changing google maps polygon vertices - javascript

Just a quick query - I'm sure it has a quick answer :)
I'm trying to loop through an array of points defining a polygon in google maps and change them (my test programme is just decrementing the latitude by a small amount, to see if I can get it to work). I've taken my experimental code from the Bermuda Triangle example, but with a LatLong array rather than MVC.
triangleCoords = [
new google.maps.LatLng(25.774, -80.190 ),
new google.maps.LatLng(18.466, -66.118 ),
new google.maps.LatLng(32.321, -64.757 )
];
bermudaTriangle = new google.maps.Polygon({
paths: triangleCoords,
strokeColor: '#FF0000',
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: '#FF0000',
fillOpacity: 0.35,
map: map
});
And I'm trying to alter the points with this:
var vertices = bermudaTriangle.getPath();
for (var i =0; i < vertices.getLength(); i++) {
var xy = vertices.getAt(i);
vertices.setAt(i, new google.maps.LatLng( xy.lat()-0.01, xy.lng() ));
}
But it doesn't work. Can anyone see what is wrong? Thanks

You've got an array of coordinates, saved as the variable vertices, which you've then updated with new values... and then what? All you've done is update an array.
If you want to redraw the polygon, you also need to then do:
bermudaTriangle.setPath(vertices);

Related

Google Maps - Unable to draw Polygons and Linestrings

I'm building an application using MEAN Stack and Google Maps Api and I'm having a little problem when it comes to draw Polygons and LineStrings.
I have a collection of geometries (Points, Polygons and LineStrings) and each time I find one of them I need to add it properly to the map.
I have no problem when it comes to render Markers but I have issues when it comes to Polygons and LineStrings.
Here's my code which contains the logic of initializing the map.
// Initializes the map
function initialize(latitude, longitude, filter) {
// If map has not been created...
if (!map) {
// Create a new map and place in the index.html page
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: new google.maps.LatLng(vm.selectedLat, vm.selectedLong)
});
}
// Loop through each location in the array and place a geometry
locations.forEach(function (n) {
if(n.type === 'LineString'){
console.log('LineString '+JSON.stringify(n.coords));
var linestring = new google.maps.Polyline({
position: n.coords,
map: map,
geodesic: true,
strokeColor: '#0404B4',
strokeOpacity: 1.0,
strokeWeight: 2
});
// For each linestring created, add a listener
google.maps.event.addListener(linestring, 'click', function () {
// When clicked, open the selected linestring's message
n.message.open(map, linestring);
});
linestring.setMap(map);
}
if(n.type === 'Polygon'){
console.log('Polygon '+JSON.stringify(n.coords));
var polygon = new google.maps.Polygon({
path: n.coords,
geodesic: true,
strokeColor: '#0404B4',
strokeOpacity: 0.8,
strokeWeight: 3,
fillColor: '#0404B4',
fillOpacity: 0.35
});
// For each polygon created, add a listener
google.maps.event.addListener(polygon, 'click', function () {
// When clicked, open the selected polygon's message
n.message.open(map, polygon);
});
polygon.setMap(map);
}
});
};
Here are the screenshots of the two console.log() of the coordinates
As you can see from the screenshot I also get
InvalidValueError: at index 0: not a LatLng or LatLngLiteral: in property lat: not a number
I tried, unsuccessfully, to find a solution to that.
Why can't I draw these geometries? How can I solve the InvalidValueError?
Thanks in advance.
Issues:
A google.maps.Polyline doesn't have a position property, it has a path property which takes an array of google.maps.LatLngLiterals (which looks like what you are passing in to the position property).
A google.maps.Polygon has a paths property which takes an array of google.maps.LatLngLiterals, but your data is not formatted correctly (and you are using path not paths). It is an array of {lat: [46.774, -48.19], lng: [46.466, -29.119]}, neither lat nor lng are Numbers, they are arrays.

GoogleMaps or Cesium to render dynamical geometries on a Map

I'm currently really confused, and I do need an advice.
My current aim is to get a Satellite view of a random building, with the tipical RoadMap\3d effect of Google maps:
and being able to use three.js on it, rendering polys overlapping that map.
I've followed example from this git repo:
ubilabs/google-maps-api-threejs-layer
But I can include particles on a map...I can't put on it geometries like polygons, splines and such.
I don't know what to do know...maybe Cesium is the answer?
But Cesium doesn't have the same "3d" option on buildings...
Any help would be appreciated!
Thanks!
For polygon, line and marker you can use google maps v3
You can see this link google developer link for a firts evaluation
i'm talking about native polygon , polyline, marker . or native drwing tools of google maps v3
https://developers.google.com/maps/documentation/javascript/examples/drawing-tools and https://developers.google.com/maps/documentation/javascript/examples/polygon-simple
but more useful is this link Dyer
http://johndyer.name/drawing-3d-objects-and-building-on-google-maps/
where with proper function you can build your 3d object
function drawExcrudedShape(map, coordinates, height, strokeColor, strokeOpacity, strokeWeight, fillColor, fillOpacity) {
var pairs = [],
polygons = [];
// build line pairs for each wall
for (var i=0; i<coordinates.length; i++) {
var point = coordinates[i],
otherIndex = (i == coordinates.length-1) ? 0 : i+1,
otherPoint = coordinates[otherIndex];
pairs.push([point, otherPoint]);
}
// draw excrusions
for (var i=0; i<pairs.length; i++) {
var first = pairs[i][0],
second = pairs[i][1],
wallCoordinates = [
new google.maps.LatLng(first[0],first[1]),
new google.maps.LatLng(first[0]+height,first[1]),
new google.maps.LatLng(second[0]+height,second[1]),
new google.maps.LatLng(second[0],second[1])
],
polygon = new google.maps.Polygon({
paths: wallCoordinates,
strokeColor: strokeColor,
strokeOpacity: strokeOpacity,
strokeWeight: strokeWeight,
fillColor: fillColor,
fillOpacity: fillOpacity
zIndex: zIndexBase+i
});
polygon.setMap(map);
polygons.push(polygon);
}
return polygons;
}

I want to create a Donut with Javascript API V3(Empty space inside like a hole)

I want to create a hole in my Javascript Google API V3, so i follow Beginning Google Map API V3. But the code is rendering the whole area. Here is my Javascript code.
(function() {
window.onload = function() {
// Creating a map
var options = {
zoom: 6,
center: new google.maps.LatLng(36.5, -79.8),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById('map'), options);
// Creating an array with the points for the outer polygon
var polyOuter = [
new google.maps.LatLng(37.303, -81.256),
new google.maps.LatLng(37.303, -78.333),
new google.maps.LatLng(35.392, -78.333),
new google.maps.LatLng(35.392, -81.256)
];
// Creating an array with the points for the inner polygon
var polyInner = [
new google.maps.LatLng(36.705, -80.459),
new google.maps.LatLng(36.705, -79),
new google.maps.LatLng(35.9, -79),
new google.maps.LatLng(35.9, -80.459)
];
var points = [polyOuter, polyInner];
// Creating the polygon
var polygon = new google.maps.Polygon
({
paths: points,
map: map,
strokeColor: '#ff0000',
strokeOpacity: 0.6,
strokeWeight: 3,
fillColor: '#FF0000',
fillOpacity: 0.35
});
};
})();
One of the paths has to be reverted so polygons are drawn in different directions, for example:
var polyInner = [
new google.maps.LatLng(35.9, -80.459),
new google.maps.LatLng(35.9, -79),
new google.maps.LatLng(36.705, -79),
new google.maps.LatLng(36.705, -80.459)
];
My assumption is that the reason is how SVG or canvas render closed loops. If I am not wrong explanation lies in nonzero winding rule. See explanation at wikipedia.
Outer path is drawn clockwise, inner path is drawn counter-clockwise.
Set a counter to zero. Pick a point in object area and draw a line in direction out of object space. If the line cross clockwise path, add one. If the line cross counter-clockwise path segment, subtract one. If the final result for selected point is non-zero, the browser fills the area. If the final result is zero, the browser does not fill it.
So, if you pick up point in the 'hole', the result will be zero and area will not be filled.

google maps flight path

I'm trying to create a map with a lot of flight paths, gathered from a database.
The method i use could probably be improved a little:
var flightPlanCoordinates1 = [
new google.maps.LatLng(53.63384159955519, 10.005816800985485),
new google.maps.LatLng(40.689837457540044, -74.17809198377654)
];
var flightPath1 = new google.maps.Polyline({
path: flightPlanCoordinates1,
geodesic: true,
strokeColor: '#FF0000',
strokeOpacity: 1.0,
strokeWeight: 2
});
flightPath1.setMap(map);
...
The above will be looped over and over to show all the routes collected from the database.
So my question is, if it would be possible to simplify this, so that all of the above does not have to be looped, only the coordinates.
What i'm thinking is that a "break" function for "flightPlanCoordinates1", to break for each route, would be a good solution.
Appreciate any help
First, define your polyline options:
var pathOptions = {
geodesic: true,
strokeColor: '#FF0000',
strokeOpacity: 1.0,
strokeWeight: 2
};
Then in your loop you can create the polyline with the options:
var path = new google.maps.Polyline(pathOptions);
Then get the start and end points (where start_lat/lng end_lat/lng are your coordinates):
var start_point = new google.maps.LatLng(start_lat, start_lng);
var end_point = new google.maps.LatLng(end_lat, end_lng);
Then apply it to the polyline and set it on the map:
path.getPath().setAt(0, start_point);
path.getPath().setAt(1, end_point);
path.setMap(map);
You get the idea?

can't draw a polyline on google maps v3, but can draw the points of it as markers (I am using OpenStreetMap layer)

the following code is used to draw a polyline on Google Maps using V3 API, but sometimes is draws the polyline and most of times doesn't despite there are point (as I can show the points on the map as markers) but no polyline appears
update 2 : I am using openstreetmap layer over Google maps. does that cause the problem when drawing the polyilne ?
w variable contains data as string , for example :
w= 35.1212,55.2333\n36.32366,56.3333
Real data sample for w : [this code can draw markers for the following points but can't draw a polyline ]
34.440501,31.515222
34.441933,31.514346
34.44247,31.514013
34.442603,31.51394
34.443607,31.513423
34.4445,31.512926
34.444762,31.512772
34.445186,31.512523
34.445257,31.512481
34.445311,31.512449
34.445614,31.512264
34.446244,31.511867
34.446939,31.511429
34.447351,31.511193
34.448081,31.512174
34.448241,31.512357
34.448576,31.512741
34.449147,31.513185
34.4499,31.513723
34.450894,31.514401
34.451925,31.515362
34.452905,31.516176
34.454194,31.517266
34.455337,31.518236
34.456215,31.51898
34.456987,31.519646
34.457583,31.520166
34.458298,31.520772
34.458989,31.52139
34.459659,31.521959
34.460476,31.522653
34.461192,31.523228
34.461869,31.523788
34.46256,31.524376
34.463302,31.525015
34.464062,31.525668
34.464433,31.525986
34.464737,31.526246
34.465247,31.526683
34.465498,31.526907
34.466666,31.52792
34.46722,31.528404
34.467327,31.528495
34.468014,31.529081
34.468379,31.52939
34.469296,31.530177
34.469771,31.530583
34.470152,31.53091
34.470951,31.531597
34.471617,31.532172
34.472388,31.532838
34.472664,31.533076
34.47295,31.533397
34.473422,31.533653
34.474028,31.534065
34.474844,31.534629
34.475725,31.535253
34.476083,31.535517
34.476697,31.535947
34.477105,31.536209
34.477627,31.536477
34.478,31.536742
34.478398,31.536989
34.478935,31.537325
34.480044,31.537975
34.480985,31.538529
34.481362,31.53878
34.481416,31.538819
34.482407,31.539419
34.482682,31.539109
34.483132,31.538603
34.483341,31.538368
34.483917,31.537753
34.484202,31.537449
34.484288,31.537357
34.484944,31.536587
34.485118,31.536383
34.485205,31.536304
34.485648,31.535903
34.485984,31.535598
34.486246,31.535381
34.486445,31.535291
34.486533,31.535254
34.486607,31.535282
34.486706,31.535354
34.486869,31.535526
34.487012,31.535692
34.487212,31.535923
34.487273,31.536006
34.487767,31.53571
34.488336,31.535395
34.48883,31.535148
34.489078,31.535032
34.489354,31.534901
34.48955,31.534788
34.489756,31.535011
34.489831,31.535097
34.490268,31.534748
34.49065,31.534473
34.490857,31.53436
34.491044,31.534319
34.491352,31.534248
34.491458,31.534237
34.491548,31.534304
34.491879,31.534209
34.492227,31.534203
34.492457,31.534214
34.492042,31.533636
34.492162,31.533542
note : I have reversed lng and lat when creating a point for some purpose
where a is array that has the points to represent as a polyine
code
var mypolyline = new google.maps.Polyline({
strokeColor: "#FF0000",
strokeOpacity: .6,
strokeWeight: 3,
clickable: true
});
// var bounds2 = new google.maps.LatLngBounds();
var a=w.split("\n");
for(var i=0;i<a.length;i++)
{
var zz=a[i].split(",");
var lat=zz[0];
var lng=zz[1];
var path = [];
var path = mypolyline.getPath();
var point = new google.maps.LatLng(parseFloat(lng),parseFloat(lat));
createMarker(i,name,point,icon[1],2);
// alert(path.length);
path.push(point);
mypolyline.setPath(path);
mypolyline.setMap(map);
}
CreateMarker() function
function createMarker(id,name,point,icon,type) {
// var marker = new google.maps.Marker(point, customIcons[type]);
var marker = new google.maps.Marker({
map: map,
position: point,
icon: icon
});
markersArray.push(marker);
google.maps.event.addListener(marker, 'click', function() {
infowindow = new google.maps.InfoWindow({ content: name });
infowindow.open(map, marker);
map.panTo(point);
});
return marker;
}
So you create an array, then you ignore that and recreate it as an MVCArray using the getPath() function. Get rid of the first line (this isn't the cause of the problems though).
var path = [];
var path = mypolyline.getPath();
Just a thought - is the path a required attribute when you first create the polyline?
It seems to me that you initially create the mypolyline without any path. So when you then do this on the first iteration, it's not going to work, because all you're passing to .setPath() is one point, but I assume a path can only work when there's at least 2 points.
path.push(point);
mypolyline.setPath(path);
Update: I think the thing to do would be to just start out with an empty array, loop over your coordinates adding them into the array. Then after the loop, create the polyline, rather than trying to update it each time you iterate over the loop. For instance:
var a=w.split("\n");
var path = [];
for(var i=0;i<a.length;i++)
{
var zz=a[i].split(",");
var lat=zz[0];
var lng=zz[1];
var point = new google.maps.LatLng(parseFloat(lng),parseFloat(lat));
createMarker(i,name,point,icon[1],2);
path.push(point);
}
var mypolyline = new google.maps.Polyline({
path: path,
map: map,
strokeColor: "#FF0000",
strokeOpacity: .6,
strokeWeight: 3,
clickable: true
});

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