Box2D.Collision.Broadphase.DynamicTree.RemoveLeaf C# (CSharp) Метод

        private void RemoveLeaf(int leaf)
        {
            if (leaf == m_root)
            {
                m_root = TreeNode.NULL_NODE;
                return;
            }

            int parent = m_nodes[leaf].Parent;
            int grandParent = m_nodes[parent].Parent;
            int sibling;
            if (m_nodes[parent].Child1 == leaf)
            {
                sibling = m_nodes[parent].Child2;
            }
            else
            {
                sibling = m_nodes[parent].Child1;
            }

            if (grandParent != TreeNode.NULL_NODE)
            {
                // Destroy parent and connect sibling to grandParent.
                if (m_nodes[grandParent].Child1 == parent)
                {
                    m_nodes[grandParent].Child1 = sibling;
                }
                else
                {
                    m_nodes[grandParent].Child2 = sibling;
                }
                m_nodes[sibling].Parent = grandParent;
                FreeNode(parent);

                // Adjust ancestor bounds.
                int index = grandParent;
                while (index != TreeNode.NULL_NODE)
                {
                    index = Balance(index);

                    int child1 = m_nodes[index].Child1;
                    int child2 = m_nodes[index].Child2;

                    m_nodes[index].AABB.Combine(m_nodes[child1].AABB, m_nodes[child2].AABB);
                    m_nodes[index].Height = 1 + MathUtils.Max(m_nodes[child1].Height, m_nodes[child2].Height);

                    index = m_nodes[index].Parent;
                }
            }
            else
            {
                m_root = sibling;
                m_nodes[sibling].Parent = TreeNode.NULL_NODE;
                FreeNode(parent);
            }

            // validate();
        }