Function huff_expand

src/cache.rs:330–362

(huff: &[(u16, u16)], source: &[u8], length: usize)

}

fn huff_expand(huff: &[(u16, u16)], source: &[u8], length: usize) -> Vec<u8> {
    let mut dest: Vec<u8> = Vec::new();
    let headptr = 254; // head node is always node 254
    let mut huffptr = headptr;
    let mut i = 0;

    let mut mask = 1;
    let mut nodeval;

    loop {
        if (source[i] & mask) == 0 {
            nodeval = huff[huffptr].0;
        } else {
            nodeval = huff[huffptr].1;
        }
        if mask == 0x80 {
            i += 1;
            mask = 1;
        } else {
            mask <<= 1;
        }
        if nodeval < 256 {
            dest.push(nodeval.try_into().unwrap());
            huffptr = headptr;
            if dest.len() >= length {
                break;
            }
        } else {
            huffptr = nodeval as usize - 256;
        }
    }
    dest
}

fn load_graphic(source: &[u8], headers: &[u32], huff: &[(u16, u16)], chunk: usize) -> Vec<u8> {
    let pos = headers[chunk] as usize;