/********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com                 *
* Copyright (c) 2010-2020 Daniel Chappuis                                       *
*********************************************************************************
*                                                                               *
* This software is provided 'as-is', without any express or implied warranty.   *
* In no event will the authors be held liable for any damages arising from the  *
* use of this software.                                                         *
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* Permission is granted to anyone to use this software for any purpose,         *
* including commercial applications, and to alter it and redistribute it        *
* freely, subject to the following restrictions:                                *
*                                                                               *
* 1. The origin of this software must not be misrepresented; you must not claim *
*    that you wrote the original software. If you use this software in a        *
*    product, an acknowledgment in the product documentation would be           *
*    appreciated but is not required.                                           *
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* 2. Altered source versions must be plainly marked as such, and must not be    *
*    misrepresented as being the original software.                             *
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* 3. This notice may not be removed or altered from any source distribution.    *
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********************************************************************************/

// Libraries
#include <reactphysics3d/mathematics/Matrix3x3.h>

// Namespaces
using namespace reactphysics3d;

// Return the inverse matrix
Matrix3x3 Matrix3x3::getInverse(decimal determinant) const {

    // Check if the determinant is equal to zero
    assert(determinant != decimal(0.0));

    decimal invDeterminant = decimal(1.0) / determinant;

    Matrix3x3 tempMatrix((mRows[1][1]*mRows[2][2]-mRows[2][1]*mRows[1][2]),
                         -(mRows[0][1]*mRows[2][2]-mRows[2][1]*mRows[0][2]),
                         (mRows[0][1]*mRows[1][2]-mRows[0][2]*mRows[1][1]),
                            -(mRows[1][0]*mRows[2][2]-mRows[2][0]*mRows[1][2]),
                         (mRows[0][0]*mRows[2][2]-mRows[2][0]*mRows[0][2]),
                         -(mRows[0][0]*mRows[1][2]-mRows[1][0]*mRows[0][2]),
                            (mRows[1][0]*mRows[2][1]-mRows[2][0]*mRows[1][1]),
                         -(mRows[0][0]*mRows[2][1]-mRows[2][0]*mRows[0][1]),
                         (mRows[0][0]*mRows[1][1]-mRows[0][1]*mRows[1][0]));

    // Return the inverse matrix
    return (invDeterminant * tempMatrix);
}