/**
 * =========================================================================
 * 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 (int num);

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

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

private:
    int m_NumPlanes;
};

#endif