Add Loader API & clean up tests/examples to use it

Cargo.toml

@@ -44,7 +44,9 @@ workspace = true
 
 [workspace]
 resolver = "2"
-members = ["example"]
+members = [
+    "examples/kiss3d",
+]
 
 # This table is shared by projects under https://github.com/taiki-e.
 # It is not intended for manual editing.

example/Cargo.toml → examples/kiss3d/Cargo.toml

@@ -1,15 +1,15 @@
 [package]
-name = "example"
+name = "kiss3d-example"
 version = "0.0.0"
 edition = "2021"
 publish = false
 
-[dev-dependencies]
-mesh-loader = { path = ".." }
+[dependencies]
+mesh-loader = { path = "../.." }
 
 anyhow = "1"
-clap = { version = "3", features = ["derive"] }
 kiss3d = { git = "https://github.com/sebcrozet/kiss3d.git", rev = "da70cd0", features = ["vertex_index_u32"] }
+lexopt = "0.3"
 
 [lints]
 workspace = true

examples/kiss3d/src/main.rs

@@ -0,0 +1,114 @@
+use std::{
+    cell::RefCell,
+    path::{Path, PathBuf},
+    rc::Rc,
+};
+
+use anyhow::Result;
+use kiss3d::{light::Light, nalgebra as na, scene::SceneNode, window::Window};
+use lexopt::prelude::*;
+use na::{Translation3, UnitQuaternion, Vector3};
+
+const DEFAULT_SCALE: f32 = 0.1;
+
+#[derive(Debug)]
+struct Args {
+    path: PathBuf,
+    scale: f32,
+}
+
+impl Args {
+    fn parse() -> Result<Self> {
+        let mut parser = lexopt::Parser::from_env();
+        let mut path = None;
+        let mut scale = None;
+        while let Some(arg) = parser.next()? {
+            match arg {
+                Value(v) => path = Some(v.into()),
+                Long("scale") => scale = Some(parser.value()?.parse()?),
+                Short('h') | Long("help") => {
+                    path = None;
+                    break;
+                }
+                arg => return Err(arg.unexpected().into()),
+            }
+        }
+        let Some(path) = path else {
+            println!(
+                "Usage: cargo run --bin {} -- <PATH> [--scale <SCALE={DEFAULT_SCALE}>]",
+                env!("CARGO_BIN_NAME")
+            );
+            std::process::exit(1);
+        };
+        Ok(Self {
+            path,
+            scale: scale.unwrap_or(DEFAULT_SCALE),
+        })
+    }
+}
+
+fn main() -> Result<()> {
+    let args = Args::parse()?;
+    eprintln!("args={args:?}");
+    let path = &args.path;
+    let scale = Vector3::new(args.scale, args.scale, args.scale);
+
+    let mut window = Window::new(&format!("{} ー mesh-loader example", args.path.display()));
+
+    let mut base = add_mesh(&mut window, path, scale)?;
+    base.set_local_scale(args.scale, args.scale, args.scale);
+
+    base.append_translation(&Translation3::new(0.0, -0.05, -0.2));
+
+    window.set_light(Light::StickToCamera);
+
+    let rot_triangle = UnitQuaternion::from_axis_angle(&Vector3::z_axis(), 0.014);
+
+    let eye = na::Point3::new(3.0f32, 1.0, 1.0);
+    let at = na::Point3::new(0.0f32, 0.0, 0.0);
+    let mut camera = kiss3d::camera::ArcBall::new(eye, at);
+    camera.set_up_axis(na::Vector3::z());
+    camera.set_dist_step(0.5);
+    while window.render_with_camera(&mut camera) {
+        base.prepend_to_local_rotation(&rot_triangle);
+    }
+
+    Ok(())
+}
+
+fn add_mesh(window: &mut Window, path: &Path, scale: na::Vector3<f32>) -> Result<SceneNode> {
+    let loader = mesh_loader::Loader::default().merge_meshes(true);
+    let mut scene = loader.load(path)?;
+    assert_eq!(scene.meshes.len(), 1); // merge_meshes guarantees this.
+    let mesh = scene.meshes.pop().unwrap();
+    eprintln!("mesh={mesh:?}");
+    let coords = mesh.vertices.into_iter().map(Into::into).collect();
+    let faces = mesh
+        .faces
+        .into_iter()
+        .map(|f| na::Point3::new(f[0], f[1], f[2]))
+        .collect();
+    let normals = if mesh.normals.is_empty() {
+        None
+    } else {
+        Some(mesh.normals.into_iter().map(Into::into).collect())
+    };
+    let uvs = if mesh.texcoords[0].is_empty() {
+        None
+    } else {
+        Some(mesh.texcoords[0].iter().copied().map(Into::into).collect())
+    };
+    let kiss3d_mesh = Rc::new(RefCell::new(kiss3d::resource::Mesh::new(
+        coords, faces, normals, uvs, false,
+    )));
+    let kiss3d_scene = window.add_mesh(kiss3d_mesh, scale);
+    // TODO(material)
+    // if let Some(color) = material.diffuse_color() {
+    //     kiss3d_scene.set_color(color[0], color[1], color[2]);
+    // }
+    // if let Some(path) = materials.get(0) {
+    //     kiss3d_scene.set_texture_from_file(path, path.to_str().unwrap());
+    // }
+
+    Ok(kiss3d_scene)
+}

src/lib.rs

@@ -26,6 +26,8 @@ mod error;
 #[cfg(any(feature = "collada", feature = "stl"))]
 mod utils;
 
+mod loader;
+pub use loader::*;
 mod common;
 pub use common::*;