refactor examples

lib/examples/demo.rs

@@ -20,6 +20,10 @@
 //!     `AppBuilder::with_hdr(ToneMapper::Aces)`. The main pass renders to an offscreen
 //!     `Rgba16Float` texture, then a fullscreen TM pass compresses it to [0,1] and writes
 //!     to the sRGB surface — highlights are softly rolled off instead of clipping to white.
+//!   * **Exposure** (Étape 22, 6.1): keys `+` / `-` adjust the tone mapping exposure live
+//!     (×1.3 / ÷1.3 per press), `0` resets to 1.0.
+//!   * **Emissive** (Étape 22, 6.2): a small glowing orange sphere sits at the center
+//!     (emissive intensity 2.0 → HDR glow, visible even in shadow).
 //!
 //! Doc (this header) follows the English convention used for examples; internal comments stay
 //! concise and French where helpful. Run with:
@@ -31,10 +35,12 @@ use winit::event::MouseButton;
 use winit::keyboard::KeyCode;
 use wsg_lib::AppHandler;
 use wsg_lib::app::AppBuilder;
+use wsg_lib::core::BloomConfig;
 use wsg_lib::core::ToneMapper;
 use wsg_lib::core::Transform;
 use wsg_lib::mesh::{cone, cube, cylinder, icosphere, plane, torus, uv_sphere};
-use wsg_lib::resources::{CameraController, Texture};
+use wsg_lib::camera::CameraController;
+use wsg_lib::resources::Texture;
 use wsg_lib::utils::WsgError;
 
 /// Generates an 8×8 RGBA checkerboard (white / brick) as raw bytes for `Texture::from_rgba8`.
@@ -169,6 +175,24 @@ impl AppHandler for Demo {
         place("cone_e", "cone_mesh", app, 4);
         place("torus_e", "torus_mesh", app, 5);
 
+        // 4b. Étape 22 (6.2): emissive demo — a small glowing sphere at the center.
+        //     The material has emissive = [1.0, 0.3, 0.05, 2.0] (orange, intensity 2.0 = HDR glow).
+        //     IMPORTANT: set emissive BEFORE create_mesh (the mesh captures the Arc at creation).
+        app.scene
+            .add_material_texture("glow_mat", "standard", "checker_texture")
+            .unwrap();
+        app.scene
+            .set_material_emissive("glow_mat", [1.0, 0.3, 0.05, 2.0])
+            .unwrap();
+        app.scene
+            .create_mesh("glow_mesh", icosphere(0.3, 3), Some("glow_mat"))
+            .unwrap();
+        let mut glow_tf = Transform::identity();
+        glow_tf.translation = Vec3::new(0.0, 0.5, 0.0);
+        app.scene
+            .add_entity_with_transform("glow_e", "glow_mesh", glow_tf)
+            .unwrap();
+
         // 5. Lights: a shadow-casting directional + a warm point + a green spot.
         //    Start from the default list (directional +Z) so we keep it and add the rest.
         let toward_light = Vec3::new(1.0, 1.2, 1.0).normalize();
@@ -239,6 +263,18 @@ impl AppHandler for Demo {
         }
         self.camera.apply_to(app.scene.camera_mut());
 
+        // ---- Étape 22 (6.1): exposure control ----
+        // `+` / `-`: multiply/divide by 1.3 (visible step). `0`: reset to 1.0.
+        if app.input.key_pressed(KeyCode::Equal) {
+            app.set_exposure(app.exposure() * 1.3);
+        }
+        if app.input.key_pressed(KeyCode::Minus) {
+            app.set_exposure(app.exposure() / 1.3);
+        }
+        if app.input.key_pressed(KeyCode::Digit0) {
+            app.set_exposure(1.0);
+        }
+
         // ---- Slow rotation of the primitives so lighting/shadow read clearly ----
         self.angle += 0.008;
         let base = *app
@@ -281,6 +317,7 @@ async fn main() -> Result<(), WsgError> {
         .title("WSG Demo")
         .with_culling(true)
         .with_hdr(ToneMapper::Aces)
+        .with_bloom(BloomConfig::default())
         .build()
         .await?;
     app.run(Demo {