czukowski

/*
 * Circular Sector Overlay for Google Maps API v3 MooTools 1.2 Class, based on CircleOverlay
 *
 * Arguments:
 *  map -- the google.maps.Map object instnace
 *  point -- the center point of the circle, google.maps.LatLng object
 *  radius -- radius of the circle, in meters, number
 *  angle -- sector angle (theta as in fig. here: http://en.wikipedia.org/wiki/Circular_sector), in degrees
 *  direction -- a point, which the sector faces, google.maps.LatLng object
 *  options -- various options, mainly drawing
 */
var CircularSectorOverlay = new Class({
    Implements: [Options],
    options: {
        numPoints: 100, // for 360 deg.
        drawOptions: {
            strokeColor: "#FF0000",
            strokeOpacity: 0.8,
            strokeWeight: 2,
            fillColor: "#FF0000",
            fillOpacity: 0.35
        }
    },

    initialize: function(map, center, radius, angle, direction, options) {
        this.setOptions(options);

        google.maps.OverlayView.call(this);
        var q = 180 / 63781370 / Math.sin(90 - center.lat()) / Math.PI;

        this._map = map;
        this._point = center;
        this._angle = angle;
        this._direction = direction;
        this._radius = radius * q * 10; // convert meters to latlang degrees

        // Fit bounds of a sector that is drawn into the map
        this.latlngbounds = new google.maps.LatLngBounds();
        this.sectorLatLngs = new Array();
        this.sectorLatLngs.push(this._point);

        var numPointsSector = Math.ceil(this.options.numPoints * angle / 360);
        var angleIncrement = this._angle / numPointsSector;
        var startAngle = Math.asin(2 * (center.lat() - direction.lat()) / 2) * Math.PI - angle / 2;

        var d2r = Math.PI / 180;
        var circleLat = this._radius;
        var circleLng = circleLat / Math.cos(center.lat() * d2r);

        for (var i = 0; i < numPointsSector; i++) {
            var theta = startAngle + i * angleIncrement;
            var vertexLat = center.lat() + circleLat * Math.sin(theta * d2r);
            var vertexLng = center.lng() + circleLng * Math.cos(theta * d2r);
            var vertextLatLng = new google.maps.LatLng(vertexLat, vertexLng);
            this.sectorLatLngs.push(vertextLatLng);
            this.latlngbounds.extend(vertextLatLng);
        }
        map.fitBounds(this.latlngbounds);
        this.set_map(map);
    },

    onAdd: function() {
        var polyOptions = this.options.drawOptions;
        polyOptions.paths = this.sectorLatLngs;
        this.polygon = new google.maps.Polygon(polyOptions);
        this.polygon.setMap(this.map);
    },

    onRemove: function() {
        this.polygon.setMap(null);
    },

    draw: function() {
        this.onRemove();
        this.onAdd();
    }
});
CircularSectorOverlay.implement(new google.maps.OverlayView());