I am trying to animate a point moving from one location to another on a map. And I would like the point to travel along the great circle arc between the locations, rather than in a straight line.
Given the starting coordinates (lng/lat) and the ending coordinates, is there a formula for interpolating along the great circle arc to get the point's coordinates at each step in its route.
I need to run this calculation on the fly (in a WebGL shader), so I can't use PostGIS or a GIS application. It needs to be a formula or algorithm.