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Diffstat (limited to 'thirdparty/bullet/src/BulletDynamics/ConstraintSolver/btSliderConstraint.cpp')
| -rw-r--r-- | thirdparty/bullet/src/BulletDynamics/ConstraintSolver/btSliderConstraint.cpp | 855 |
1 files changed, 855 insertions, 0 deletions
diff --git a/thirdparty/bullet/src/BulletDynamics/ConstraintSolver/btSliderConstraint.cpp b/thirdparty/bullet/src/BulletDynamics/ConstraintSolver/btSliderConstraint.cpp new file mode 100644 index 0000000000..d63cef0316 --- /dev/null +++ b/thirdparty/bullet/src/BulletDynamics/ConstraintSolver/btSliderConstraint.cpp @@ -0,0 +1,855 @@ +/* +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. +*/ + +/* +Added by Roman Ponomarev (rponom@gmail.com) +April 04, 2008 +*/ + + + +#include "btSliderConstraint.h" +#include "BulletDynamics/Dynamics/btRigidBody.h" +#include "LinearMath/btTransformUtil.h" +#include <new> + +#define USE_OFFSET_FOR_CONSTANT_FRAME true + +void btSliderConstraint::initParams() +{ + m_lowerLinLimit = btScalar(1.0); + m_upperLinLimit = btScalar(-1.0); + m_lowerAngLimit = btScalar(0.); + m_upperAngLimit = btScalar(0.); + m_softnessDirLin = SLIDER_CONSTRAINT_DEF_SOFTNESS; + m_restitutionDirLin = SLIDER_CONSTRAINT_DEF_RESTITUTION; + m_dampingDirLin = btScalar(0.); + m_cfmDirLin = SLIDER_CONSTRAINT_DEF_CFM; + m_softnessDirAng = SLIDER_CONSTRAINT_DEF_SOFTNESS; + m_restitutionDirAng = SLIDER_CONSTRAINT_DEF_RESTITUTION; + m_dampingDirAng = btScalar(0.); + m_cfmDirAng = SLIDER_CONSTRAINT_DEF_CFM; + m_softnessOrthoLin = SLIDER_CONSTRAINT_DEF_SOFTNESS; + m_restitutionOrthoLin = SLIDER_CONSTRAINT_DEF_RESTITUTION; + m_dampingOrthoLin = SLIDER_CONSTRAINT_DEF_DAMPING; + m_cfmOrthoLin = SLIDER_CONSTRAINT_DEF_CFM; + m_softnessOrthoAng = SLIDER_CONSTRAINT_DEF_SOFTNESS; + m_restitutionOrthoAng = SLIDER_CONSTRAINT_DEF_RESTITUTION; + m_dampingOrthoAng = SLIDER_CONSTRAINT_DEF_DAMPING; + m_cfmOrthoAng = SLIDER_CONSTRAINT_DEF_CFM; + m_softnessLimLin = SLIDER_CONSTRAINT_DEF_SOFTNESS; + m_restitutionLimLin = SLIDER_CONSTRAINT_DEF_RESTITUTION; + m_dampingLimLin = SLIDER_CONSTRAINT_DEF_DAMPING; + m_cfmLimLin = SLIDER_CONSTRAINT_DEF_CFM; + m_softnessLimAng = SLIDER_CONSTRAINT_DEF_SOFTNESS; + m_restitutionLimAng = SLIDER_CONSTRAINT_DEF_RESTITUTION; + m_dampingLimAng = SLIDER_CONSTRAINT_DEF_DAMPING; + m_cfmLimAng = SLIDER_CONSTRAINT_DEF_CFM; + + m_poweredLinMotor = false; + m_targetLinMotorVelocity = btScalar(0.); + m_maxLinMotorForce = btScalar(0.); + m_accumulatedLinMotorImpulse = btScalar(0.0); + + m_poweredAngMotor = false; + m_targetAngMotorVelocity = btScalar(0.); + m_maxAngMotorForce = btScalar(0.); + m_accumulatedAngMotorImpulse = btScalar(0.0); + + m_flags = 0; + m_flags = 0; + + m_useOffsetForConstraintFrame = USE_OFFSET_FOR_CONSTANT_FRAME; + + calculateTransforms(m_rbA.getCenterOfMassTransform(),m_rbB.getCenterOfMassTransform()); +} + + + + + +btSliderConstraint::btSliderConstraint(btRigidBody& rbA, btRigidBody& rbB, const btTransform& frameInA, const btTransform& frameInB, bool useLinearReferenceFrameA) + : btTypedConstraint(SLIDER_CONSTRAINT_TYPE, rbA, rbB), + m_useSolveConstraintObsolete(false), + m_frameInA(frameInA), + m_frameInB(frameInB), + m_useLinearReferenceFrameA(useLinearReferenceFrameA) +{ + initParams(); +} + + + +btSliderConstraint::btSliderConstraint(btRigidBody& rbB, const btTransform& frameInB, bool useLinearReferenceFrameA) + : btTypedConstraint(SLIDER_CONSTRAINT_TYPE, getFixedBody(), rbB), + m_useSolveConstraintObsolete(false), + m_frameInB(frameInB), + m_useLinearReferenceFrameA(useLinearReferenceFrameA) +{ + ///not providing rigidbody A means implicitly using worldspace for body A + m_frameInA = rbB.getCenterOfMassTransform() * m_frameInB; +// m_frameInA.getOrigin() = m_rbA.getCenterOfMassTransform()(m_frameInA.getOrigin()); + + initParams(); +} + + + + + + +void btSliderConstraint::getInfo1(btConstraintInfo1* info) +{ + if (m_useSolveConstraintObsolete) + { + info->m_numConstraintRows = 0; + info->nub = 0; + } + else + { + info->m_numConstraintRows = 4; // Fixed 2 linear + 2 angular + info->nub = 2; + //prepare constraint + calculateTransforms(m_rbA.getCenterOfMassTransform(),m_rbB.getCenterOfMassTransform()); + testAngLimits(); + testLinLimits(); + if(getSolveLinLimit() || getPoweredLinMotor()) + { + info->m_numConstraintRows++; // limit 3rd linear as well + info->nub--; + } + if(getSolveAngLimit() || getPoweredAngMotor()) + { + info->m_numConstraintRows++; // limit 3rd angular as well + info->nub--; + } + } +} + +void btSliderConstraint::getInfo1NonVirtual(btConstraintInfo1* info) +{ + + info->m_numConstraintRows = 6; // Fixed 2 linear + 2 angular + 1 limit (even if not used) + info->nub = 0; +} + +void btSliderConstraint::getInfo2(btConstraintInfo2* info) +{ + getInfo2NonVirtual(info,m_rbA.getCenterOfMassTransform(),m_rbB.getCenterOfMassTransform(), m_rbA.getLinearVelocity(),m_rbB.getLinearVelocity(), m_rbA.getInvMass(),m_rbB.getInvMass()); +} + + + + + + + +void btSliderConstraint::calculateTransforms(const btTransform& transA,const btTransform& transB) +{ + if(m_useLinearReferenceFrameA || (!m_useSolveConstraintObsolete)) + { + m_calculatedTransformA = transA * m_frameInA; + m_calculatedTransformB = transB * m_frameInB; + } + else + { + m_calculatedTransformA = transB * m_frameInB; + m_calculatedTransformB = transA * m_frameInA; + } + m_realPivotAInW = m_calculatedTransformA.getOrigin(); + m_realPivotBInW = m_calculatedTransformB.getOrigin(); + m_sliderAxis = m_calculatedTransformA.getBasis().getColumn(0); // along X + if(m_useLinearReferenceFrameA || m_useSolveConstraintObsolete) + { + m_delta = m_realPivotBInW - m_realPivotAInW; + } + else + { + m_delta = m_realPivotAInW - m_realPivotBInW; + } + m_projPivotInW = m_realPivotAInW + m_sliderAxis.dot(m_delta) * m_sliderAxis; + btVector3 normalWorld; + int i; + //linear part + for(i = 0; i < 3; i++) + { + normalWorld = m_calculatedTransformA.getBasis().getColumn(i); + m_depth[i] = m_delta.dot(normalWorld); + } +} + + + +void btSliderConstraint::testLinLimits(void) +{ + m_solveLinLim = false; + m_linPos = m_depth[0]; + if(m_lowerLinLimit <= m_upperLinLimit) + { + if(m_depth[0] > m_upperLinLimit) + { + m_depth[0] -= m_upperLinLimit; + m_solveLinLim = true; + } + else if(m_depth[0] < m_lowerLinLimit) + { + m_depth[0] -= m_lowerLinLimit; + m_solveLinLim = true; + } + else + { + m_depth[0] = btScalar(0.); + } + } + else + { + m_depth[0] = btScalar(0.); + } +} + + + +void btSliderConstraint::testAngLimits(void) +{ + m_angDepth = btScalar(0.); + m_solveAngLim = false; + if(m_lowerAngLimit <= m_upperAngLimit) + { + const btVector3 axisA0 = m_calculatedTransformA.getBasis().getColumn(1); + const btVector3 axisA1 = m_calculatedTransformA.getBasis().getColumn(2); + const btVector3 axisB0 = m_calculatedTransformB.getBasis().getColumn(1); +// btScalar rot = btAtan2Fast(axisB0.dot(axisA1), axisB0.dot(axisA0)); + btScalar rot = btAtan2(axisB0.dot(axisA1), axisB0.dot(axisA0)); + rot = btAdjustAngleToLimits(rot, m_lowerAngLimit, m_upperAngLimit); + m_angPos = rot; + if(rot < m_lowerAngLimit) + { + m_angDepth = rot - m_lowerAngLimit; + m_solveAngLim = true; + } + else if(rot > m_upperAngLimit) + { + m_angDepth = rot - m_upperAngLimit; + m_solveAngLim = true; + } + } +} + +btVector3 btSliderConstraint::getAncorInA(void) +{ + btVector3 ancorInA; + ancorInA = m_realPivotAInW + (m_lowerLinLimit + m_upperLinLimit) * btScalar(0.5) * m_sliderAxis; + ancorInA = m_rbA.getCenterOfMassTransform().inverse() * ancorInA; + return ancorInA; +} + + + +btVector3 btSliderConstraint::getAncorInB(void) +{ + btVector3 ancorInB; + ancorInB = m_frameInB.getOrigin(); + return ancorInB; +} + + +void btSliderConstraint::getInfo2NonVirtual(btConstraintInfo2* info, const btTransform& transA,const btTransform& transB, const btVector3& linVelA,const btVector3& linVelB, btScalar rbAinvMass,btScalar rbBinvMass ) +{ + const btTransform& trA = getCalculatedTransformA(); + const btTransform& trB = getCalculatedTransformB(); + + btAssert(!m_useSolveConstraintObsolete); + int i, s = info->rowskip; + + btScalar signFact = m_useLinearReferenceFrameA ? btScalar(1.0f) : btScalar(-1.0f); + + // difference between frames in WCS + btVector3 ofs = trB.getOrigin() - trA.getOrigin(); + // now get weight factors depending on masses + btScalar miA = rbAinvMass; + btScalar miB = rbBinvMass; + bool hasStaticBody = (miA < SIMD_EPSILON) || (miB < SIMD_EPSILON); + btScalar miS = miA + miB; + btScalar factA, factB; + if(miS > btScalar(0.f)) + { + factA = miB / miS; + } + else + { + factA = btScalar(0.5f); + } + factB = btScalar(1.0f) - factA; + btVector3 ax1, p, q; + btVector3 ax1A = trA.getBasis().getColumn(0); + btVector3 ax1B = trB.getBasis().getColumn(0); + if(m_useOffsetForConstraintFrame) + { + // get the desired direction of slider axis + // as weighted sum of X-orthos of frameA and frameB in WCS + ax1 = ax1A * factA + ax1B * factB; + ax1.normalize(); + // construct two orthos to slider axis + btPlaneSpace1 (ax1, p, q); + } + else + { // old way - use frameA + ax1 = trA.getBasis().getColumn(0); + // get 2 orthos to slider axis (Y, Z) + p = trA.getBasis().getColumn(1); + q = trA.getBasis().getColumn(2); + } + // make rotations around these orthos equal + // the slider axis should be the only unconstrained + // rotational axis, the angular velocity of the two bodies perpendicular to + // the slider axis should be equal. thus the constraint equations are + // p*w1 - p*w2 = 0 + // q*w1 - q*w2 = 0 + // where p and q are unit vectors normal to the slider axis, and w1 and w2 + // are the angular velocity vectors of the two bodies. + info->m_J1angularAxis[0] = p[0]; + info->m_J1angularAxis[1] = p[1]; + info->m_J1angularAxis[2] = p[2]; + info->m_J1angularAxis[s+0] = q[0]; + info->m_J1angularAxis[s+1] = q[1]; + info->m_J1angularAxis[s+2] = q[2]; + + info->m_J2angularAxis[0] = -p[0]; + info->m_J2angularAxis[1] = -p[1]; + info->m_J2angularAxis[2] = -p[2]; + info->m_J2angularAxis[s+0] = -q[0]; + info->m_J2angularAxis[s+1] = -q[1]; + info->m_J2angularAxis[s+2] = -q[2]; + // compute the right hand side of the constraint equation. set relative + // body velocities along p and q to bring the slider back into alignment. + // if ax1A,ax1B are the unit length slider axes as computed from bodyA and + // bodyB, we need to rotate both bodies along the axis u = (ax1 x ax2). + // if "theta" is the angle between ax1 and ax2, we need an angular velocity + // along u to cover angle erp*theta in one step : + // |angular_velocity| = angle/time = erp*theta / stepsize + // = (erp*fps) * theta + // angular_velocity = |angular_velocity| * (ax1 x ax2) / |ax1 x ax2| + // = (erp*fps) * theta * (ax1 x ax2) / sin(theta) + // ...as ax1 and ax2 are unit length. if theta is smallish, + // theta ~= sin(theta), so + // angular_velocity = (erp*fps) * (ax1 x ax2) + // ax1 x ax2 is in the plane space of ax1, so we project the angular + // velocity to p and q to find the right hand side. +// btScalar k = info->fps * info->erp * getSoftnessOrthoAng(); + btScalar currERP = (m_flags & BT_SLIDER_FLAGS_ERP_ORTANG) ? m_softnessOrthoAng : m_softnessOrthoAng * info->erp; + btScalar k = info->fps * currERP; + + btVector3 u = ax1A.cross(ax1B); + info->m_constraintError[0] = k * u.dot(p); + info->m_constraintError[s] = k * u.dot(q); + if(m_flags & BT_SLIDER_FLAGS_CFM_ORTANG) + { + info->cfm[0] = m_cfmOrthoAng; + info->cfm[s] = m_cfmOrthoAng; + } + + int nrow = 1; // last filled row + int srow; + btScalar limit_err; + int limit; + + // next two rows. + // we want: velA + wA x relA == velB + wB x relB ... but this would + // result in three equations, so we project along two orthos to the slider axis + + btTransform bodyA_trans = transA; + btTransform bodyB_trans = transB; + nrow++; + int s2 = nrow * s; + nrow++; + int s3 = nrow * s; + btVector3 tmpA(0,0,0), tmpB(0,0,0), relA(0,0,0), relB(0,0,0), c(0,0,0); + if(m_useOffsetForConstraintFrame) + { + // get vector from bodyB to frameB in WCS + relB = trB.getOrigin() - bodyB_trans.getOrigin(); + // get its projection to slider axis + btVector3 projB = ax1 * relB.dot(ax1); + // get vector directed from bodyB to slider axis (and orthogonal to it) + btVector3 orthoB = relB - projB; + // same for bodyA + relA = trA.getOrigin() - bodyA_trans.getOrigin(); + btVector3 projA = ax1 * relA.dot(ax1); + btVector3 orthoA = relA - projA; + // get desired offset between frames A and B along slider axis + btScalar sliderOffs = m_linPos - m_depth[0]; + // desired vector from projection of center of bodyA to projection of center of bodyB to slider axis + btVector3 totalDist = projA + ax1 * sliderOffs - projB; + // get offset vectors relA and relB + relA = orthoA + totalDist * factA; + relB = orthoB - totalDist * factB; + // now choose average ortho to slider axis + p = orthoB * factA + orthoA * factB; + btScalar len2 = p.length2(); + if(len2 > SIMD_EPSILON) + { + p /= btSqrt(len2); + } + else + { + p = trA.getBasis().getColumn(1); + } + // make one more ortho + q = ax1.cross(p); + // fill two rows + tmpA = relA.cross(p); + tmpB = relB.cross(p); + for (i=0; i<3; i++) info->m_J1angularAxis[s2+i] = tmpA[i]; + for (i=0; i<3; i++) info->m_J2angularAxis[s2+i] = -tmpB[i]; + tmpA = relA.cross(q); + tmpB = relB.cross(q); + if(hasStaticBody && getSolveAngLimit()) + { // to make constraint between static and dynamic objects more rigid + // remove wA (or wB) from equation if angular limit is hit + tmpB *= factB; + tmpA *= factA; + } + for (i=0; i<3; i++) info->m_J1angularAxis[s3+i] = tmpA[i]; + for (i=0; i<3; i++) info->m_J2angularAxis[s3+i] = -tmpB[i]; + for (i=0; i<3; i++) info->m_J1linearAxis[s2+i] = p[i]; + for (i=0; i<3; i++) info->m_J1linearAxis[s3+i] = q[i]; + for (i=0; i<3; i++) info->m_J2linearAxis[s2+i] = -p[i]; + for (i=0; i<3; i++) info->m_J2linearAxis[s3+i] = -q[i]; + } + else + { // old way - maybe incorrect if bodies are not on the slider axis + // see discussion "Bug in slider constraint" http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=4024&start=0 + c = bodyB_trans.getOrigin() - bodyA_trans.getOrigin(); + btVector3 tmp = c.cross(p); + for (i=0; i<3; i++) info->m_J1angularAxis[s2+i] = factA*tmp[i]; + for (i=0; i<3; i++) info->m_J2angularAxis[s2+i] = factB*tmp[i]; + tmp = c.cross(q); + for (i=0; i<3; i++) info->m_J1angularAxis[s3+i] = factA*tmp[i]; + for (i=0; i<3; i++) info->m_J2angularAxis[s3+i] = factB*tmp[i]; + + for (i=0; i<3; i++) info->m_J1linearAxis[s2+i] = p[i]; + for (i=0; i<3; i++) info->m_J1linearAxis[s3+i] = q[i]; + for (i=0; i<3; i++) info->m_J2linearAxis[s2+i] = -p[i]; + for (i=0; i<3; i++) info->m_J2linearAxis[s3+i] = -q[i]; + } + // compute two elements of right hand side + + // k = info->fps * info->erp * getSoftnessOrthoLin(); + currERP = (m_flags & BT_SLIDER_FLAGS_ERP_ORTLIN) ? m_softnessOrthoLin : m_softnessOrthoLin * info->erp; + k = info->fps * currERP; + + btScalar rhs = k * p.dot(ofs); + info->m_constraintError[s2] = rhs; + rhs = k * q.dot(ofs); + info->m_constraintError[s3] = rhs; + if(m_flags & BT_SLIDER_FLAGS_CFM_ORTLIN) + { + info->cfm[s2] = m_cfmOrthoLin; + info->cfm[s3] = m_cfmOrthoLin; + } + + + // check linear limits + limit_err = btScalar(0.0); + limit = 0; + if(getSolveLinLimit()) + { + limit_err = getLinDepth() * signFact; + limit = (limit_err > btScalar(0.0)) ? 2 : 1; + } + bool powered = getPoweredLinMotor(); + // if the slider has joint limits or motor, add in the extra row + if (limit || powered) + { + nrow++; + srow = nrow * info->rowskip; + info->m_J1linearAxis[srow+0] = ax1[0]; + info->m_J1linearAxis[srow+1] = ax1[1]; + info->m_J1linearAxis[srow+2] = ax1[2]; + info->m_J2linearAxis[srow+0] = -ax1[0]; + info->m_J2linearAxis[srow+1] = -ax1[1]; + info->m_J2linearAxis[srow+2] = -ax1[2]; + // linear torque decoupling step: + // + // we have to be careful that the linear constraint forces (+/- ax1) applied to the two bodies + // do not create a torque couple. in other words, the points that the + // constraint force is applied at must lie along the same ax1 axis. + // a torque couple will result in limited slider-jointed free + // bodies from gaining angular momentum. + if(m_useOffsetForConstraintFrame) + { + // this is needed only when bodyA and bodyB are both dynamic. + if(!hasStaticBody) + { + tmpA = relA.cross(ax1); + tmpB = relB.cross(ax1); + info->m_J1angularAxis[srow+0] = tmpA[0]; + info->m_J1angularAxis[srow+1] = tmpA[1]; + info->m_J1angularAxis[srow+2] = tmpA[2]; + info->m_J2angularAxis[srow+0] = -tmpB[0]; + info->m_J2angularAxis[srow+1] = -tmpB[1]; + info->m_J2angularAxis[srow+2] = -tmpB[2]; + } + } + else + { // The old way. May be incorrect if bodies are not on the slider axis + btVector3 ltd; // Linear Torque Decoupling vector (a torque) + ltd = c.cross(ax1); + info->m_J1angularAxis[srow+0] = factA*ltd[0]; + info->m_J1angularAxis[srow+1] = factA*ltd[1]; + info->m_J1angularAxis[srow+2] = factA*ltd[2]; + info->m_J2angularAxis[srow+0] = factB*ltd[0]; + info->m_J2angularAxis[srow+1] = factB*ltd[1]; + info->m_J2angularAxis[srow+2] = factB*ltd[2]; + } + // right-hand part + btScalar lostop = getLowerLinLimit(); + btScalar histop = getUpperLinLimit(); + if(limit && (lostop == histop)) + { // the joint motor is ineffective + powered = false; + } + info->m_constraintError[srow] = 0.; + info->m_lowerLimit[srow] = 0.; + info->m_upperLimit[srow] = 0.; + currERP = (m_flags & BT_SLIDER_FLAGS_ERP_LIMLIN) ? m_softnessLimLin : info->erp; + if(powered) + { + if(m_flags & BT_SLIDER_FLAGS_CFM_DIRLIN) + { + info->cfm[srow] = m_cfmDirLin; + } + btScalar tag_vel = getTargetLinMotorVelocity(); + btScalar mot_fact = getMotorFactor(m_linPos, m_lowerLinLimit, m_upperLinLimit, tag_vel, info->fps * currERP); + info->m_constraintError[srow] -= signFact * mot_fact * getTargetLinMotorVelocity(); + info->m_lowerLimit[srow] += -getMaxLinMotorForce() / info->fps; + info->m_upperLimit[srow] += getMaxLinMotorForce() / info->fps; + } + if(limit) + { + k = info->fps * currERP; + info->m_constraintError[srow] += k * limit_err; + if(m_flags & BT_SLIDER_FLAGS_CFM_LIMLIN) + { + info->cfm[srow] = m_cfmLimLin; + } + if(lostop == histop) + { // limited low and high simultaneously + info->m_lowerLimit[srow] = -SIMD_INFINITY; + info->m_upperLimit[srow] = SIMD_INFINITY; + } + else if(limit == 1) + { // low limit + info->m_lowerLimit[srow] = -SIMD_INFINITY; + info->m_upperLimit[srow] = 0; + } + else + { // high limit + info->m_lowerLimit[srow] = 0; + info->m_upperLimit[srow] = SIMD_INFINITY; + } + // bounce (we'll use slider parameter abs(1.0 - m_dampingLimLin) for that) + btScalar bounce = btFabs(btScalar(1.0) - getDampingLimLin()); + if(bounce > btScalar(0.0)) + { + btScalar vel = linVelA.dot(ax1); + vel -= linVelB.dot(ax1); + vel *= signFact; + // only apply bounce if the velocity is incoming, and if the + // resulting c[] exceeds what we already have. + if(limit == 1) + { // low limit + if(vel < 0) + { + btScalar newc = -bounce * vel; + if (newc > info->m_constraintError[srow]) + { + info->m_constraintError[srow] = newc; + } + } + } + else + { // high limit - all those computations are reversed + if(vel > 0) + { + btScalar newc = -bounce * vel; + if(newc < info->m_constraintError[srow]) + { + info->m_constraintError[srow] = newc; + } + } + } + } + info->m_constraintError[srow] *= getSoftnessLimLin(); + } // if(limit) + } // if linear limit + // check angular limits + limit_err = btScalar(0.0); + limit = 0; + if(getSolveAngLimit()) + { + limit_err = getAngDepth(); + limit = (limit_err > btScalar(0.0)) ? 1 : 2; + } + // if the slider has joint limits, add in the extra row + powered = getPoweredAngMotor(); + if(limit || powered) + { + nrow++; + srow = nrow * info->rowskip; + info->m_J1angularAxis[srow+0] = ax1[0]; + info->m_J1angularAxis[srow+1] = ax1[1]; + info->m_J1angularAxis[srow+2] = ax1[2]; + + info->m_J2angularAxis[srow+0] = -ax1[0]; + info->m_J2angularAxis[srow+1] = -ax1[1]; + info->m_J2angularAxis[srow+2] = -ax1[2]; + + btScalar lostop = getLowerAngLimit(); + btScalar histop = getUpperAngLimit(); + if(limit && (lostop == histop)) + { // the joint motor is ineffective + powered = false; + } + currERP = (m_flags & BT_SLIDER_FLAGS_ERP_LIMANG) ? m_softnessLimAng : info->erp; + if(powered) + { + if(m_flags & BT_SLIDER_FLAGS_CFM_DIRANG) + { + info->cfm[srow] = m_cfmDirAng; + } + btScalar mot_fact = getMotorFactor(m_angPos, m_lowerAngLimit, m_upperAngLimit, getTargetAngMotorVelocity(), info->fps * currERP); + info->m_constraintError[srow] = mot_fact * getTargetAngMotorVelocity(); + info->m_lowerLimit[srow] = -getMaxAngMotorForce() / info->fps; + info->m_upperLimit[srow] = getMaxAngMotorForce() / info->fps; + } + if(limit) + { + k = info->fps * currERP; + info->m_constraintError[srow] += k * limit_err; + if(m_flags & BT_SLIDER_FLAGS_CFM_LIMANG) + { + info->cfm[srow] = m_cfmLimAng; + } + if(lostop == histop) + { + // limited low and high simultaneously + info->m_lowerLimit[srow] = -SIMD_INFINITY; + info->m_upperLimit[srow] = SIMD_INFINITY; + } + else if(limit == 1) + { // low limit + info->m_lowerLimit[srow] = 0; + info->m_upperLimit[srow] = SIMD_INFINITY; + } + else + { // high limit + info->m_lowerLimit[srow] = -SIMD_INFINITY; + info->m_upperLimit[srow] = 0; + } + // bounce (we'll use slider parameter abs(1.0 - m_dampingLimAng) for that) + btScalar bounce = btFabs(btScalar(1.0) - getDampingLimAng()); + if(bounce > btScalar(0.0)) + { + btScalar vel = m_rbA.getAngularVelocity().dot(ax1); + vel -= m_rbB.getAngularVelocity().dot(ax1); + // only apply bounce if the velocity is incoming, and if the + // resulting c[] exceeds what we already have. + if(limit == 1) + { // low limit + if(vel < 0) + { + btScalar newc = -bounce * vel; + if(newc > info->m_constraintError[srow]) + { + info->m_constraintError[srow] = newc; + } + } + } + else + { // high limit - all those computations are reversed + if(vel > 0) + { + btScalar newc = -bounce * vel; + if(newc < info->m_constraintError[srow]) + { + info->m_constraintError[srow] = newc; + } + } + } + } + info->m_constraintError[srow] *= getSoftnessLimAng(); + } // if(limit) + } // if angular limit or powered +} + + +///override the default global value of a parameter (such as ERP or CFM), optionally provide the axis (0..5). +///If no axis is provided, it uses the default axis for this constraint. +void btSliderConstraint::setParam(int num, btScalar value, int axis) +{ + switch(num) + { + case BT_CONSTRAINT_STOP_ERP : + if(axis < 1) + { + m_softnessLimLin = value; + m_flags |= BT_SLIDER_FLAGS_ERP_LIMLIN; + } + else if(axis < 3) + { + m_softnessOrthoLin = value; + m_flags |= BT_SLIDER_FLAGS_ERP_ORTLIN; + } + else if(axis == 3) + { + m_softnessLimAng = value; + m_flags |= BT_SLIDER_FLAGS_ERP_LIMANG; + } + else if(axis < 6) + { + m_softnessOrthoAng = value; + m_flags |= BT_SLIDER_FLAGS_ERP_ORTANG; + } + else + { + btAssertConstrParams(0); + } + break; + case BT_CONSTRAINT_CFM : + if(axis < 1) + { + m_cfmDirLin = value; + m_flags |= BT_SLIDER_FLAGS_CFM_DIRLIN; + } + else if(axis == 3) + { + m_cfmDirAng = value; + m_flags |= BT_SLIDER_FLAGS_CFM_DIRANG; + } + else + { + btAssertConstrParams(0); + } + break; + case BT_CONSTRAINT_STOP_CFM : + if(axis < 1) + { + m_cfmLimLin = value; + m_flags |= BT_SLIDER_FLAGS_CFM_LIMLIN; + } + else if(axis < 3) + { + m_cfmOrthoLin = value; + m_flags |= BT_SLIDER_FLAGS_CFM_ORTLIN; + } + else if(axis == 3) + { + m_cfmLimAng = value; + m_flags |= BT_SLIDER_FLAGS_CFM_LIMANG; + } + else if(axis < 6) + { + m_cfmOrthoAng = value; + m_flags |= BT_SLIDER_FLAGS_CFM_ORTANG; + } + else + { + btAssertConstrParams(0); + } + break; + } +} + +///return the local value of parameter +btScalar btSliderConstraint::getParam(int num, int axis) const +{ + btScalar retVal(SIMD_INFINITY); + switch(num) + { + case BT_CONSTRAINT_STOP_ERP : + if(axis < 1) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_ERP_LIMLIN); + retVal = m_softnessLimLin; + } + else if(axis < 3) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_ERP_ORTLIN); + retVal = m_softnessOrthoLin; + } + else if(axis == 3) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_ERP_LIMANG); + retVal = m_softnessLimAng; + } + else if(axis < 6) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_ERP_ORTANG); + retVal = m_softnessOrthoAng; + } + else + { + btAssertConstrParams(0); + } + break; + case BT_CONSTRAINT_CFM : + if(axis < 1) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_CFM_DIRLIN); + retVal = m_cfmDirLin; + } + else if(axis == 3) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_CFM_DIRANG); + retVal = m_cfmDirAng; + } + else + { + btAssertConstrParams(0); + } + break; + case BT_CONSTRAINT_STOP_CFM : + if(axis < 1) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_CFM_LIMLIN); + retVal = m_cfmLimLin; + } + else if(axis < 3) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_CFM_ORTLIN); + retVal = m_cfmOrthoLin; + } + else if(axis == 3) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_CFM_LIMANG); + retVal = m_cfmLimAng; + } + else if(axis < 6) + { + btAssertConstrParams(m_flags & BT_SLIDER_FLAGS_CFM_ORTANG); + retVal = m_cfmOrthoAng; + } + else + { + btAssertConstrParams(0); + } + break; + } + return retVal; +} + + + |