(Assuming that the pk3 file is unzipped locally)
extern crate quake3_loader;
use std::fs::{File};
use std::path::{Path};
use std::io::{Read};
fn main() {
let path = Path::new("pak0/maps/q3dm1.bsp");
let mut file = File::open(path).unwrap();
let mut bytes = Vec::new();
file.read_to_end(&mut bytes).unwrap();
let bsp = quake3_loader::read_bsp(&bytes);
println!("{:?}", bsp);
}