using System;
using System.Drawing;

namespace MyFramework
{
    public enum QuadTreeNodeType
    {
        Root,
        Node,
        Leaf
    }

    /// <summary>
    /// Description of QuadTreeNode.
    /// </summary>
    public class CQuadTreeNode
    {
        public int iIndex;
        public int iSize;
        public CVector3 v3Center;

        public QuadTreeNodeType Type;

        public CQuadTreeNode qtnParent;
        public CQuadTreeNode[] qtnChild;

        public Rectangle BoundingBox;

        public CQuadTreeNode(CQuadTree quadtree, CQuadTreeNode parent, CVector3 v3center, int size)
        {
            qtnParent = parent;
            if (qtnParent == null)
                Type = QuadTreeNodeType.Root;

            iSize = size;

            v3Center = v3center;

            BoundingBox = new Rectangle((int)v3Center.X - (iSize / 2),	// X
                                        (int)v3Center.Z - (iSize / 2), 	// Y
                                        iSize, 							// W
                                        iSize);							// H

            iIndex = quadtree.iNodeIndex;
            quadtree.iNodeIndex++;

            if (iSize > quadtree.iPatchSize)
            {
                Type = QuadTreeNodeType.Node;
                Subdivide(quadtree, this, iSize / 2);
            }
            else
            {
                Type = QuadTreeNodeType.Leaf;
            }
        }

        public void Subdivide(CQuadTree quadtree, CQuadTreeNode parent, int size)
        {
            qtnChild = new CQuadTreeNode[4];

            CVector3 v1 = new CVector3(v3Center.X - (size / 2), 0, v3Center.Z - (size / 2));
            CVector3 v2 = new CVector3(v3Center.X + (size / 2), 0, v3Center.Z - (size / 2));
            CVector3 v3 = new CVector3(v3Center.X - (size / 2), 0, v3Center.Z + (size / 2));
            CVector3 v4 = new CVector3(v3Center.X + (size / 2), 0, v3Center.Z + (size / 2));

            qtnChild[0] = new CQuadTreeNode(quadtree, this, v1, size);
            qtnChild[1] = new CQuadTreeNode(quadtree, this, v2, size);
            qtnChild[2] = new CQuadTreeNode(quadtree, this, v3, size);
            qtnChild[3] = new CQuadTreeNode(quadtree, this, v4, size);
        }
    }

    /// <summary>
    /// Description of QuadTree.
    /// </summary>
    public class CQuadTree
    {
        public int iSize;
        public int iPatchSize;
        public int iNodeIndex;

        CQuadTreeNode qtnRoot;

        public CQuadTree(int size, int patchsize)
        {
            iSize = size;
            iPatchSize = patchsize;
            iNodeIndex = 0;

            qtnRoot = new CQuadTreeNode(this, null, new CVector3(iSize / 2, 0, iSize / 2), size);
        }
    }
}