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Diffstat (limited to 'thirdparty/bullet/src/Bullet3Common/b3TransformUtil.h')
| -rw-r--r-- | thirdparty/bullet/src/Bullet3Common/b3TransformUtil.h | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/thirdparty/bullet/src/Bullet3Common/b3TransformUtil.h b/thirdparty/bullet/src/Bullet3Common/b3TransformUtil.h new file mode 100644 index 0000000000..6ce580c132 --- /dev/null +++ b/thirdparty/bullet/src/Bullet3Common/b3TransformUtil.h @@ -0,0 +1,228 @@ +/* +Copyright (c) 2003-2013 Gino van den Bergen / 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. +*/ + + +#ifndef B3_TRANSFORM_UTIL_H +#define B3_TRANSFORM_UTIL_H + +#include "b3Transform.h" +#define B3_ANGULAR_MOTION_THRESHOLD b3Scalar(0.5)*B3_HALF_PI + + + + +B3_FORCE_INLINE b3Vector3 b3AabbSupport(const b3Vector3& halfExtents,const b3Vector3& supportDir) +{ + return b3MakeVector3(supportDir.getX() < b3Scalar(0.0) ? -halfExtents.getX() : halfExtents.getX(), + supportDir.getY() < b3Scalar(0.0) ? -halfExtents.getY() : halfExtents.getY(), + supportDir.getZ() < b3Scalar(0.0) ? -halfExtents.getZ() : halfExtents.getZ()); +} + + + + + + +/// Utils related to temporal transforms +class b3TransformUtil +{ + +public: + + static void integrateTransform(const b3Transform& curTrans,const b3Vector3& linvel,const b3Vector3& angvel,b3Scalar timeStep,b3Transform& predictedTransform) + { + predictedTransform.setOrigin(curTrans.getOrigin() + linvel * timeStep); +// #define QUATERNION_DERIVATIVE + #ifdef QUATERNION_DERIVATIVE + b3Quaternion predictedOrn = curTrans.getRotation(); + predictedOrn += (angvel * predictedOrn) * (timeStep * b3Scalar(0.5)); + predictedOrn.normalize(); + #else + //Exponential map + //google for "Practical Parameterization of Rotations Using the Exponential Map", F. Sebastian Grassia + + b3Vector3 axis; + b3Scalar fAngle = angvel.length(); + //limit the angular motion + if (fAngle*timeStep > B3_ANGULAR_MOTION_THRESHOLD) + { + fAngle = B3_ANGULAR_MOTION_THRESHOLD / timeStep; + } + + if ( fAngle < b3Scalar(0.001) ) + { + // use Taylor's expansions of sync function + axis = angvel*( b3Scalar(0.5)*timeStep-(timeStep*timeStep*timeStep)*(b3Scalar(0.020833333333))*fAngle*fAngle ); + } + else + { + // sync(fAngle) = sin(c*fAngle)/t + axis = angvel*( b3Sin(b3Scalar(0.5)*fAngle*timeStep)/fAngle ); + } + b3Quaternion dorn (axis.getX(),axis.getY(),axis.getZ(),b3Cos( fAngle*timeStep*b3Scalar(0.5) )); + b3Quaternion orn0 = curTrans.getRotation(); + + b3Quaternion predictedOrn = dorn * orn0; + predictedOrn.normalize(); + #endif + predictedTransform.setRotation(predictedOrn); + } + + static void calculateVelocityQuaternion(const b3Vector3& pos0,const b3Vector3& pos1,const b3Quaternion& orn0,const b3Quaternion& orn1,b3Scalar timeStep,b3Vector3& linVel,b3Vector3& angVel) + { + linVel = (pos1 - pos0) / timeStep; + b3Vector3 axis; + b3Scalar angle; + if (orn0 != orn1) + { + calculateDiffAxisAngleQuaternion(orn0,orn1,axis,angle); + angVel = axis * angle / timeStep; + } else + { + angVel.setValue(0,0,0); + } + } + + static void calculateDiffAxisAngleQuaternion(const b3Quaternion& orn0,const b3Quaternion& orn1a,b3Vector3& axis,b3Scalar& angle) + { + b3Quaternion orn1 = orn0.nearest(orn1a); + b3Quaternion dorn = orn1 * orn0.inverse(); + angle = dorn.getAngle(); + axis = b3MakeVector3(dorn.getX(),dorn.getY(),dorn.getZ()); + axis[3] = b3Scalar(0.); + //check for axis length + b3Scalar len = axis.length2(); + if (len < B3_EPSILON*B3_EPSILON) + axis = b3MakeVector3(b3Scalar(1.),b3Scalar(0.),b3Scalar(0.)); + else + axis /= b3Sqrt(len); + } + + static void calculateVelocity(const b3Transform& transform0,const b3Transform& transform1,b3Scalar timeStep,b3Vector3& linVel,b3Vector3& angVel) + { + linVel = (transform1.getOrigin() - transform0.getOrigin()) / timeStep; + b3Vector3 axis; + b3Scalar angle; + calculateDiffAxisAngle(transform0,transform1,axis,angle); + angVel = axis * angle / timeStep; + } + + static void calculateDiffAxisAngle(const b3Transform& transform0,const b3Transform& transform1,b3Vector3& axis,b3Scalar& angle) + { + b3Matrix3x3 dmat = transform1.getBasis() * transform0.getBasis().inverse(); + b3Quaternion dorn; + dmat.getRotation(dorn); + + ///floating point inaccuracy can lead to w component > 1..., which breaks + dorn.normalize(); + + angle = dorn.getAngle(); + axis = b3MakeVector3(dorn.getX(),dorn.getY(),dorn.getZ()); + axis[3] = b3Scalar(0.); + //check for axis length + b3Scalar len = axis.length2(); + if (len < B3_EPSILON*B3_EPSILON) + axis = b3MakeVector3(b3Scalar(1.),b3Scalar(0.),b3Scalar(0.)); + else + axis /= b3Sqrt(len); + } + +}; + + +///The b3ConvexSeparatingDistanceUtil can help speed up convex collision detection +///by conservatively updating a cached separating distance/vector instead of re-calculating the closest distance +class b3ConvexSeparatingDistanceUtil +{ + b3Quaternion m_ornA; + b3Quaternion m_ornB; + b3Vector3 m_posA; + b3Vector3 m_posB; + + b3Vector3 m_separatingNormal; + + b3Scalar m_boundingRadiusA; + b3Scalar m_boundingRadiusB; + b3Scalar m_separatingDistance; + +public: + + b3ConvexSeparatingDistanceUtil(b3Scalar boundingRadiusA,b3Scalar boundingRadiusB) + :m_boundingRadiusA(boundingRadiusA), + m_boundingRadiusB(boundingRadiusB), + m_separatingDistance(0.f) + { + } + + b3Scalar getConservativeSeparatingDistance() + { + return m_separatingDistance; + } + + void updateSeparatingDistance(const b3Transform& transA,const b3Transform& transB) + { + const b3Vector3& toPosA = transA.getOrigin(); + const b3Vector3& toPosB = transB.getOrigin(); + b3Quaternion toOrnA = transA.getRotation(); + b3Quaternion toOrnB = transB.getRotation(); + + if (m_separatingDistance>0.f) + { + + + b3Vector3 linVelA,angVelA,linVelB,angVelB; + b3TransformUtil::calculateVelocityQuaternion(m_posA,toPosA,m_ornA,toOrnA,b3Scalar(1.),linVelA,angVelA); + b3TransformUtil::calculateVelocityQuaternion(m_posB,toPosB,m_ornB,toOrnB,b3Scalar(1.),linVelB,angVelB); + b3Scalar maxAngularProjectedVelocity = angVelA.length() * m_boundingRadiusA + angVelB.length() * m_boundingRadiusB; + b3Vector3 relLinVel = (linVelB-linVelA); + b3Scalar relLinVelocLength = relLinVel.dot(m_separatingNormal); + if (relLinVelocLength<0.f) + { + relLinVelocLength = 0.f; + } + + b3Scalar projectedMotion = maxAngularProjectedVelocity +relLinVelocLength; + m_separatingDistance -= projectedMotion; + } + + m_posA = toPosA; + m_posB = toPosB; + m_ornA = toOrnA; + m_ornB = toOrnB; + } + + void initSeparatingDistance(const b3Vector3& separatingVector,b3Scalar separatingDistance,const b3Transform& transA,const b3Transform& transB) + { + m_separatingDistance = separatingDistance; + + if (m_separatingDistance>0.f) + { + m_separatingNormal = separatingVector; + + const b3Vector3& toPosA = transA.getOrigin(); + const b3Vector3& toPosB = transB.getOrigin(); + b3Quaternion toOrnA = transA.getRotation(); + b3Quaternion toOrnB = transB.getRotation(); + m_posA = toPosA; + m_posB = toPosB; + m_ornA = toOrnA; + m_ornB = toOrnB; + } + } + +}; + + +#endif //B3_TRANSFORM_UTIL_H + |