Adding Curved Flight path using R's Leaflet Package

Question

Currently I'm able to draw a straight line between countries using the following code:

library(leaflet) 
leaflet() %>% addTiles() %>% addPolylines(lat=c(38.8833, 35.00), lng=c(-77.0167, 103.00))

What I'm trying to produce is a more realistic flight path, where the straight line is actually curved. Similar to this:

For the sake of this question, I'd like to tailor the answer within the Leaflet package. Any help would be much appreciated.

Answer 1

following up on mrub, just pass the object you get from gcIntermediate to leaflet. something like this:

library(leaflet)
library(geosphere)
gcIntermediate(c(5,52), c(-120,37),
               n=100, 
               addStartEnd=TRUE,
               sp=TRUE) %>% 
leaflet() %>% 
addTiles() %>% 
addPolylines()