57 lines
2.1 KiB
C++
57 lines
2.1 KiB
C++
/*! \file btGImpactMassUtil.h
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\author Francisco Leon Najera
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*/
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/*
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This source file is part of GIMPACT Library.
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For the latest info, see http://gimpact.sourceforge.net/
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Copyright (c) 2007 Francisco Leon Najera. C.C. 80087371.
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email: projectileman@yahoo.com
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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 use of this software.
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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 freely,
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subject to the following restrictions:
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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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*/
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#ifndef GIMPACT_MASS_UTIL_H
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#define GIMPACT_MASS_UTIL_H
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#include "LinearMath/btTransform.h"
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SIMD_FORCE_INLINE btVector3 gim_inertia_add_transformed(
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const btVector3& source_inertia, const btVector3& added_inertia, const btTransform& transform)
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{
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btMatrix3x3 rotatedTensor = transform.getBasis().scaled(added_inertia) * transform.getBasis().transpose();
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btScalar x2 = transform.getOrigin()[0];
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x2 *= x2;
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btScalar y2 = transform.getOrigin()[1];
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y2 *= y2;
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btScalar z2 = transform.getOrigin()[2];
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z2 *= z2;
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btScalar ix = rotatedTensor[0][0] * (y2 + z2);
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btScalar iy = rotatedTensor[1][1] * (x2 + z2);
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btScalar iz = rotatedTensor[2][2] * (x2 + y2);
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return btVector3(source_inertia[0] + ix, source_inertia[1] + iy, source_inertia[2] + iz);
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}
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SIMD_FORCE_INLINE btVector3 gim_get_point_inertia(const btVector3& point, btScalar mass)
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{
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btScalar x2 = point[0] * point[0];
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btScalar y2 = point[1] * point[1];
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btScalar z2 = point[2] * point[2];
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return btVector3(mass * (y2 + z2), mass * (x2 + z2), mass * (x2 + y2));
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}
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#endif //GIMPACT_MESH_SHAPE_H
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