feat: add a few more debug demos

benchmarks2d/vertical_stacks2.rs

@@ -0,0 +1,53 @@
+use rapier2d::prelude::*;
+use rapier_testbed2d::Testbed;
+
+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();
+
+    /*
+     * Ground
+     */
+    let ground_size = 100.0;
+    let ground_thickness = 1.0;
+
+    let rigid_body = RigidBodyBuilder::fixed();
+    let ground_handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_thickness);
+    colliders.insert_with_parent(collider, ground_handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 30;
+    let rad = 0.5;
+
+    let shift = rad * 2.0;
+    let centery = shift / 2.0 + ground_thickness;
+
+    for i in 0..num {
+        for j in 0usize..1 + i * 2 {
+            let fj = j as f32;
+            let fi = i as f32;
+            let x = (fj - fi) * shift; // (shift + rad / 2.0);
+            let y = (num as f32 - fi - 1.0) * shift + centery;
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::dynamic().translation(vector![x, y]);
+            let handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::cuboid(rad, rad);
+            colliders.insert_with_parent(collider, handle, &mut bodies);
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
+    testbed.look_at(point![0.0, 2.5], 5.0);
+}