use std::f32::consts::PI;

use anyhow::Result;

use rtchallenge::{
    canvas::Canvas,
    matrices::Matrix4x4,
    tuples::{Color, Tuple},
};

fn draw_dot(c: &mut Canvas, x: usize, y: usize) {
    let red = Color::new(1., 0., 0.);
    c.set(x.saturating_sub(1), y.saturating_sub(1), red);
    c.set(x, y.saturating_sub(1), red);
    c.set(x + 1, y.saturating_sub(1), red);
    c.set(x.saturating_sub(1), y, red);
    c.set(x, y, red);
    c.set(x + 1, y, red);
    c.set(x.saturating_sub(1), y + 1, red);
    c.set(x, y + 1, red);
    c.set(x + 1, y + 1, red);
}
fn main() -> Result<()> {
    let w = 200;
    let h = w;
    let mut c = Canvas::new(w, h);
    let t = Matrix4x4::translate(0., 0.75, 0.);
    let p = Tuple::point(0., 0., 0.);
    let rot_hour = Matrix4x4::rotation_z(-PI / 6.);

    let mut p = t * p;
    let w = w as f32;
    let h = h as f32;
    let h_w = w / 2.0;
    let h_h = h / 2.0;
    for _ in 0..12 {
        let x = (h_w + h_w * p.x) as usize;
        // Y-axis is 0 at the top, and h at the bottom, flip it.
        let y = (h - (h_h + h_h * p.y)) as usize;
        draw_dot(&mut c, x, y);
        p = rot_hour * p;
    }

    let path = "/tmp/eoc4.png";
    println!("saving output to {}", path);
    c.write_to_file(path)?;
    Ok(())
}