78 lines
2.7 KiB
C++
78 lines
2.7 KiB
C++
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/*
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Bullet Continuous Collision Detection and Physics Library
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Copyright (c) 2003-2009 Erwin Coumans http://bulletphysics.org
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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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#include "btMinkowskiSumShape.h"
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btMinkowskiSumShape::btMinkowskiSumShape(const btConvexShape* shapeA,const btConvexShape* shapeB)
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: btConvexInternalShape (),
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m_shapeA(shapeA),
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m_shapeB(shapeB)
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{
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m_shapeType = MINKOWSKI_DIFFERENCE_SHAPE_PROXYTYPE;
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m_transA.setIdentity();
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m_transB.setIdentity();
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}
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btVector3 btMinkowskiSumShape::localGetSupportingVertexWithoutMargin(const btVector3& vec)const
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{
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btVector3 supVertexA = m_transA(m_shapeA->localGetSupportingVertexWithoutMargin(vec*m_transA.getBasis()));
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btVector3 supVertexB = m_transB(m_shapeB->localGetSupportingVertexWithoutMargin(-vec*m_transB.getBasis()));
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return supVertexA - supVertexB;
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}
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void btMinkowskiSumShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
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{
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///@todo: could make recursive use of batching. probably this shape is not used frequently.
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for (int i=0;i<numVectors;i++)
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{
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supportVerticesOut[i] = localGetSupportingVertexWithoutMargin(vectors[i]);
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}
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}
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btScalar btMinkowskiSumShape::getMargin() const
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{
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return m_shapeA->getMargin() + m_shapeB->getMargin();
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}
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void btMinkowskiSumShape::calculateLocalInertia(btScalar mass,btVector3& inertia) const
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{
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(void)mass;
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//inertia of the AABB of the Minkowski sum
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btTransform identity;
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identity.setIdentity();
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btVector3 aabbMin,aabbMax;
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getAabb(identity,aabbMin,aabbMax);
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btVector3 halfExtents = (aabbMax-aabbMin)*btScalar(0.5);
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btScalar margin = getMargin();
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btScalar lx=btScalar(2.)*(halfExtents.x()+margin);
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btScalar ly=btScalar(2.)*(halfExtents.y()+margin);
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btScalar lz=btScalar(2.)*(halfExtents.z()+margin);
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const btScalar x2 = lx*lx;
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const btScalar y2 = ly*ly;
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const btScalar z2 = lz*lz;
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const btScalar scaledmass = mass * btScalar(0.08333333);
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inertia = scaledmass * (btVector3(y2+z2,x2+z2,x2+y2));
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}
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