MPF image loading doesn't match disassembly

[im-apbecker]

Hi.

I've been reading through the client disassembly and making my own library for working with DA file types, network protocols, etc. I found this repo and looked to see if it could fill in any gaps I have in my own code. I noticed that your MPF file loading doesn't match up with the client disassembly method (exists at: 0x50f490):

Your code does a direct compare of the flag value with 4, but should only be checking if bit 2 is on (n & 4) != 0, as well as seeking a fixed amount forward to skip over the as-of-yet unknown data instead of sizing that dynamically as the client does. Reference code that matches the client:

impl MpfImage {
  pub fn read_from(buf: &[u8]) -> Self {
    let mut cursor = Cursor::new(buf);

    let magic = u32::read_le(&mut cursor).unwrap();

    if magic != 0xffffffff {
      cursor.seek(io::SeekFrom::Current(-4)).unwrap();
    } else {
      let some_flags = u32::read_le(&mut cursor).unwrap();

      if (some_flags & 4) != 0 {
        let some_count = u32::read_le(&mut cursor).unwrap() as usize;
        let some_count_or_4 = some_count.min(4);
        let mut unknown_16_words = [[0; 4]; 4];

        for n in 0..some_count {
          let mut buf = [0; 4];

          cursor.read_exact(&mut buf).unwrap();

          if n < some_count_or_4 {
            unknown_16_words[n][3] = buf[0];
            unknown_16_words[n][0] = buf[1];
            unknown_16_words[n][1] = buf[2];
            unknown_16_words[n][2] = 0; // should be buf[3]?
          }
        }
      }
    }

    MpfImage::read(&mut cursor).unwrap()
  }
}