maclarian 0.1.3

Larian file format library for Baldur's Gate 3 - PAK, LSF, LSX, GR2, DDS, and more
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35

//! Utility functions for glTF → GR2 conversion.
//!
//! Re-exports shared utilities from the parent module, plus GR2-specific functions.

pub(crate) use crate::converter::gr2_gltf::shared::{encode_qtangent, f32_to_half};

/// Calculate CRC32 checksum (GR2 uses standard CRC-32)
#[must_use]
pub fn crc32(data: &[u8]) -> u32 {
    const TABLE: [u32; 256] = {
        let mut table = [0u32; 256];
        let mut i = 0u32;
        while i < 256 {
            let mut crc = i;
            let mut j = 0;
            while j < 8 {
                if crc & 1 != 0 {
                    crc = (crc >> 1) ^ 0xEDB88320;
                } else {
                    crc >>= 1;
                }
                j += 1;
            }
            table[i as usize] = crc;
            i += 1;
        }
        table
    };

    let mut crc = 0xFFFFFFFFu32;
    for &byte in data {
        crc = TABLE[((crc ^ u32::from(byte)) & 0xFF) as usize] ^ (crc >> 8);
    }
    !crc
}