/******************************************************************************
 * Copyright (C) Ultraleap, Inc. 2011-2021.                                   *
 *                                                                            *
 * Use subject to the terms of the Apache License 2.0 available at            *
 * http://www.apache.org/licenses/LICENSE-2.0, or another agreement           *
 * between Ultraleap and you, your company or other organization.             *
 ******************************************************************************/

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace Leap.Unity.Examples
{

    /// <summary>
    /// This utility script scans through its Transform's children and tells PhysX to
    /// ignore collisions between all pairs of Colliders it finds. This is particlarly
    /// useful, for example, for interfaces, where buttons shouldn't collide with other
    /// buttons.
    /// 
    /// This is not the recommended strategy in general: It is much more optimal for your
    /// application to put interface objects on a layer and disable self-collision for that
    /// layer in your Physics settings (Edit / Project Settings / Physics).
    /// </summary>
    public class IgnoreCollisionsInChildren : MonoBehaviour
    {

        void Start()
        {
            IgnoreCollisionsInChildrenOf(this.transform);
        }

        public static void IgnoreCollisionsInChildrenOf(Transform t, bool ignore = true)
        {
            var colliders = Pool<List<Collider>>.Spawn();
            try
            {
                t.GetComponentsInChildren<Collider>(true, colliders);

                for (int i = 0; i < colliders.Count; i++)
                {
                    for (int j = 0; j < colliders.Count; j++)
                    {
                        if (i == j) continue;

                        Physics.IgnoreCollision(colliders[i], colliders[j], ignore);
                    }
                }
            }
            finally
            {
                colliders.Clear();
                Pool<List<Collider>>.Recycle(colliders);
            }
        }

    }

}