polytrack_codes/v4/
mod.rs

1#![allow(clippy::cast_possible_truncation)]
2#[cfg(test)]
3mod tests;
4
5use crate::tools::{self, Track, hash_vec};
6
7pub const CP_IDS: [u8; 4] = [52, 65, 75, 77];
8
9#[derive(Debug, PartialEq, Eq)]
10pub struct TrackInfo {
11    pub parts: Vec<Part>,
12}
13
14#[derive(Debug, PartialEq, Eq)]
15pub struct Part {
16    pub id: u8,
17    pub amount: u32,
18    pub blocks: Vec<Block>,
19}
20
21#[derive(Debug, PartialEq, Eq)]
22pub struct Block {
23    pub x: i32,
24    pub y: i32,
25    pub z: i32,
26
27    pub rotation: u8,
28    pub cp_order: Option<u16>,
29}
30
31#[must_use]
32pub fn decode_track_code(track_code: &str) -> Option<Track> {
33    let track_code = track_code.get(2..)?;
34    let metadata = tools::decode(track_code.get(..2)?)?;
35    let name_len = *metadata.first()? as usize;
36    let track_name_raw = tools::decode(track_code.get(2..2 + name_len)?)?;
37    let name = String::from_utf8(track_name_raw).ok()?;
38    let track_data = tools::decompress(&tools::decode(track_code.get(2 + name_len..)?)?)?;
39    Some(Track {
40        name,
41        author: None,
42        track_data,
43    })
44}
45
46#[must_use]
47pub fn decode_track_data(data: &[u8]) -> Option<TrackInfo> {
48    #[inline]
49    fn read_u8(buf: &[u8], offset: &mut usize) -> Option<u8> {
50        let res = buf.get(*offset).copied();
51        *offset += 1;
52        res
53    }
54    #[inline]
55    fn read_u16(buf: &[u8], offset: &mut usize) -> Option<u16> {
56        let res = Some(u16::from(*buf.get(*offset)?) | (u16::from(*buf.get(*offset + 1)?) << 8));
57        *offset += 2;
58        res
59    }
60    #[inline]
61    fn read_u32(buf: &[u8], offset: &mut usize) -> Option<u32> {
62        let res = Some(
63            u32::from(*buf.get(*offset)?)
64                | (u32::from(*buf.get(*offset + 1)?) << 8)
65                | (u32::from(*buf.get(*offset + 2)?) << 16)
66                | (u32::from(*buf.get(*offset + 3)?) << 24),
67        );
68        *offset += 4;
69        res
70    }
71    #[inline]
72    fn read_i24(buf: &[u8], offset: &mut usize) -> Option<i32> {
73        let res = Some(
74            i32::from(*buf.get(*offset)?)
75                | (i32::from(*buf.get(*offset + 1)?) << 8)
76                | (i32::from(*buf.get(*offset + 2)?) << 16),
77        );
78        *offset += 3;
79        res
80    }
81
82    let mut offset = 0;
83    let mut parts = Vec::new();
84    while offset < data.len() {
85        let id = read_u16(data, &mut offset)? as u8;
86        let amount = read_u32(data, &mut offset)?;
87
88        let mut blocks = Vec::new();
89        for _ in 0..amount {
90            let x = read_i24(data, &mut offset)? - i32::pow(2, 23);
91            let y = read_i24(data, &mut offset)?;
92            let z = read_i24(data, &mut offset)? - i32::pow(2, 23);
93
94            let rotation = read_u8(data, &mut offset)? & 3;
95
96            let cp_order = if CP_IDS.contains(&id) {
97                Some(read_u16(data, &mut offset)?)
98            } else {
99                None
100            };
101            blocks.push(Block {
102                x,
103                y,
104                z,
105                rotation,
106                cp_order,
107            });
108        }
109        parts.push(Part { id, amount, blocks });
110    }
111
112    Some(TrackInfo { parts })
113}
114
115#[must_use]
116pub fn export_to_id(track_code: &str) -> Option<String> {
117    let track_data = decode_track_code(track_code)?;
118    let id = hash_vec(track_data.track_data);
119    Some(id)
120}
polytrack_codes/v4/mod.rs

polytrack_codes/v4/
mod.rs
