use rapier3d::prelude::*;
use rapier_testbed3d::Testbed;

// This shows a bug when a cylinder is in contact with a very large
// but very thin cuboid. In this case the EPA returns an incorrect
// contact normal, resulting in the cylinder falling through the floor.
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();

    /*
     * The ground
     */
    let ground_size = 5.0;
    let ground_height = 0.1;

    let rigid_body = RigidBodyBuilder::fixed().translation(vector![0.0, -ground_height, 0.0]);
    let handle = bodies.insert(rigid_body);
    let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size);
    colliders.insert_with_parent(collider, handle, &mut bodies);

    /*
     * A rectangle that only rotates along the `x` axis.
     */
    let rigid_body = RigidBodyBuilder::dynamic()
        .translation(vector![0.0, 3.0, 0.0])
        .lock_translations()
        .enabled_rotations(true, false, false);
    let handle = bodies.insert(rigid_body);
    let collider = ColliderBuilder::cuboid(0.2, 0.6, 2.0);
    colliders.insert_with_parent(collider, handle, &mut bodies);

    /*
     * A tilted capsule that cannot rotate.
     */
    let rigid_body = RigidBodyBuilder::dynamic()
        .translation(vector![0.0, 5.0, 0.0])
        .rotation(Vector::x() * 1.0)
        .lock_rotations();
    let handle = bodies.insert(rigid_body);
    let collider = ColliderBuilder::capsule_y(0.6, 0.4);
    colliders.insert_with_parent(collider, handle, &mut bodies);
    let collider = ColliderBuilder::capsule_x(0.6, 0.4);
    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![10.0, 3.0, 0.0], point![0.0, 3.0, 0.0]);
}