Function main

examples/runners/cpu/src/main.rs:99–160

()

}

fn main() {
    const WIDTH: usize = 1280;
    const HEIGHT: usize = 720;

    let mut window = Window::new(
        "Rust GPU - CPU shader evaluation",
        WIDTH,
        HEIGHT,
        WindowOptions::default(),
    )
    .expect("Window creation failed");

    let push_constants = ShaderConstants {
        width: WIDTH as u32,
        height: HEIGHT as u32,
        time: 0f32,

        // FIXME(eddyb) implement mouse support for the cpu runner.
        cursor_x: 0.0,
        cursor_y: 0.0,
        drag_start_x: 0.0,
        drag_start_y: 0.0,
        drag_end_x: 0.0,
        drag_end_y: 0.0,
        mouse_button_pressed: 0,
        mouse_button_press_time: [f32::NEG_INFINITY; 3],
    };

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

    let start_time = Instant::now();

    let buffer = (0..WIDTH * HEIGHT)
        .into_par_iter()
        .map(|i| {
            let screen_pos = vec2(
                (i % WIDTH) as f32 / WIDTH as f32 * 2.0 - 1.0,
                -((i / WIDTH) as f32 / HEIGHT as f32 * 2.0 - 1.0),
            );

            let frag_coord = (vec2(screen_pos.x, -screen_pos.y) + Vec2::ONE) / Vec2::splat(2.0)
                * vec2(WIDTH as f32, HEIGHT as f32);

            // evaluate the fragment shader for the specific pixel
            let color = shader_module::fs(&push_constants, frag_coord, 1);

            color_u32_from_vec4(color)
        })
        .collect::<Vec<_>>();

    println!(
        "Evaluating {} pixels took {} ms",
        buffer.len(),
        start_time.elapsed().as_millis()
    );

    while window.is_open() && !window.is_key_down(Key::Escape) {