gasm_host/
keymap.rs

1//! Keyboard layouts: the same text format as the web player (`gasm-host.js`
2//! `parseKeymap`). A line per binding: `<pad 1-4> <button> <key code>...`, where key
3//! codes are W3C `KeyboardEvent.code` names (winit's `KeyCode` uses the same names).
4//! Keyboard bindings for pad N >= 2 apply while fewer than N gamepads are connected.
5
6use winit::keyboard::KeyCode;
7
8pub const DEFAULT_KEYMAP: &str = include_str!("default-keymap.txt");
9pub const BUTTONS: [&str; 12] = ["a", "b", "x", "y", "l", "r", "select", "start", "up", "down", "left", "right"];
10
11/// (key, zero-based pad, button bit)
12pub type Keymap = Vec<(KeyCode, usize, u32)>;
13
14pub fn parse(text: &str) -> Result<Keymap, String> {
15    let mut map = Vec::new();
16    let mut errors = Vec::new();
17    for (i, raw) in text.lines().enumerate() {
18        let line = raw.split('#').next().unwrap_or("").trim();
19        if line.is_empty() {
20            continue;
21        }
22        let mut parts = line.split_whitespace();
23        let (pad, button) = (parts.next(), parts.next());
24        let keys: Vec<&str> = parts.collect();
25        let pad = pad.and_then(|p| p.parse::<usize>().ok()).filter(|p| (1..=4).contains(p));
26        let bit = button.and_then(|b| BUTTONS.iter().position(|n| n.eq_ignore_ascii_case(b)));
27        let (Some(pad), Some(bit), false) = (pad, bit, keys.is_empty()) else {
28            errors.push(format!("line {}: expected \"<pad 1-4> <button> <key>...\", got {line:?}", i + 1));
29            continue;
30        };
31        for k in keys {
32            match key_from_code(normalize(k)) {
33                Some(KeyCode::Escape) => errors.push(format!("line {}: Escape is reserved (quit)", i + 1)),
34                Some(code) => map.push((code, pad - 1, 1u32 << bit)),
35                None => errors.push(format!("line {}: unknown key code {k:?}", i + 1)),
36            }
37        }
38    }
39    if errors.is_empty() { Ok(map) } else { Err(errors.join("\n")) }
40}
41
42/// Pads from held keys; keyboard pad N (zero-based n >= 1) only while `gamepads <= n`.
43pub fn pads(map: &Keymap, held: &std::collections::HashSet<KeyCode>, gamepads: usize) -> [u32; 4] {
44    let mut pads = [0u32; 4];
45    for (key, pad, bit) in map {
46        if held.contains(key) && (*pad == 0 || gamepads <= *pad) {
47            pads[*pad] |= bit;
48        }
49    }
50    pads
51}
52
53macro_rules! codes {
54    ($($name:ident),* $(,)?) => {
55        /// W3C KeyboardEvent.code name -> winit KeyCode.
56        pub fn key_from_code(s: &str) -> Option<KeyCode> {
57            match s { $(stringify!($name) => Some(KeyCode::$name),)* _ => None }
58        }
59    };
60}
61
62codes!(
63    KeyA, KeyB, KeyC, KeyD, KeyE, KeyF, KeyG, KeyH, KeyI, KeyJ, KeyK, KeyL, KeyM,
64    KeyN, KeyO, KeyP, KeyQ, KeyR, KeyS, KeyT, KeyU, KeyV, KeyW, KeyX, KeyY, KeyZ,
65    Digit0, Digit1, Digit2, Digit3, Digit4, Digit5, Digit6, Digit7, Digit8, Digit9,
66    ArrowUp, ArrowDown, ArrowLeft, ArrowRight,
67    Numpad0, Numpad1, Numpad2, Numpad3, Numpad4, Numpad5, Numpad6, Numpad7, Numpad8, Numpad9,
68    NumpadAdd, NumpadSubtract, NumpadMultiply, NumpadDivide, NumpadDecimal, NumpadEnter, NumpadEqual, NumpadComma,
69    F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12,
70    Space, Enter, Tab, Backspace, Escape, CapsLock,
71    ShiftLeft, ShiftRight, ControlLeft, ControlRight, AltLeft, AltRight, SuperLeft, SuperRight,
72    Comma, Period, Slash, Semicolon, Quote, BracketLeft, BracketRight, Backslash, Minus, Equal, Backquote, IntlBackslash,
73    Insert, Delete, Home, End, PageUp, PageDown,
74);
75
76/// Browser names for keys whose winit name differs.
77pub fn normalize(s: &str) -> &str {
78    match s { "MetaLeft" | "OSLeft" => "SuperLeft", "MetaRight" | "OSRight" => "SuperRight", other => other }
79}
80
81#[cfg(test)]
82mod tests {
83    use super::*;
84    use std::collections::HashSet;
85
86    #[test]
87    fn default_keymap_parses_and_two_players_share_a_keyboard() {
88        let map = parse(DEFAULT_KEYMAP).unwrap();
89        let held: HashSet<_> = [KeyCode::KeyX, KeyCode::KeyL, KeyCode::ControlRight].into();
90        let p = pads(&map, &held, 0);
91        assert_eq!(p[0], 1 << 0); // X = A on pad 1
92        assert_eq!(p[1], (1 << 11) | (1 << 7)); // L = right, RCtrl = start on pad 2
93        assert_eq!(pads(&map, &held, 2)[1], 0); // two gamepads: keyboard player 2 off
94        assert!(parse("1 jump KeyX").is_err());
95        assert!(parse("5 a KeyX").is_err());
96        assert!(parse("1 a Escape").is_err());
97    }
98}
gasm_host/keymap.rs

gasm_host/
keymap.rs
