khanat-opennel-code/code/nel/include/nel/3d/frustum.h

109 lines
3.6 KiB
C++

// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010 Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#ifndef NL_FRUSTUM_H
#define NL_FRUSTUM_H
#include "nel/misc/types_nl.h"
#include "nel/misc/vector.h"
namespace NL3D
{
using NLMISC::CVector;
// ***************************************************************************
/**
* A Screen frustum, perspective or orthogonal. No default ctor. Useful for camera.
* \author Lionel Berenguier
* \author Nevrax France
* \date 2000
*/
class CFrustum
{
public:
/// NB: znear and zfar must be >0 (if perspective).
float Left, Right, Bottom, Top, Near, Far;
bool Perspective;
/// Un-initialized frustum.
CFrustum()
{
}
/// ctor.
CFrustum(float left, float right, float bottom, float top, float znear, float zfar, bool perspective= true)
{
init( left, right, bottom, top, znear, zfar, perspective);
}
/// Init a frustum.
void init(float left, float right, float bottom, float top, float znear, float zfar, bool perspective= true);
/// Init a centered frustum.
void init(float width, float height, float znear, float zfar, bool perspective= true);
/** Setup a perspective frustum, giving a fov in radians.
* \param fov the horizontal angle of view, in radians. (Pi/2 as example)
* \param aspectRatio the ratio horizontal/vertical (1.33 as example).
* \param znear the front clipping plane distance.
* \param zfar the back clipping plane distance.
*/
void initPerspective(float fov, float aspectRatio, float znear, float zfar);
/// Get the value of the frustum.
void getValues(float &left, float &right, float &bottom, float &top, float &znear, float &zfar) const;
/** project a vector (x,y,z) onto frustum.
* \param vec the point in 3D frustum space. Axis is NL3D axis: Xright, Yfront, Ztop.
* \return the point in 2D: Xright, Ytop, Z=0. Screen is mapped to X:[0..1], Y: [0..1].
*/
CVector project(const CVector &vec) const;
/** project a vector (x,y,z) onto frustum.
* \param vec the point in 3D frustum space. Axis is NL3D axis: Xright, Yfront, Ztop.
* \return the point in 2D: Xright, Ytop, Z=0. Screen is mapped to X:[0..1], Y: [0..1] Z is a positive screen depth in world units.
*/
CVector projectZ(const CVector &vec) const;
/** unproject a point from screen to the frustum space.
* \param vec the point on the screen, in Left hand axis (XRight, YTop, ZFront). Z must be in [0..1] and hyperbolic.
* \return the point in the frustum space (NL3D right hand axis).
*/
CVector unProject(const CVector &vec) const;
/** unproject a point from screen to the frustum space.
* \param vec the point on the screen, in Left hand axis (XRight, YTop, ZFront). Z is a positive depth in world unit.
* \return the point in the frustum space (NL3D right hand axis).
*/
CVector unProjectZ(const CVector &vec) const;
/** return the aspect ration of this frustum. this is simply (Right-Left)/(Top-Bottom)
*/
float getAspectRatio() const;
};
} // NL3D
#endif // NL_FRUSTUM_H
/* End of frustum.h */