com.dlsc.gmapsfx.html.v3_epoly.js Maven / Gradle / Ivy
/*********************************************************************\
* *
* epolys.js by Mike Williams *
* updated to API v3 by Larry Ross *
* *
* A Google Maps API Extension *
* *
* Adds various Methods to google.maps.Polygon and google.maps.Polyline *
* *
* .Contains(latlng) returns true is the poly contains the specified *
* GLatLng *
* *
* .Area() returns the approximate area of a poly that is *
* not self-intersecting *
* *
* .Distance() returns the length of the poly path *
* *
* .Bounds() returns a GLatLngBounds that bounds the poly *
* *
* .GetPointAtDistance() returns a GLatLng at the specified distance *
* along the path. *
* The distance is specified in metres *
* Reurns null if the path is shorter than that *
* *
* .GetPointsAtDistance() returns an array of GLatLngs at the *
* specified interval along the path. *
* The distance is specified in metres *
* *
* .GetIndexAtDistance() returns the vertex number at the specified *
* distance along the path. *
* The distance is specified in metres *
* Returns null if the path is shorter than that *
* *
* .Bearing(v1?,v2?) returns the bearing between two vertices *
* if v1 is null, returns bearing from first to last *
* if v2 is null, returns bearing from v1 to next *
* *
* *
***********************************************************************
* *
* This Javascript is provided by Mike Williams *
* Blackpool Community Church Javascript Team *
* http://www.blackpoolchurch.org/ *
* http://econym.org.uk/gmap/ *
* *
* This work is licenced under a Creative Commons Licence *
* http://creativecommons.org/licenses/by/2.0/uk/ *
* *
***********************************************************************
* *
* Version 1.1 6-Jun-2007 *
* Version 1.2 1-Jul-2007 - fix: Bounds was omitting vertex zero *
* add: Bearing *
* Version 1.3 28-Nov-2008 add: GetPointsAtDistance() *
* Version 1.4 12-Jan-2009 fix: GetPointsAtDistance() *
* Version 3.0 11-Aug-2010 update to v3 *
* *
\*********************************************************************/
// === first support methods that don't (yet) exist in v3
google.maps.LatLng.prototype.distanceFrom = function(newLatLng) {
var EarthRadiusMeters = 6378137.0; // meters
var lat1 = this.lat();
var lon1 = this.lng();
var lat2 = newLatLng.lat();
var lon2 = newLatLng.lng();
var dLat = (lat2-lat1) * Math.PI / 180;
var dLon = (lon2-lon1) * Math.PI / 180;
var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(lat1 * Math.PI / 180 ) * Math.cos(lat2 * Math.PI / 180 ) *
Math.sin(dLon/2) * Math.sin(dLon/2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = EarthRadiusMeters * c;
return d;
}
google.maps.LatLng.prototype.latRadians = function() {
return this.lat() * Math.PI/180;
}
google.maps.LatLng.prototype.lngRadians = function() {
return this.lng() * Math.PI/180;
}
// === A method for testing if a point is inside a polygon
// === Returns true if poly contains point
// === Algorithm shamelessly stolen from http://alienryderflex.com/polygon/
google.maps.Polygon.prototype.Contains = function(point) {
var j=0;
var oddNodes = false;
var x = point.lng();
var y = point.lat();
for (var i=0; i < this.getPath().getLength(); i++) {
j++;
if (j == this.getPath().getLength()) {j = 0;}
if (((this.getPath().getAt(i).lat() < y) && (this.getPath().getAt(j).lat() >= y))
|| ((this.getPath().getAt(j).lat() < y) && (this.getPath().getAt(i).lat() >= y))) {
if ( this.getPath().getAt(i).lng() + (y - this.getPath().getAt(i).lat())
/* (this.getPath().getAt(j).lat()-this.getPath().getAt(i).lat())*/
(this.getPath().getAt(j).lng() - this.getPath().getAt(i).lng()) next) {
var p1= this.getPath().getAt(i-1);
var p2= this.getPath().getAt(i);
var m = (next-olddist)/(dist-olddist);
points.push(new google.maps.LatLng( p1.lat() + (p2.lat()-p1.lat())*m, p1.lng() + (p2.lng()-p1.lng())*m));
next += metres;
}
}
return points;
}
// === A method which returns the Vertex number at a given distance along the path ===
// === Returns null if the path is shorter than the specified distance ===
google.maps.Polygon.prototype.GetIndexAtDistance = function(metres) {
// some awkward special cases
if (metres == 0) return this.getPath().getAt(0);
if (metres < 0) return null;
var dist=0;
var olddist=0;
for (var i=1; (i < this.getPath().getLength() && dist < metres); i++) {
olddist = dist;
dist += this.getPath().getAt(i).distanceFrom(this.getPath().getAt(i-1));
}
if (dist < metres) {return null;}
return i;
}
// === A function which returns the bearing between two vertices in decgrees from 0 to 360===
// === If v1 is null, it returns the bearing between the first and last vertex ===
// === If v1 is present but v2 is null, returns the bearing from v1 to the next vertex ===
// === If either vertex is out of range, returns void ===
google.maps.Polygon.prototype.Bearing = function(v1,v2) {
if (v1 == null) {
v1 = 0;
v2 = this.getPath().getLength()-1;
} else if (v2 == null) {
v2 = v1+1;
}
if ((v1 < 0) || (v1 >= this.getPath().getLength()) || (v2 < 0) || (v2 >= this.getPath().getLength())) {
return;
}
var from = this.getPath().getAt(v1);
var to = this.getPath().getAt(v2);
if (from.equals(to)) {
return 0;
}
var lat1 = from.latRadians();
var lon1 = from.lngRadians();
var lat2 = to.latRadians();
var lon2 = to.lngRadians();
var angle = - Math.atan2( Math.sin( lon1 - lon2 ) * Math.cos( lat2 ), Math.cos( lat1 ) * Math.sin( lat2 ) - Math.sin( lat1 ) * Math.cos( lat2 ) * Math.cos( lon1 - lon2 ) );
if ( angle < 0.0 ) angle += Math.PI * 2.0;
angle = angle * 180.0 / Math.PI;
return parseFloat(angle.toFixed(1));
}
// === Copy all the above functions to GPolyline ===
google.maps.Polyline.prototype.Contains = google.maps.Polygon.prototype.Contains;
google.maps.Polyline.prototype.Area = google.maps.Polygon.prototype.Area;
google.maps.Polyline.prototype.Distance = google.maps.Polygon.prototype.Distance;
google.maps.Polyline.prototype.Bounds = google.maps.Polygon.prototype.Bounds;
google.maps.Polyline.prototype.GetPointAtDistance = google.maps.Polygon.prototype.GetPointAtDistance;
google.maps.Polyline.prototype.GetPointsAtDistance = google.maps.Polygon.prototype.GetPointsAtDistance;
google.maps.Polyline.prototype.GetIndexAtDistance = google.maps.Polygon.prototype.GetIndexAtDistance;
google.maps.Polyline.prototype.Bearing = google.maps.Polygon.prototype.Bearing;