53 lines
3.0 KiB
C++
53 lines
3.0 KiB
C++
/********************************************************************************
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* ReactPhysics3D physics library, http://www.reactphysics3d.com *
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* Copyright (c) 2010-2020 Daniel Chappuis *
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*********************************************************************************
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* *
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* This software is provided 'as-is', without any express or implied warranty. *
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* In no event will the authors be held liable for any damages arising from the *
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* use of this software. *
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* *
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* Permission is granted to anyone to use this software for any purpose, *
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* including commercial applications, and to alter it and redistribute it *
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* freely, subject to the following restrictions: *
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* *
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* 1. The origin of this software must not be misrepresented; you must not claim *
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* that you wrote the original software. If you use this software in a *
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* product, an acknowledgment in the product documentation would be *
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* appreciated but is not required. *
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* *
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* 2. Altered source versions must be plainly marked as such, and must not be *
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* misrepresented as being the original software. *
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* *
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* 3. This notice may not be removed or altered from any source distribution. *
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* *
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********************************************************************************/
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// Libraries
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#include <reactphysics3d/mathematics/Matrix3x3.h>
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// Namespaces
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using namespace reactphysics3d;
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// Return the inverse matrix
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Matrix3x3 Matrix3x3::getInverse(decimal determinant) const {
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// Check if the determinant is equal to zero
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assert(determinant != decimal(0.0));
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decimal invDeterminant = decimal(1.0) / determinant;
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Matrix3x3 tempMatrix((mRows[1][1]*mRows[2][2]-mRows[2][1]*mRows[1][2]),
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-(mRows[0][1]*mRows[2][2]-mRows[2][1]*mRows[0][2]),
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(mRows[0][1]*mRows[1][2]-mRows[0][2]*mRows[1][1]),
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-(mRows[1][0]*mRows[2][2]-mRows[2][0]*mRows[1][2]),
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(mRows[0][0]*mRows[2][2]-mRows[2][0]*mRows[0][2]),
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-(mRows[0][0]*mRows[1][2]-mRows[1][0]*mRows[0][2]),
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(mRows[1][0]*mRows[2][1]-mRows[2][0]*mRows[1][1]),
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-(mRows[0][0]*mRows[2][1]-mRows[2][0]*mRows[0][1]),
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(mRows[0][0]*mRows[1][1]-mRows[0][1]*mRows[1][0]));
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// Return the inverse matrix
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return (invDeterminant * tempMatrix);
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}
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