Console script written on Go that convert an equirectangular/latlong map into an array of cubemap faces (like you would use to send to OpenGL)
go install
go build
./sphere2cubeGo -i panorama.jpg
You can specify size of the tile face via param -s
./sphere2cubeGo -i panorama.jpg -s 2048
Also you can specify output dir via param -o
./sphere2cubeGo -i panorama.jpg -s 2048 -o /path/to/result/dir