/**
 * =========================================================================
 * File        : Frustum.cpp
 * Project     : 0 A.D.
 * Description : CFrustum is a collection of planes which define
 *               a viewing space.
 * =========================================================================
 */

/*
Usually associated with the camera, there are 6 planes which define the
view pyramid. But we allow more planes per frustum which may be used for
portal rendering, where a portal may have 3 or more edges.
*/

#ifndef INCLUDED_FRUSTUM
#define INCLUDED_FRUSTUM

#include "maths/Plane.h"

//10 planes should be enough
#define MAX_NUM_FRUSTUM_PLANES		(10)

class CBound;

class CFrustum
{
public:
	CFrustum ();
	~CFrustum ();

	//Set the number of planes to use for
	//calculations. This is clipped to
	//[0,MAX_NUM_FRUSTUM_PLANES]
	void SetNumPlanes (size_t num);

	size_t GetNumPlanes() const { return m_NumPlanes; }

	//The following methods return true if the shape is
	//partially or completely in front of the frustum planes
	bool IsPointVisible (const CVector3D &point) const;
	bool DoesSegmentIntersect(const CVector3D& start, const CVector3D &end);
	bool IsSphereVisible (const CVector3D &center, float radius) const;
	bool IsBoxVisible (const CVector3D &position,const CBound &bounds) const;

	CPlane& operator[](size_t idx) { return m_aPlanes[idx]; }
	const CPlane& operator[](size_t idx) const { return m_aPlanes[idx]; }

public:
	//make the planes public for ease of use
	CPlane m_aPlanes[MAX_NUM_FRUSTUM_PLANES];

private:
	size_t m_NumPlanes;
};

#endif