docs: mark Étape 5 / 3D MVP reached (PLAN, ROADMAP, DRAFT, README)

README.md

@@ -2,7 +2,7 @@
 
 WSG is a Rust library that wraps [wgpu](https://github.com/gfx-rs/wgpu) and [winit](https://crates.io/crates/winit) for simple GPU drawing. It groups the five core wgpu objects (Instance, Surface, Adapter, Device, Queue) behind a single `Context`, adds small building blocks (`Mesh`, `Material`, `PipelineCache`, `Frame`), and exposes the low-level primitives for advanced users.
 
-> **Status: unstable development version.** The manual workflow below is fully working, and the high-level "declarative" workflow (automatic `App` scene rendering) works for flat/NDC drawing. The GPU-driven two-pass pipeline described in the architecture docs is **not implemented yet** — see [Status](#status) and [Roadmap](#roadmap).
+> **Status: unstable development version.** The manual workflow below is fully working, the high-level "declarative" workflow (automatic `App` scene rendering) works for flat/NDC drawing, and the **3D MVP is reached** : the `cube` example (Étape 5) renders a rotating, Phong-lit cube through `App::render_scene`. The GPU-driven two-pass pipeline described in the architecture docs is **not implemented yet** — see [Status](#status) and [Roadmap](#roadmap).
 
 ## Status
 
@@ -12,9 +12,9 @@ WSG is a Rust library that wraps [wgpu](https://github.com/gfx-rs/wgpu) and [win
 | `App` / `AppBuilder` / `AppHandler` event-loop facade | ✅ Working — window, events, frame presentation, and **automatic scene rendering** (the per-frame view is exposed via `Frame::view()`) |
 | `Scene` resource/entity registry | ✅ Working — the engine renders every registered entity automatically in one batched render pass (`App::render_scene`) |
 | GPU-driven two-pass pipeline (Compute → indirect draw) | 📋 Roadmap — spec in [docs/tech/ARCHI_CPU_GPU.md](docs/tech/ARCHI_CPU_GPU.md) |
-| 3D infrastructure (uniform bind groups, MVP + camera in the pipeline) | ✅ Working at the engine level — the `Renderer` uploads per-frame camera matrices (active `Camera`) and per-entity world matrices to shared uniform buffers every frame; the bundled `basic` shader still ignores them, so visible 3D awaits wiring `standard_shader.wgsl` to an example |
+| 3D infrastructure (uniform bind groups, MVP + camera in the pipeline) | ✅ Working — the `Renderer` uploads per-frame camera matrices (active `Camera`) and per-entity world matrices to shared uniform buffers every frame; the **MVP is reached** (Étape 5) : the `cube` example renders a rotating Phong-lit cube via the `standard` shader |
 
-Note: the bundled `basic_shader.wgsl` treats vertex positions as already in NDC space, so what you can see today is flat, untransformed drawing (e.g. a colored quad) — not a 3D scene. The Phong-lit `standard_shader.wgsl` exists and validates, and the uniform plumbing (bind groups + per-frame camera + per-entity world matrices) is in place, but it is not yet bound to a visible example.
+Note: the `standard_shader.wgsl` (Phong, with an explicit **unlit** mode) is now the **single** shader the library ships. The old `basic_shader.wgsl` was removed as a separate pipeline family (Étape 5) : flat 2D drawing is the unlit variant of `standard` (`Renderer::set_unlit(true)` or `app.renderer_mut().set_unlit(true)`, DRAFT « 2D ⊂ 3D »). See the `cube` example (3D, lit) and the `simple` example (2D, unlit).
 
 ## What it does
 
@@ -39,12 +39,14 @@ fn main() {
     let format = context.configure(&context.adapter, 800, 600).expect("surface config failed");
 
     // Renderer + shader cache (falls back to the embedded shader if the file is missing)
-    let renderer = Renderer::new(&context, format);
+    // `set_unlit(true)` selects flat 2D rendering (the quad below is drawn in NDC space, unlit).
+    let mut renderer = Renderer::new(&context, format);
+    renderer.set_unlit(true);
     let mut cache = PipelineCache::new(Arc::new(context.device.clone()));
-    cache.register_shader("basic", utils::BASIC_SHADER_PATH).unwrap();
+    cache.register_shader("standard", utils::STANDARD_SHADER_PATH).unwrap();
 
     // Material + mesh
-    let material = Material::new(renderer.format(), "basic", &mut cache);
+    let material = Material::new(renderer.format(), "standard", &mut cache);
     let vertices: [Vertex; 4] = [
         Vertex { position: [-0.5, 0.5, 0.0],  normal: [0.0, 0.0, 1.0], uv: [0.0, 0.0], color: [1.0, 0.0, 0.0, 1.0] },
         Vertex { position: [ 0.5, 0.5, 0.0],  normal: [0.0, 0.0, 1.0], uv: [1.0, 0.0], color: [0.0, 1.0, 0.0, 1.0] },
@@ -92,9 +94,10 @@ async fn main() -> Result<(), wsg_lib::utils::WsgError> {
     let app = AppBuilder::new().build().await?;
 
     // Register your scene once (string IDs), then App renders it automatically each frame:
-    //   app.cache.register_shader("basic", wsg_lib::utils::BASIC_SHADER_PATH)?;
+    //   app.renderer_mut().set_unlit(true); // select flat 2D rendering (optional)
+    //   app.cache.register_shader("standard", wsg_lib::utils::STANDARD_SHADER_PATH)?;
     //   app.scene.add_mesh("quad", Arc::new(mesh))?;
-    //   app.scene.add_material("mat", Arc::new(Material::new(app.renderer.format(), "basic", &mut app.cache)))?;
+    //   app.scene.add_material("mat", Arc::new(Material::new(app.renderer.format(), "standard", &mut app.cache)))?;
     //   app.scene.add_entity("my_quad", "quad", "mat")?;
 
     app.run(MyGame)
@@ -140,10 +143,11 @@ pollster = "0.4"   # only if you use the async AppBuilder
 | Action | Command |
 |--------|---------|
 | Build everything | `cargo build --workspace` |
+| Run the 3D MVP example | `cargo run -p wsg-lib --example cube` |
 | Run the working example | `cargo run -p wsg-lib --example manual` |
 | Check everything (incl. examples) | `cargo check --all-targets` |
 
-The `manual` example is the reference for the low-level workflow. The `simple` example (App facade) registers a colored quad and renders it automatically through the declarative path — it draws a scene without importing wgpu.
+The `manual` example is the reference for the low-level workflow. The `simple` example (App facade) registers a colored quad and renders it automatically through the declarative path — it draws a scene without importing wgpu. The `cube` example (Étape 5) demonstrates the 3D MVP: a rotating Phong-lit cube, also through the declarative path and without importing wgpu.
 
 ## Documentation
 
@@ -160,6 +164,6 @@ The architecture docs live in `docs/tech/` and are written in **French**. Each d
 1. ✅ **Scene auto-rendering** — `App::render_scene` iterates registered entities and draws them in one encoder/submit per frame; the frame view is exposed to `AppHandler::render` for custom draws. (Done 2026-09-16.)
 2. **GPU-driven two-pass pipeline** — Compute Pass (world matrices + frustum culling) filling an indirect draw buffer, single `draw_indexed_indirect` (see ARCHI_CPU_GPU).
 3. **CPU→GPU transform sync** — persistent transform buffers with ring (triple) buffering.
-4. **Real 3D pipeline** — MVP uniforms + camera support in the vertex shader. *(Engine-side plumbing done 2026-09-16: uniform bind groups, per-frame active camera matrices, per-entity world matrices; visible 3D awaits wiring `standard_shader.wgsl` to an example — Étape 5.)*
+4. ✅ **Real 3D pipeline (MVP atteint)** — MVP uniforms + camera support in the vertex shader. *(Engine plumbing done 2026-09-16 ; Étape 5, 2026-09-17 : `standard` branché sur l'exemple `cube` — un cube unitaire éclairé (Phong) qui tourne, rendu automatiquement par `App::render_scene`. Retrait de `basic` : le 2D plat = variante unlit de `standard` via `Renderer::set_unlit`.)*
 5. **Typed resource handles** — keep String IDs for the MVP (current design, source of truth in `Scene`); slotmap-based generational handles (`ARCHI_ARENES.md`) are deferred to a later performance pass.
 6. **Error unification** — replace `Result<_, String>` in `Scene`/`PipelineCache` with typed errors.