Bullet Collision Detection & Physics Library: btGImpactMassUtil.h Source File

Bullet Collision Detection & Physics Library

btGImpactMassUtil.h
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1
4 /*
5 This source file is part of GIMPACT Library.
6
7 For the latest info, see http://gimpact.sourceforge.net/
8
9 Copyright (c) 2007 Francisco Leon Najera. C.C. 80087371.
10 email: projectileman@yahoo.com
11
12
13 This software is provided 'as-is', without any express or implied warranty.
14 In no event will the authors be held liable for any damages arising from the use of this software.
15 Permission is granted to anyone to use this software for any purpose,
16 including commercial applications, and to alter it and redistribute it freely,
17 subject to the following restrictions:
18
19 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.
20 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
21 3. This notice may not be removed or altered from any source distribution.
22 */
23
24
25 #ifndef GIMPACT_MASS_UTIL_H
26 #define GIMPACT_MASS_UTIL_H
27
28 #include "LinearMath/btTransform.h"
29
30
31
32 SIMD_FORCE_INLINE btVector3 gim_inertia_add_transformed(
33 const btVector3 & source_inertia, const btVector3 & added_inertia, const btTransform & transform)
34 {
35 btMatrix3x3 rotatedTensor = transform.getBasis().scaled(added_inertia) * transform.getBasis().transpose();
36
37 btScalar x2 = transform.getOrigin()[0];
38 x2*= x2;
39 btScalar y2 = transform.getOrigin()[1];
40 y2*= y2;
41 btScalar z2 = transform.getOrigin()[2];
42 z2*= z2;
43
44 btScalar ix = rotatedTensor[0][0]*(y2+z2);
45 btScalar iy = rotatedTensor[1][1]*(x2+z2);
46 btScalar iz = rotatedTensor[2][2]*(x2+y2);
47
48 return btVector3(source_inertia[0]+ix,source_inertia[1]+iy,source_inertia[2] + iz);
49 }
50
51 SIMD_FORCE_INLINE btVector3 gim_get_point_inertia(const btVector3 & point, btScalar mass)
52 {
53 btScalar x2 = point[0]*point[0];
54 btScalar y2 = point[1]*point[1];
55 btScalar z2 = point[2]*point[2];
56 return btVector3(mass*(y2+z2),mass*(x2+z2),mass*(x2+y2));
57 }
58
59
60 #endif //GIMPACT_MESH_SHAPE_H
SIMD_FORCE_INLINE
#define SIMD_FORCE_INLINE
Definition: btScalar.h:81
btTransform.h
btMatrix3x3::transpose
btMatrix3x3 transpose() const
Return the transpose of the matrix.
Definition: btMatrix3x3.h:958
btTransform::getOrigin
btVector3 & getOrigin()
Return the origin vector translation.
Definition: btTransform.h:117
gim_inertia_add_transformed
btVector3 gim_inertia_add_transformed(const btVector3 &source_inertia, const btVector3 &added_inertia, const btTransform &transform)
Definition: btGImpactMassUtil.h:32
btMatrix3x3::scaled
btMatrix3x3 scaled(const btVector3 &s) const
Create a scaled copy of the matrix.
Definition: btMatrix3x3.h:590
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:112
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:34
gim_get_point_inertia
btVector3 gim_get_point_inertia(const btVector3 &point, btScalar mass)
Definition: btGImpactMassUtil.h:51
btMatrix3x3
The btMatrix3x3 class implements a 3x3 rotation matrix, to perform linear algebra in combination with...
Definition: btMatrix3x3.h:48
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:292