//! Draw a 3 dimensional shape using solid
//! This draws the classic csg example in the wiki on Constructive Solid Geometry
//! (https://en.wikipedia.org/wiki/Constructive_solid_geometry)
//!
//! >>> cargo run --example csg
//!
//! Writes an .stl file to target/stl/csg.stl
use crater::{
    csg::{
        algebra::CSGAlgebra,
        marching_cubes::{marching_cubes, MarchingCubesParams},
        surfaces::{IntoSurface, Surface3D},
        transformations::{RotateAbout, Translate},
    },
    utils::Parallel,
};

fn main() {
    let c_r = 1.0;
    let s_r = 2.0 * c_r;
    let b_r = 0.7 * s_r;
    let c1 = -Surface3D::Cylinder { r: c_r }.into_surface();
    let c2 = -Surface3D::Cylinder { r: c_r }
        .into_surface()
        .transform(RotateAbout(2, 0, std::f64::consts::FRAC_PI_2));
    let c3 = -Surface3D::Cylinder { r: c_r }
        .into_surface()
        .transform(RotateAbout(2, 1, std::f64::consts::FRAC_PI_2));

    let sphere = -Surface3D::Sphere { r: s_r }.into_surface();

    let box_sides = (
        Surface3D::Plane {
            normal: [1.0, 0.0, 0.0],
        }
        .into_surface()
        .transform(Translate([b_r, 0.0, 0.0])),
        Surface3D::Plane {
            normal: [1.0, 0.0, 0.0],
        }
        .into_surface()
        .transform(Translate([-b_r, 0.0, 0.0])),
        Surface3D::Plane {
            normal: [0.0, 1.0, 0.0],
        }
        .into_surface()
        .transform(Translate([0.0, b_r, 0.0])),
        Surface3D::Plane {
            normal: [0.0, 1.0, 0.0],
        }
        .into_surface()
        .transform(Translate([0.0, -b_r, 0.0])),
        Surface3D::Plane {
            normal: [0.0, 0.0, 1.0],
        }
        .into_surface()
        .transform(Translate([0.0, 0.0, b_r])),
        Surface3D::Plane {
            normal: [0.0, 0.0, 1.0],
        }
        .into_surface()
        .transform(Translate([0.0, 0.0, -b_r])),
    );

    let box_region =
        -box_sides.0 & --box_sides.1 & -box_sides.2 & --box_sides.3 & -box_sides.4 & --box_sides.5;

    let csg = (sphere & box_region) & -(c1 | c2 | c3);

    // Run marching cubes to render this shape
    let resolution = 100;
    let params = MarchingCubesParams {
        region: csg,
        bounds: (
            [-3.0 * c_r, -3.0 * c_r, -3.0 * c_r],
            [3.0 * c_r, 3.0 * c_r, 3.0 * c_r],
        ),
        resolution: (resolution, resolution, resolution),
        algebra: CSGAlgebra::default(),
    };
    let mesh = marching_cubes::<Parallel>(params);
    let mut path_buf = std::path::PathBuf::from("./target/stl/");
    path_buf.push("csg");
    path_buf.set_extension("stl");
    std::fs::create_dir_all(&path_buf.parent().expect("Failed to get parent directory"))
        .expect("Failed to create directory");
    mesh.write_stl(path_buf.to_str().unwrap())
        .expect("Failed to write csg.stl");
}