Message passing is terribly inefficient for graphics calculations. You can bind Elixir to something else, but implementing the GUI in Elixir sounds ill advised.
No one is saying you have to abandon Elixir. But you have to write your “fast” C library anyway. Combining the result of NIFs with calculations done by Elixir is probably not very smart. You should handle all the math inside the NIF and only return tbe final result, to minimize overhead.
