I am relatively new to map projections but believe I have understood how one could translate lat/lon to the map tile coordinates X and Y, which is nicely explained here:
When requesting Google static maps, we need to supply a zoom value which makes sense to me. However for the function get_openstreetmap(), I am quite puzzled on the scale parameter and how one could possibly translate scale to zoom. That seems impossible/difficult since zoom values are discrete integers and scale more or less continuous. If scale->zoom is not done, how does the package project lat/lon to Y/X ? I dug through the sources but the only function I could find was LonLat2XY() which also requires a zoom level.
What function performs the translation for OSM maps?