extern crate minifb;

use minifb::{Key, ScaleMode, Window, WindowOptions};

const WIDTH: usize = 640 / 2;
const HEIGHT: usize = 360 / 2;

fn main() {
    let mut noise;
    let mut carry;
    let mut seed = 0xbeefu32;

    let mut window = Window::new(
        "Noise Test - Press ESC to exit",
        WIDTH,
        HEIGHT,
        WindowOptions {
            resize: true,
            scale_mode: ScaleMode::UpperLeft,
            ..WindowOptions::default()
        },
    )
    .expect("Unable to create window");

    // Limit to max ~60 fps update rate
    window.limit_update_rate(Some(std::time::Duration::from_micros(16600)));

    let mut buffer: Vec<u32> = Vec::with_capacity(WIDTH * HEIGHT);

    let mut size = (0, 0);

    while window.is_open() && !window.is_key_down(Key::Escape) {
        let new_size = (window.get_size().0, window.get_size().1);
        if new_size != size {
            size = new_size;
            buffer.resize(size.0 * size.1, 0);
        }

        for i in buffer.iter_mut() {
            noise = seed;
            noise >>= 3;
            noise ^= seed;
            carry = noise & 1;
            noise >>= 1;
            seed >>= 1;
            seed |= carry << 30;
            noise &= 0xFF;
            *i = (noise << 16) | (noise << 8) | noise;
        }

        window.get_keys().map(|keys| {
            for t in keys {
                match t {
                    Key::W => println!("holding w!"),
                    Key::T => println!("holding t!"),
                    _ => (),
                }
            }
        });

        window
            .update_with_buffer(&buffer, new_size.0, new_size.1)
            .unwrap();
    }
}