Write read

Read and write: chain STEP and BRep round-trips with progressive rotation.

//! Read and write: chain STEP and BRep round-trips with progressive rotation.

use cadrum::{DVec3, Solid};
use std::f64::consts::FRAC_PI_8;

fn main() -> Result<(), cadrum::Error> {
	let example_name = std::path::Path::new(file!()).file_stem().unwrap().to_str().unwrap();
	let step_path = format!("{example_name}.step");
	let brep_path = format!("{example_name}.brep");

	// 0. Original: read colored_box.step
	let manifest_dir = env!("CARGO_MANIFEST_DIR");
	let original = Solid::read_step(&mut std::fs::File::open(format!("{manifest_dir}/steps/colored_box.step")).expect("open file"))?;

	// 1. STEP round-trip: rotate 30° → write → read
	let a_written: Vec<Solid> = original.clone().into_iter().map(|s| s.rotate_x(FRAC_PI_8)).collect();
	Solid::write_step(&a_written, &mut std::fs::File::create(&step_path).expect("create file"))?;
	let a = Solid::read_step(&mut std::fs::File::open(&step_path).expect("open file"))?;

	// 2. BRep round-trip: rotate another 30° → write → read
	let b_written: Vec<Solid> = a.clone().into_iter().map(|s| s.rotate_x(FRAC_PI_8)).collect();
	Solid::write_brep(&b_written, &mut std::fs::File::create(&brep_path).expect("create file"))?;
	let b = Solid::read_brep(&mut std::fs::File::open(&brep_path).expect("open file"))?;

	// 3. Arrange side by side and export SVG + STL
	let [min, max] = original[0].bounding_box();
	let spacing = (max - min).length() * 1.5;
	let all: Vec<Solid> = [original, a, b].into_iter().enumerate().flat_map(|(i, solids)| solids.into_iter().map(move |s| s.translate(DVec3::X * spacing * i as f64))).collect();

	let mesh = Solid::mesh(&all, Default::default())?;
	let scene = mesh.scene(cadrum::SceneOption { view: DVec3::new(1.0, 1.0, 2.0), ..Default::default() });
	scene.write_svg(&mut std::fs::File::create(format!("{example_name}.svg")).unwrap())?;
	scene.write_png([640, 640], &mut std::fs::File::create(format!("{example_name}.png")).unwrap())?;

	mesh.write_stl(&mut std::fs::File::create(format!("{example_name}.stl")).unwrap())?;
	mesh.write_gltf_binary(&mut std::fs::File::create(format!("{example_name}.glb")).unwrap())?;

	// 4. Print summary
	let stl_path = format!("{example_name}.stl");
	for (label, path) in [("STEP", &step_path), ("BRep", &brep_path), ("STL", &stl_path)] {
		let size = std::fs::metadata(path).map(|m| m.len()).unwrap_or(0);
		println!("{label:12} {path:30} {size:>8} bytes");
	}

	Ok(())
}

Output: 02_write_read.png | 02_write_read.step | 02_write_read.glb | 02_write_read.brep | 02_write_read.stl | 02_write_read.svg