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Diffstat (limited to 'extern/bullet2/LinearMath/btTransformUtil.h')
| -rw-r--r-- | extern/bullet2/LinearMath/btTransformUtil.h | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/extern/bullet2/LinearMath/btTransformUtil.h b/extern/bullet2/LinearMath/btTransformUtil.h new file mode 100644 index 00000000000..dd9057546d8 --- /dev/null +++ b/extern/bullet2/LinearMath/btTransformUtil.h @@ -0,0 +1,228 @@ +/* +Copyright (c) 2003-2006 Gino van den Bergen / 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. +*/ + + +#ifndef SIMD_TRANSFORM_UTIL_H +#define SIMD_TRANSFORM_UTIL_H + +#include "btTransform.h" +#define ANGULAR_MOTION_THRESHOLD btScalar(0.5)*SIMD_HALF_PI + + + + +SIMD_FORCE_INLINE btVector3 btAabbSupport(const btVector3& halfExtents,const btVector3& supportDir) +{ + return btVector3(supportDir.x() < btScalar(0.0) ? -halfExtents.x() : halfExtents.x(), + supportDir.y() < btScalar(0.0) ? -halfExtents.y() : halfExtents.y(), + supportDir.z() < btScalar(0.0) ? -halfExtents.z() : halfExtents.z()); +} + + + + + + +/// Utils related to temporal transforms +class btTransformUtil +{ + +public: + + static void integrateTransform(const btTransform& curTrans,const btVector3& linvel,const btVector3& angvel,btScalar timeStep,btTransform& predictedTransform) + { + predictedTransform.setOrigin(curTrans.getOrigin() + linvel * timeStep); +// #define QUATERNION_DERIVATIVE + #ifdef QUATERNION_DERIVATIVE + btQuaternion predictedOrn = curTrans.getRotation(); + predictedOrn += (angvel * predictedOrn) * (timeStep * btScalar(0.5)); + predictedOrn.normalize(); + #else + //Exponential map + //google for "Practical Parameterization of Rotations Using the Exponential Map", F. Sebastian Grassia + + btVector3 axis; + btScalar fAngle = angvel.length(); + //limit the angular motion + if (fAngle*timeStep > ANGULAR_MOTION_THRESHOLD) + { + fAngle = ANGULAR_MOTION_THRESHOLD / timeStep; + } + + if ( fAngle < btScalar(0.001) ) + { + // use Taylor's expansions of sync function + axis = angvel*( btScalar(0.5)*timeStep-(timeStep*timeStep*timeStep)*(btScalar(0.020833333333))*fAngle*fAngle ); + } + else + { + // sync(fAngle) = sin(c*fAngle)/t + axis = angvel*( btSin(btScalar(0.5)*fAngle*timeStep)/fAngle ); + } + btQuaternion dorn (axis.x(),axis.y(),axis.z(),btCos( fAngle*timeStep*btScalar(0.5) )); + btQuaternion orn0 = curTrans.getRotation(); + + btQuaternion predictedOrn = dorn * orn0; + predictedOrn.normalize(); + #endif + predictedTransform.setRotation(predictedOrn); + } + + static void calculateVelocityQuaternion(const btVector3& pos0,const btVector3& pos1,const btQuaternion& orn0,const btQuaternion& orn1,btScalar timeStep,btVector3& linVel,btVector3& angVel) + { + linVel = (pos1 - pos0) / timeStep; + btVector3 axis; + btScalar angle; + if (orn0 != orn1) + { + calculateDiffAxisAngleQuaternion(orn0,orn1,axis,angle); + angVel = axis * angle / timeStep; + } else + { + angVel.setValue(0,0,0); + } + } + + static void calculateDiffAxisAngleQuaternion(const btQuaternion& orn0,const btQuaternion& orn1a,btVector3& axis,btScalar& angle) + { + btQuaternion orn1 = orn0.nearest(orn1a); + btQuaternion dorn = orn1 * orn0.inverse(); + angle = dorn.getAngle(); + axis = btVector3(dorn.x(),dorn.y(),dorn.z()); + axis[3] = btScalar(0.); + //check for axis length + btScalar len = axis.length2(); + if (len < SIMD_EPSILON*SIMD_EPSILON) + axis = btVector3(btScalar(1.),btScalar(0.),btScalar(0.)); + else + axis /= btSqrt(len); + } + + static void calculateVelocity(const btTransform& transform0,const btTransform& transform1,btScalar timeStep,btVector3& linVel,btVector3& angVel) + { + linVel = (transform1.getOrigin() - transform0.getOrigin()) / timeStep; + btVector3 axis; + btScalar angle; + calculateDiffAxisAngle(transform0,transform1,axis,angle); + angVel = axis * angle / timeStep; + } + + static void calculateDiffAxisAngle(const btTransform& transform0,const btTransform& transform1,btVector3& axis,btScalar& angle) + { + btMatrix3x3 dmat = transform1.getBasis() * transform0.getBasis().inverse(); + btQuaternion dorn; + dmat.getRotation(dorn); + + ///floating point inaccuracy can lead to w component > 1..., which breaks + dorn.normalize(); + + angle = dorn.getAngle(); + axis = btVector3(dorn.x(),dorn.y(),dorn.z()); + axis[3] = btScalar(0.); + //check for axis length + btScalar len = axis.length2(); + if (len < SIMD_EPSILON*SIMD_EPSILON) + axis = btVector3(btScalar(1.),btScalar(0.),btScalar(0.)); + else + axis /= btSqrt(len); + } + +}; + + +///The btConvexSeparatingDistanceUtil can help speed up convex collision detection +///by conservatively updating a cached separating distance/vector instead of re-calculating the closest distance +class btConvexSeparatingDistanceUtil +{ + btQuaternion m_ornA; + btQuaternion m_ornB; + btVector3 m_posA; + btVector3 m_posB; + + btVector3 m_separatingNormal; + + btScalar m_boundingRadiusA; + btScalar m_boundingRadiusB; + btScalar m_separatingDistance; + +public: + + btConvexSeparatingDistanceUtil(btScalar boundingRadiusA,btScalar boundingRadiusB) + :m_boundingRadiusA(boundingRadiusA), + m_boundingRadiusB(boundingRadiusB), + m_separatingDistance(0.f) + { + } + + btScalar getConservativeSeparatingDistance() + { + return m_separatingDistance; + } + + void updateSeparatingDistance(const btTransform& transA,const btTransform& transB) + { + const btVector3& toPosA = transA.getOrigin(); + const btVector3& toPosB = transB.getOrigin(); + btQuaternion toOrnA = transA.getRotation(); + btQuaternion toOrnB = transB.getRotation(); + + if (m_separatingDistance>0.f) + { + + + btVector3 linVelA,angVelA,linVelB,angVelB; + btTransformUtil::calculateVelocityQuaternion(m_posA,toPosA,m_ornA,toOrnA,btScalar(1.),linVelA,angVelA); + btTransformUtil::calculateVelocityQuaternion(m_posB,toPosB,m_ornB,toOrnB,btScalar(1.),linVelB,angVelB); + btScalar maxAngularProjectedVelocity = angVelA.length() * m_boundingRadiusA + angVelB.length() * m_boundingRadiusB; + btVector3 relLinVel = (linVelB-linVelA); + btScalar relLinVelocLength = (linVelB-linVelA).dot(m_separatingNormal); + if (relLinVelocLength<0.f) + { + relLinVelocLength = 0.f; + } + + btScalar projectedMotion = maxAngularProjectedVelocity +relLinVelocLength; + m_separatingDistance -= projectedMotion; + } + + m_posA = toPosA; + m_posB = toPosB; + m_ornA = toOrnA; + m_ornB = toOrnB; + } + + void initSeparatingDistance(const btVector3& separatingVector,btScalar separatingDistance,const btTransform& transA,const btTransform& transB) + { + m_separatingDistance = separatingDistance; + + if (m_separatingDistance>0.f) + { + m_separatingNormal = separatingVector; + + const btVector3& toPosA = transA.getOrigin(); + const btVector3& toPosB = transB.getOrigin(); + btQuaternion toOrnA = transA.getRotation(); + btQuaternion toOrnB = transB.getRotation(); + m_posA = toPosA; + m_posB = toPosB; + m_ornA = toOrnA; + m_ornB = toOrnB; + } + } + +}; + + +#endif //SIMD_TRANSFORM_UTIL_H + |