primitive meshes

lib/src/mesh/mod.rs

@@ -0,0 +1,58 @@
+//! # Mesh module — geometry sources for WSG
+//!
+//! This module is the single entry point for **where geometry data comes from**:
+//!
+//! - **`primitives`** — procedural generators (cube, sphere, torus, …), each behind a
+//!   feature flag so you only compile what you need.
+//! - **`import`** — file loaders (OBJ, glTF), each behind a feature flag.
+//!
+//! All sources produce a [`Geometry`] (CPU-side vertex data: positions, normals, UVs,
+//! indices). Turning that into a GPU renderable is the job of [`crate::scene::Scene::add_mesh`].
+//!
+//! ## Usage
+//!
+//! ```rust
+//! use wsg_lib::mesh::cube;
+//!
+//! // Procedural (feature "prim-cube")
+//! let geom = cube(2.0);
+//! assert_eq!(geom.positions.len(), 24);
+//! ```
+//!
+//! ## Features
+//!
+//! | Feature | Provides |
+//! |---------|----------|
+//! | `prim-cube` | `cube(size)` |
+//! | `prim-sphere` | `uv_sphere(…)`, `icosphere(…)` |
+//! | `prim-cylinder` | `cylinder(…)` |
+//! | `prim-cone` | `cone(…)` |
+//! | `prim-torus` | `torus(…)` |
+//! | `prim-plane` | `plane(…)` |
+//! | `all-prims` | all of the above |
+//! | `import-obj` | `load_obj(path)` |
+//! | `import-gltf` | `load_gltf(path)` |
+
+pub mod primitives;
+
+#[cfg(feature = "import-obj")]
+pub mod import;
+
+// Flat re-exports at the `wsg::mesh` level for convenience.
+#[cfg(feature = "prim-cube")]
+pub use primitives::cube;
+#[cfg(feature = "prim-plane")]
+pub use primitives::plane;
+#[cfg(feature = "prim-sphere")]
+pub use primitives::{icosphere, uv_sphere};
+#[cfg(feature = "prim-cylinder")]
+pub use primitives::cylinder;
+#[cfg(feature = "prim-cone")]
+pub use primitives::cone;
+#[cfg(feature = "prim-torus")]
+pub use primitives::torus;
+
+#[cfg(feature = "import-obj")]
+pub use import::load_obj;
+#[cfg(feature = "import-gltf")]
+pub use import::load_gltf;