/**

 * @file  octree.h

 * @brief Octree class

 *

 * This file is part of Pyrit Ray Tracer.

 *

 * Copyright 2007, 2008  Radek Brich

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#ifndef OCTREE_H

#define OCTREE_H

#include "container.h"

#include "vector.h"

#include "scene.h"

#include <assert.h>

using namespace std;

/**

 * a node of octree

 */

class OctreeNode

{

    union {

		OctreeNode *children; // pointer to first of eight children

		ShapeList *shapes;    // pointer to shape array, if this is leaf

		off_t leaf;             // leaf indicator (bit 0)

	};

public:

	OctreeNode()

	{

		shapes = new ShapeList();

		assert(sizeof(off_t)==sizeof(void*) && !isLeaf());

		setLeaf();

	};

	~OctreeNode();

	bool isLeaf() { return leaf & 1; };

	void setLeaf() { leaf = leaf | 1; };

	void makeChildren() { children = new OctreeNode[8]; assert(!isLeaf()); }; // this also cleans leaf bit

	OctreeNode *getChild(const int num) { assert(!isLeaf()); return children + num; };

	void addShape(const Shape* aShape) { getShapes()->push_back(aShape); };

	ShapeList *getShapes() { return (ShapeList*)((size_t)shapes & ~(size_t)1); };

	void setShapes(ShapeList *const ashapes) { shapes = ashapes; assert(!isLeaf()); setLeaf(); };

	void subdivide(const BBox &bbox, int maxdepth);

};

/**

 * optimized octree

 */

class Octree: public Container

{

	OctreeNode *root;

	bool built;

public:

	void addShape(const Shape* aShape) { Container::addShape(aShape); built = false; };

	const Shape *nearest_intersection(const Shape *origin_shape, const Ray &ray,

		Float &nearest_distance);

	void optimize() { build(); };

	/** build the octree

	 * this is alias of optimize() */

	void build();

	void save(ostream &str, OctreeNode *node = NULL) {};

	void load(istream &str, OctreeNode *node = NULL) {};

};

#endif