feat(examples): 3D MVP cube via standard shader, drop basic (Étape 5)

lib/examples/cube.rs

@@ -0,0 +1,122 @@
+//! Étape 5 — MVP 3D : un cube unitaire éclairé qui tourne, rendu automatiquement par la boucle `App`.
+//!
+//! Démonstration de l'objectif MVP du ROADMAP 1.3 + 1.5 : un mesh 3D avec éclairage Phong à l'écran.
+//! On suit le workflow déclaratif (comme `simple`) : `AppBuilder` + scène automatique, **sans importer
+//! wgpu**. La seule nouveauté déclarative est l'enregistrement du shader `standard` (Phong) au lieu de
+//! `basic`. La caméra active par défaut (`Scene::default`, position (0,0,3), fov 45°) cadre le cube, et
+//! `AppHandler::update` fait tourner l'entité via `set_entity_transform` chaque frame.
+use glam::Quat;
+use std::sync::Arc;
+use wsg_lib::AppHandler;
+use wsg_lib::app::AppBuilder;
+use wsg_lib::resources::{Material, Mesh, Vertex};
+use wsg_lib::utils::WsgError;
+
+/// Handler de démonstration : fait tourner le cube dans `update`.
+struct Cube {
+    /// Angle de rotation cumulé (radians), incrémenté à chaque frame.
+    angle: f32,
+}
+
+/// Génère les sommets d'un cube unitaire centré à l'origine (arête de 1), une normale par face.
+/// 24 sommets (4 par face) + 36 indices ; la couleur est blanche, l'UV est laissé à zéro (inutilisé
+/// par `standard` pour un matériau sans texture).
+fn cube_vertices() -> Vec<Vertex> {
+    let s = 0.5; // demi-arête
+    let color = [1.0, 1.0, 1.0, 1.0];
+    // Chaque face : (normale sortante, 4 coins). Le culling est désactivé par défaut (PrimitiveState
+    // par défaut), donc l'ordre d'enroulement n'affecte pas la visibilité ; seules les normales comptent
+    // pour l'éclairage.
+    let faces: [([f32; 3], [[f32; 3]; 4]); 6] = [
+        (
+            [0.0, 0.0, 1.0],
+            [[-s, -s, s], [s, -s, s], [s, s, s], [-s, s, s]],
+        ), // +Z
+        (
+            [0.0, 0.0, -1.0],
+            [[s, -s, -s], [-s, -s, -s], [-s, s, -s], [s, s, -s]],
+        ), // -Z
+        (
+            [1.0, 0.0, 0.0],
+            [[s, -s, -s], [s, s, -s], [s, s, s], [s, -s, s]],
+        ), // +X
+        (
+            [-1.0, 0.0, 0.0],
+            [[-s, -s, s], [-s, s, s], [-s, s, -s], [-s, -s, -s]],
+        ), // -X
+        (
+            [0.0, 1.0, 0.0],
+            [[-s, s, -s], [s, s, -s], [s, s, s], [-s, s, s]],
+        ), // +Y
+        (
+            [0.0, -1.0, 0.0],
+            [[-s, -s, s], [s, -s, s], [s, -s, -s], [-s, -s, -s]],
+        ), // -Y
+    ];
+
+    let mut verts = Vec::with_capacity(24);
+    for (normal, corners) in faces {
+        for corner in corners {
+            verts.push(Vertex {
+                position: corner,
+                normal,
+                uv: [0.0, 0.0],
+                color,
+            });
+        }
+    }
+    verts
+}
+
+/// Génère les indices d'un cube à partir de ses 24 sommets (2 triangles par face, 36 indices).
+fn cube_indices() -> Vec<u16> {
+    let mut indices = Vec::with_capacity(36);
+    for face in 0..6u16 {
+        let b = face * 4;
+        indices.extend_from_slice(&[b, b + 1, b + 2, b, b + 2, b + 3]);
+    }
+    indices
+}
+
+impl AppHandler for Cube {
+    fn setup(&mut self, app: &mut wsg_lib::App) {
+        let format = app.renderer().format();
+
+        // Shader Phong `standard` (porteur des bind groups frame + object) au lieu de `basic`.
+        app.cache()
+            .register_shader("standard", wsg_lib::utils::STANDARD_SHADER_PATH)
+            .unwrap();
+
+        let mesh = Arc::new(Mesh::new(
+            app.renderer().device(),
+            &cube_vertices(),
+            Some(&cube_indices()),
+        ));
+        let material = Arc::new(Material::new(format, "standard", app.cache()));
+
+        app.scene.add_mesh("cube_mesh", mesh).unwrap();
+        app.scene.add_material("cube_material", material).unwrap();
+        app.scene
+            .add_entity("cube", "cube_mesh", "cube_material")
+            .unwrap();
+    }
+
+    fn update(&mut self, app: &mut wsg_lib::App) {
+        // Rotation cumulée du cube (double axe pour un mouvement plus lisible).
+        self.angle += 0.02;
+        let base = *app
+            .scene
+            .entity_transform("cube")
+            .expect("cube entity present");
+        let mut transform = base;
+        transform.rotation =
+            Quat::from_rotation_y(self.angle) * Quat::from_rotation_x(self.angle * 0.3);
+        app.scene.set_entity_transform("cube", transform);
+    }
+}
+
+#[pollster::main]
+async fn main() -> Result<(), WsgError> {
+    let app = AppBuilder::new().title("WSG Cube").build().await?;
+    app.run(Cube { angle: 0.0 })
+}

lib/examples/manual.rs

@@ -1,7 +1,7 @@
 //! Workflow bas-niveau : utilisation directe du `Context`, `Renderer`, `PipelineCache`, `Mesh` et
-//! `Material`, contournant la façade `App`. Rendu d'un quad plat éclairé via la boucle winit 0.30
+//! `Material`, contournant la façade `App`. Rendu d'un quad plat (shader `standard` **unlit**) via la
-//! (`EventLoop::run_app` + `ApplicationHandler`). La fenêtre et le GPU sont créés dans `resumed()`,
+//! boucle winit 0.30 (`EventLoop::run_app` + `ApplicationHandler`). La fenêtre et le GPU sont créés
-//! comme l'exigent winit 0.30 et la migration faite dans `app.rs`.
+//! dans `resumed()`, comme l'exigent winit 0.30 et la migration faite dans `app.rs`.
 use std::sync::Arc;
 use winit::application::ApplicationHandler;
 use winit::dpi::LogicalSize;
@@ -59,13 +59,16 @@ impl ApplicationHandler for App {
         let device = Arc::new(context.device.clone());
         let mut cache = PipelineCache::new(device);
         cache
-            .register_shader("basic", utils::BASIC_SHADER_PATH)
+            .register_shader("standard", utils::STANDARD_SHADER_PATH)
             .unwrap();
 
-        let renderer = Renderer::new(&context, format);
+        // Rendu 2D plat : `standard` en mode unlit (les bind groups frame+object sont posés par
+        // draw_entity, la matrice frame par défaut est l'identité → positions NDC inchangées).
+        let mut renderer = Renderer::new(&context, format);
+        renderer.set_unlit(true);
 
         // 3. Material : On utilise renderer.device() et renderer.format()
-        let material = Material::new(renderer.format(), "basic", &mut cache);
+        let material = Material::new(renderer.format(), "standard", &mut cache);
 
         // Mesh : On utilise le device du renderer
         let vertices = [

lib/examples/simple.rs

@@ -16,9 +16,11 @@ impl AppHandler for MonQuad {
     fn setup(&mut self, app: &mut wsg_lib::App) {
         let format = app.renderer().format();
 
-        // Enregistrement du shader, création du matériau et du mesh du quad (sans importer wgpu).
+        // Exemple 2D plat : le shader `standard` en mode **unlit** (options.x = 1) renvoie la couleur
+        // du vertex telle quelle. Ainsi le 2D est un cas particulier du 3D — un seul pipeline pour tous.
+        app.renderer_mut().set_unlit(true);
         app.cache()
-            .register_shader("basic", wsg_lib::utils::BASIC_SHADER_PATH)
+            .register_shader("standard", wsg_lib::utils::STANDARD_SHADER_PATH)
             .unwrap();
         let vertices = [
             Vertex {
@@ -53,12 +55,14 @@ impl AppHandler for MonQuad {
             &vertices,
             Some(&indices),
         ));
-        let material = Arc::new(Material::new(format, "basic", app.cache()));
+        let material = Arc::new(Material::new(format, "standard", app.cache()));
 
         app.scene.add_mesh("quad_mesh", mesh).unwrap();
-        app.scene.add_material("basic_material", material).unwrap();
         app.scene
-            .add_entity("quad", "quad_mesh", "basic_material")
+            .add_material("standard_material", material)
+            .unwrap();
+        app.scene
+            .add_entity("quad", "quad_mesh", "standard_material")
             .unwrap();
     }
 }

lib/src/app.rs

@@ -72,6 +72,16 @@ impl App {
             .expect("renderer not initialized yet — call app.run(handler) first")
     }
 
+    /// Returns a mutable reference to the GPU renderer.
+    /// Panics if called before `App::run` has created the renderer (i.e. before `resumed` fires).
+    /// Callers can configure the renderer here, e.g. `app.renderer_mut().set_unlit(true)` in `setup`
+    /// to select flat 2D rendering (DRAFT Étape 5).
+    pub fn renderer_mut(&mut self) -> &mut Renderer {
+        self.renderer
+            .as_mut()
+            .expect("renderer not initialized yet — call app.run(handler) first")
+    }
+
     /// Returns a reference to the GPU hardware context.
     /// Panics if called before `App::run` has created the context (i.e. before `resumed` fires).
     pub fn context(&self) -> &Context {

lib/src/core/renderer.rs

@@ -55,6 +55,10 @@ pub struct Renderer {
     /// entity label. Needed because `render_scene(&self, &Scene)` is immutable; the model matrix is
     /// rewritten each frame for every entity.
     object_cache: RefCell<HashMap<String, (wgpu::Buffer, wgpu::BindGroup)>>,
+    /// Flat (unlit) rendering flag, exposed via [`Renderer::set_unlit`]. When true, `options.x` of the
+    /// `FrameUniforms` is set to 1 so the `standard` shader returns vertex colors as-is — flat 2D
+    /// rendering is thus a special case of the 3D lit path (DRAFT Étape 5). Defaults to `false` (lit).
+    unlit: bool,
 }
 
 impl Renderer {
@@ -72,14 +76,12 @@ impl Renderer {
         // Shared frame uniforms: identity camera + white directional light, lit mode by default.
         // Values become meaningful once an active camera is wired (Étape 4.3); for now the default
         // is a coherent scene when a shader actually reads them, and irrelevant to shaders that don't.
-        let default_frame = FrameUniforms::default();
         let frame_buffer = device.create_buffer(&wgpu::BufferDescriptor {
             label: Some("frame uniform buffer"),
             size: FRAME_UNIFORMS_SIZE,
             usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
             mapped_at_creation: false,
         });
-        queue.write_buffer(&frame_buffer, 0, bytemuck::bytes_of(&default_frame));
         let frame_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
             label: Some("frame bind group"),
             layout: &frame_layout,
@@ -109,7 +111,7 @@ impl Renderer {
             }],
         });
 
-        Self {
+        let renderer = Self {
             queue,
             device,
             format,
@@ -118,7 +120,35 @@ impl Renderer {
             frame_bind_group,
             shared_object_bind_group,
             object_cache: RefCell::new(HashMap::new()),
-        }
+            unlit: false,
+        };
+        // Seed the shared frame buffer with an identity camera + current unlit flag so the low-level
+        // `render` path (which has no window/camera) sees coherent values before `render_scene` runs.
+        renderer.write_default_frame_uniforms();
+        renderer
+    }
+
+    /// Writes the shared per-frame uniform buffer using an identity camera (view = proj = identity)
+    /// and the current [`Renderer::set_unlit`] flag. This is the initial state for the low-level
+    /// `render` path, which is independent of any window and therefore has no camera or aspect ratio.
+    /// Called at construction and whenever the renderer transitions between lit and unlit mode.
+    fn write_default_frame_uniforms(&self) {
+        let frame = FrameUniforms {
+            options: [if self.unlit { 1 } else { 0 }, 0, 0, 0],
+            ..FrameUniforms::default()
+        };
+        self.queue
+            .write_buffer(&self.frame_buffer, 0, bytemuck::bytes_of(&frame));
+    }
+
+    /// Toggles flat (unlit) rendering. When true, the `standard` shader returns vertex colors as-is
+    /// (`options.x = 1`), so flat 2D rendering is a special case of the 3D lit path (DRAFT Étape 5 :
+    /// « 2D ⊂ 3D »). Rewrites the shared frame buffer immediately so the low-level `render` path picks
+    /// up the change ; the `render_scene` path reads the flag each frame in `write_frame_uniforms`.
+    /// Inputs: unlit — true for flat rendering, false (default) for Phong-lit rendering.
+    pub fn set_unlit(&mut self, unlit: bool) {
+        self.unlit = unlit;
+        self.write_default_frame_uniforms();
     }
 
     /// Rewrites the shared per-frame uniform buffer from the scene's active camera and the current
@@ -135,7 +165,7 @@ impl Renderer {
             cam_pos: camera.position.extend(1.0),
             light_dir: Vec4::new(0.0, 0.0, 1.0, 0.0),
             light_color: Vec4::ONE,
-            options: [0, 0, 0, 0],
+            options: [if self.unlit { 1 } else { 0 }, 0, 0, 0],
         };
         self.queue
             .write_buffer(&self.frame_buffer, 0, bytemuck::bytes_of(&frame));

lib/src/lib.rs

@@ -22,7 +22,7 @@
 //! ```ignore
 //! use wsg_lib::core::{Context, Renderer};
 //! use wsg_lib::resources::{Mesh, Material, Vertex};
-//! use wsg_lib::utils::BASIC_SHADER;
+//! use wsg_lib::utils::STANDARD_SHADER;
 //! ```
 
 // Warn if a public API item has no rustdoc comment, keeping API coverage at 100%.

lib/src/pipeline/README.md

@@ -6,11 +6,11 @@ The `pipeline` module contains the shader compilation cache that avoids duplicat
 
 | File | Responsibility |
 |------|---------------|
-| **pipeline_cache** | PipelineCache — maps (shader_id, format) keys to compiled RenderPipelines. Loads WGSL from disk or falls back to embedded BASIC_SHADER constant. Creates pipelines on-demand via build_pipeline(). |
+| **pipeline_cache** | PipelineCache — maps (shader_id, format) keys to compiled RenderPipelines. Loads WGSL from disk or falls back to embedded STANDARD_SHADER constant. Creates pipelines on-demand via build_pipeline(). |
 
 ## Interaction with Other Modules
 
-- **utils::conf**: Provides BASIC_SHADER_PATH (disk path) and BASIC_SHADER (embedded fallback).
+- **utils::conf**: Provides STANDARD_SHADER_PATH (disk path) and STANDARD_SHADER (embedded fallback).
 - **resources::vertex**: Vertex struct field offsets define the CPU-side layout that build_pipeline() uses as the vertex buffer contract.
 - **resources::material**: Material::new() calls get_or_create() during construction to obtain a shared RenderPipeline.
 

lib/src/pipeline/mod.rs

@@ -6,7 +6,7 @@
 //!
 //! ## Interaction with Other Modules
 //! - `material` calls `get_or_create()` during its own construction to obtain a shared RenderPipeline.
-//! - `conf::BASIC_SHADER` provides fallback WGSL source when an external file is not found.
+//! - `conf::STANDARD_SHADER` provides fallback WGSL source when an external file is not found.
 //! - `vertex::Vertex` defines the CPU-side layout that `build_pipeline()` uses as the vertex buffer contract.
 
 pub mod pipeline_cache;

lib/src/pipeline/pipeline_cache.rs

@@ -7,7 +7,7 @@
 //!
 //! ## Interaction with Other Modules
 //! - **Material** calls `get_or_create()` during its own construction to obtain a shared RenderPipeline.
-//! - **conf::BASIC_SHADER** provides fallback WGSL source when an external file is not found.
+//! - **conf::STANDARD_SHADER** provides fallback WGSL source when an external file is not found.
 //! - **vertex::Vertex** defines the CPU-side layout that `build_pipeline` uses as the vertex buffer contract.
 //!
 //! ## Technical Points
@@ -16,7 +16,7 @@
 //! - **Batching**: Multiple Materials with the same shader_id share one pipeline, enabling material-level batching in Renderer.
 
 use crate::resources::Vertex;
-use crate::utils::BASIC_SHADER;
+use crate::utils::STANDARD_SHADER;
 
 use std::collections::HashMap;
 use std::sync::Arc;
@@ -79,7 +79,7 @@ impl PipelineCache {
             device,
             pipelines: HashMap::new(),
             // Maps shader IDs to file paths on disk for WGSL loading in load_shader().
-            // When a path exists, it reads from it; otherwise falls back to BASIC_SHADER constant.
+            // When a path exists, it reads from it; otherwise falls back to STANDARD_SHADER constant.
             shader_paths: HashMap::new(),
         }
     }
@@ -139,13 +139,13 @@ impl PipelineCache {
         pipeline_arc
     }
 
-    /// Loads a WGSL shader module: reads from disk first, falls back to the embedded BASIC_SHADER constant.
+    /// Loads a WGSL shader module: reads from disk first, falls back to the embedded STANDARD_SHADER constant.
     /// Inputs: device (GPU command source for shader compilation), path (file path or shader_id string).
     /// Returns a compiled wgpu::ShaderModule. Called internally by `get_or_create()` when compiling a new pipeline.
     fn load_shader(&self, device: &wgpu::Device, path: &str) -> wgpu::ShaderModule {
         let source = std::fs::read_to_string(path).unwrap_or_else(|_| {
             println!("Shader not found: {}, falling back to default", path);
-            BASIC_SHADER.to_string()
+            STANDARD_SHADER.to_string()
         });
 
         device.create_shader_module(wgpu::ShaderModuleDescriptor {

lib/src/resources/README.md

@@ -14,4 +14,4 @@ The `resources` module defines three immutable data types that flow through the
 
 - **pipeline**: build_pipeline() reads Vertex field offsets to construct VertexBufferLayout attributes array.
 - **scene**: Scene stores Arc<Mesh> and Arc<Material> instances keyed by identifier strings.
-- **utils**: Mesh creation uses BASIC_SHADER fallback when external shader files are missing.
+- **utils**: PipelineCache uses the embedded STANDARD_SHADER fallback when external shader files are missing.

lib/src/shaders/README.md

@@ -2,39 +2,24 @@
 
 ## Overview
 
-Contains WGSL shader source files used by the PipelineCache module. These are loaded at runtime from disk when referenced by their registered ID in PipelineCache.register_shader(). If a file is missing, PipelineCache falls back to the embedded BASIC_SHADER constant defined in utils::conf.
+Contains WGSL shader source files used by the PipelineCache module. These are loaded at runtime from
+disk when referenced by their registered ID in PipelineCache.register_shader(). If a file is missing,
+PipelineCache falls back to the embedded STANDARD_SHADER constant defined in utils::conf.
+
+Depuis l'Étape 5, il n'existe plus qu'**un seul shader** : `standard_shader.wgsl` (Phong). L'ancien
+`basic_shader.wgsl` a été supprimé comme pipeline séparé — le rendu 2D plat est désormais la **variante
+unlit** de `standard` (décision actée dans le DRAFT : « 2D ⊂ 3D »).
 
 ## Files
 
 | File | Purpose |
 |------|---------|
-| **basic_shader.wgsl** | Legacy flat/unlit vertex/fragment shader pair (vs_main / fs_main) with position, uv, and color attributes. Scheduled to be replaced by the unlit variant of `standard_shader.wgsl` (DRAFT Étape 2.3 / 5). |
 | **standard_shader.wgsl** | Standard (Phong) vertex/fragment shader — ambient + directional diffuse with an explicit unlit mode. Carries the full uniform contract (frame @group(0) + object @group(1)). |
 
-## Shader Contract (basic_shader.wgsl)
-
-The WGSL shader defines:
-
-- `@vertex fn vs_main(model: VertexInput) -> VertexOutput` — vertex entry point
-- `@fragment fn fs_main(in: VertexOutput) -> @location(0) vec4<f32>` — fragment entry point writing RGBA output
-
-### Vertex Input Layout
-
-| Location | Attribute | Type | Offset (bytes) |
-|----------|-----------|------|----------------|
-| 0 | position | vec3<f32> | 0 |
-| 1 | uv | vec2<f32> | 12 |
-| 2 | color | vec3<f32> | 24 |
-
-**Note**: This shader uses a 39-byte vertex stride (3+2+3 floats). It does NOT include normal data or alpha channel interpolation — it outputs fully opaque geometry with per-vertex color passthrough. This differs from the full `Vertex` struct layout (56 bytes with normal + alpha) defined in resources::Vertex; if a full shader matching the Vertex struct is needed, extend this shader accordingly.
-
-> **Statut** : ce shader n'est plus un pipeline séparé ; il est destiné à disparaître au profit de la variante
-> unlit de `standard_shader.wgsl` (DRAFT Étape 2.3 / Étape 5, « un seul layout pour tous »).
-
 ## Shader Contract (standard_shader.wgsl)
 
-`standard_shader.wgsl` est le shader unifié (Phong) de WSG. Il corrige le défaut latente de `basic`
+`standard_shader.wgsl` est le shader unifié (Phong) de WSG. Il expose les deux bind groups partagés
-(contrat vertex incomplet) et expose les deux bind groups partagés par tout matériau.
+par tout matériau (Étape 3 : un seul layout pour tous).
 
 ### Vertex Input Layout (56-byte stride — correspond au `resources::Vertex`)
 
@@ -57,4 +42,6 @@ The WGSL shader defines:
 ### Mode unlit
 
 Un flag `options.x != 0` neutralise la directionnelle et renvoie la couleur du vertex telle quelle
-(couleur plate). Ainsi le rendu 2D plat est un **cas particulier** de la 3D éclairée.
+(couleur plate). Côté API, `Renderer::set_unlit(true)` (ou `app.renderer_mut().set_unlit(true)`)
+positionne ce flag dans les frame uniforms. Ainsi le rendu 2D plat est un **cas particulier** de la 3D
+éclairée.

lib/src/shaders/basic_shader.wgsl

@@ -1,42 +0,0 @@
-//! # Basic Shader Module
-//!
-//! Default vertex/fragment shader pair used by PipelineCache when no external .wgsl file is found.
-//! This shader implements a simple unlit rendering path: passes through position and color attributes
-//! from VertexInput to fragment output, producing flat-colored geometry without lighting calculations.
-//!
-//! ## Shader Contract
-//! Must define entry points matching PipelineCache::build_pipeline():
-//! - @vertex fn vs_main(model: VertexInput) -> VertexOutput
-//!   - model.position → @location(0), vec3<f32>, offset 0 bytes in vertex buffer
-//!   - model.uv → @location(1), vec2<f32>, offset 12 bytes in vertex buffer
-//!   - model.color → @location(2), vec3<f32>, offset 24 bytes in vertex buffer
-//! - @fragment fn fs_main(in: VertexOutput) -> @location(0) vec4<f32>
-//!   - Writes RGBA output where alpha is hardcoded to 1.0 (fully opaque).
-//!
-//! ## Technical Notes
-//! - No normal or UV interpolation — this is an unlit shader that directly outputs the per-vertex color.
-//! - The clip_position is computed as vec4<f32>(position, 1.0), assuming position is already in NDC space.
-
-struct VertexInput {
-    @location(0) position: vec3<f32>,
-    @location(1) uv: vec2<f32>,
-    @location(2) color: vec3<f32>,
-};
-
-struct VertexOutput {
-    @builtin(position) clip_position: vec4<f32>,
-    @location(0) color: vec3<f32>,
-};
-
-@vertex
-fn vs_main(model: VertexInput) -> VertexOutput {
-    var out: VertexOutput;
-    out.clip_position = vec4<f32>(model.position, 1.0);
-    out.color = model.color; // On transmet la couleur au fragment shader
-    return out;
-}
-
-@fragment
-fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
-    return vec4<f32>(in.color, 1.0);
-}

lib/src/utils/README.md

@@ -6,11 +6,11 @@ The `utils` module defines two leaf concepts that other modules consume but have
 
 | File | Responsibility |
 |------|---------------|
-| **conf** | Shared constants for shader paths (BASIC_SHADER_PATH) and embedded WGSL source code (BASIC_SHADER). Centralized here so all submodules import from one place instead of duplicating literal strings. Enables PipelineCache to fall back to an embedded default shader when the file-based one is missing. |
+| **conf** | Shared constants for shader paths (STANDARD_SHADER_PATH) and embedded WGSL source code (STANDARD_SHADER). Centralized here so all submodules import from one place instead of duplicating literal strings. Enables PipelineCache to fall back to an embedded default shader when the file-based one is missing. |
 | **error** | WsgError enum — application-level error type mapping specific wgpu failure modes to user-friendly messages via thiserror. Every variant maps a GPU initialization or rendering failure to a recoverable or fatal outcome. |
 
 ## Interaction with Other Modules
 
-- **pipeline::pipeline_cache**: load_shader() reads BASIC_SHADER_PATH from disk; falls back to BASIC_SHADER if unreadable.
+- **pipeline::pipeline_cache**: load_shader() reads STANDARD_SHADER_PATH from disk; falls back to STANDARD_SHADER if unreadable.
 - **core::context**: Returns WsgError variants from all fallible methods (new, configure, begin_frame).
 - **core::renderer**: Does not use errors directly — panics on invalid state rather than returning Result.

lib/src/utils/conf.rs

@@ -6,26 +6,19 @@
 //! Also provides application defaults for window title, width, and height used by AppBuilder.
 //!
 //! ## Interaction with Other Modules
-//! - **pipeline_cache::load_shader()** reads `BASIC_SHADER_PATH` from disk; if unreadable, falls back to `BASIC_SHADER`.
+//! - **pipeline_cache::load_shader()** reads `STANDARD_SHADER_PATH` from disk; if unreadable, falls back to `STANDARD_SHADER`.
 //! - Both constants are compile-time values (`include_str!`) ensuring the fallback shader is always available even without external files.
 //! - **app::AppBuilder** reads APP_DEFAULT_TITLE, APP_DEFAULT_WIDTH, and APP_DEFAULT_HEIGHT for default window configuration.
 
-/// Path to the default WGSL shader file on disk (runtime). Used by PipelineCache::load_shader() for file-based loading.
-pub const BASIC_SHADER_PATH: &str = "assets/shaders/basic_shader.wgsl";
-
-/// The basic WGSL shader source code, embedded at compile time via `include_str!`.
-/// Serves as a fallback when `BASIC_SHADER_PATH` cannot be read at runtime.
-pub const BASIC_SHADER: &str = include_str!("../shaders/basic_shader.wgsl");
-
 /// Path to the standard (Phong) WGSL shader file on disk (runtime). Used by PipelineCache::load_shader()
-/// once standardized (Étape 3) : this shader carries the full uniform contract (frame + object bind groups)
+/// for file-based loading. This is the unified pipeline shader (Étape 3 : un seul layout pour tous) :
-/// and supports an unlit mode so flat 2D rendering is a special case of the 3D lit path.
+/// it carries the full uniform contract (frame + object bind groups) and supports an unlit mode so flat
+/// 2D rendering is a special case of the 3D lit path. The `basic` family was removed (Étape 5).
 pub const STANDARD_SHADER_PATH: &str = "assets/shaders/standard_shader.wgsl";
 
 /// The standard (Phong) WGSL shader source code, embedded at compile time via `include_str!`.
-/// Not yet compiled by any pipeline (Étape 2 : shader seul, non branché). Becomes the unified
+/// Serves as the fallback when `STANDARD_SHADER_PATH` cannot be read at runtime. Because every
-/// pipeline shader once the uniform infrastructure exists (Étape 3). The unlit variant is the
+/// pipeline uses the unified layout (frame @0 + object @1), this is the only shader the library ships.
-/// replacement for the flat `basic` family.
 pub const STANDARD_SHADER: &str = include_str!("../shaders/standard_shader.wgsl");
 
 /// Default application title displayed in the OS taskbar/window decorations.

lib/src/utils/mod.rs

@@ -5,7 +5,7 @@
 //! Both are consumed by other modules but have no internal dependencies on them.
 //!
 //! ## Interaction with Other Modules
-//! - `pipeline_cache` loads shaders from disk using conf::BASIC_SHADER_PATH; falls back to BASIC_SHADER.
+//! - `pipeline_cache` loads shaders from disk using conf::STANDARD_SHADER_PATH; falls back to STANDARD_SHADER.
 //! - `context` returns WsgError variants from all fallible methods (new, configure, begin_frame).
 //! - `renderer` does not use errors directly (panics on invalid state rather than returning Result).
 
@@ -13,6 +13,6 @@ pub mod conf;
 pub mod error;
 
 // Re-exports
-pub use conf::BASIC_SHADER;
+pub use conf::STANDARD_SHADER;
-pub use conf::BASIC_SHADER_PATH;
+pub use conf::STANDARD_SHADER_PATH;
 pub use error::WsgError;