/*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
**]  All rights reserved.
*
* vi:ts=4 sw=4 tw=75
*
* Distributable under the terms and conditions of the 2-clause BSD license;
* see the file COPYING for a complete text of the license.
*
**************************************************************************/

#ifndef _MOOF_ENTITY_HH_
#define _MOOF_ENTITY_HH_

/**
 * \file entity.hh
 * Interface class for cullable and drawable objects.
 */

#include <boost/shared_ptr.hpp>

#include <moof/aabb.hh>
#include <moof/cullable.hh>
#include <moof/drawable.hh>
#include <moof/sphere.hh>


namespace moof {


class frustum;


class entity;

/**
 * Entity pointer.
 */
typedef boost::shared_ptr<entity> entity_ptr;


/**
 * Interface for game objects that can be drawn to the screen and have a
 * specified volume (take up space).
 */
class entity : public cullable, public drawable
{
public:

	virtual ~entity() {}

	/**
	 * Draw the entity only if it is visible.  This method melds the
	 * cullable and drawable interfaces, and the default implementation is
	 * usually on the money.
	 * \param alpha The fraction between the last timestep and the next
	 * timestep.
	 * \param frustum The camera frustum for determining visibility.
	 */
	virtual void draw_if_visible(scalar alpha, const frustum& frustum) const
	{
		if (is_visible(frustum)) draw(alpha);
	}

	/**
	 * Get whether or not the entity is within a frustum.  The default
	 * implementation returns the visibility of the bounding sphere and
	 * box.
	 * \param frustum The camera frustum.
	 * \return True if the entity is visible, false otherwise.
	 */
	virtual bool is_visible(const frustum& frustum) const
	{
		return sphere_.is_visible(frustum) && aabb_.is_visible(frustum);
	}


	/**
	 * Get the axis-aligned bounding box surrounding the entity.
	 * \return The AABB.
	 */
	const moof::aabb<3>& aabb() const
	{
		return aabb_;
	}

	/** Get the bounding sphere surrounding the entity.
	 * \return The sphere.
	 */
	const moof::sphere<3>& sphere() const
	{
		return sphere_;
	}


protected:

	moof::aabb<3>	aabb_;
	moof::sphere<3>	sphere_;
};


} // namespace moof

#endif // _MOOF_ENTITY_HH_