gistfile1.txt

fn cksh(a: u32, sh: u32) -> u32 {
    let result = a >> sh; 
    if result > 0 {
        result
    } else {
        1
    }
}

fn mipsize(w: u32, h: u32, d: u32, x: u32) -> u32 {
    (cksh(w, x).wrapping_mul(cksh(h, x)))
        .wrapping_mul(cksh(d, x))
}

fn moffset(w: u32, h: u32, d: u32) -> u32 {
    let mut x = 0u32;
    for k in 0..MIP {
        x = x.wrapping_add(mipsize(w, h, d, k));
    }

    x
}

fn main() {
    let args = std::env::args().collect::<Vec<_>>();
    let w = u32::from_str_radix(&args[1], 16).unwrap();
    let h = u32::from_str_radix(&args[2], 16).unwrap();
    let d = u32::from_str_radix(&args[3], 16).unwrap();
    println!("{:x} {:x}", mipsize(w, h, d, 3), moffset(w, h, d)); 

    let a = std::thread::spawn(|| work(0));
    let b = std::thread::spawn(|| work(1));
    let c = std::thread::spawn(|| work(2));
    let d = std::thread::spawn(|| work(3));
    d.join();
    c.join();
    b.join();
    a.join();
}

fn work(n: u32) { 
    let scale = 1<<(MIP - 1); 
    for w in (0xFFFF / 4 * n)/scale ..(0xFFFF / 4 * (n + 1))/scale {
        let w = w*scale; 
        for h in w/scale..0xFFFF/scale{
            let h = scale*h;
            for d in h/scale..0xFFFF/scale {
                let d = scale*d;
                let u = mipsize(w, h, d, MIP-1); 
                if u >= 0x388e5970 && u < 0x38900000 {
                        let v = mipsize(w, h, d, MIP);
                        if v < 0x8_0000 {
                            println!("!!!!FOUND {:x} {:x} {:x} {:x} {:x}", u, v, w, h, d);
                        }
                    }
            }
        }
        if w % 4096 == 0 { 
            println!("-- {:x}", w);
        }
    }
}

const MIP: u32 = 3;