WebAssembly based Auto Splitter for A Hat in Time written in Rust.

a_hat_in_time.rs

use asl::{ASLState, Address};
use parking_lot::Mutex;
use scroll::{Pread, LE};

#[derive(ASLState)]
#[Process = "HatinTimeGame.exe"]
#[allow(dead_code)]
struct EmptyState {}

#[derive(Debug, Default)]
struct State {
    base_address: Option<Address>,
    current: Option<GameState>,
    old: Option<GameState>,
}

impl State {
    fn update_game_state(&mut self) {
        if let Some(base) = self.base_address {
            let mut buf = [0; 68];
            asl::read_into_buf(base, &mut buf);
            let current_state: GameState = buf.pread_with(0, LE).unwrap();
            self.old = self.current.replace(current_state);
        }
    }

    fn get(&self) -> Option<(&GameState, &GameState)> {
        Some((self.current.as_ref()?, self.old.as_ref()?))
    }
}

static STATE: Mutex<State> = Mutex::new(State {
    base_address: None,
    current: None,
    old: None,
});

#[derive(Debug, Clone, Pread)]
struct GameState {
    timer_state: i32,
    unpause_time: f64,
    game_timer_is_paused: i32,
    act_timer_is_paused: i32,
    act_timer_is_visible: i32,
    unpause_time_is_dirty: i32,
    just_got_time_piece: i32,
    game_time: f64,
    act_time: f64,
    real_game_time: f64,
    real_act_time: f64,
    time_piece_count: i32,
}

#[no_mangle]
pub extern "C" fn disconnect() {
    *STATE.lock() = State::default();
}

#[no_mangle]
pub extern "C" fn update() {
    let mut state = STATE.lock();
    if state.base_address.is_none() {
        state.base_address = asl::scan_signature(
            "54 49 4D 52
?? ?? ?? ??
?? ?? ?? ?? ?? ?? ?? ??
?? ?? ?? ??
?? ?? ?? ??
?? ?? ?? ??
?? ?? ?? ??
?? ?? ?? ??
?? ?? ?? ?? ?? ?? ?? ??
?? ?? ?? ?? ?? ?? ?? ??
?? ?? ?? ?? ?? ?? ?? ??
?? ?? ?? ?? ?? ?? ?? ??
?? ?? ?? ??
45 4E 44 20",
        );

        if let Some(Address(base)) = &mut state.base_address {
            *base += 4;
            state.current = None;
            state.old = None;
            asl::set_tick_rate(60.0);
        } else {
            asl::set_tick_rate(1.0);
        }
    }
    state.update_game_state();
}

#[no_mangle]
pub extern "C" fn should_start() -> bool {
    let state = STATE.lock();
    if let Some((current, old)) = state.get() {
        current.timer_state == 1 && old.timer_state == 0
    } else {
        false
    }
}

#[no_mangle]
pub extern "C" fn should_split() -> bool {
    let state = STATE.lock();
    if let Some((current, old)) = state.get() {
        let just_got_time_piece = current.time_piece_count == old.time_piece_count + 1
            && current.act_timer_is_visible == 1;
        let is_in_credits = current.timer_state == 2;
        just_got_time_piece || is_in_credits
    } else {
        false
    }
}

#[no_mangle]
pub extern "C" fn should_reset() -> bool {
    let state = STATE.lock();
    if let Some((current, old)) = state.get() {
        current.timer_state == 0 && old.timer_state == 1
    } else {
        false
    }
}

#[no_mangle]
pub extern "C" fn is_loading() -> bool {
    true
}

#[no_mangle]
pub extern "C" fn game_time() -> f64 {
    let state = STATE.lock();
    if let Some(current) = &state.current {
        current.real_game_time
    } else {
        0.0
    }
}