walls!

src/main.rs

@@ -23,9 +23,7 @@ struct Model {
     engine: PhysicsEngine,
 }
 
-fn random_vec(_app: &App) -> nalgebra::Vector2<f32> {
-    let boundary = _app.window_rect();
-
+fn random_vec_in_rect(boundary: &Rect) -> nalgebra::Vector2<f32> {
     let x = random_range(-100., 100.);
     let y = random_range(-150., boundary.top());
 
@@ -36,13 +34,15 @@ fn fill_particles(app: &App, colliders: &mut ColliderSet, bodies: &mut RigidBody
     // Keeping track of already placed balls to avoid overlap
     // Need to look into a way to do this with rapier directly
     let mut positions: Vec<nalgebra::Vector2<f32>> = Vec::new();
+    let boundary = &app.window_rect();
+
     for _ in 0..PARTICLE_COUNT {
-        let mut xy = random_vec(app);
+        let mut xy = random_vec_in_rect(boundary);
         while !positions
             .iter()
             .all(|pos| pos.metric_distance(&xy) > PARTICLE_SIZE * 2.)
         {
-            xy = random_vec(app)
+            xy = random_vec_in_rect(boundary)
         }
         positions.push(xy);
 
@@ -79,9 +79,27 @@ fn model(app: &App) -> Model {
         ..Default::default()
     };
 
+    let boundary = app.window_rect();
+
     /* Create the ground. */
-    let collider = ColliderBuilder::cuboid(100., 10.)
-        .translation(vector![0., -200.])
+    let collider = ColliderBuilder::cuboid(boundary.w(), 4.)
+        .translation(vector![0., boundary.bottom()])
+        .build();
+    engine.state.colliders.insert(collider);
+
+    /* Create the walls. */
+    let collider = ColliderBuilder::cuboid(4., boundary.h())
+        .translation(vector![boundary.left(), 0.])
+        .build();
+    engine.state.colliders.insert(collider);
+    let collider = ColliderBuilder::cuboid(4., boundary.h())
+        .translation(vector![boundary.right(), 0.])
+        .build();
+    engine.state.colliders.insert(collider);
+
+    /* Create the ceiling. */
+    let collider = ColliderBuilder::cuboid(boundary.w(), 4.)
+        .translation(vector![0., boundary.top()])
         .build();
     engine.state.colliders.insert(collider);
 
@@ -97,6 +115,8 @@ fn event(app: &App, model: &mut Model, event: WindowEvent) {
     }
 
     if let Resized(_) = event {
+        // Rust borrowing rules means I need to first gather a list of handles,
+        // then delete them all
         let handles: Vec<RigidBodyHandle> = model
             .engine
             .state