forked from 0ad/0ad
84 lines
2.5 KiB
C++
84 lines
2.5 KiB
C++
/* Copyright (C) 2009 Wildfire Games.
|
|
* This file is part of 0 A.D.
|
|
*
|
|
* 0 A.D. is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* 0 A.D. 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
/*
|
|
* A Plane in R3 and several utility methods.
|
|
*/
|
|
|
|
// Note that the format used for the plane equation is
|
|
// Ax + By + Cz + D = 0, where <A,B,C> is the normal vector.
|
|
|
|
#ifndef INCLUDED_PLANE
|
|
#define INCLUDED_PLANE
|
|
|
|
#include "Vector3D.h"
|
|
#include "Vector4D.h"
|
|
|
|
enum PLANESIDE
|
|
{
|
|
PS_FRONT,
|
|
PS_BACK,
|
|
PS_ON
|
|
};
|
|
|
|
class CPlane
|
|
{
|
|
public:
|
|
CPlane();
|
|
CPlane(const CVector4D& coeffs) : m_Norm(coeffs.X, coeffs.Y, coeffs.Z), m_Dist(coeffs.W) { }
|
|
|
|
//sets the plane equation from 3 points on that plane
|
|
void Set(const CVector3D& p1, const CVector3D& p2, const CVector3D& p3);
|
|
|
|
//sets the plane equation from a normal and a point on
|
|
//that plane
|
|
void Set(const CVector3D& norm, const CVector3D& point);
|
|
|
|
//normalizes the plane equation
|
|
void Normalize();
|
|
|
|
//returns the side of the plane on which this point lies
|
|
PLANESIDE ClassifyPoint(const CVector3D& point) const;
|
|
//returns true if this point is on the back side
|
|
inline bool IsPointOnBackSide(const CVector3D& point) const;
|
|
|
|
//solves the plane equation for a particular point
|
|
inline float DistanceToPlane(const CVector3D& point) const;
|
|
|
|
//calculates the intersection point of a line with this
|
|
//plane. Returns false if there is no intersection
|
|
bool FindLineSegIntersection(const CVector3D& start, const CVector3D& end, CVector3D* intsect) const;
|
|
bool FindRayIntersection(const CVector3D& start, const CVector3D& direction, CVector3D* intsect) const;
|
|
|
|
public:
|
|
CVector3D m_Norm; //normal vector of the plane
|
|
float m_Dist; //Plane distance (ie D in the plane eq.)
|
|
static const float m_EPS;
|
|
};
|
|
|
|
float CPlane::DistanceToPlane(const CVector3D& point) const
|
|
{
|
|
return m_Norm.X * point.X + m_Norm.Y * point.Y + m_Norm.Z * point.Z + m_Dist;
|
|
}
|
|
|
|
bool CPlane::IsPointOnBackSide(const CVector3D& point) const
|
|
{
|
|
return DistanceToPlane(point) < -m_EPS;
|
|
}
|
|
|
|
#endif
|