| /* |
| Bullet Continuous Collision Detection and Physics Library |
| Copyright (c) 2003-2009 Erwin Coumans http://bulletphysics.org |
| |
| This software is provided 'as-is', without any express or implied warranty. |
| In no event will the authors be held liable for any damages arising from the use of this software. |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it freely, |
| subject to the following restrictions: |
| |
| 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. |
| 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| |
| |
| |
| #include "BulletCollision/CollisionShapes/btMultiSphereShape.h" |
| #include "BulletCollision/CollisionShapes/btCollisionMargin.h" |
| #include "LinearMath/btQuaternion.h" |
| |
| btMultiSphereShape::btMultiSphereShape (const btVector3* positions,const btScalar* radi,int numSpheres) |
| :btConvexInternalAabbCachingShape () |
| { |
| m_shapeType = MULTI_SPHERE_SHAPE_PROXYTYPE; |
| //btScalar startMargin = btScalar(BT_LARGE_FLOAT); |
| |
| m_localPositionArray.resize(numSpheres); |
| m_radiArray.resize(numSpheres); |
| for (int i=0;i<numSpheres;i++) |
| { |
| m_localPositionArray[i] = positions[i]; |
| m_radiArray[i] = radi[i]; |
| |
| } |
| |
| recalcLocalAabb(); |
| |
| } |
| |
| |
| btVector3 btMultiSphereShape::localGetSupportingVertexWithoutMargin(const btVector3& vec0)const |
| { |
| int i; |
| btVector3 supVec(0,0,0); |
| |
| btScalar maxDot(btScalar(-BT_LARGE_FLOAT)); |
| |
| |
| btVector3 vec = vec0; |
| btScalar lenSqr = vec.length2(); |
| if (lenSqr < (SIMD_EPSILON*SIMD_EPSILON)) |
| { |
| vec.setValue(1,0,0); |
| } else |
| { |
| btScalar rlen = btScalar(1.) / btSqrt(lenSqr ); |
| vec *= rlen; |
| } |
| |
| btVector3 vtx; |
| btScalar newDot; |
| |
| const btVector3* pos = &m_localPositionArray[0]; |
| const btScalar* rad = &m_radiArray[0]; |
| int numSpheres = m_localPositionArray.size(); |
| |
| for (i=0;i<numSpheres;i++) |
| { |
| vtx = (*pos) +vec*m_localScaling*(*rad) - vec * getMargin(); |
| pos++; |
| rad++; |
| newDot = vec.dot(vtx); |
| if (newDot > maxDot) |
| { |
| maxDot = newDot; |
| supVec = vtx; |
| } |
| } |
| |
| return supVec; |
| |
| } |
| |
| void btMultiSphereShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const |
| { |
| |
| for (int j=0;j<numVectors;j++) |
| { |
| btScalar maxDot(btScalar(-BT_LARGE_FLOAT)); |
| |
| const btVector3& vec = vectors[j]; |
| |
| btVector3 vtx; |
| btScalar newDot; |
| |
| const btVector3* pos = &m_localPositionArray[0]; |
| const btScalar* rad = &m_radiArray[0]; |
| int numSpheres = m_localPositionArray.size(); |
| for (int i=0;i<numSpheres;i++) |
| { |
| vtx = (*pos) +vec*m_localScaling*(*rad) - vec * getMargin(); |
| pos++; |
| rad++; |
| newDot = vec.dot(vtx); |
| if (newDot > maxDot) |
| { |
| maxDot = newDot; |
| supportVerticesOut[j] = vtx; |
| } |
| } |
| } |
| } |
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| void btMultiSphereShape::calculateLocalInertia(btScalar mass,btVector3& inertia) const |
| { |
| //as an approximation, take the inertia of the box that bounds the spheres |
| |
| btVector3 localAabbMin,localAabbMax; |
| getCachedLocalAabb(localAabbMin,localAabbMax); |
| btVector3 halfExtents = (localAabbMax-localAabbMin)*btScalar(0.5); |
| |
| btScalar lx=btScalar(2.)*(halfExtents.x()); |
| btScalar ly=btScalar(2.)*(halfExtents.y()); |
| btScalar lz=btScalar(2.)*(halfExtents.z()); |
| |
| inertia.setValue(mass/(btScalar(12.0)) * (ly*ly + lz*lz), |
| mass/(btScalar(12.0)) * (lx*lx + lz*lz), |
| mass/(btScalar(12.0)) * (lx*lx + ly*ly)); |
| |
| } |
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