0ad/source/terrain/Bound.cpp
notpete cc2b6afdac Initial revision.
This was SVN commit r96.
2003-11-25 18:34:05 +00:00

141 lines
3.3 KiB
C++
Executable File

//-----------------------------------------------------------
//
// Name: Bound.h
// Last Update: 25/11/03
// Author: Rich Cross
// Contact: rich@0ad.wildfiregames.com
//
// Description: Basic axis aligned bounding box class
//
//-----------------------------------------------------------
// necessary includes
#include <float.h>
#include "Bound.h"
//-----------------------------------------------------------
// operator+=: extend this bound to include given bound
//-----------------------------------------------------------
CBound& CBound::operator+=(const CBound& b)
{
for (int i=0;i<3;++i) {
if (b[0][i]<m_Data[0][i])
m_Data[0][i]=b[0][i];
if (b[1][i]>m_Data[1][i])
m_Data[1][i]=b[1][i];
}
return *this;
}
//-----------------------------------------------------------
// operator+=: extend this bound to include given point
//-----------------------------------------------------------
CBound& CBound::operator+=(const CVector3D& pt)
{
for (int i=0;i<3;++i) {
if (pt[i]<m_Data[0][i])
m_Data[0][i]=pt[i];
else if (pt[i]>m_Data[1][i])
m_Data[1][i]=pt[i];
}
return *this;
}
//-----------------------------------------------------------
// RayIntersect: intersect ray with this bound; return true
// if ray hits (and store entry and exit times), or false
// otherwise
// note: incoming ray direction must be normalised
//-----------------------------------------------------------
bool CBound::RayIntersect(const CVector3D& origin,const CVector3D& dir,
float& tmin,float& tmax) const
{
float t1,t2;
float tnear,tfar;
if (dir[0]==0) {
if (origin[0]<m_Data[0][0] || origin[0]>m_Data[1][0])
return false;
else {
tnear=(float) FLT_MIN;
tfar=(float) FLT_MAX;
}
} else {
t1=(m_Data[0][0]-origin[0])/dir[0];
t2=(m_Data[1][0]-origin[0])/dir[0];
if (dir[0]<0) {
tnear = t2;
tfar = t1;
} else {
tnear = t1;
tfar = t2;
}
if (tfar<0)
return false;
}
if (dir[1]==0 && (origin[1]<m_Data[0][1] || origin[1]>m_Data[1][1]))
return false;
else {
t1=(m_Data[0][1]-origin[1])/dir[1];
t2=(m_Data[1][1]-origin[1])/dir[1];
if (dir[1]<0) {
if (t2>tnear)
tnear = t2;
if (t1<tfar)
tfar = t1;
} else {
if (t1>tnear)
tnear = t1;
if (t2<tfar)
tfar = t2;
}
if (tnear>tfar || tfar<0)
return false;
}
if (dir[2]==0 && (origin[2]<m_Data[0][2] || origin[2]>m_Data[1][2]))
return false;
else {
t1=(m_Data[0][2]-origin[2])/dir[2];
t2=(m_Data[1][2]-origin[2])/dir[2];
if (dir[2]<0) {
if (t2>tnear)
tnear = t2;
if (t1<tfar)
tfar = t1;
} else {
if (t1>tnear)
tnear = t1;
if (t2<tfar)
tfar = t2;
}
if (tnear>tfar || tfar<0)
return false;
}
tmin=tnear;
tmax=tfar;
return true;
}
//-----------------------------------------------------------
// SetEmpty: initialise this bound as empty
//-----------------------------------------------------------
void CBound::SetEmpty()
{
m_Data[0]=CVector3D(FLT_MAX,FLT_MAX,FLT_MAX);
m_Data[1]=CVector3D(FLT_MIN,FLT_MIN,FLT_MIN);
}