chip8/src/periph.rs

#[derive(Copy, Clone)]
pub struct Display {
    pub buf: [u8; Self::SCREEN_SIZE],
}

impl Display {
    const SCREEN_SIZE: usize = 64 * 32;

    pub fn clear(&mut self) {
        self.buf = [0; Self::SCREEN_SIZE]
    }
}

impl Default for Display {
    fn default() -> Self {
        Display {
            buf: [0; Self::SCREEN_SIZE],
        }
    }
}

#[derive(Debug, Copy, Clone)]
pub struct Timer {
    remaining: u8,
    enabled: bool,
}

impl Default for Timer {
    fn default() -> Self {
        Timer {
            remaining: 0,
            enabled: false,
        }
    }
}

impl Timer {
    pub fn set(&mut self, secs: u8) {
        self.remaining = secs;
        self.enabled = true;
    }

    pub fn get(&self) -> u8 {
        self.remaining
    }

    pub fn tick(&mut self) {
        if self.enabled {
            self.remaining -= 1;

            if self.remaining == 0 {
                println!("Beep!");
                self.enabled = false;
            }
        }
    }
}

#[derive(Debug, Copy, Clone)]
pub struct Keypad {
    keys: [bool; 16],
}

impl Default for Keypad {
    fn default() -> Self {
        Self { keys: [false; 16] }
    }
}

impl Keypad {
    pub fn get_pressed(&self) -> Option<u8> {
        let mut found: Option<u8> = None;

        for (index, key) in self.keys.iter().enumerate() {
            if *key {
                found = Some(index as u8);
                break;
            }
        }

        found
    }
}