/** Animation loop / drawing and moving (and shaking :) that happens between each segment on the route (A > B)
  @param {L.LatLng} latlng data|array for the particular animation part
  @param {L.Marker} startMarker is a starting position for this animation part - A
  @param {L.Marker} targetMarker is target position for this animation part - B 
  @param {Integer} currentIndex a current requested animation part index 
*/
animatePolyline: function (latlng, startMarker, targetMarker, currentIndex) {
  if (latlng && latlng.length > 0) {

    // Define start and end positions
    var start = startMarker ? startMarker : self.markers.moving; //photos[0];
    var end = targetMarker ? new L.LatLng(targetMarker.getLatLng().lat,
      targetMarker.getLatLng().lng) : {};

    // "End" marker should never be visible during the animation
    self.markers.end.setOpacity('0');

    // And make sure that target marker is visible during the animation, if it's not "end" one
    if (targetMarker != self.markers.end) {
      targetMarker.setOpacity('1');
    }

    // Here we create an array of each nth item (panDividerFactor property) in the current polyline array in order to run camera that often    
    var indexes = [];
    for (e = 0; e &
      #60; latlng.length; e++) {
      if (latlng[e]) {
        if ((e % self.panDividerFactor) = =
      0) {
      indexes.push(latlng[e]);
    }
  }
}

// Listen for ongoing animation
document.addEventListener('mapAnimation', self.listeners.mapAnimation);

// Current animation was interrupted with the other one; most likely user interaction / slide prev/next navigation
if (self.timeout.delay._default == self.timeout.delay.broken) {

  // If there was a previous animation make sure to remove vector(svg) and draw canvas polyline (so the line does not "fly" together with flyToBounds() below
  if (self.polylineSlides[currentIndex - 1] && self.polylineSlides[currentIndex -
      1].polyline) {
    self.map.removeLayer(self.polylineSlides[currentIndex - 1].polyline);
    self.polylineSlides[currentIndex - 1].polyline = self.setPolyline(self.polylineSlides[
      currentIndex - 1].data, {
      renderer: L.canvas({
        padding: 0
      })
    });
  }

  // Make sure image/marker becomes visible in this case too
  if (startMarker && startMarker != targetMarker) {
    startMarker.setZIndexOffset(1);
    $(startMarker._icon).addClass('slide-active dirty');
  }

  // Place marker on the requested destination/slide
  self.markers.moving.setLatLng(latlng[0]);

  // And flyTo requested destination/slide
  self.map.flyTo(latlng[0], self.zoom, {
    animate: true,
    duration: self.timeout.delay.brokenFly
  });

  // Broadcast this event, declare this animation as complete
  var event = new CustomEvent('mapAnimationComplete', {
    'detail': {
      broken: true,
      currentIndex: parseInt(currentIndex) - 1
    }
  });
  // Dispatch/Trigger/Fire the event
  document.dispatchEvent(event);
}

var zoom = self.map.getZoom();

setTimeout(function () {

  // Define timeout array for this animation part; This is to be cleared on interruption or if animation completed
  self.polylineSlides[currentIndex].timeout = [];

  // Define polyline for this animation part (A > B) to be "filled" progressively in a loop below
  self.polylineSlides[currentIndex].polyline = self.setPolyline([latlng[0]], {
    renderer: L.svg({
      padding: 0
    })
  });

  // Our glorious loop starts here
  for (i = 0; i &
    #60; latlng.length; i++) {  
             
          // Broadcast this event, tell everyone that animation is ongoing
          var animateEvent = new CustomEvent(
      'mapAnimation', {
        'detail': {
          currentIndex: parseInt(currentIndex),
          index: i
        }
      }); document.dispatchEvent(animateEvent);

    // Each polyline segment needs to be packed into timeout array so that we can safely clear it per need
    self.polylineSlides[currentIndex].timeout[i] = setTimeout(function (
      coords, index) {

      var currPolyline = self.polylineSlides[currentIndex].polyline;

      // The main magic, progressively draw polyline and move "moving" marker 
      if (!coords[index].equals(end)) {
        // Move marker
        self.markers.moving.setLatLng(coords[index]);

        // Populate polyline with points (drawing it)
        self.polylineSlides[currentIndex].polyline.addLatLng(coords[index]);
      }

      // Camera move during the animation; each nth (panDividerFactor property) time of the whole loop
      if (indexes.indexOf(coords[index])) {

        // Currently we use flyToBound() which makes the whole animation kind of fancy 
        var startCoords = self.polylineSlides[currentIndex].polyline.getLatLngs()[
          index];;
        var endCoords = targetMarker.getLatLng()

        if (startCoords && endCoords) {
          var p1 = new L.latLng(startCoords.lat, startCoords.lng);
          var p2 = new L.latLng(endCoords.lat, endCoords.lng);
          var bounds = new L.latLngBounds(p1, p2);
          self.map.flyToBounds(bounds, {
            maxZoom: 15,
            duration: self.panDuration,
            easeLinearity: 1.25
          });
        }
      }

      // Animation reached its last point (targetMarker)
      if (coords.length - 1 == index) {

        // Revert animation delay value to default, from "flying" one to a "moving" one
        self.timeout.delay._default = self.timeout.delay.linear;

        //self.map.flyTo(coords[index], newZoom, {animate: true, duration: 1.55, easeLinearity: 0.55}); //2.32

        // Broadcast this event, declare this animation as complete
        var event = new CustomEvent('mapAnimationComplete', {
          'detail': {
            currentIndex: parseInt(currentIndex)
          }
        });
        document.dispatchEvent(event);

        // Since animation for this very polyline, part of the route, was completed, make sure that line is canvas now rather than vector (svg)
        // Canvas line does not "fly" together with flyToBounds() above
        self.map.removeLayer(self.polylineSlides[currentIndex].polyline);
        self.polylineSlides[currentIndex].polyline = self.setPolyline(
          self.polylineSlides[currentIndex].data, {
            renderer: L.canvas({
              padding: 0
            })
          });
        // self.map.addLayer(self.polylineSlides[currentIndex].polyline);

        // Make target marker visible (if not "end" marker)
        if (targetMarker !== self.markers.end) {
          targetMarker.setZIndexOffset(1);
          $(targetMarker._icon).addClass('slide-active dirty');
        } else { // Last portion, do some specific changes

          self.markers.end.setOpacity('1');
          $(self.markers.end._icon).addClass('slide-active');
          self.markers.moving.setOpacity('0');

          // Once the "end" slide is reached fly to bounds of entire route 
          setTimeout(function () {
            //self.map.setMaxBounds([currentPath[0], currentMarkerCoord]);
            self.map.flyToBounds(self.polyline.getBounds(), {
              animate: true,
              duration: self.endSlideBounds.duration
            });
          }, self.endSlideBounds.delay);
        }
      }

    }, self.drawingSpeed._default * i, latlng, i);

  }

}, self.timeout.delay._default);

}

}