Lat/Lng data from touchstart event

[eprtha]

I'm struggling for quite long time to get the Lat/Lng data from touch events but not successful yet. If anyone knows how to do it, please share. Thanks in advance.

[sebastian-marinescu]

Check out their API-example: https://examples.webglearth.com/#apidemo

In the canvas-box, with the WebglEarth-demo in it, in the bottom right corner you see the coordinates on mouseover. If you scroll down, you see the source-code of that demo.

There you will find some answers, specifically this bit looks relevant for you:

        // Print coordinates of the mouse
        map.on('mousemove', function(e) {
          document.getElementById('coords').innerHTML = e.latlng.lat + ', ' + e.latlng.lng;
        });

Something similar is also used in another API-example.

I think this should give you a good idea 👍

[eprtha]

Thanks for the response. That function is for mouse event which contains lat/lng data. But touch event data seems no lat/lng data in it ;-(

[sebastian-marinescu]

Please for the future, it's best to provide a jsbin/codepen with a (not-)working example.

For now: I couldn't reproduce your issue, because it works for me.

WebGL Earth Touch Test: https://codepen.io/sebastian-marinescu/pen/NWZWowv

I am guessing you where adding the event-listener on document/body?

[sebastian-marinescu]

The important thing in the JS:

 var lastTouchedLatLng = undefined;

  earth.on('touchstart', function(e) {
    console.log('onTouchstart: ', e);
    if (e.latlng) {
      lastTouchedLatLng = e.latlng; 
    }
  });

  earth.on('touchmove', function(e) {
    console.log('onTouchmove: ', e);
    if (e.latlng) {
      lastTouchedLatLng = e.latlng; 
    }
  });

  earth.on('touchend', function(e) {
    console.log('onTouchend: ', e);
    if (lastTouchedLatLng) {
     console.info('Last Latitude/Longitude: ', lastTouchedLatLng); 
    }
  });

In touchend, there really aren't lat/lng-coordinates, but in touchstart and touchmove, there are. So we save the last touched coordinates in theses two events, and in the end in "touchend" we do something with it.

[eprtha]

I really appreciate your help. I found out the problem based on your advice :-) It was caused by using earth.addEventListener instead of earth.on. Thanks.

[sebastian-marinescu]

I'm glad it helped :)

Good luck with your project, and don't forget to close this issue 👍