Ysurac / FlightAirMap

        // AMD

        define(['leaflet', 'mapbox-gl'], factory);

    } else if (typeof exports === 'object') {

        // Node, CommonJS-like

        module.exports = factory(require('leaflet'), require('mapbox-gl'));

    } else {

        // Browser globals (root is window)

        root.returnExports = factory(window.L, window.mapboxgl);

    }

}(this, function (L, mapboxgl) {

    L.MapboxGL = L.Layer.extend({

        options: {

        updateInterval: 32

        },

        initialize: function (options) {

            L.setOptions(this, options);

            if (options.accessToken) {

                mapboxgl.accessToken = options.accessToken;

            } else {

                throw new Error('You should provide a Mapbox GL access token as a token option.');

            }

            /**

             * Create a version of `fn` that only fires once every `time` millseconds.

             *

             * @param {Function} fn the function to be throttled

             * @param {number} time millseconds required between function calls

             * @param {*} context the value of `this` with which the function is called

             * @returns {Function} debounced function

             * @private

             */

            var throttle = function (fn, time, context) {

                var lock, args, wrapperFn, later;

                later = function () {

                    // reset lock and call if queued

                    lock = false;

                    if (args) {

                        wrapperFn.apply(context, args);

                        args = false;

                    }

                };

                wrapperFn = function () {

                    if (lock) {

                        // called too soon, queue to call later

                        args = arguments;

                    } else {

                        // call and lock until later

                        fn.apply(context, arguments);

                        setTimeout(later, time);

                        lock = true;

                    }

                };

                return wrapperFn;

            };

            // setup throttling the update event when panning

            this._throttledUpdate = throttle(L.Util.bind(this._update, this), this.options.updateInterval);

        },

        onAdd: function (map) {

            if (!this._glContainer) {

                this._initContainer();

            }

            map._panes.tilePane.appendChild(this._glContainer);

            this._initGL();

            this._offset = this._map.containerPointToLayerPoint([0, 0]);

            // work around https://github.com/mapbox/mapbox-gl-leaflet/issues/47

            if (map.options.zoomAnimation) {

                L.DomEvent.on(map._proxy, L.DomUtil.TRANSITION_END, this._transitionEnd, this);

            }

        },

        onRemove: function (map) {

            if (this._map.options.zoomAnimation) {

                L.DomEvent.off(this._map._proxy, L.DomUtil.TRANSITION_END, this._transitionEnd, this);

            }

            map.getPanes().tilePane.removeChild(this._glContainer);

            this._glMap.remove();

            this._glMap = null;

        },

        getEvents: function () {

            return {

                move: this._throttledUpdate, // sensibly throttle updating while panning

                zoomanim: this._animateZoom, // applys the zoom animation to the <canvas>

                zoom: this._pinchZoom, // animate every zoom event for smoother pinch-zooming

                zoomstart: this._zoomStart, // flag starting a zoom to disable panning

                zoomend: this._zoomEnd

            };

        },

        _initContainer: function () {

            var container = this._glContainer = L.DomUtil.create('div', 'leaflet-gl-layer');

            var size = this._map.getSize();

            container.style.width  = size.x + 'px';

            container.style.height = size.y + 'px';

        },

        _initGL: function () {

            var center = this._map.getCenter();

            var options = L.extend({}, this.options, {

                container: this._glContainer,

                interactive: false,

                center: [center.lng, center.lat],

                zoom: this._map.getZoom() - 1,

                attributionControl: false

            });

            this._glMap = new mapboxgl.Map(options);

            // allow GL base map to pan beyond min/max latitudes

            this._glMap.transform.latRange = null;

            if (this._glMap._canvas.canvas) {

                // older versions of mapbox-gl surfaced the canvas differently

                this._glMap._actualCanvas = this._glMap._canvas.canvas;

            } else {

                this._glMap._actualCanvas = this._glMap._canvas;

            }

            // treat child <canvas> element like L.ImageOverlay

            L.DomUtil.addClass(this._glMap._actualCanvas, 'leaflet-image-layer');

            L.DomUtil.addClass(this._glMap._actualCanvas, 'leaflet-zoom-animated');

        },

        // update the map constantly during a pinch zoom

        this._glMap.jumpTo({

            zoom: this._map.getZoom() - 1,

            center: this._map.getCenter()

        });

        },

        // borrowed from L.ImageOverlay https://github.com/Leaflet/Leaflet/blob/master/src/layer/ImageOverlay.js#L139-L144

        _animateZoom: function (e) {

        var scale = this._map.getZoomScale(e.zoom),

            offset = this._map._latLngToNewLayerPoint(this._map.getBounds().getNorthWest(), e.zoom, e.center);

        L.DomUtil.setTransform(this._glMap._actualCanvas, offset.subtract(this._offset), scale);

        },

        this._zooming = true;

        },

        _zoomEnd: function () {

        var scale = this._map.getZoomScale(this._map.getZoom()),

            offset = this._map._latLngToNewLayerPoint(this._map.getBounds().getNorthWest(), this._map.getZoom(), this._map.getCenter());

        L.DomUtil.setTransform(this._glMap._actualCanvas, offset.subtract(this._offset), scale);

        this._zooming = false;

        },

        L.Util.requestAnimFrame(function () {

            var zoom = this._map.getZoom(),

            center = this._map.getCenter(),

            offset = this._map.latLngToContainerPoint(this._map.getBounds().getNorthWest());

            // reset the scale and offset

            L.DomUtil.setTransform(this._glMap._actualCanvas, offset, 1);

            // enable panning once the gl map is ready again

            this._glMap.once('moveend', L.Util.bind(function () {

                this._zoomEnd();

            }, this));

            // update the map position

            this._glMap.jumpTo({

                center: center,

                zoom: zoom - 1

            });

        }, this);

        }

    });

    L.mapboxGL = function (options) {

        return new L.MapboxGL(options);

    };

}));