinity)
		// );

		// 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;

		//
		const mouseBefore = new Vector3(0, 0, 0);
		const mouseAfter = new Vector3(0, 0, 0);

		//
		// 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();

			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(deltaTime = null) {
				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 && state === STATE.NONE) {
					rotateLeft(getAutoRotationAngle(deltaTime));
				}

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

				// move target to panned location

				if (scope.enableDamping === true) {
					scope.target.addScaledVector(panOffset, scope.dampingFactor);
				} else {
					scope.target.add(panOffset);
				}
				function _clampTarget() {
					if (scope.clampPosition) {
						// scope.targetBounds.copy(scope.positionBounds);
						// scope.targetBounds.min.add(offset);
						// scope.targetBounds.max.add(offset);
						scope.target.clamp(scope.positionBounds.min, scope.positionBounds.max);
						// console.log('clamp target', scope.target.toArray());
					}
				}
				function _clampPosition() {
					if (scope.clampPosition) {
						position.clamp(scope.positionBounds.min, scope.positionBounds.max);
						// console.log('clamp position', position.toArray());
					}
				}
				_clampTarget();

				// adjust the camera position based on zoom only if we're not zooming to the cursor or if it's an ortho camera
				// we adjust zoom later in these cases
				if ((scope.zoomToCursor && performCursorZoom) || scope.object.isOrthographicCamera) {
					spherical.radius = clampDistance(spherical.radius);
				} else {
					spherical.radius = clampDistance(spherical.radius * scale);
				}

				offset.setFromSpherical(spherical);

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

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

				scope.object.lookAt(scope.target);

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

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

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

				// adjust camera position
				let zoomChanged = false;
				if (scope.zoomToCursor && performCursorZoom) {
					let newRadius = null;
					if (scope.object.isPerspectiveCamera) {
						// move the camera down the pointer ray
						// this method avoids floating point error
						const prevRadius = offset.length();
						newRadius = clampDistance(prevRadius * scale);

						const radiusDelta = prevRadius - newRadius;
						scope.object.position.addScaledVector(dollyDirection, radiusDelta);
						_clampPosition();
						scope.object.updateMatrixWorld();
					} else if (scope.object.isOrthographicCamera) {
						// adjust the ortho camera position based on zoom changes
						mouseBefore.x = mouse.x;
						mouseBefore.y = mouse.y;
						mouseBefore.z = 0;
						mouseBefore.unproject(scope.object);

						scope.object.zoom = Math.max(scope.minZoom, Math.min(scope.maxZoom, scope.object.zoom / scale));
						scope.object.updateProjectionMatrix();
						zoomChanged = true;

						mouseAfter.x = mouse.x;
						mouseAfter.y = mouse.y;
						mouseAfter.z = 0;
						mouseAfter.unproject(scope.object);

						scope.object.position.sub(mouseAfter).add(mouseBefore);
						_clampPosition();
						scope.object.updateMatrixWorld();

						newRadius = offset.length();
					} else {
						console.warn(
							'WARNING: OrbitControls.js encountered an unknown camera type - zoom to cursor disabled.'
						);
						scope.zoomToCursor = false;
					}

					// handle the placement of the target
					if (newRadius !== null) {
						if (this.screenSpacePanning) {
							// position the orbit target in front of the new camera position
							scope.target
								.set(0, 0, -1)
								.transformDirection(scope.object.matrix)
								.multiplyScalar(newRadius)
								.add(scope.object.position);
							_clampTarget();
						} else {
							// get the ray and translation plane to compute target
							_ray.origin.copy(scope.object.position);
							_ray.direction.set(0, 0, -1).transformDirection(scope.object.matrix);

							// if the camera is 20 degrees above the horizon then don't adjust the focus target to avoid
							// extremely large values
							if (Math.abs(scope.object.up.dot(_ray.direction)) < TILT_LIMIT) {
								object.lookAt(scope.target);
							} else {
								_plane.setFromNormalAndCoplanarPoint(scope.object.up, scope.target);
								_ray.intersectPlane(_plane, scope.target);
								_clampTarget();
							}
						}
					}
				} else if (scope.object.isOrthographicCamera) {
					scope.object.zoom = Math.max(scope.minZoom, Math.min(scope.maxZoom, scope.object.zoom / scale));
					scope.object.updateProjectionMatrix();
					zoomChanged = true;
				}

				scale = 1;
				performCursorZoom = false;

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

				if (
					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);

					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.ownerDocument.removeEventListener('pointermove', onPointerMove);
			scope.domElement.ownerDocument.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;

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

		let state = STATE.NONE;

		const EPS = 0.000001;

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

		let scale = 1;
		const panOffset = new Vector3();

		const rotateStart = new Vector2();
		const rotateEnd = new Vector2();
		const rotateDelta = new Vector2();

		const panStart = new Vector2();
		const panEnd = new Vector2();
		const panDelta = new Vector2();

		const dollyStart = new Vector2();
		const dollyEnd = new Vector2();
		const dollyDelta = new Vector2();

		const dollyDirection = new Vector3();
		const mouse = new Vector2();
		let performCursorZoom = false;

		const pointers = [];
		const pointerPositions = {};

		function getAutoRotationAngle(deltaTime) {
			if (deltaTime !== null) {
				return ((2 * Math.PI) / 60) * scope.autoRotateSpeed * deltaTime;
			} else {
				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);

				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);

				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.object.isOrthographicCamera) {
				scale /= dollyScale;
			} 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.object.isOrthographicCamera) {
				scale *= dollyScale;
			} else {
				console.warn('WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.');
				scope.enableZoom = false;
			}
		}

		function updateMouseParameters(event) {
			if (!scope.zoomToCursor) {
				return;
			}

			performCursorZoom = true;

			const rect = scope.domElement.getBoundingClientRect();
			const x = event.clientX - rect.left;
			const y = event.clientY - rect.top;
			const w = rect.width;
			const h = rect.height;

			mouse.x = (x / w) * 2 - 1;
			mouse.y = -(y / h) * 2 + 1;

			dollyDirection.set(mouse.x, mouse.y, 1).unproject(scope.object).sub(scope.object.position).normalize();
		}

		function clampDistance(dist) {
			return Math.max(scope.minDistance, Math.min(scope.maxDistance, dist));
		}

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

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

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

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

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

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

			const element = scope.domElement;

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

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

			rotateStart.copy(rotateEnd);

			scope.update();
		}

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

			dollyDelta.subVectors(dollyEnd, dollyStart);

			if (dollyDelta.y > 0) {
				dollyOut(getZoomScale());
			} else if (dollyDelta.y < 0) {
				dollyIn(getZoomScale());
			}

			dollyStart.copy(dollyEnd);

			scope.update();
		}

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

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

			pan(panDelta.x, panDelta.y);

			panStart.copy(panEnd);

			scope.update();
		}

		function handleMouseWheel(event) {
			updateMouseParameters(event);

			if (event.deltaY < 0) {
				dollyIn(getZoomScale());
			} else if (event.deltaY > 0) {
				dollyOut(getZoomScale());
			}

			scope.update();
		}

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

				rotateStart.set(x, y);
			}
		}

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

				panStart.set(x, y);
			}
		}

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

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

			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 (pointers.length == 1) {
				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);

				rotateEnd.set(x, y);
			}

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

			const element = scope.domElement;

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

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

			rotateStart.copy(rotateEnd);
		}

		function handleTouchMovePan(event) {
			if (pointers.length === 1) {
				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);

				panEnd.set(x, y);
			}

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

			pan(panDelta.x, panDelta.y);

			panStart.copy(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);

			dollyEnd.set(0, distance);

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

			dollyOut(dollyDelta.y);

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

				scope.domElement.ownerDocument.addEventListener('pointermove', onPointerMove);
				scope.domElement.ownerDocument.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 (pointers.length === 0) {
				scope.domElement.releasePointerCapture(event.pointerId);

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

			scope.dispatchEvent(_endEvent);

			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);

					state = STATE.DOLLY;

					break;

				case MOUSE.ROTATE:
					// when using the physical player,
					// we need to be able to rotate the camera while
					// having shiftKey pressed to run.
					// Therefore the following condition is replaced,
					// so that we only check the modifier key
					// if enablePan is true.
					//
					// if (event.ctrlKey || event.metaKey || event.shiftKey) {
					// if (scope.enablePan === false) return;
					//
					if (scope.enablePan === true && (event.ctrlKey || event.metaKey || event.shiftKey)) {
						handleMouseDownPan(event);

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

						handleMouseDownRotate(event);

						state = STATE.ROTATE;
					}

					break;

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

						handleMouseDownRotate(event);

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

						handleMouseDownPan(event);

						state = STATE.PAN;
					}

					break;

				default:
					state = STATE.NONE;
			}

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

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

							handleTouchStartRotate();

							state = STATE.TOUCH_ROTATE;

							break;

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

							handleTouchStartPan();

							state = STATE.TOUCH_PAN;

							break;

						default:
							state = STATE.NONE;
					}

					break;

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

							handleTouchStartDollyPan();

							state = STATE.TOUCH_DOLLY_PAN;

							break;

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

							handleTouchStartDollyRotate();

							state = STATE.TOUCH_DOLLY_ROTATE;

							break;

						default:
							state = STATE.NONE;
					}

					break;

				default:
					state = STATE.NONE;
			}

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

		function onTouchMove(event) {
			trackPointer(event);

			switch (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:
					state = STATE.NONE;
			}
		}

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

			event.preventDefault();
		}

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

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

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

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

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

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

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

			return 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};