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Diffstat (limited to 'extern/bullet2/BulletCollision/NarrowPhaseCollision/btVoronoiSimplexSolver.cpp')
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1 files changed, 609 insertions, 0 deletions
diff --git a/extern/bullet2/BulletCollision/NarrowPhaseCollision/btVoronoiSimplexSolver.cpp b/extern/bullet2/BulletCollision/NarrowPhaseCollision/btVoronoiSimplexSolver.cpp new file mode 100644 index 00000000000..a775198ab29 --- /dev/null +++ b/extern/bullet2/BulletCollision/NarrowPhaseCollision/btVoronoiSimplexSolver.cpp @@ -0,0 +1,609 @@ + +/* +Bullet Continuous Collision Detection and Physics Library +Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ + +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. + + Elsevier CDROM license agreements grants nonexclusive license to use the software + for any purpose, commercial or non-commercial as long as the following credit is included + identifying the original source of the software: + + Parts of the source are "from the book Real-Time Collision Detection by + Christer Ericson, published by Morgan Kaufmann Publishers, + (c) 2005 Elsevier Inc." + +*/ + + +#include "btVoronoiSimplexSolver.h" + +#define VERTA 0 +#define VERTB 1 +#define VERTC 2 +#define VERTD 3 + +#define CATCH_DEGENERATE_TETRAHEDRON 1 +void btVoronoiSimplexSolver::removeVertex(int index) +{ + + btAssert(m_numVertices>0); + m_numVertices--; + m_simplexVectorW[index] = m_simplexVectorW[m_numVertices]; + m_simplexPointsP[index] = m_simplexPointsP[m_numVertices]; + m_simplexPointsQ[index] = m_simplexPointsQ[m_numVertices]; +} + +void btVoronoiSimplexSolver::reduceVertices (const btUsageBitfield& usedVerts) +{ + if ((numVertices() >= 4) && (!usedVerts.usedVertexD)) + removeVertex(3); + + if ((numVertices() >= 3) && (!usedVerts.usedVertexC)) + removeVertex(2); + + if ((numVertices() >= 2) && (!usedVerts.usedVertexB)) + removeVertex(1); + + if ((numVertices() >= 1) && (!usedVerts.usedVertexA)) + removeVertex(0); + +} + + + + + +//clear the simplex, remove all the vertices +void btVoronoiSimplexSolver::reset() +{ + m_cachedValidClosest = false; + m_numVertices = 0; + m_needsUpdate = true; + m_lastW = btVector3(btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT)); + m_cachedBC.reset(); +} + + + + //add a vertex +void btVoronoiSimplexSolver::addVertex(const btVector3& w, const btVector3& p, const btVector3& q) +{ + m_lastW = w; + m_needsUpdate = true; + + m_simplexVectorW[m_numVertices] = w; + m_simplexPointsP[m_numVertices] = p; + m_simplexPointsQ[m_numVertices] = q; + + m_numVertices++; +} + +bool btVoronoiSimplexSolver::updateClosestVectorAndPoints() +{ + + if (m_needsUpdate) + { + m_cachedBC.reset(); + + m_needsUpdate = false; + + switch (numVertices()) + { + case 0: + m_cachedValidClosest = false; + break; + case 1: + { + m_cachedP1 = m_simplexPointsP[0]; + m_cachedP2 = m_simplexPointsQ[0]; + m_cachedV = m_cachedP1-m_cachedP2; //== m_simplexVectorW[0] + m_cachedBC.reset(); + m_cachedBC.setBarycentricCoordinates(btScalar(1.),btScalar(0.),btScalar(0.),btScalar(0.)); + m_cachedValidClosest = m_cachedBC.isValid(); + break; + }; + case 2: + { + //closest point origin from line segment + const btVector3& from = m_simplexVectorW[0]; + const btVector3& to = m_simplexVectorW[1]; + btVector3 nearest; + + btVector3 p (btScalar(0.),btScalar(0.),btScalar(0.)); + btVector3 diff = p - from; + btVector3 v = to - from; + btScalar t = v.dot(diff); + + if (t > 0) { + btScalar dotVV = v.dot(v); + if (t < dotVV) { + t /= dotVV; + diff -= t*v; + m_cachedBC.m_usedVertices.usedVertexA = true; + m_cachedBC.m_usedVertices.usedVertexB = true; + } else { + t = 1; + diff -= v; + //reduce to 1 point + m_cachedBC.m_usedVertices.usedVertexB = true; + } + } else + { + t = 0; + //reduce to 1 point + m_cachedBC.m_usedVertices.usedVertexA = true; + } + m_cachedBC.setBarycentricCoordinates(1-t,t); + nearest = from + t*v; + + m_cachedP1 = m_simplexPointsP[0] + t * (m_simplexPointsP[1] - m_simplexPointsP[0]); + m_cachedP2 = m_simplexPointsQ[0] + t * (m_simplexPointsQ[1] - m_simplexPointsQ[0]); + m_cachedV = m_cachedP1 - m_cachedP2; + + reduceVertices(m_cachedBC.m_usedVertices); + + m_cachedValidClosest = m_cachedBC.isValid(); + break; + } + case 3: + { + //closest point origin from triangle + btVector3 p (btScalar(0.),btScalar(0.),btScalar(0.)); + + const btVector3& a = m_simplexVectorW[0]; + const btVector3& b = m_simplexVectorW[1]; + const btVector3& c = m_simplexVectorW[2]; + + closestPtPointTriangle(p,a,b,c,m_cachedBC); + m_cachedP1 = m_simplexPointsP[0] * m_cachedBC.m_barycentricCoords[0] + + m_simplexPointsP[1] * m_cachedBC.m_barycentricCoords[1] + + m_simplexPointsP[2] * m_cachedBC.m_barycentricCoords[2]; + + m_cachedP2 = m_simplexPointsQ[0] * m_cachedBC.m_barycentricCoords[0] + + m_simplexPointsQ[1] * m_cachedBC.m_barycentricCoords[1] + + m_simplexPointsQ[2] * m_cachedBC.m_barycentricCoords[2]; + + m_cachedV = m_cachedP1-m_cachedP2; + + reduceVertices (m_cachedBC.m_usedVertices); + m_cachedValidClosest = m_cachedBC.isValid(); + + break; + } + case 4: + { + + + btVector3 p (btScalar(0.),btScalar(0.),btScalar(0.)); + + const btVector3& a = m_simplexVectorW[0]; + const btVector3& b = m_simplexVectorW[1]; + const btVector3& c = m_simplexVectorW[2]; + const btVector3& d = m_simplexVectorW[3]; + + bool hasSeperation = closestPtPointTetrahedron(p,a,b,c,d,m_cachedBC); + + if (hasSeperation) + { + + m_cachedP1 = m_simplexPointsP[0] * m_cachedBC.m_barycentricCoords[0] + + m_simplexPointsP[1] * m_cachedBC.m_barycentricCoords[1] + + m_simplexPointsP[2] * m_cachedBC.m_barycentricCoords[2] + + m_simplexPointsP[3] * m_cachedBC.m_barycentricCoords[3]; + + m_cachedP2 = m_simplexPointsQ[0] * m_cachedBC.m_barycentricCoords[0] + + m_simplexPointsQ[1] * m_cachedBC.m_barycentricCoords[1] + + m_simplexPointsQ[2] * m_cachedBC.m_barycentricCoords[2] + + m_simplexPointsQ[3] * m_cachedBC.m_barycentricCoords[3]; + + m_cachedV = m_cachedP1-m_cachedP2; + reduceVertices (m_cachedBC.m_usedVertices); + } else + { +// printf("sub distance got penetration\n"); + + if (m_cachedBC.m_degenerate) + { + m_cachedValidClosest = false; + } else + { + m_cachedValidClosest = true; + //degenerate case == false, penetration = true + zero + m_cachedV.setValue(btScalar(0.),btScalar(0.),btScalar(0.)); + } + break; + } + + m_cachedValidClosest = m_cachedBC.isValid(); + + //closest point origin from tetrahedron + break; + } + default: + { + m_cachedValidClosest = false; + } + }; + } + + return m_cachedValidClosest; + +} + +//return/calculate the closest vertex +bool btVoronoiSimplexSolver::closest(btVector3& v) +{ + bool succes = updateClosestVectorAndPoints(); + v = m_cachedV; + return succes; +} + + + +btScalar btVoronoiSimplexSolver::maxVertex() +{ + int i, numverts = numVertices(); + btScalar maxV = btScalar(0.); + for (i=0;i<numverts;i++) + { + btScalar curLen2 = m_simplexVectorW[i].length2(); + if (maxV < curLen2) + maxV = curLen2; + } + return maxV; +} + + + + //return the current simplex +int btVoronoiSimplexSolver::getSimplex(btVector3 *pBuf, btVector3 *qBuf, btVector3 *yBuf) const +{ + int i; + for (i=0;i<numVertices();i++) + { + yBuf[i] = m_simplexVectorW[i]; + pBuf[i] = m_simplexPointsP[i]; + qBuf[i] = m_simplexPointsQ[i]; + } + return numVertices(); +} + + + + +bool btVoronoiSimplexSolver::inSimplex(const btVector3& w) +{ + bool found = false; + int i, numverts = numVertices(); + //btScalar maxV = btScalar(0.); + + //w is in the current (reduced) simplex + for (i=0;i<numverts;i++) + { +#ifdef BT_USE_EQUAL_VERTEX_THRESHOLD + if ( m_simplexVectorW[i].distance2(w) <= m_equalVertexThreshold) +#else + if (m_simplexVectorW[i] == w) +#endif + found = true; + } + + //check in case lastW is already removed + if (w == m_lastW) + return true; + + return found; +} + +void btVoronoiSimplexSolver::backup_closest(btVector3& v) +{ + v = m_cachedV; +} + + +bool btVoronoiSimplexSolver::emptySimplex() const +{ + return (numVertices() == 0); + +} + +void btVoronoiSimplexSolver::compute_points(btVector3& p1, btVector3& p2) +{ + updateClosestVectorAndPoints(); + p1 = m_cachedP1; + p2 = m_cachedP2; + +} + + + + +bool btVoronoiSimplexSolver::closestPtPointTriangle(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c,btSubSimplexClosestResult& result) +{ + result.m_usedVertices.reset(); + + // Check if P in vertex region outside A + btVector3 ab = b - a; + btVector3 ac = c - a; + btVector3 ap = p - a; + btScalar d1 = ab.dot(ap); + btScalar d2 = ac.dot(ap); + if (d1 <= btScalar(0.0) && d2 <= btScalar(0.0)) + { + result.m_closestPointOnSimplex = a; + result.m_usedVertices.usedVertexA = true; + result.setBarycentricCoordinates(1,0,0); + return true;// a; // barycentric coordinates (1,0,0) + } + + // Check if P in vertex region outside B + btVector3 bp = p - b; + btScalar d3 = ab.dot(bp); + btScalar d4 = ac.dot(bp); + if (d3 >= btScalar(0.0) && d4 <= d3) + { + result.m_closestPointOnSimplex = b; + result.m_usedVertices.usedVertexB = true; + result.setBarycentricCoordinates(0,1,0); + + return true; // b; // barycentric coordinates (0,1,0) + } + // Check if P in edge region of AB, if so return projection of P onto AB + btScalar vc = d1*d4 - d3*d2; + if (vc <= btScalar(0.0) && d1 >= btScalar(0.0) && d3 <= btScalar(0.0)) { + btScalar v = d1 / (d1 - d3); + result.m_closestPointOnSimplex = a + v * ab; + result.m_usedVertices.usedVertexA = true; + result.m_usedVertices.usedVertexB = true; + result.setBarycentricCoordinates(1-v,v,0); + return true; + //return a + v * ab; // barycentric coordinates (1-v,v,0) + } + + // Check if P in vertex region outside C + btVector3 cp = p - c; + btScalar d5 = ab.dot(cp); + btScalar d6 = ac.dot(cp); + if (d6 >= btScalar(0.0) && d5 <= d6) + { + result.m_closestPointOnSimplex = c; + result.m_usedVertices.usedVertexC = true; + result.setBarycentricCoordinates(0,0,1); + return true;//c; // barycentric coordinates (0,0,1) + } + + // Check if P in edge region of AC, if so return projection of P onto AC + btScalar vb = d5*d2 - d1*d6; + if (vb <= btScalar(0.0) && d2 >= btScalar(0.0) && d6 <= btScalar(0.0)) { + btScalar w = d2 / (d2 - d6); + result.m_closestPointOnSimplex = a + w * ac; + result.m_usedVertices.usedVertexA = true; + result.m_usedVertices.usedVertexC = true; + result.setBarycentricCoordinates(1-w,0,w); + return true; + //return a + w * ac; // barycentric coordinates (1-w,0,w) + } + + // Check if P in edge region of BC, if so return projection of P onto BC + btScalar va = d3*d6 - d5*d4; + if (va <= btScalar(0.0) && (d4 - d3) >= btScalar(0.0) && (d5 - d6) >= btScalar(0.0)) { + btScalar w = (d4 - d3) / ((d4 - d3) + (d5 - d6)); + + result.m_closestPointOnSimplex = b + w * (c - b); + result.m_usedVertices.usedVertexB = true; + result.m_usedVertices.usedVertexC = true; + result.setBarycentricCoordinates(0,1-w,w); + return true; + // return b + w * (c - b); // barycentric coordinates (0,1-w,w) + } + + // P inside face region. Compute Q through its barycentric coordinates (u,v,w) + btScalar denom = btScalar(1.0) / (va + vb + vc); + btScalar v = vb * denom; + btScalar w = vc * denom; + + result.m_closestPointOnSimplex = a + ab * v + ac * w; + result.m_usedVertices.usedVertexA = true; + result.m_usedVertices.usedVertexB = true; + result.m_usedVertices.usedVertexC = true; + result.setBarycentricCoordinates(1-v-w,v,w); + + return true; +// return a + ab * v + ac * w; // = u*a + v*b + w*c, u = va * denom = btScalar(1.0) - v - w + +} + + + + + +/// Test if point p and d lie on opposite sides of plane through abc +int btVoronoiSimplexSolver::pointOutsideOfPlane(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c, const btVector3& d) +{ + btVector3 normal = (b-a).cross(c-a); + + btScalar signp = (p - a).dot(normal); // [AP AB AC] + btScalar signd = (d - a).dot( normal); // [AD AB AC] + +#ifdef CATCH_DEGENERATE_TETRAHEDRON +#ifdef BT_USE_DOUBLE_PRECISION +if (signd * signd < (btScalar(1e-8) * btScalar(1e-8))) + { + return -1; + } +#else + if (signd * signd < (btScalar(1e-4) * btScalar(1e-4))) + { +// printf("affine dependent/degenerate\n");// + return -1; + } +#endif + +#endif + // Points on opposite sides if expression signs are opposite + return signp * signd < btScalar(0.); +} + + +bool btVoronoiSimplexSolver::closestPtPointTetrahedron(const btVector3& p, const btVector3& a, const btVector3& b, const btVector3& c, const btVector3& d, btSubSimplexClosestResult& finalResult) +{ + btSubSimplexClosestResult tempResult; + + // Start out assuming point inside all halfspaces, so closest to itself + finalResult.m_closestPointOnSimplex = p; + finalResult.m_usedVertices.reset(); + finalResult.m_usedVertices.usedVertexA = true; + finalResult.m_usedVertices.usedVertexB = true; + finalResult.m_usedVertices.usedVertexC = true; + finalResult.m_usedVertices.usedVertexD = true; + + int pointOutsideABC = pointOutsideOfPlane(p, a, b, c, d); + int pointOutsideACD = pointOutsideOfPlane(p, a, c, d, b); + int pointOutsideADB = pointOutsideOfPlane(p, a, d, b, c); + int pointOutsideBDC = pointOutsideOfPlane(p, b, d, c, a); + + if (pointOutsideABC < 0 || pointOutsideACD < 0 || pointOutsideADB < 0 || pointOutsideBDC < 0) + { + finalResult.m_degenerate = true; + return false; + } + + if (!pointOutsideABC && !pointOutsideACD && !pointOutsideADB && !pointOutsideBDC) + { + return false; + } + + + btScalar bestSqDist = FLT_MAX; + // If point outside face abc then compute closest point on abc + if (pointOutsideABC) + { + closestPtPointTriangle(p, a, b, c,tempResult); + btVector3 q = tempResult.m_closestPointOnSimplex; + + btScalar sqDist = (q - p).dot( q - p); + // Update best closest point if (squared) distance is less than current best + if (sqDist < bestSqDist) { + bestSqDist = sqDist; + finalResult.m_closestPointOnSimplex = q; + //convert result bitmask! + finalResult.m_usedVertices.reset(); + finalResult.m_usedVertices.usedVertexA = tempResult.m_usedVertices.usedVertexA; + finalResult.m_usedVertices.usedVertexB = tempResult.m_usedVertices.usedVertexB; + finalResult.m_usedVertices.usedVertexC = tempResult.m_usedVertices.usedVertexC; + finalResult.setBarycentricCoordinates( + tempResult.m_barycentricCoords[VERTA], + tempResult.m_barycentricCoords[VERTB], + tempResult.m_barycentricCoords[VERTC], + 0 + ); + + } + } + + + // Repeat test for face acd + if (pointOutsideACD) + { + closestPtPointTriangle(p, a, c, d,tempResult); + btVector3 q = tempResult.m_closestPointOnSimplex; + //convert result bitmask! + + btScalar sqDist = (q - p).dot( q - p); + if (sqDist < bestSqDist) + { + bestSqDist = sqDist; + finalResult.m_closestPointOnSimplex = q; + finalResult.m_usedVertices.reset(); + finalResult.m_usedVertices.usedVertexA = tempResult.m_usedVertices.usedVertexA; + + finalResult.m_usedVertices.usedVertexC = tempResult.m_usedVertices.usedVertexB; + finalResult.m_usedVertices.usedVertexD = tempResult.m_usedVertices.usedVertexC; + finalResult.setBarycentricCoordinates( + tempResult.m_barycentricCoords[VERTA], + 0, + tempResult.m_barycentricCoords[VERTB], + tempResult.m_barycentricCoords[VERTC] + ); + + } + } + // Repeat test for face adb + + + if (pointOutsideADB) + { + closestPtPointTriangle(p, a, d, b,tempResult); + btVector3 q = tempResult.m_closestPointOnSimplex; + //convert result bitmask! + + btScalar sqDist = (q - p).dot( q - p); + if (sqDist < bestSqDist) + { + bestSqDist = sqDist; + finalResult.m_closestPointOnSimplex = q; + finalResult.m_usedVertices.reset(); + finalResult.m_usedVertices.usedVertexA = tempResult.m_usedVertices.usedVertexA; + finalResult.m_usedVertices.usedVertexB = tempResult.m_usedVertices.usedVertexC; + + finalResult.m_usedVertices.usedVertexD = tempResult.m_usedVertices.usedVertexB; + finalResult.setBarycentricCoordinates( + tempResult.m_barycentricCoords[VERTA], + tempResult.m_barycentricCoords[VERTC], + 0, + tempResult.m_barycentricCoords[VERTB] + ); + + } + } + // Repeat test for face bdc + + + if (pointOutsideBDC) + { + closestPtPointTriangle(p, b, d, c,tempResult); + btVector3 q = tempResult.m_closestPointOnSimplex; + //convert result bitmask! + btScalar sqDist = (q - p).dot( q - p); + if (sqDist < bestSqDist) + { + bestSqDist = sqDist; + finalResult.m_closestPointOnSimplex = q; + finalResult.m_usedVertices.reset(); + // + finalResult.m_usedVertices.usedVertexB = tempResult.m_usedVertices.usedVertexA; + finalResult.m_usedVertices.usedVertexC = tempResult.m_usedVertices.usedVertexC; + finalResult.m_usedVertices.usedVertexD = tempResult.m_usedVertices.usedVertexB; + + finalResult.setBarycentricCoordinates( + 0, + tempResult.m_barycentricCoords[VERTA], + tempResult.m_barycentricCoords[VERTC], + tempResult.m_barycentricCoords[VERTB] + ); + + } + } + + //help! we ended up full ! + + if (finalResult.m_usedVertices.usedVertexA && + finalResult.m_usedVertices.usedVertexB && + finalResult.m_usedVertices.usedVertexC && + finalResult.m_usedVertices.usedVertexD) + { + return true; + } + + return true; +} + |