172 lines
4.0 KiB
C++
Executable File
172 lines
4.0 KiB
C++
Executable File
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Name: Bound.cpp
|
|
// Author: Rich Cross
|
|
// Contact: rich@wildfiregames.com
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include "precompiled.h"
|
|
|
|
// necessary includes
|
|
#include <assert.h>
|
|
#include <float.h>
|
|
#include "Bound.h"
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// operator+=: extend this bound to include given bound
|
|
CBound& CBound::operator+=(const CBound& b)
|
|
{
|
|
#define CMPT(c) if (b[0].c < m_Data[0].c) m_Data[0].c = b[0].c; \
|
|
else if (b[1].c > m_Data[1].c) m_Data[1].c = b[1].c
|
|
CMPT(X);
|
|
CMPT(Y);
|
|
CMPT(Z);
|
|
#undef CMPT
|
|
|
|
return *this;
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// operator+=: extend this bound to include given point
|
|
CBound& CBound::operator+=(const CVector3D& pt)
|
|
{
|
|
#define CMPT(c) if (pt.c < m_Data[0].c) m_Data[0].c = pt.c; \
|
|
else if (pt.c > m_Data[1].c) m_Data[1].c = pt.c
|
|
CMPT(X);
|
|
CMPT(Y);
|
|
CMPT(Z);
|
|
#undef CMPT
|
|
|
|
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_MAX;
|
|
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_MAX,-FLT_MAX,-FLT_MAX);
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// IsEmpty: tests whether this bound is empty
|
|
bool CBound::IsEmpty()
|
|
{
|
|
return (m_Data[0].X == FLT_MAX && m_Data[0].Y == FLT_MAX && m_Data[0].Z == FLT_MAX
|
|
&& m_Data[1].X == -FLT_MAX && m_Data[1].Y == -FLT_MAX && m_Data[1].Z == -FLT_MAX);
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// Transform: transform this bound by given matrix; return transformed bound
|
|
// in 'result' parameter - slightly modified version of code in Graphic Gems
|
|
// (can't remember which one it was, though)
|
|
void CBound::Transform(const CMatrix3D& m,CBound& result) const
|
|
{
|
|
assert(this!=&result);
|
|
|
|
for (int i=0;i<3;++i) {
|
|
// handle translation
|
|
result[0][i]=result[1][i]=m(i,3);
|
|
|
|
// Now find the extreme points by considering the product of the
|
|
// min and max with each component of matrix
|
|
for(int j=0;j<3;j++) {
|
|
float a=m(j,i)*m_Data[0][j];
|
|
float b=m(j,i)*m_Data[1][j];
|
|
|
|
if (a<b) {
|
|
result[0][i]+=a;
|
|
result[1][i]+=b;
|
|
} else {
|
|
result[0][i]+=b;
|
|
result[1][i]+=a;
|
|
}
|
|
}
|
|
}
|
|
}
|