forked from bartvdbraak/blender
116 lines
2.4 KiB
C++
116 lines
2.4 KiB
C++
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/*
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* Copyright (c) 2005 Erwin Coumans http://www.erwincoumans.com
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*
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* Permission to use, copy, modify, distribute and sell this software
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* and its documentation for any purpose is hereby granted without fee,
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* provided that the above copyright notice appear in all copies.
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* Erwin Coumans makes no representations about the suitability
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* of this software for any purpose.
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* It is provided "as is" without express or implied warranty.
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*/
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#include "MultiSphereShape.h"
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#include "NarrowPhaseCollision/CollisionMargin.h"
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#include "SimdQuaternion.h"
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MultiSphereShape::MultiSphereShape (const SimdVector3& inertiaHalfExtents,const SimdVector3* positions,const SimdScalar* radi,int numSpheres)
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:m_inertiaHalfExtents(inertiaHalfExtents)
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{
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m_minRadius = 1e30f;
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m_numSpheres = numSpheres;
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for (int i=0;i<m_numSpheres;i++)
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{
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m_localPositions[i] = positions[i];
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m_radi[i] = radi[i];
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if (radi[i] < m_minRadius)
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m_minRadius = radi[i];
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}
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SetMargin(m_minRadius);
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}
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SimdVector3 MultiSphereShape::LocalGetSupportingVertexWithoutMargin(const SimdVector3& vec0)const
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{
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int i;
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SimdVector3 supVec(0,0,0);
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SimdScalar maxDot(-1e30f);
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SimdVector3 vec = vec0;
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SimdScalar lenSqr = vec.length2();
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if (lenSqr < 0.0001f)
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{
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vec.setValue(1,0,0);
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} else
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{
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float rlen = 1.f / sqrtf(lenSqr );
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vec *= rlen;
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}
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SimdVector3 vtx;
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SimdScalar newDot;
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const SimdVector3* pos = &m_localPositions[0];
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const SimdScalar* rad = &m_radi[0];
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for (i=0;i<m_numSpheres;i++)
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{
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vtx = (*pos) +vec*((*rad)-m_minRadius);
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pos++;
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rad++;
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newDot = vec.dot(vtx);
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if (newDot > maxDot)
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{
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maxDot = newDot;
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supVec = vtx;
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}
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}
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return supVec;
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}
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void MultiSphereShape::CalculateLocalInertia(SimdScalar mass,SimdVector3& inertia)
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{
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//as an approximation, take the inertia of the box that bounds the spheres
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SimdTransform ident;
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ident.setIdentity();
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// SimdVector3 aabbMin,aabbMax;
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// GetAabb(ident,aabbMin,aabbMax);
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SimdVector3 halfExtents = m_inertiaHalfExtents;//(aabbMax - aabbMin)* 0.5f;
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float margin = CONVEX_DISTANCE_MARGIN;
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SimdScalar lx=2.f*(halfExtents[0]+margin);
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SimdScalar ly=2.f*(halfExtents[1]+margin);
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SimdScalar lz=2.f*(halfExtents[2]+margin);
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const SimdScalar x2 = lx*lx;
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const SimdScalar y2 = ly*ly;
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const SimdScalar z2 = lz*lz;
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const SimdScalar scaledmass = mass * 0.08333333f;
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inertia[0] = scaledmass * (y2+z2);
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inertia[1] = scaledmass * (x2+z2);
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inertia[2] = scaledmass * (x2+y2);
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}
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