fix snapshots in 2d examples (#875)

src_testbed/testbed.rs

@@ -1248,21 +1248,17 @@ fn update_testbed(
             state
                 .action_flags
                 .set(TestbedActionFlags::TAKE_SNAPSHOT, false);
-            // FIXME
-            println!(
-                "!!!!!!!!! Snapshots are not working any more. Requires broad-phase serialization."
-            );
-            // state.snapshot = PhysicsSnapshot::new(
-            //     harness.state.timestep_id,
-            //     &*harness.physics.broad_phase,
-            //     &harness.physics.narrow_phase,
-            //     &harness.physics.islands,
-            //     &harness.physics.bodies,
-            //     &harness.physics.colliders,
-            //     &harness.physics.impulse_joints,
-            //     &harness.physics.multibody_joints,
-            // )
-            // .ok();
+            state.snapshot = PhysicsSnapshot::new(
+                harness.state.timestep_id,
+                &harness.physics.broad_phase,
+                &harness.physics.narrow_phase,
+                &harness.physics.islands,
+                &harness.physics.bodies,
+                &harness.physics.colliders,
+                &harness.physics.impulse_joints,
+                &harness.physics.multibody_joints,
+            )
+            .ok();
 
             if let Some(snap) = &state.snapshot {
                 snap.print_snapshot_len();

src_testbed/ui.rs

@@ -411,7 +411,7 @@ Hashes at frame: {}
         serialization_time.as_secs_f64() * 1000.0,
         timestep_id,
         bf.len() as f32 / 1000.0,
-        format!("{:?}", hash_bf).split_at(10).0,
+        format!("{hash_bf:?}").split_at(10).0,
         nf.len() as f32 / 1000.0,
         format!("{hash_nf:?}").split_at(10).0,
         bs.len() as f32 / 1000.0,