punktfunk/crates/pf-presenter/src/keymap_sdl.rs

//! SDL scancodes / mouse buttons → the punktfunk input wire contract.
//!
//! Same VK codes as `pf_client_core::keymap` (the wire carries Windows Virtual-Keys, the
//! GameStream convention), keyed on SDL scancodes instead of evdev codes: SDL normalizes
//! the platform keycode to its USB-HID-derived scancode table, so this stays
//! layout-independent exactly like the evdev table. Coverage mirrors `keymap::evdev_to_vk`
//! one-to-one — a key the wire contract doesn't cover (media keys etc.) returns `None`
//! and is dropped rather than guessed.

use sdl3::keyboard::Scancode;

/// Map an SDL scancode to the Windows VK code the host expects.
pub fn scancode_to_vk(sc: Scancode) -> Option<u8> {
    use Scancode as S;
    Some(match sc {
        // --- Navigation / editing / whitespace ---
        S::Backspace => 0x08,
        S::Tab => 0x09,
        S::Return => 0x0D,
        S::Pause => 0x13,
        S::CapsLock => 0x14,
        S::Escape => 0x1B,
        S::Space => 0x20,
        S::PageUp => 0x21,
        S::PageDown => 0x22,
        S::End => 0x23,
        S::Home => 0x24,
        S::Left => 0x25,
        S::Up => 0x26,
        S::Right => 0x27,
        S::Down => 0x28,
        S::PrintScreen => 0x2C,
        S::Insert => 0x2D,
        S::Delete => 0x2E,

        // --- Digit row ---
        S::_0 => 0x30,
        S::_1 => 0x31,
        S::_2 => 0x32,
        S::_3 => 0x33,
        S::_4 => 0x34,
        S::_5 => 0x35,
        S::_6 => 0x36,
        S::_7 => 0x37,
        S::_8 => 0x38,
        S::_9 => 0x39,

        // --- Letters ---
        S::A => 0x41,
        S::B => 0x42,
        S::C => 0x43,
        S::D => 0x44,
        S::E => 0x45,
        S::F => 0x46,
        S::G => 0x47,
        S::H => 0x48,
        S::I => 0x49,
        S::J => 0x4A,
        S::K => 0x4B,
        S::L => 0x4C,
        S::M => 0x4D,
        S::N => 0x4E,
        S::O => 0x4F,
        S::P => 0x50,
        S::Q => 0x51,
        S::R => 0x52,
        S::S => 0x53,
        S::T => 0x54,
        S::U => 0x55,
        S::V => 0x56,
        S::W => 0x57,
        S::X => 0x58,
        S::Y => 0x59,
        S::Z => 0x5A,

        // --- Meta / context-menu ---
        S::LGui => 0x5B,
        S::RGui => 0x5C,
        S::Application => 0x5D,

        // --- Numpad ---
        S::Kp0 => 0x60,
        S::Kp1 => 0x61,
        S::Kp2 => 0x62,
        S::Kp3 => 0x63,
        S::Kp4 => 0x64,
        S::Kp5 => 0x65,
        S::Kp6 => 0x66,
        S::Kp7 => 0x67,
        S::Kp8 => 0x68,
        S::Kp9 => 0x69,
        S::KpMultiply => 0x6A,
        S::KpPlus => 0x6B,
        // KP-Enter → VK_SEPARATOR mirrors the evdev table (KEY_KPENTER → 0x6C).
        S::KpEnter => 0x6C,
        S::KpMinus => 0x6D,
        S::KpPeriod => 0x6E,
        S::KpDivide => 0x6F,

        // --- Function keys ---
        S::F1 => 0x70,
        S::F2 => 0x71,
        S::F3 => 0x72,
        S::F4 => 0x73,
        S::F5 => 0x74,
        S::F6 => 0x75,
        S::F7 => 0x76,
        S::F8 => 0x77,
        S::F9 => 0x78,
        S::F10 => 0x79,
        S::F11 => 0x7A,
        S::F12 => 0x7B,

        // --- Locks ---
        S::NumLockClear => 0x90,
        S::ScrollLock => 0x91,

        // --- Left/right modifiers ---
        S::LShift => 0xA0,
        S::RShift => 0xA1,
        S::LCtrl => 0xA2,
        S::RCtrl => 0xA3,
        S::LAlt => 0xA4,
        S::RAlt => 0xA5,

        // --- OEM punctuation (US-layout positions) ---
        S::Semicolon => 0xBA,
        S::Equals => 0xBB,
        S::Comma => 0xBC,
        S::Minus => 0xBD,
        S::Period => 0xBE,
        S::Slash => 0xBF,
        S::Grave => 0xC0,
        S::LeftBracket => 0xDB,
        S::Backslash => 0xDC,
        S::RightBracket => 0xDD,
        S::Apostrophe => 0xDE,
        S::NonUsBackslash => 0xE2,

        _ => return None,
    })
}

/// SDL mouse button → the GameStream button id the wire expects (1=left, 2=middle,
/// 3=right, 4=X1, 5=X2) — the SDL twin of `keymap::gdk_button_to_gs`.
pub fn mouse_button_to_gs(b: sdl3::mouse::MouseButton) -> Option<u32> {
    use sdl3::mouse::MouseButton as B;
    Some(match b {
        B::Left => 1,
        B::Middle => 2,
        B::Right => 3,
        B::X1 => 4,
        B::X2 => 5,
        _ => return None,
    })
}

#[cfg(test)]
mod tests {
    use super::*;
    use pf_client_core::keymap::evdev_to_vk;

    /// Both tables feed the same wire: for every key the evdev table knows, the SDL
    /// scancode of the same physical key must map to the same VK.
    #[test]
    fn agrees_with_the_evdev_table() {
        use Scancode as S;
        let same_key: &[(Scancode, u16)] = &[
            (S::Backspace, 14),
            (S::Tab, 15),
            (S::Return, 28),
            (S::Escape, 1),
            (S::Space, 57),
            (S::PageUp, 104),
            (S::Left, 105),
            (S::_0, 11),
            (S::_1, 2),
            (S::_9, 10),
            (S::A, 30),
            (S::Q, 16),
            (S::Z, 44),
            (S::LGui, 125),
            (S::Kp0, 82),
            (S::Kp9, 73),
            (S::KpEnter, 96),
            (S::F1, 59),
            (S::F11, 87),
            (S::F12, 88),
            (S::NumLockClear, 69),
            (S::LShift, 42),
            (S::RAlt, 100),
            (S::Semicolon, 39),
            (S::Grave, 41),
            (S::NonUsBackslash, 86),
        ];
        for &(sc, ev) in same_key {
            assert_eq!(scancode_to_vk(sc), evdev_to_vk(ev), "scancode {sc:?}");
        }
        assert_eq!(scancode_to_vk(Scancode::Mute), None); // not in the wire contract
    }
}