Subversion Repositories gelsvn

/* ----------------------------------------------------------------------- *
 * 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 "ArithSqMat3x3Float.h"
#include "Mat3x3f.h"
#include "Mat3x3d.h"

namespace CGLA {

        template<class V, class M>
        M invert(const ArithSqMat3x3Float<V,M>& _a)
        {
    // Based on Cramer's rule (Akenine-Möller et al. 2008, Section A.3.1) and
    // Cedrick Collomb. A tutorial on inverting 3 by 3 matrices with cross products.
    // http://www.emptyloop.com/technotes/

    M a = transpose(_a);
    V a1a2 = cross(a[1], a[2]);
    float det = dot(a[0], a1a2);
    if(fabs(det) < TINYf)
      throw(Mat3x3fSingular("Tried to invert singular matrix"));
    return M(a1a2, cross(a[2], a[0]), cross(a[0], a[1]))*(1.0f/det);
        }                                                                               
        template class ArithSqMat3x3Float<Vec3f,Mat3x3f>;
        template Mat3x3f invert(const ArithSqMat3x3Float<Vec3f,Mat3x3f>&);

        template class ArithSqMat3x3Float<Vec3d,Mat3x3d>;
        template Mat3x3d invert(const ArithSqMat3x3Float<Vec3d,Mat3x3d>&);
}