Snippet for generating self-loops on Lantern map

selfloops.js

// Use this in place of the existing pathConnection defined in vis.js

$scope.pathConnection = function (peer) {
    var pSelf = projection([model.location.lon, model.location.lat]),
        pPeer = projection([peer.lon, peer.lat]),
        xS = pSelf[0], yS = pSelf[1], xP = pPeer[0], yP = pPeer[1];
    
    var distanceBetweenPeers = Math.sqrt(Math.pow(xS - xP, 2) + Math.pow(yS - yP, 2));
    if (distanceBetweenPeers < 30) {
      // Peer and self are very close, draw a loopy arc
      var xC1 = Math.min(xS, xP) - 20;
      var xC2 = Math.max(xS, xP) + 20;
      var yC = Math.max(yS, yP) + 30;
      return 'M'+xS+','+yS+' C '+xC1+','+yC+' '+xC2+','+yC+' '+xP+','+yP;
    } else {
      // Peer and self are at different positions, draw arc between them
      var controlPoint = [abs(xS+xP)/2, min(yS, yP) - abs(xP-xS)*0.3],
          xC = controlPoint[0], yC = controlPoint[1];
      return $scope.inGiveMode ?
          'M'+xP+','+yP+' Q '+xC+','+yC+' '+xS+','+yS :
          'M'+xS+','+yS+' Q '+xC+','+yC+' '+xP+','+yP;
    }
  };