You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

146 lines
4.0 KiB

#ifndef GFXSYMMAT4_INCLUDED // C++
#define GFXSYMMAT4_INCLUDED
#if !defined(__GNUC__)
# pragma once
#endif
/************************************************************************
4X4 Symmetric Matrix class
$Id: symmat4.h 441 2005-05-03 18:05:36Z garland $
************************************************************************/
#include "mat4.h"
namespace gfx
{
class SymMat4
{
public:
double elt[10];
inline int index(int i, int j) const
{
// if n=dim(), and if i<=j:
// index = ( n*(n+1)/2 - (n-i)*(n-i+1)/2 ) + (j-i)
//
if (i<=j) return (10 - (4-i)*(5-i)/2 + (j-i));
else return (10 - (4-j)*(5-j)/2 + (i-j));
}
public:
// Standard constructors
//
SymMat4(double s=0.0) { *this = 0.0; }
SymMat4(const SymMat4 &m) {*this=m;}
// Descriptive interface
//
typedef double value_type;
typedef Vec4 vector_type;
typedef Mat4 inverse_type;
static int dim() { return 4; }
static int size() {return 10;}
// Access methods
//
double& operator()(int i, int j) { return elt[index(i,j)]; }
double operator()(int i, int j) const { return elt[index(i,j)]; }
inline Vec4 row(int i) const;
inline Vec4 col(int i) const;
Mat4 fullmatrix() const;
operator double*() { return elt; }
operator const double*() { return elt; }
operator const double*() const { return elt; }
// Assignment methods
//
inline SymMat4& operator=(const SymMat4& m);
inline SymMat4& operator=(double s);
inline SymMat4& operator+=(const SymMat4& m);
inline SymMat4& operator-=(const SymMat4& m);
inline SymMat4& operator*=(double s);
inline SymMat4& operator/=(double s);
static SymMat4 I();
static SymMat4 outer_product(const Vec4& v);
};
////////////////////////////////////////////////////////////////////////
//
// Method definitions
//
inline Vec4 SymMat4::row(int i) const
{ return Vec4((*this)(i,0), (*this)(i,1), (*this)(i,2), (*this)(i,3)); }
inline Vec4 SymMat4::col(int j) const
{ return Vec4((*this)(0,j), (*this)(1,j), (*this)(2,j), (*this)(3,j)); }
inline SymMat4& SymMat4::operator=(const SymMat4& m)
{ for(int i=0; i<size(); i++) elt[i] = m.elt[i]; return *this; }
inline SymMat4& SymMat4::operator=(double s)
{ for(int i=0; i<size(); i++) elt[i] = s; return *this; }
inline SymMat4& SymMat4::operator+=(const SymMat4& m)
{ for(int i=0; i<size(); i++) elt[i]+=m.elt[i]; return *this; }
inline SymMat4& SymMat4::operator-=(const SymMat4& m)
{ for(int i=0; i<size(); i++) elt[i]-=m.elt[i]; return *this; }
inline SymMat4& SymMat4::operator*=(double s)
{ for(int i=0; i<size(); i++) elt[i] *= s; return *this; }
inline SymMat4& SymMat4::operator/=(double s)
{ for(int i=0; i<size(); i++) elt[i] /= s; return *this; }
////////////////////////////////////////////////////////////////////////
//
// Operator definitions
//
inline SymMat4 operator+(SymMat4 n, const SymMat4& m) { n += m; return n; }
inline SymMat4 operator-(SymMat4 n, const SymMat4& m) { n -= m; return n; }
inline SymMat4 operator*(double s, SymMat4 m) { m*=s; return m; }
inline SymMat4 operator*(SymMat4 m, double s) { m*=s; return m; }
inline SymMat4 operator/(SymMat4 m, double s) { m/=s; return m; }
inline SymMat4 operator-(const SymMat4& m)
{
SymMat4 temp;
for(int i=0; i<m.size(); i++) temp.elt[i]= -m.elt[i];
return temp;
}
inline Vec4 operator*(const SymMat4& m, const Vec4& v)
{ return Vec4(m.row(0)*v, m.row(1)*v, m.row(2)*v, m.row(3)*v); }
extern SymMat4 operator*(const SymMat4& n, const SymMat4& m);
////////////////////////////////////////////////////////////////////////
//
// Misc. function definitions
//
inline double trace(const SymMat4& m) { return m(0,0)+m(1,1)+m(2,2)+m(3,3); }
inline SymMat4 transpose(const SymMat4& m) { return m; }
extern double invert(Mat4& m_inv, const SymMat4& m);
extern bool eigen(const SymMat4& m, Vec4& eig_vals, Vec4 eig_vecs[4]);
} // namespace gfx
// GFXSYMMAT4_INCLUDED
#endif