btUniformScalingShape.cpp

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00001 /*
00002 Bullet Continuous Collision Detection and Physics Library
00003 Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org
00004 
00005 This software is provided 'as-is', without any express or implied warranty.
00006 In no event will the authors be held liable for any damages arising from the use of this software.
00007 Permission is granted to anyone to use this software for any purpose, 
00008 including commercial applications, and to alter it and redistribute it freely, 
00009 subject to the following restrictions:
00010 
00011 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.
00012 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
00013 3. This notice may not be removed or altered from any source distribution.
00014 */
00015 
00016 #include "btUniformScalingShape.h"
00017 
00018 btUniformScalingShape::btUniformScalingShape(   btConvexShape* convexChildShape,btScalar uniformScalingFactor):
00019 btConvexShape (), m_childConvexShape(convexChildShape),
00020 m_uniformScalingFactor(uniformScalingFactor)
00021 {
00022         m_shapeType = UNIFORM_SCALING_SHAPE_PROXYTYPE;
00023 }
00024         
00025 btUniformScalingShape::~btUniformScalingShape()
00026 {
00027 }
00028         
00029 
00030 btVector3       btUniformScalingShape::localGetSupportingVertexWithoutMargin(const btVector3& vec)const
00031 {
00032         btVector3 tmpVertex;
00033         tmpVertex = m_childConvexShape->localGetSupportingVertexWithoutMargin(vec);
00034         return tmpVertex*m_uniformScalingFactor;
00035 }
00036 
00037 void    btUniformScalingShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
00038 {
00039         m_childConvexShape->batchedUnitVectorGetSupportingVertexWithoutMargin(vectors,supportVerticesOut,numVectors);
00040         int i;
00041         for (i=0;i<numVectors;i++)
00042         {
00043                 supportVerticesOut[i] = supportVerticesOut[i] * m_uniformScalingFactor;
00044         }
00045 }
00046 
00047 
00048 btVector3       btUniformScalingShape::localGetSupportingVertex(const btVector3& vec)const
00049 {
00050         btVector3 tmpVertex;
00051         tmpVertex = m_childConvexShape->localGetSupportingVertex(vec);
00052         return tmpVertex*m_uniformScalingFactor;
00053 }
00054 
00055 
00056 void    btUniformScalingShape::calculateLocalInertia(btScalar mass,btVector3& inertia) const
00057 {
00058 
00060         btVector3 tmpInertia;
00061         m_childConvexShape->calculateLocalInertia(mass,tmpInertia);
00062         inertia = tmpInertia * m_uniformScalingFactor;
00063 }
00064 
00065 
00067 void btUniformScalingShape::getAabb(const btTransform& trans,btVector3& aabbMin,btVector3& aabbMax) const
00068 {
00069         getAabbSlow(trans,aabbMin,aabbMax);
00070 
00071 }
00072 
00073 void btUniformScalingShape::getAabbSlow(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const
00074 {
00075 #if 1
00076         btVector3 _directions[] =
00077         {
00078                 btVector3( 1.,  0.,  0.),
00079                 btVector3( 0.,  1.,  0.),
00080                 btVector3( 0.,  0.,  1.),
00081                 btVector3( -1., 0.,  0.),
00082                 btVector3( 0., -1.,  0.),
00083                 btVector3( 0.,  0., -1.)
00084         };
00085         
00086         btVector3 _supporting[] =
00087         {
00088                 btVector3( 0., 0., 0.),
00089                 btVector3( 0., 0., 0.),
00090                 btVector3( 0., 0., 0.),
00091                 btVector3( 0., 0., 0.),
00092                 btVector3( 0., 0., 0.),
00093                 btVector3( 0., 0., 0.)
00094         };
00095 
00096         for (int i=0;i<6;i++)
00097         {
00098                 _directions[i] = _directions[i]*t.getBasis();
00099         }
00100         
00101         batchedUnitVectorGetSupportingVertexWithoutMargin(_directions, _supporting, 6);
00102         
00103         btVector3 aabbMin1(0,0,0),aabbMax1(0,0,0);
00104 
00105         for ( int i = 0; i < 3; ++i )
00106         {
00107                 aabbMax1[i] = t(_supporting[i])[i];
00108                 aabbMin1[i] = t(_supporting[i + 3])[i];
00109         }
00110         btVector3 marginVec(getMargin(),getMargin(),getMargin());
00111         aabbMin = aabbMin1-marginVec;
00112         aabbMax = aabbMax1+marginVec;
00113         
00114 #else
00115 
00116         btScalar margin = getMargin();
00117         for (int i=0;i<3;i++)
00118         {
00119                 btVector3 vec(btScalar(0.),btScalar(0.),btScalar(0.));
00120                 vec[i] = btScalar(1.);
00121                 btVector3 sv = localGetSupportingVertex(vec*t.getBasis());
00122                 btVector3 tmp = t(sv);
00123                 aabbMax[i] = tmp[i]+margin;
00124                 vec[i] = btScalar(-1.);
00125                 sv = localGetSupportingVertex(vec*t.getBasis());
00126                 tmp = t(sv);
00127                 aabbMin[i] = tmp[i]-margin;
00128         }
00129 
00130 #endif
00131 }
00132 
00133 void    btUniformScalingShape::setLocalScaling(const btVector3& scaling) 
00134 {
00135         m_childConvexShape->setLocalScaling(scaling);
00136 }
00137 
00138 const btVector3& btUniformScalingShape::getLocalScaling() const
00139 {
00140         return m_childConvexShape->getLocalScaling();
00141 }
00142 
00143 void    btUniformScalingShape::setMargin(btScalar margin)
00144 {
00145         m_childConvexShape->setMargin(margin);
00146 }
00147 btScalar        btUniformScalingShape::getMargin() const
00148 {
00149         return m_childConvexShape->getMargin() * m_uniformScalingFactor;
00150 }
00151 
00152 int             btUniformScalingShape::getNumPreferredPenetrationDirections() const
00153 {
00154         return m_childConvexShape->getNumPreferredPenetrationDirections();
00155 }
00156         
00157 void    btUniformScalingShape::getPreferredPenetrationDirection(int index, btVector3& penetrationVector) const
00158 {
00159         m_childConvexShape->getPreferredPenetrationDirection(index,penetrationVector);
00160 }