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/* ----------------------------------------------------------------------- *
* This file is part of GEL, http://www.imm.dtu.dk/GEL
* Copyright (C) the authors and DTU Informatics
* For license and list of authors, see ../../doc/intro.pdf
* ----------------------------------------------------------------------- */
#include "ArithSqMat4x4Float.h"
#include "Mat4x4f.h"
#include "Mat4x4d.h"
namespace CGLA {
namespace
{
/* Aux func. computes 3x3 determinants. */
template<class T>
inline T d3x3f( T a0, T a1, T a2,
T b0, T b1, T b2,
T c0, T c1, T c2 )
{
return a0*b1*c2 +
a1*b2*c0 +
a2*b0*c1 -
a2*b1*c0 -
a0*b2*c1 -
a1*b0*c2 ;
}
}
template<class V, class M>
M invert_affine(const ArithSqMat4x4Float<V,M>& this_mat)
{
// The following com[3]e has been copied from a gem in Graphics Gems II by
// Kevin Wu.
// From the EULA: "Using the code is permitted in any program, product, or
// library, non-commercial or commercial. Giving credit is not required, though is a nice gesture"
// The function is very fast, but it can only invert affine matrices. An
// exception NotAffine is thrown if the matrix is not affine, and another
// exception Singular is thrown if the matrix is singular.
typedef typename M::ScalarType ScalarType;
M new_mat;
ScalarType det_1;
ScalarType pos, neg, temp;
if (!(is_tiny(this_mat[3][0]) &&
is_tiny(this_mat[3][1]) &&
is_tiny(this_mat[3][2]) &&
is_tiny(this_mat[3][3]-1.0)))
throw(Mat4x4fNotAffine("Can only invert affine matrices"));
#define ACCUMULATE if (temp >= 0.0) pos += temp; else neg += temp
/*
* Calculate the determinant of submatrix A and determine if the
* the matrix is singular as limited by the float precision
* floating-point this_mat representation.
*/
pos = neg = 0.0;
temp = this_mat[0][0] * this_mat[1][1] * this_mat[2][2];
ACCUMULATE;
temp = this_mat[1][0] * this_mat[2][1] * this_mat[0][2];
ACCUMULATE;
temp = this_mat[2][0] * this_mat[0][1] * this_mat[1][2];
ACCUMULATE;
temp = -this_mat[2][0] * this_mat[1][1] * this_mat[0][2];
ACCUMULATE;
temp = -this_mat[1][0] * this_mat[0][1] * this_mat[2][2];
ACCUMULATE;
temp = -this_mat[0][0] * this_mat[2][1] * this_mat[1][2];
ACCUMULATE;
det_1 = pos + neg;
/* Is the submatrix A singular? */
if ((det_1 == 0.0) || (fabs(det_1 / (pos - neg)) < MINUTE))
{
/* Mat4x4f M has no inverse */
throw(Mat4x4fSingular("Tried to invert Singular matrix"));
}
else {
/* Calculate inverse(A) = adj(A) / det(A) */
det_1 = 1.0 / det_1;
new_mat[0][0] = ( this_mat[1][1] * this_mat[2][2] -
this_mat[2][1] * this_mat[1][2] )
* det_1;
new_mat[0][1] = - ( this_mat[0][1] * this_mat[2][2] -
this_mat[2][1] * this_mat[0][2] )
* det_1;
new_mat[0][2] = ( this_mat[0][1] * this_mat[1][2] -
this_mat[1][1] * this_mat[0][2] )
* det_1;
new_mat[1][0] = - ( this_mat[1][0] * this_mat[2][2] -
this_mat[2][0] * this_mat[1][2] )
* det_1;
new_mat[1][1] = ( this_mat[0][0] * this_mat[2][2] -
this_mat[2][0] * this_mat[0][2] )
* det_1;
new_mat[1][2] = - ( this_mat[0][0] * this_mat[1][2] -
this_mat[1][0] * this_mat[0][2] )
* det_1;
new_mat[2][0] = ( this_mat[1][0] * this_mat[2][1] -
this_mat[2][0] * this_mat[1][1] )
* det_1;
new_mat[2][1] = - ( this_mat[0][0] * this_mat[2][1] -
this_mat[2][0] * this_mat[0][1] )
* det_1;
new_mat[2][2] = ( this_mat[0][0] * this_mat[1][1] -
this_mat[1][0] * this_mat[0][1] )
* det_1;
/* Calculate -C * inverse(A) */
new_mat[0][3] = - ( this_mat[0][3] * new_mat[0][0] +
this_mat[1][3] * new_mat[0][1] +
this_mat[2][3] * new_mat[0][2] );
new_mat[1][3] = - ( this_mat[0][3] * new_mat[1][0] +
this_mat[1][3] * new_mat[1][1] +
this_mat[2][3] * new_mat[1][2] );
new_mat[2][3] = - ( this_mat[0][3] * new_mat[2][0] +
this_mat[1][3] * new_mat[2][1] +
this_mat[2][3] * new_mat[2][2] );
/* Fill in last column */
new_mat[3][0] = new_mat[3][1] = new_mat[3][2] = 0.0;
new_mat[3][3] = 1.0;
return new_mat;
}
#undef ACCUMULATE
}
template<class V, class M>
M adjoint(const ArithSqMat4x4Float<V,M>& in)
{
double a1, a2, a3, a4, b1, b2, b3, b4;
double c1, c2, c3, c4, d1, d2, d3, d4;
/* assign to individual variable names to aid */
/* selecting correct values */
a1 = in[0][0]; b1 = in[0][1];
c1 = in[0][2]; d1 = in[0][3];
a2 = in[1][0]; b2 = in[1][1];
c2 = in[1][2]; d2 = in[1][3];
a3 = in[2][0]; b3 = in[2][1];
c3 = in[2][2]; d3 = in[2][3];
a4 = in[3][0]; b4 = in[3][1];
c4 = in[3][2]; d4 = in[3][3];
/* row column labeling reversed since we transpose rows & columns */
M out;
out[0][0] = d3x3f( b2, b3, b4, c2, c3, c4, d2, d3, d4);
out[1][0] = - d3x3f( a2, a3, a4, c2, c3, c4, d2, d3, d4);
out[2][0] = d3x3f( a2, a3, a4, b2, b3, b4, d2, d3, d4);
out[3][0] = - d3x3f( a2, a3, a4, b2, b3, b4, c2, c3, c4);
out[0][1] = - d3x3f( b1, b3, b4, c1, c3, c4, d1, d3, d4);
out[1][1] = d3x3f( a1, a3, a4, c1, c3, c4, d1, d3, d4);
out[2][1] = - d3x3f( a1, a3, a4, b1, b3, b4, d1, d3, d4);
out[3][1] = d3x3f( a1, a3, a4, b1, b3, b4, c1, c3, c4);
out[0][2] = d3x3f( b1, b2, b4, c1, c2, c4, d1, d2, d4);
out[1][2] = - d3x3f( a1, a2, a4, c1, c2, c4, d1, d2, d4);
out[2][2] = d3x3f( a1, a2, a4, b1, b2, b4, d1, d2, d4);
out[3][2] = - d3x3f( a1, a2, a4, b1, b2, b4, c1, c2, c4);
out[0][3] = - d3x3f( b1, b2, b3, c1, c2, c3, d1, d2, d3);
out[1][3] = d3x3f( a1, a2, a3, c1, c2, c3, d1, d2, d3);
out[2][3] = - d3x3f( a1, a2, a3, b1, b2, b3, d1, d2, d3);
out[3][3] = d3x3f( a1, a2, a3, b1, b2, b3, c1, c2, c3);
return out;
}
template<class V, class M>
M invert(const ArithSqMat4x4Float<V,M>& in)
{
double det = determinant( in );
if (is_tiny(det))
throw(Mat4x4fSingular("Tried to invert Singular matrix"));
M out = adjoint(in);
out/=det;
return out;
}
template class ArithSqMat4x4Float<Vec4f, Mat4x4f>;
template Mat4x4f adjoint(const ArithSqMat4x4Float<Vec4f,Mat4x4f>&);
template Mat4x4f invert(const ArithSqMat4x4Float<Vec4f,Mat4x4f>&);
template Mat4x4f invert_affine(const ArithSqMat4x4Float<Vec4f,Mat4x4f>&);
template class ArithSqMat4x4Float<Vec4d, Mat4x4d>;
template Mat4x4d adjoint(const ArithSqMat4x4Float<Vec4d,Mat4x4d>&);
template Mat4x4d invert(const ArithSqMat4x4Float<Vec4d,Mat4x4d>&);
template Mat4x4d invert_affine(const ArithSqMat4x4Float<Vec4d,Mat4x4d>&);
}