spine-runtimes/spine-ts/spine-threejs/example/OrbitalControls.js

let EventDispatcher = THREE.EventDispatcher;
let MOUSE = THREE.MOUSE;
let Quaternion = THREE.Quaternion;
let Spherical = THREE.Spherical;
let TOUCH = THREE.TOUCH;
let Vector2 = THREE.Vector2;
let Vector3 = THREE.Vector3;

// This set of controls 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' };

class OrbitControls extends EventDispatcher {

	constructor(object, domElement) {

		super();

		if (domElement === undefined) console.warn('THREE.OrbitControls: The second parameter "domElement" is now mandatory.');
		if (domElement === document) console.error('THREE.OrbitControls: "document" should not be used as the target "domElement". Please use "renderer.domElement" instead.');

		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.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 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 && 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 *= 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(panOffset, scope.dampingFactor);

				} else {

					scope.target.add(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);

					panOffset.multiplyScalar(1 - scope.dampingFactor);

				} else {

					sphericalDelta.set(0, 0, 0);

					panOffset.set(0, 0, 0);

				}

				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 (zoomChanged ||
					lastPosition.distanceToSquared(scope.object.position) > EPS ||
					8 * (1 - lastQuaternion.dot(scope.object.quaternion)) > EPS) {

					scope.dispatchEvent(_changeEvent);

					lastPosition.copy(scope.object.position);
					lastQuaternion.copy(scope.object.quaternion);
					zoomChanged = false;

					return true;

				}

				return false;

			};

		}();

		this.dispose = function () {

			scope.domElement.removeEventListener('contextmenu', onContextMenu);

			scope.domElement.removeEventListener('pointerdown', onPointerDown);
			scope.domElement.removeEventListener('pointercancel', onPointerCancel);
			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.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();
		let zoomChanged = false;

		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 pointers = [];
		const 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);

				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) {

				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();
				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) {

				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();
				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) {

			rotateStart.set(event.clientX, event.clientY);

		}

		function handleMouseDownDolly(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) {

			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:
					pan(0, scope.keyPanSpeed);
					needsUpdate = true;
					break;

				case scope.keys.BOTTOM:
					pan(0, - scope.keyPanSpeed);
					needsUpdate = true;
					break;

				case scope.keys.LEFT:
					pan(scope.keyPanSpeed, 0);
					needsUpdate = true;
					break;

				case scope.keys.RIGHT:
					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.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 (pointers.length === 0) {

				scope.domElement.releasePointerCapture(event.pointerId);

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

			}

			scope.dispatchEvent(_endEvent);

			state = STATE.NONE;

		}

		function onPointerCancel(event) {

			removePointer(event);

		}

		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:

					if (event.ctrlKey || event.metaKey || event.shiftKey) {

						if (scope.enablePan === false) return;

						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) {

			if (scope.enabled === false) return;

			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', onPointerCancel);
		scope.domElement.addEventListener('wheel', onMouseWheel, { passive: false });

		// force an update at start

		this.update();

	}

}


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

class MapControls extends OrbitControls {

	constructor(object, domElement) {

		super(object, domElement);

		this.screenSpacePanning = false; // pan orthogonal to world-space direction camera.up

		this.mouseButtons.LEFT = MOUSE.PAN;
		this.mouseButtons.RIGHT = MOUSE.ROTATE;

		this.touches.ONE = TOUCH.PAN;
		this.touches.TWO = TOUCH.DOLLY_ROTATE;

	}

}