72 lines
2.8 KiB
C++
72 lines
2.8 KiB
C++
/*
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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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