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Diffstat (limited to 'thirdparty/bullet/BulletCollision/CollisionShapes/btConvexPolyhedron.cpp')
| -rw-r--r-- | thirdparty/bullet/BulletCollision/CollisionShapes/btConvexPolyhedron.cpp | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/thirdparty/bullet/BulletCollision/CollisionShapes/btConvexPolyhedron.cpp b/thirdparty/bullet/BulletCollision/CollisionShapes/btConvexPolyhedron.cpp new file mode 100644 index 0000000000..4f45319a83 --- /dev/null +++ b/thirdparty/bullet/BulletCollision/CollisionShapes/btConvexPolyhedron.cpp @@ -0,0 +1,303 @@ +/* +Bullet Continuous Collision Detection and Physics Library +Copyright (c) 2011 Advanced Micro Devices, Inc. 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. +*/ + + +///This file was written by Erwin Coumans +///Separating axis rest based on work from Pierre Terdiman, see +///And contact clipping based on work from Simon Hobbs + +#include "btConvexPolyhedron.h" +#include "LinearMath/btHashMap.h" + + +btConvexPolyhedron::btConvexPolyhedron() +{ + +} +btConvexPolyhedron::~btConvexPolyhedron() +{ + +} + + +inline bool IsAlmostZero(const btVector3& v) +{ + if(btFabs(v.x())>1e-6 || btFabs(v.y())>1e-6 || btFabs(v.z())>1e-6) return false; + return true; +} + +struct btInternalVertexPair +{ + btInternalVertexPair(short int v0,short int v1) + :m_v0(v0), + m_v1(v1) + { + if (m_v1>m_v0) + btSwap(m_v0,m_v1); + } + short int m_v0; + short int m_v1; + int getHash() const + { + return m_v0+(m_v1<<16); + } + bool equals(const btInternalVertexPair& other) const + { + return m_v0==other.m_v0 && m_v1==other.m_v1; + } +}; + +struct btInternalEdge +{ + btInternalEdge() + :m_face0(-1), + m_face1(-1) + { + } + short int m_face0; + short int m_face1; +}; + +// + +#ifdef TEST_INTERNAL_OBJECTS +bool btConvexPolyhedron::testContainment() const +{ + for(int p=0;p<8;p++) + { + btVector3 LocalPt; + if(p==0) LocalPt = m_localCenter + btVector3(m_extents[0], m_extents[1], m_extents[2]); + else if(p==1) LocalPt = m_localCenter + btVector3(m_extents[0], m_extents[1], -m_extents[2]); + else if(p==2) LocalPt = m_localCenter + btVector3(m_extents[0], -m_extents[1], m_extents[2]); + else if(p==3) LocalPt = m_localCenter + btVector3(m_extents[0], -m_extents[1], -m_extents[2]); + else if(p==4) LocalPt = m_localCenter + btVector3(-m_extents[0], m_extents[1], m_extents[2]); + else if(p==5) LocalPt = m_localCenter + btVector3(-m_extents[0], m_extents[1], -m_extents[2]); + else if(p==6) LocalPt = m_localCenter + btVector3(-m_extents[0], -m_extents[1], m_extents[2]); + else if(p==7) LocalPt = m_localCenter + btVector3(-m_extents[0], -m_extents[1], -m_extents[2]); + + for(int i=0;i<m_faces.size();i++) + { + const btVector3 Normal(m_faces[i].m_plane[0], m_faces[i].m_plane[1], m_faces[i].m_plane[2]); + const btScalar d = LocalPt.dot(Normal) + m_faces[i].m_plane[3]; + if(d>0.0f) + return false; + } + } + return true; +} +#endif + +void btConvexPolyhedron::initialize() +{ + + btHashMap<btInternalVertexPair,btInternalEdge> edges; + + btScalar TotalArea = 0.0f; + + m_localCenter.setValue(0, 0, 0); + for(int i=0;i<m_faces.size();i++) + { + int numVertices = m_faces[i].m_indices.size(); + int NbTris = numVertices; + for(int j=0;j<NbTris;j++) + { + int k = (j+1)%numVertices; + btInternalVertexPair vp(m_faces[i].m_indices[j],m_faces[i].m_indices[k]); + btInternalEdge* edptr = edges.find(vp); + btVector3 edge = m_vertices[vp.m_v1]-m_vertices[vp.m_v0]; + edge.normalize(); + + bool found = false; + + for (int p=0;p<m_uniqueEdges.size();p++) + { + + if (IsAlmostZero(m_uniqueEdges[p]-edge) || + IsAlmostZero(m_uniqueEdges[p]+edge)) + { + found = true; + break; + } + } + + if (!found) + { + m_uniqueEdges.push_back(edge); + } + + if (edptr) + { + btAssert(edptr->m_face0>=0); + btAssert(edptr->m_face1<0); + edptr->m_face1 = i; + } else + { + btInternalEdge ed; + ed.m_face0 = i; + edges.insert(vp,ed); + } + } + } + +#ifdef USE_CONNECTED_FACES + for(int i=0;i<m_faces.size();i++) + { + int numVertices = m_faces[i].m_indices.size(); + m_faces[i].m_connectedFaces.resize(numVertices); + + for(int j=0;j<numVertices;j++) + { + int k = (j+1)%numVertices; + btInternalVertexPair vp(m_faces[i].m_indices[j],m_faces[i].m_indices[k]); + btInternalEdge* edptr = edges.find(vp); + btAssert(edptr); + btAssert(edptr->m_face0>=0); + btAssert(edptr->m_face1>=0); + + int connectedFace = (edptr->m_face0==i)?edptr->m_face1:edptr->m_face0; + m_faces[i].m_connectedFaces[j] = connectedFace; + } + } +#endif//USE_CONNECTED_FACES + + for(int i=0;i<m_faces.size();i++) + { + int numVertices = m_faces[i].m_indices.size(); + int NbTris = numVertices-2; + + const btVector3& p0 = m_vertices[m_faces[i].m_indices[0]]; + for(int j=1;j<=NbTris;j++) + { + int k = (j+1)%numVertices; + const btVector3& p1 = m_vertices[m_faces[i].m_indices[j]]; + const btVector3& p2 = m_vertices[m_faces[i].m_indices[k]]; + btScalar Area = ((p0 - p1).cross(p0 - p2)).length() * 0.5f; + btVector3 Center = (p0+p1+p2)/3.0f; + m_localCenter += Area * Center; + TotalArea += Area; + } + } + m_localCenter /= TotalArea; + + + + +#ifdef TEST_INTERNAL_OBJECTS + if(1) + { + m_radius = FLT_MAX; + for(int i=0;i<m_faces.size();i++) + { + const btVector3 Normal(m_faces[i].m_plane[0], m_faces[i].m_plane[1], m_faces[i].m_plane[2]); + const btScalar dist = btFabs(m_localCenter.dot(Normal) + m_faces[i].m_plane[3]); + if(dist<m_radius) + m_radius = dist; + } + + + btScalar MinX = FLT_MAX; + btScalar MinY = FLT_MAX; + btScalar MinZ = FLT_MAX; + btScalar MaxX = -FLT_MAX; + btScalar MaxY = -FLT_MAX; + btScalar MaxZ = -FLT_MAX; + for(int i=0; i<m_vertices.size(); i++) + { + const btVector3& pt = m_vertices[i]; + if(pt.x()<MinX) MinX = pt.x(); + if(pt.x()>MaxX) MaxX = pt.x(); + if(pt.y()<MinY) MinY = pt.y(); + if(pt.y()>MaxY) MaxY = pt.y(); + if(pt.z()<MinZ) MinZ = pt.z(); + if(pt.z()>MaxZ) MaxZ = pt.z(); + } + mC.setValue(MaxX+MinX, MaxY+MinY, MaxZ+MinZ); + mE.setValue(MaxX-MinX, MaxY-MinY, MaxZ-MinZ); + + + +// const btScalar r = m_radius / sqrtf(2.0f); + const btScalar r = m_radius / sqrtf(3.0f); + const int LargestExtent = mE.maxAxis(); + const btScalar Step = (mE[LargestExtent]*0.5f - r)/1024.0f; + m_extents[0] = m_extents[1] = m_extents[2] = r; + m_extents[LargestExtent] = mE[LargestExtent]*0.5f; + bool FoundBox = false; + for(int j=0;j<1024;j++) + { + if(testContainment()) + { + FoundBox = true; + break; + } + + m_extents[LargestExtent] -= Step; + } + if(!FoundBox) + { + m_extents[0] = m_extents[1] = m_extents[2] = r; + } + else + { + // Refine the box + const btScalar Step = (m_radius - r)/1024.0f; + const int e0 = (1<<LargestExtent) & 3; + const int e1 = (1<<e0) & 3; + + for(int j=0;j<1024;j++) + { + const btScalar Saved0 = m_extents[e0]; + const btScalar Saved1 = m_extents[e1]; + m_extents[e0] += Step; + m_extents[e1] += Step; + + if(!testContainment()) + { + m_extents[e0] = Saved0; + m_extents[e1] = Saved1; + break; + } + } + } + } +#endif +} + +void btConvexPolyhedron::project(const btTransform& trans, const btVector3& dir, btScalar& minProj, btScalar& maxProj, btVector3& witnesPtMin,btVector3& witnesPtMax) const +{ + minProj = FLT_MAX; + maxProj = -FLT_MAX; + int numVerts = m_vertices.size(); + for(int i=0;i<numVerts;i++) + { + btVector3 pt = trans * m_vertices[i]; + btScalar dp = pt.dot(dir); + if(dp < minProj) + { + minProj = dp; + witnesPtMin = pt; + } + if(dp > maxProj) + { + maxProj = dp; + witnesPtMax = pt; + } + } + if(minProj>maxProj) + { + btSwap(minProj,maxProj); + btSwap(witnesPtMin,witnesPtMax); + } +} |