feat: migrate to glam whenever relevant + migrate testbed to kiss3d instead of bevy + release v0.32.0 (#909)

* feat: migrate to glam whenever relevant + migrate testbed to kiss3d instead of bevy

* chore: update changelog

* Fix warnings and tests

* Release v0.32.0

examples3d/stress_tests/many_kinematics3.rs

@@ -0,0 +1,68 @@
+use rapier_testbed3d::Testbed;
+use rapier3d::prelude::*;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let impulse_joints = ImpulseJointSet::new();
+    let multibody_joints = MultibodyJointSet::new();
+
+    /*
+     * Create the balls
+     */
+    let num = 30;
+    let rad = 1.0;
+
+    let shift = rad * 6.0 + 1.0;
+    let centerx = shift * (num as f32) / 2.0;
+    let centery = shift * (num as f32) / 2.0;
+    let centerz = shift * (num as f32) / 2.0;
+
+    for i in 0..num {
+        for j in 0usize..num {
+            for k in 0..num {
+                let x = i as f32 * shift - centerx;
+                let y = j as f32 * shift - centery;
+                let z = k as f32 * shift - centerz;
+
+                // Build the rigid body.
+                let velocity = Vec3::new(
+                    rand::random::<f32>() - 0.5,
+                    rand::random::<f32>() - 0.5,
+                    rand::random::<f32>() - 0.5,
+                ) * 30.0;
+                let rigid_body = RigidBodyBuilder::new(RigidBodyType::KinematicVelocityBased)
+                    .translation(Vec3::new(x, y, z))
+                    .linvel(velocity);
+                let handle = bodies.insert(rigid_body);
+                let collider = ColliderBuilder::ball(rad);
+                colliders.insert_with_parent(collider, handle, &mut bodies);
+            }
+        }
+    }
+
+    testbed.add_callback(move |_, physics, _, _| {
+        for (_, rb) in physics.bodies.iter_mut() {
+            let mut linvel = rb.linvel();
+
+            for dim in 0..3 {
+                if (linvel[dim] > 0.0 && rb.translation()[dim] > (shift * num as f32) / 2.0)
+                    || (linvel[dim] < 0.0 && rb.translation()[dim] < -(shift * num as f32) / 2.0)
+                {
+                    linvel[dim] = -linvel[dim];
+                }
+            }
+
+            rb.set_linvel(linvel, false);
+        }
+    });
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
+    testbed.look_at(Vec3::new(100.0, 100.0, 100.0), Vec3::ZERO);
+}