diff -r 000000000000 -r 2f259fa3e83a ode/src/joint.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ode/src/joint.cpp Tue Feb 02 01:00:49 2010 +0200 @@ -0,0 +1,3847 @@ +/************************************************************************* + * * + * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. * + * All rights reserved. Email: russ@q12.org Web: www.q12.org * + * * + * This library is free software; you can redistribute it and/or * + * modify it under the terms of EITHER: * + * (1) The GNU Lesser General Public License as published by the Free * + * Software Foundation; either version 2.1 of the License, or (at * + * your option) any later version. The text of the GNU Lesser * + * General Public License is included with this library in the * + * file LICENSE.TXT. * + * (2) The BSD-style license that is included with this library in * + * the file LICENSE-BSD.TXT. * + * * + * This library is distributed in the hope that it will be useful, * + * but WITHOUT ANY WARRANTY; without even the implied warranty of * + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files * + * LICENSE.TXT and LICENSE-BSD.TXT for more details. * + * * + *************************************************************************/ + +/* + +design note: the general principle for giving a joint the option of connecting +to the static environment (i.e. the absolute frame) is to check the second +body (joint->node[1].body), and if it is zero then behave as if its body +transform is the identity. + +*/ + +#include +#include +#include +#include +#include "joint.h" + +#define dCROSSMUL(a,op,b,c) \ +do { \ + (a)[0] op dMUL(REAL(0.5),(dMUL((b)[1],(c)[2]) - dMUL((b)[2],(c)[1]))); \ + (a)[1] op dMUL(REAL(0.5),(dMUL((b)[2],(c)[0]) - dMUL((b)[0],(c)[2]))); \ + (a)[2] op dMUL(REAL(0.5),(dMUL((b)[0],(c)[1]) - dMUL((b)[1],(c)[0]))); \ +} while(0) + +//**************************************************************************** +// externs + +// extern "C" void dBodyAddTorque (dBodyID, dReal fx, dReal fy, dReal fz); +// extern "C" void dBodyAddForce (dBodyID, dReal fx, dReal fy, dReal fz); + +//**************************************************************************** +// utility + +// set three "ball-and-socket" rows in the constraint equation, and the +// corresponding right hand side. + +static inline void setBall (dxJoint *joint, dxJoint::Info2 *info, + dVector3 anchor1, dVector3 anchor2) +{ + // anchor points in global coordinates with respect to body PORs. + dVector3 a1,a2; + + int s = info->rowskip; + + // set jacobian + info->J1l[0] = REAL(1.0); + info->J1l[s+1] = REAL(1.0); + info->J1l[2*s+2] = REAL(1.0); + dMULTIPLY0_331 (a1,joint->node[0].body->posr.R,anchor1); + dCROSSMAT (info->J1a,a1,s,-,+); + if (joint->node[1].body) { + info->J2l[0] = -REAL(1.0); + info->J2l[s+1] = -REAL(1.0); + info->J2l[2*s+2] = -REAL(1.0); + dMULTIPLY0_331 (a2,joint->node[1].body->posr.R,anchor2); + dCROSSMAT (info->J2a,a2,s,+,-); + } + + // set right hand side + dReal k = dMUL(info->fps,info->erp); + if (joint->node[1].body) { + for (int j=0; j<3; j++) { + info->c[j] = dMUL(k,(a2[j] + joint->node[1].body->posr.pos[j] - + a1[j] - joint->node[0].body->posr.pos[j])); + } + } + else { + for (int j=0; j<3; j++) { + info->c[j] = dMUL(k,(anchor2[j] - a1[j] - + joint->node[0].body->posr.pos[j])); + } + } +} + + +// this is like setBall(), except that `axis' is a unit length vector +// (in global coordinates) that should be used for the first jacobian +// position row (the other two row vectors will be derived from this). +// `erp1' is the erp value to use along the axis. + +static inline void setBall2 (dxJoint *joint, dxJoint::Info2 *info, + dVector3 anchor1, dVector3 anchor2, + dVector3 axis, dReal erp1) +{ + // anchor points in global coordinates with respect to body PORs. + dVector3 a1,a2; + + int i,s = info->rowskip; + + // get vectors normal to the axis. in setBall() axis,q1,q2 is [1 0 0], + // [0 1 0] and [0 0 1], which makes everything much easier. + dVector3 q1,q2; + dPlaneSpace (axis,q1,q2); + + // set jacobian + for (i=0; i<3; i++) info->J1l[i] = axis[i]; + for (i=0; i<3; i++) info->J1l[s+i] = q1[i]; + for (i=0; i<3; i++) info->J1l[2*s+i] = q2[i]; + dMULTIPLY0_331 (a1,joint->node[0].body->posr.R,anchor1); + dCROSS (info->J1a,=,a1,axis); + dCROSS (info->J1a+s,=,a1,q1); + dCROSS (info->J1a+2*s,=,a1,q2); + if (joint->node[1].body) { + for (i=0; i<3; i++) info->J2l[i] = -axis[i]; + for (i=0; i<3; i++) info->J2l[s+i] = -q1[i]; + for (i=0; i<3; i++) info->J2l[2*s+i] = -q2[i]; + dMULTIPLY0_331 (a2,joint->node[1].body->posr.R,anchor2); + dCROSS (info->J2a,= -,a2,axis); + dCROSS (info->J2a+s,= -,a2,q1); + dCROSS (info->J2a+2*s,= -,a2,q2); + } + + // set right hand side - measure error along (axis,q1,q2) + dReal k1 = dMUL(info->fps,erp1); + dReal k = dMUL(info->fps,info->erp); + + for (i=0; i<3; i++) a1[i] += joint->node[0].body->posr.pos[i]; + if (joint->node[1].body) { + for (i=0; i<3; i++) a2[i] += joint->node[1].body->posr.pos[i]; + info->c[0] = dMUL(k1,(dDOT(axis,a2) - dDOT(axis,a1))); + info->c[1] = dMUL(k,(dDOT(q1,a2) - dDOT(q1,a1))); + info->c[2] = dMUL(k,(dDOT(q2,a2) - dDOT(q2,a1))); + } + else { + info->c[0] = dMUL(k1,(dDOT(axis,anchor2) - dDOT(axis,a1))); + info->c[1] = dMUL(k,(dDOT(q1,anchor2) - dDOT(q1,a1))); + info->c[2] = dMUL(k,(dDOT(q2,anchor2) - dDOT(q2,a1))); + } +} + + +// set three orientation rows in the constraint equation, and the +// corresponding right hand side. + +static void setFixedOrientation(dxJoint *joint, dxJoint::Info2 *info, dQuaternion qrel, int start_row) +{ + int s = info->rowskip; + int start_index = start_row * s; + + // 3 rows to make body rotations equal + info->J1a[start_index] = REAL(1.0); + info->J1a[start_index + s + 1] = REAL(1.0); + info->J1a[start_index + s*2+2] = REAL(1.0); + if (joint->node[1].body) { + info->J2a[start_index] = REAL(-1.0); + info->J2a[start_index + s+1] = REAL(-1.0); + info->J2a[start_index + s*2+2] = REAL(-1.0); + } + + // compute the right hand side. the first three elements will result in + // relative angular velocity of the two bodies - this is set to bring them + // back into alignment. the correcting angular velocity is + // |angular_velocity| = angle/time = erp*theta / stepsize + // = (erp*fps) * theta + // angular_velocity = |angular_velocity| * u + // = (erp*fps) * theta * u + // where rotation along unit length axis u by theta brings body 2's frame + // to qrel with respect to body 1's frame. using a small angle approximation + // for sin(), this gives + // angular_velocity = (erp*fps) * 2 * v + // where the quaternion of the relative rotation between the two bodies is + // q = [cos(theta/2) sin(theta/2)*u] = [s v] + + // get qerr = relative rotation (rotation error) between two bodies + dQuaternion qerr,e; + if (joint->node[1].body) { + dQuaternion qq; + dQMultiply1 (qq,joint->node[0].body->q,joint->node[1].body->q); + dQMultiply2 (qerr,qq,qrel); + } + else { + dQMultiply3 (qerr,joint->node[0].body->q,qrel); + } + if (qerr[0] < 0) { + qerr[1] = -qerr[1]; // adjust sign of qerr to make theta small + qerr[2] = -qerr[2]; + qerr[3] = -qerr[3]; + } + dMULTIPLY0_331 (e,joint->node[0].body->posr.R,qerr+1); // @@@ bad SIMD padding! + dReal k = dMUL(info->fps,info->erp); + info->c[start_row] = 2*dMUL(k,e[0]); + info->c[start_row+1] = 2*dMUL(k,e[1]); + info->c[start_row+2] = 2*dMUL(k,e[2]); +} + + +// compute anchor points relative to bodies + +static void setAnchors (dxJoint *j, dReal x, dReal y, dReal z, + dVector3 anchor1, dVector3 anchor2) +{ + if (j->node[0].body) { + dReal q[4]; + q[0] = x - j->node[0].body->posr.pos[0]; + q[1] = y - j->node[0].body->posr.pos[1]; + q[2] = z - j->node[0].body->posr.pos[2]; + q[3] = 0; + dMULTIPLY1_331 (anchor1,j->node[0].body->posr.R,q); + if (j->node[1].body) { + q[0] = x - j->node[1].body->posr.pos[0]; + q[1] = y - j->node[1].body->posr.pos[1]; + q[2] = z - j->node[1].body->posr.pos[2]; + q[3] = 0; + dMULTIPLY1_331 (anchor2,j->node[1].body->posr.R,q); + } + else { + anchor2[0] = x; + anchor2[1] = y; + anchor2[2] = z; + } + } + anchor1[3] = 0; + anchor2[3] = 0; +} + + +// compute axes relative to bodies. either axis1 or axis2 can be 0. + +static void setAxes (dxJoint *j, dReal x, dReal y, dReal z, + dVector3 axis1, dVector3 axis2) +{ + if (j->node[0].body) { + dReal q[4]; + q[0] = x; + q[1] = y; + q[2] = z; + q[3] = 0; + dNormalize3 (q); + if (axis1) { + dMULTIPLY1_331 (axis1,j->node[0].body->posr.R,q); + axis1[3] = 0; + } + if (axis2) { + if (j->node[1].body) { + dMULTIPLY1_331 (axis2,j->node[1].body->posr.R,q); + } + else { + axis2[0] = x; + axis2[1] = y; + axis2[2] = z; + } + axis2[3] = 0; + } + } +} + + +static void getAnchor (dxJoint *j, dVector3 result, dVector3 anchor1) +{ + if (j->node[0].body) { + dMULTIPLY0_331 (result,j->node[0].body->posr.R,anchor1); + result[0] += j->node[0].body->posr.pos[0]; + result[1] += j->node[0].body->posr.pos[1]; + result[2] += j->node[0].body->posr.pos[2]; + } +} + + +static void getAnchor2 (dxJoint *j, dVector3 result, dVector3 anchor2) +{ + if (j->node[1].body) { + dMULTIPLY0_331 (result,j->node[1].body->posr.R,anchor2); + result[0] += j->node[1].body->posr.pos[0]; + result[1] += j->node[1].body->posr.pos[1]; + result[2] += j->node[1].body->posr.pos[2]; + } + else { + result[0] = anchor2[0]; + result[1] = anchor2[1]; + result[2] = anchor2[2]; + } +} + + +static void getAxis (dxJoint *j, dVector3 result, dVector3 axis1) +{ + if (j->node[0].body) { + dMULTIPLY0_331 (result,j->node[0].body->posr.R,axis1); + } +} + + +static void getAxis2 (dxJoint *j, dVector3 result, dVector3 axis2) +{ + if (j->node[1].body) { + dMULTIPLY0_331 (result,j->node[1].body->posr.R,axis2); + } + else { + result[0] = axis2[0]; + result[1] = axis2[1]; + result[2] = axis2[2]; + } +} + + +static dReal getHingeAngleFromRelativeQuat (dQuaternion qrel, dVector3 axis) +{ + // the angle between the two bodies is extracted from the quaternion that + // represents the relative rotation between them. recall that a quaternion + // q is: + // [s,v] = [ cos(theta/2) , sin(theta/2) * u ] + // where s is a scalar and v is a 3-vector. u is a unit length axis and + // theta is a rotation along that axis. we can get theta/2 by: + // theta/2 = atan2 ( sin(theta/2) , cos(theta/2) ) + // but we can't get sin(theta/2) directly, only its absolute value, i.e.: + // |v| = |sin(theta/2)| * |u| + // = |sin(theta/2)| + // using this value will have a strange effect. recall that there are two + // quaternion representations of a given rotation, q and -q. typically as + // a body rotates along the axis it will go through a complete cycle using + // one representation and then the next cycle will use the other + // representation. this corresponds to u pointing in the direction of the + // hinge axis and then in the opposite direction. the result is that theta + // will appear to go "backwards" every other cycle. here is a fix: if u + // points "away" from the direction of the hinge (motor) axis (i.e. more + // than 90 degrees) then use -q instead of q. this represents the same + // rotation, but results in the cos(theta/2) value being sign inverted. + + // extract the angle from the quaternion. cost2 = cos(theta/2), + // sint2 = |sin(theta/2)| + dReal cost2 = qrel[0]; + dReal sint2 = dSqrt (dMUL(qrel[1],qrel[1])+dMUL(qrel[2],qrel[2])+dMUL(qrel[3],qrel[3])); + dReal theta = (dDOT(qrel+REAL(1.0),axis) >= 0) ? // @@@ padding assumptions + (2 * dArcTan2(sint2,cost2)) : // if u points in direction of axis + (2 * dArcTan2(sint2,-cost2)); // if u points in opposite direction + + // the angle we get will be between 0..2*pi, but we want to return angles + // between -pi..pi + if (theta > dPI) theta -= 2*dPI; + + // the angle we've just extracted has the wrong sign + theta = -theta; + + return theta; +} + + +// given two bodies (body1,body2), the hinge axis that they are connected by +// w.r.t. body1 (axis), and the initial relative orientation between them +// (q_initial), return the relative rotation angle. the initial relative +// orientation corresponds to an angle of zero. if body2 is 0 then measure the +// angle between body1 and the static frame. +// +// this will not return the correct angle if the bodies rotate along any axis +// other than the given hinge axis. + +static dReal getHingeAngle (dxBody *body1, dxBody *body2, dVector3 axis, + dQuaternion q_initial) +{ + // get qrel = relative rotation between the two bodies + dQuaternion qrel; + if (body2) { + dQuaternion qq; + dQMultiply1 (qq,body1->q,body2->q); + dQMultiply2 (qrel,qq,q_initial); + } + else { + // pretend body2->q is the identity + dQMultiply3 (qrel,body1->q,q_initial); + } + + return getHingeAngleFromRelativeQuat (qrel,axis); +} + +//**************************************************************************** +// dxJointLimitMotor + +void dxJointLimitMotor::init (dxWorld *world) +{ + vel = 0; + fmax = 0; + lostop = -dInfinity; + histop = dInfinity; + fudge_factor = REAL(1.0); + normal_cfm = world->global_cfm; + stop_erp = world->global_erp; + stop_cfm = world->global_cfm; + bounce = 0; + limit = 0; + limit_err = 0; +} + + +void dxJointLimitMotor::set (int num, dReal value) +{ + switch (num) { + case dParamLoStop: + lostop = value; + break; + case dParamHiStop: + histop = value; + break; + case dParamVel: + vel = value; + break; + case dParamFMax: + if (value >= 0) fmax = value; + break; + case dParamFudgeFactor: + if (value >= 0 && value <= REAL(1.0)) fudge_factor = value; + break; + case dParamBounce: + bounce = value; + break; + case dParamCFM: + normal_cfm = value; + break; + case dParamStopERP: + stop_erp = value; + break; + case dParamStopCFM: + stop_cfm = value; + break; + } +} + + +dReal dxJointLimitMotor::get (int num) +{ + switch (num) { + case dParamLoStop: return lostop; + case dParamHiStop: return histop; + case dParamVel: return vel; + case dParamFMax: return fmax; + case dParamFudgeFactor: return fudge_factor; + case dParamBounce: return bounce; + case dParamCFM: return normal_cfm; + case dParamStopERP: return stop_erp; + case dParamStopCFM: return stop_cfm; + default: return 0; + } +} + + +int dxJointLimitMotor::testRotationalLimit (dReal angle) +{ + if (angle <= lostop) { + limit = 1; + limit_err = angle - lostop; + return 1; + } + else if (angle >= histop) { + limit = 2; + limit_err = angle - histop; + return 1; + } + else { + limit = 0; + return 0; + } +} + + +int dxJointLimitMotor::addLimot (dxJoint *joint, + dxJoint::Info2 *info, int row, + const dVector3 ax1, int rotational) +{ + int srow = row * info->rowskip; + + // if the joint is powered, or has joint limits, add in the extra row + int powered = fmax > 0; + if (powered || limit) { + dReal *J1 = rotational ? info->J1a : info->J1l; + dReal *J2 = rotational ? info->J2a : info->J2l; + + J1[srow+0] = ax1[0]; + J1[srow+1] = ax1[1]; + J1[srow+2] = ax1[2]; + if (joint->node[1].body) { + J2[srow+0] = -ax1[0]; + J2[srow+1] = -ax1[1]; + J2[srow+2] = -ax1[2]; + } + + // linear limot torque decoupling step: + // + // if this is a linear limot (e.g. from a slider), 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 powered or limited slider-jointed free + // bodies from gaining angular momentum. + // the solution used here is to apply the constraint forces at the point + // halfway between the body centers. there is no penalty (other than an + // extra tiny bit of computation) in doing this adjustment. note that we + // only need to do this if the constraint connects two bodies. + + dVector3 ltd = {}; // Linear Torque Decoupling vector (a torque) + if (!rotational && joint->node[1].body) { + dVector3 c; + c[0]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[0]-joint->node[0].body->posr.pos[0])); + c[1]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[1]-joint->node[0].body->posr.pos[1])); + c[2]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[2]-joint->node[0].body->posr.pos[2])); + dCROSS (ltd,=,c,ax1); + info->J1a[srow+0] = ltd[0]; + info->J1a[srow+1] = ltd[1]; + info->J1a[srow+2] = ltd[2]; + info->J2a[srow+0] = ltd[0]; + info->J2a[srow+1] = ltd[1]; + info->J2a[srow+2] = ltd[2]; + } + + // if we're limited low and high simultaneously, the joint motor is + // ineffective + if (limit && (lostop == histop)) powered = 0; + + if (powered) { + info->cfm[row] = normal_cfm; + if (! limit) { + info->c[row] = vel; + info->lo[row] = -fmax; + info->hi[row] = fmax; + } + else { + // the joint is at a limit, AND is being powered. if the joint is + // being powered into the limit then we apply the maximum motor force + // in that direction, because the motor is working against the + // immovable limit. if the joint is being powered away from the limit + // then we have problems because actually we need *two* lcp + // constraints to handle this case. so we fake it and apply some + // fraction of the maximum force. the fraction to use can be set as + // a fudge factor. + + dReal fm = fmax; + if ((vel > 0) || (vel==0 && limit==2)) fm = -fm; + + // if we're powering away from the limit, apply the fudge factor + if ((limit==1 && vel > 0) || (limit==2 && vel < 0)) fm *= fudge_factor; + + if (rotational) { + dBodyAddTorque (joint->node[0].body,-dMUL(fm,ax1[0]),-dMUL(fm,ax1[1]), + -dMUL(fm,ax1[2])); + if (joint->node[1].body) + dBodyAddTorque (joint->node[1].body,dMUL(fm,ax1[0]),dMUL(fm,ax1[1]),dMUL(fm,ax1[2])); + } + else { + dBodyAddForce (joint->node[0].body,-dMUL(fm,ax1[0]),-dMUL(fm,ax1[1]),-dMUL(fm,ax1[2])); + if (joint->node[1].body) { + dBodyAddForce (joint->node[1].body,dMUL(fm,ax1[0]),dMUL(fm,ax1[1]),dMUL(fm,ax1[2])); + + // linear limot torque decoupling step: refer to above discussion + dBodyAddTorque (joint->node[0].body,-dMUL(fm,ltd[0]),-dMUL(fm,ltd[1]), + -dMUL(fm,ltd[2])); + dBodyAddTorque (joint->node[1].body,-dMUL(fm,ltd[0]),-dMUL(fm,ltd[1]), + -dMUL(fm,ltd[2])); + } + } + } + } + + if (limit) { + dReal k = dMUL(info->fps,stop_erp); + info->c[row] = -dMUL(k,limit_err); + info->cfm[row] = stop_cfm; + + if (lostop == histop) { + // limited low and high simultaneously + info->lo[row] = -dInfinity; + info->hi[row] = dInfinity; + } + else { + if (limit == 1) { + // low limit + info->lo[row] = REAL(0.0); + info->hi[row] = dInfinity; + } + else { + // high limit + info->lo[row] = -dInfinity; + info->hi[row] = REAL(0.0); + } + + // deal with bounce + if (bounce > 0) { + // calculate joint velocity + dReal vel; + if (rotational) { + vel = dDOT(joint->node[0].body->avel,ax1); + if (joint->node[1].body) + vel -= dDOT(joint->node[1].body->avel,ax1); + } + else { + vel = dDOT(joint->node[0].body->lvel,ax1); + if (joint->node[1].body) + vel -= dDOT(joint->node[1].body->lvel,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) { + dReal newc = -dMUL(bounce,vel); + if (newc > info->c[row]) info->c[row] = newc; + } + } + else { + // high limit - all those computations are reversed + if (vel > 0) { + dReal newc = -dMUL(bounce,vel); + if (newc < info->c[row]) info->c[row] = newc; + } + } + } + } + } + return 1; + } + else return 0; +} + +//**************************************************************************** +// ball and socket + +static void ballInit (dxJointBall *j) +{ + dSetZero (j->anchor1,4); + dSetZero (j->anchor2,4); +} + + +static void ballGetInfo1 (dxJointBall */*j*/, dxJoint::Info1 *info) +{ + info->m = 3; + info->nub = 3; +} + + +static void ballGetInfo2 (dxJointBall *joint, dxJoint::Info2 *info) +{ + setBall (joint,info,joint->anchor1,joint->anchor2); +} + + +EXPORT_C void dJointSetBallAnchor (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointBall* joint = (dxJointBall*)j; + setAnchors (joint,x,y,z,joint->anchor1,joint->anchor2); +} + + +EXPORT_C void dJointSetBallAnchor2 (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointBall* joint = (dxJointBall*)j; + joint->anchor2[0] = x; + joint->anchor2[1] = y; + joint->anchor2[2] = z; + joint->anchor2[3] = 0; + +} + +EXPORT_C void dJointGetBallAnchor (dJointID j, dVector3 result) +{ + dxJointBall* joint = (dxJointBall*)j; + if (joint->flags & dJOINT_REVERSE) + getAnchor2 (joint,result,joint->anchor2); + else + getAnchor (joint,result,joint->anchor1); +} + + +EXPORT_C void dJointGetBallAnchor2 (dJointID j, dVector3 result) +{ + dxJointBall* joint = (dxJointBall*)j; + if (joint->flags & dJOINT_REVERSE) + getAnchor (joint,result,joint->anchor1); + else + getAnchor2 (joint,result,joint->anchor2); +} + + +dxJoint::Vtable __dball_vtable = { + sizeof(dxJointBall), + (dxJoint::init_fn*) ballInit, + (dxJoint::getInfo1_fn*) ballGetInfo1, + (dxJoint::getInfo2_fn*) ballGetInfo2, + dJointTypeBall}; + +//**************************************************************************** +// hinge + +static void hingeInit (dxJointHinge *j) +{ + dSetZero (j->anchor1,4); + dSetZero (j->anchor2,4); + dSetZero (j->axis1,4); + j->axis1[0] = REAL(1.0); + dSetZero (j->axis2,4); + j->axis2[0] = REAL(1.0); + dSetZero (j->qrel,4); + j->limot.init (j->world); +} + + +static void hingeGetInfo1 (dxJointHinge *j, dxJoint::Info1 *info) +{ + info->nub = 5; + + // see if joint is powered + if (j->limot.fmax > 0) + info->m = 6; // powered hinge needs an extra constraint row + else info->m = 5; + + // see if we're at a joint limit. + if ((j->limot.lostop >= -dPI || j->limot.histop <= dPI) && + j->limot.lostop <= j->limot.histop) { + dReal angle = getHingeAngle (j->node[0].body,j->node[1].body,j->axis1, + j->qrel); + if (j->limot.testRotationalLimit (angle)) info->m = 6; + } +} + + +static void hingeGetInfo2 (dxJointHinge *joint, dxJoint::Info2 *info) +{ + // set the three ball-and-socket rows + setBall (joint,info,joint->anchor1,joint->anchor2); + + // set the two hinge rows. the hinge axis should be the only unconstrained + // rotational axis, the angular velocity of the two bodies perpendicular to + // the hinge 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 hinge axis, and w1 and w2 + // are the angular velocity vectors of the two bodies. + + dVector3 ax1; // length 1 joint axis in global coordinates, from 1st body + dVector3 p,q; // plane space vectors for ax1 + dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); + dPlaneSpace (ax1,p,q); + + int s3=3*info->rowskip; + int s4=4*info->rowskip; + + info->J1a[s3+0] = p[0]; + info->J1a[s3+1] = p[1]; + info->J1a[s3+2] = p[2]; + info->J1a[s4+0] = q[0]; + info->J1a[s4+1] = q[1]; + info->J1a[s4+2] = q[2]; + + if (joint->node[1].body) { + info->J2a[s3+0] = -p[0]; + info->J2a[s3+1] = -p[1]; + info->J2a[s3+2] = -p[2]; + info->J2a[s4+0] = -q[0]; + info->J2a[s4+1] = -q[1]; + info->J2a[s4+2] = -q[2]; + } + + // compute the right hand side of the constraint equation. set relative + // body velocities along p and q to bring the hinge back into alignment. + // if ax1,ax2 are the unit length hinge axes as computed from body1 and + // body2, 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. + + dVector3 ax2,b; + if (joint->node[1].body) { + dMULTIPLY0_331 (ax2,joint->node[1].body->posr.R,joint->axis2); + } + else { + ax2[0] = joint->axis2[0]; + ax2[1] = joint->axis2[1]; + ax2[2] = joint->axis2[2]; + } + dCROSS (b,=,ax1,ax2); + dReal k = dMUL(info->fps,info->erp); + info->c[3] = dMUL(k,dDOT(b,p)); + info->c[4] = dMUL(k,dDOT(b,q)); + + // if the hinge is powered, or has joint limits, add in the stuff + joint->limot.addLimot (joint,info,5,ax1,1); +} + + +// compute initial relative rotation body1 -> body2, or env -> body1 + +static void hingeComputeInitialRelativeRotation (dxJointHinge *joint) +{ + if (joint->node[0].body) { + if (joint->node[1].body) { + dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); + } + else { + // set joint->qrel to the transpose of the first body q + joint->qrel[0] = joint->node[0].body->q[0]; + for (int i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; + } + } +} + + +EXPORT_C void dJointSetHingeAnchor (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointHinge* joint = (dxJointHinge*)j; + setAnchors (joint,x,y,z,joint->anchor1,joint->anchor2); + hingeComputeInitialRelativeRotation (joint); +} + + +EXPORT_C void dJointSetHingeAnchorDelta (dJointID j, dReal x, dReal y, dReal z, dReal dx, dReal dy, dReal dz) +{ + dxJointHinge* joint = (dxJointHinge*)j; + + if (joint->node[0].body) { + dReal q[4]; + q[0] = x - joint->node[0].body->posr.pos[0]; + q[1] = y - joint->node[0].body->posr.pos[1]; + q[2] = z - joint->node[0].body->posr.pos[2]; + q[3] = REAL(0.0); + dMULTIPLY1_331 (joint->anchor1,joint->node[0].body->posr.R,q); + + if (joint->node[1].body) { + q[0] = x - joint->node[1].body->posr.pos[0]; + q[1] = y - joint->node[1].body->posr.pos[1]; + q[2] = z - joint->node[1].body->posr.pos[2]; + q[3] = 0; + dMULTIPLY1_331 (joint->anchor2,joint->node[1].body->posr.R,q); + } + else { + // Move the relative displacement between the passive body and the + // anchor in the same direction as the passive body has just moved + joint->anchor2[0] = x + dx; + joint->anchor2[1] = y + dy; + joint->anchor2[2] = z + dz; + } + } + joint->anchor1[3] = 0; + joint->anchor2[3] = 0; + + hingeComputeInitialRelativeRotation (joint); +} + + + +EXPORT_C void dJointSetHingeAxis (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointHinge* joint = (dxJointHinge*)j; + + setAxes (joint,x,y,z,joint->axis1,joint->axis2); + hingeComputeInitialRelativeRotation (joint); +} + + +EXPORT_C void dJointGetHingeAnchor (dJointID j, dVector3 result) +{ + dxJointHinge* joint = (dxJointHinge*)j; + if (joint->flags & dJOINT_REVERSE) + getAnchor2 (joint,result,joint->anchor2); + else + getAnchor (joint,result,joint->anchor1); +} + + +EXPORT_C void dJointGetHingeAnchor2 (dJointID j, dVector3 result) +{ + dxJointHinge* joint = (dxJointHinge*)j; + + if (joint->flags & dJOINT_REVERSE) + getAnchor (joint,result,joint->anchor1); + else + getAnchor2 (joint,result,joint->anchor2); +} + + +EXPORT_C void dJointGetHingeAxis (dJointID j, dVector3 result) +{ + dxJointHinge* joint = (dxJointHinge*)j; + + getAxis (joint,result,joint->axis1); +} + + +EXPORT_C void dJointSetHingeParam (dJointID j, int parameter, dReal value) +{ + dxJointHinge* joint = (dxJointHinge*)j; + + joint->limot.set (parameter,value); +} + + +EXPORT_C dReal dJointGetHingeParam (dJointID j, int parameter) +{ + dxJointHinge* joint = (dxJointHinge*)j; + + return joint->limot.get (parameter); +} + + +EXPORT_C dReal dJointGetHingeAngle (dJointID j) +{ + dxJointHinge* joint = (dxJointHinge*)j; + + if (joint->node[0].body) { + dReal ang = getHingeAngle (joint->node[0].body,joint->node[1].body,joint->axis1, + joint->qrel); + if (joint->flags & dJOINT_REVERSE) + return -ang; + else + return ang; + } + else return 0; +} + + +EXPORT_C dReal dJointGetHingeAngleRate (dJointID j) +{ + dxJointHinge* joint = (dxJointHinge*)j; + + if (joint->node[0].body) { + dVector3 axis; + dMULTIPLY0_331 (axis,joint->node[0].body->posr.R,joint->axis1); + dReal rate = dDOT(axis,joint->node[0].body->avel); + if (joint->node[1].body) rate -= dDOT(axis,joint->node[1].body->avel); + if (joint->flags & dJOINT_REVERSE) rate = - rate; + return rate; + } + else return 0; +} + + +EXPORT_C void dJointAddHingeTorque (dJointID j, dReal torque) +{ + dxJointHinge* joint = (dxJointHinge*)j; + dVector3 axis; + + + if (joint->flags & dJOINT_REVERSE) + torque = -torque; + + getAxis (joint,axis,joint->axis1); + axis[0] = dMUL(axis[0],torque); + axis[1] = dMUL(axis[1],torque); + axis[2] = dMUL(axis[2],torque); + + if (joint->node[0].body != 0) + dBodyAddTorque (joint->node[0].body, axis[0], axis[1], axis[2]); + if (joint->node[1].body != 0) + dBodyAddTorque(joint->node[1].body, -axis[0], -axis[1], -axis[2]); +} + + +dxJoint::Vtable __dhinge_vtable = { + sizeof(dxJointHinge), + (dxJoint::init_fn*) hingeInit, + (dxJoint::getInfo1_fn*) hingeGetInfo1, + (dxJoint::getInfo2_fn*) hingeGetInfo2, + dJointTypeHinge}; + +//**************************************************************************** +// slider + +static void sliderInit (dxJointSlider *j) +{ + dSetZero (j->axis1,4); + j->axis1[0] = REAL(1.0); + dSetZero (j->qrel,4); + dSetZero (j->offset,4); + j->limot.init (j->world); +} + + +EXPORT_C dReal dJointGetSliderPosition (dJointID j) +{ + dxJointSlider* joint = (dxJointSlider*)j; + + + // get axis1 in global coordinates + dVector3 ax1,q; + dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); + + if (joint->node[1].body) { + // get body2 + offset point in global coordinates + dMULTIPLY0_331 (q,joint->node[1].body->posr.R,joint->offset); + for (int i=0; i<3; i++) q[i] = joint->node[0].body->posr.pos[i] - q[i] - + joint->node[1].body->posr.pos[i]; + } + else { + for (int i=0; i<3; i++) q[i] = joint->node[0].body->posr.pos[i] - + joint->offset[i]; + + } + return dDOT(ax1,q); +} + + +EXPORT_C dReal dJointGetSliderPositionRate (dJointID j) +{ + dxJointSlider* joint = (dxJointSlider*)j; + + + // get axis1 in global coordinates + dVector3 ax1; + dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); + + if (joint->node[1].body) { + return dDOT(ax1,joint->node[0].body->lvel) - + dDOT(ax1,joint->node[1].body->lvel); + } + else { + return dDOT(ax1,joint->node[0].body->lvel); + } +} + + +static void sliderGetInfo1 (dxJointSlider *j, dxJoint::Info1 *info) +{ + info->nub = 5; + + // see if joint is powered + if (j->limot.fmax > 0) + info->m = 6; // powered slider needs an extra constraint row + else info->m = 5; + + // see if we're at a joint limit. + j->limot.limit = 0; + if ((j->limot.lostop > -dInfinity || j->limot.histop < dInfinity) && + j->limot.lostop <= j->limot.histop) { + // measure joint position + dReal pos = dJointGetSliderPosition (j); + if (pos <= j->limot.lostop) { + j->limot.limit = 1; + j->limot.limit_err = pos - j->limot.lostop; + info->m = 6; + } + else if (pos >= j->limot.histop) { + j->limot.limit = 2; + j->limot.limit_err = pos - j->limot.histop; + info->m = 6; + } + } +} + + +static void sliderGetInfo2 (dxJointSlider *joint, dxJoint::Info2 *info) +{ + int i,s = info->rowskip; + int s3=3*s,s4=4*s; + + // pull out pos and R for both bodies. also get the `connection' + // vector pos2-pos1. + + dReal *pos1,*pos2,*R1,*R2; + dVector3 c; + pos1 = joint->node[0].body->posr.pos; + R1 = joint->node[0].body->posr.R; + if (joint->node[1].body) { + pos2 = joint->node[1].body->posr.pos; + R2 = joint->node[1].body->posr.R; + for (i=0; i<3; i++) c[i] = pos2[i] - pos1[i]; + } + else { + pos2 = 0; + R2 = 0; + } + + // 3 rows to make body rotations equal + setFixedOrientation(joint, info, joint->qrel, 0); + + // remaining two rows. we want: vel2 = vel1 + w1 x c ... but this would + // result in three equations, so we project along the planespace vectors + // so that sliding along the slider axis is disregarded. for symmetry we + // also substitute (w1+w2)/2 for w1, as w1 is supposed to equal w2. + + dVector3 ax1; // joint axis in global coordinates (unit length) + dVector3 p,q; // plane space of ax1 + dMULTIPLY0_331 (ax1,R1,joint->axis1); + dPlaneSpace (ax1,p,q); + if (joint->node[1].body) { + dVector3 tmp; + dCROSSMUL (tmp, = ,c,p); + for (i=0; i<3; i++) info->J1a[s3+i] = tmp[i]; + for (i=0; i<3; i++) info->J2a[s3+i] = tmp[i]; + dCROSSMUL (tmp, = ,c,q); + for (i=0; i<3; i++) info->J1a[s4+i] = tmp[i]; + for (i=0; i<3; i++) info->J2a[s4+i] = tmp[i]; + for (i=0; i<3; i++) info->J2l[s3+i] = -p[i]; + for (i=0; i<3; i++) info->J2l[s4+i] = -q[i]; + } + for (i=0; i<3; i++) info->J1l[s3+i] = p[i]; + for (i=0; i<3; i++) info->J1l[s4+i] = q[i]; + + // compute last two elements of right hand side. we want to align the offset + // point (in body 2's frame) with the center of body 1. + dReal k = dMUL(info->fps,info->erp); + if (joint->node[1].body) { + dVector3 ofs; // offset point in global coordinates + dMULTIPLY0_331 (ofs,R2,joint->offset); + for (i=0; i<3; i++) c[i] += ofs[i]; + info->c[3] = dMUL(k,dDOT(p,c)); + info->c[4] = dMUL(k,dDOT(q,c)); + } + else { + dVector3 ofs; // offset point in global coordinates + for (i=0; i<3; i++) ofs[i] = joint->offset[i] - pos1[i]; + info->c[3] = dMUL(k,dDOT(p,ofs)); + info->c[4] = dMUL(k,dDOT(q,ofs)); + } + + // if the slider is powered, or has joint limits, add in the extra row + joint->limot.addLimot (joint,info,5,ax1,0); +} + + +EXPORT_C void dJointSetSliderAxis (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointSlider* joint = (dxJointSlider*)j; + int i; + + setAxes (joint,x,y,z,joint->axis1,0); + + // compute initial relative rotation body1 -> body2, or env -> body1 + // also compute center of body1 w.r.t body 2 + if (joint->node[1].body) { + dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); + dVector3 c; + for (i=0; i<3; i++) + c[i] = joint->node[0].body->posr.pos[i] - joint->node[1].body->posr.pos[i]; + dMULTIPLY1_331 (joint->offset,joint->node[1].body->posr.R,c); + } + else { + // set joint->qrel to the transpose of the first body's q + joint->qrel[0] = joint->node[0].body->q[0]; + for (i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; + for (i=0; i<3; i++) joint->offset[i] = joint->node[0].body->posr.pos[i]; + } +} + + +EXPORT_C void dJointSetSliderAxisDelta (dJointID j, dReal x, dReal y, dReal z, dReal dx, dReal dy, dReal dz) +{ + dxJointSlider* joint = (dxJointSlider*)j; + int i; + + setAxes (joint,x,y,z,joint->axis1,0); + + // compute initial relative rotation body1 -> body2, or env -> body1 + // also compute center of body1 w.r.t body 2 + if (joint->node[1].body) { + dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); + dVector3 c; + for (i=0; i<3; i++) + c[i] = joint->node[0].body->posr.pos[i] - joint->node[1].body->posr.pos[i]; + dMULTIPLY1_331 (joint->offset,joint->node[1].body->posr.R,c); + } + else { + // set joint->qrel to the transpose of the first body's q + joint->qrel[0] = joint->node[0].body->q[0]; + + for (i=1; i<4; i++) + joint->qrel[i] = -joint->node[0].body->q[i]; + + joint->offset[0] = joint->node[0].body->posr.pos[0] + dx; + joint->offset[1] = joint->node[0].body->posr.pos[1] + dy; + joint->offset[2] = joint->node[0].body->posr.pos[2] + dz; + } +} + + + +EXPORT_C void dJointGetSliderAxis (dJointID j, dVector3 result) +{ + dxJointSlider* joint = (dxJointSlider*)j; + + getAxis (joint,result,joint->axis1); +} + + +EXPORT_C void dJointSetSliderParam (dJointID j, int parameter, dReal value) +{ + dxJointSlider* joint = (dxJointSlider*)j; + + joint->limot.set (parameter,value); +} + + +EXPORT_C dReal dJointGetSliderParam (dJointID j, int parameter) +{ + dxJointSlider* joint = (dxJointSlider*)j; + + return joint->limot.get (parameter); +} + + +EXPORT_C void dJointAddSliderForce (dJointID j, dReal force) +{ + dxJointSlider* joint = (dxJointSlider*)j; + dVector3 axis; + + + if (joint->flags & dJOINT_REVERSE) + force -= force; + + getAxis (joint,axis,joint->axis1); + axis[0] = dMUL(axis[0],force); + axis[1] = dMUL(axis[1],force); + axis[2] = dMUL(axis[2],force); + + if (joint->node[0].body != 0) + dBodyAddForce (joint->node[0].body,axis[0],axis[1],axis[2]); + if (joint->node[1].body != 0) + dBodyAddForce(joint->node[1].body, -axis[0], -axis[1], -axis[2]); + + if (joint->node[0].body != 0 && joint->node[1].body != 0) { + // linear torque decoupling: + // we have to compensate the torque, that this slider force may generate + // if body centers are not aligned along the slider axis + + dVector3 ltd; // Linear Torque Decoupling vector (a torque) + + dVector3 c; + c[0]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[0]-joint->node[0].body->posr.pos[0])); + c[1]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[1]-joint->node[0].body->posr.pos[1])); + c[2]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[2]-joint->node[0].body->posr.pos[2])); + dCROSS (ltd,=,c,axis); + + dBodyAddTorque (joint->node[0].body,ltd[0],ltd[1], ltd[2]); + dBodyAddTorque (joint->node[1].body,ltd[0],ltd[1], ltd[2]); + } +} + + +dxJoint::Vtable __dslider_vtable = { + sizeof(dxJointSlider), + (dxJoint::init_fn*) sliderInit, + (dxJoint::getInfo1_fn*) sliderGetInfo1, + (dxJoint::getInfo2_fn*) sliderGetInfo2, + dJointTypeSlider}; + +//**************************************************************************** +// contact + +static void contactInit (dxJointContact */*j*/) +{ + +} + + +static void contactGetInfo1 (dxJointContact *j, dxJoint::Info1 *info) +{ + // make sure mu's >= 0, then calculate number of constraint rows and number + // of unbounded rows. + int m = 1, nub=0; + if (j->contact.surface.mu < 0) j->contact.surface.mu = 0; + if (j->contact.surface.mode & dContactMu2) { + if (j->contact.surface.mu > 0) m++; + if (j->contact.surface.mu2 < 0) j->contact.surface.mu2 = 0; + if (j->contact.surface.mu2 > 0) m++; + if (j->contact.surface.mu == dInfinity) nub ++; + if (j->contact.surface.mu2 == dInfinity) nub ++; + } + else { + if (j->contact.surface.mu > REAL(0.0)) m += 2; + if (j->contact.surface.mu == dInfinity) nub += 2; + } + + j->the_m = m; + info->m = m; + info->nub = nub; +} + + +static void contactGetInfo2 (dxJointContact *j, dxJoint::Info2 *info) +{ + int s = info->rowskip; + int s2 = 2*s; + + // get normal, with sign adjusted for body1/body2 polarity + dVector3 normal; + if (j->flags & dJOINT_REVERSE) { + normal[0] = - j->contact.geom.normal[0]; + normal[1] = - j->contact.geom.normal[1]; + normal[2] = - j->contact.geom.normal[2]; + } + else { + normal[0] = j->contact.geom.normal[0]; + normal[1] = j->contact.geom.normal[1]; + normal[2] = j->contact.geom.normal[2]; + } + normal[3] = 0; // @@@ hmmm + + // c1,c2 = contact points with respect to body PORs + dVector3 c1,c2 = {}; + c1[0] = j->contact.geom.pos[0] - j->node[0].body->posr.pos[0]; + c1[1] = j->contact.geom.pos[1] - j->node[0].body->posr.pos[1]; + c1[2] = j->contact.geom.pos[2] - j->node[0].body->posr.pos[2]; + + // set jacobian for normal + info->J1l[0] = normal[0]; + info->J1l[1] = normal[1]; + info->J1l[2] = normal[2]; + dCROSS (info->J1a,=,c1,normal); + if (j->node[1].body) { + c2[0] = j->contact.geom.pos[0] - j->node[1].body->posr.pos[0]; + c2[1] = j->contact.geom.pos[1] - j->node[1].body->posr.pos[1]; + c2[2] = j->contact.geom.pos[2] - j->node[1].body->posr.pos[2]; + info->J2l[0] = -normal[0]; + info->J2l[1] = -normal[1]; + info->J2l[2] = -normal[2]; + dCROSS (info->J2a,= -,c2,normal); + } + + // set right hand side and cfm value for normal + dReal erp = info->erp; + if (j->contact.surface.mode & dContactSoftERP) + erp = j->contact.surface.soft_erp; + dReal k = dMUL(info->fps,erp); + dReal depth = j->contact.geom.depth - j->world->contactp.min_depth; + if (depth < 0) depth = 0; + + const dReal maxvel = j->world->contactp.max_vel; + info->c[0] = dMUL(k,depth); + if (info->c[0] > maxvel) + info->c[0] = maxvel; + + if (j->contact.surface.mode & dContactSoftCFM) + info->cfm[0] = j->contact.surface.soft_cfm; + + // deal with bounce + if (j->contact.surface.mode & dContactBounce) { + // calculate outgoing velocity (-ve for incoming contact) + dReal outgoing = dDOT(info->J1l,j->node[0].body->lvel) + + dDOT(info->J1a,j->node[0].body->avel); + if (j->node[1].body) { + outgoing += dDOT(info->J2l,j->node[1].body->lvel) + + dDOT(info->J2a,j->node[1].body->avel); + } + // only apply bounce if the outgoing velocity is greater than the + // threshold, and if the resulting c[0] exceeds what we already have. + if (j->contact.surface.bounce_vel >= 0 && + (-outgoing) > j->contact.surface.bounce_vel) { + dReal newc = - dMUL(j->contact.surface.bounce,outgoing); + if (newc > info->c[0]) info->c[0] = newc; + } + } + + // set LCP limits for normal + info->lo[0] = 0; + info->hi[0] = dInfinity; + + // now do jacobian for tangential forces + dVector3 t1,t2; // two vectors tangential to normal + + // first friction direction + if (j->the_m >= 2) { + if (j->contact.surface.mode & dContactFDir1) { // use fdir1 ? + t1[0] = j->contact.fdir1[0]; + t1[1] = j->contact.fdir1[1]; + t1[2] = j->contact.fdir1[2]; + dCROSS (t2,=,normal,t1); + } + else { + dPlaneSpace (normal,t1,t2); + } + info->J1l[s+0] = t1[0]; + info->J1l[s+1] = t1[1]; + info->J1l[s+2] = t1[2]; + dCROSS (info->J1a+s,=,c1,t1); + if (j->node[1].body) { + info->J2l[s+0] = -t1[0]; + info->J2l[s+1] = -t1[1]; + info->J2l[s+2] = -t1[2]; + dCROSS (info->J2a+s,= -,c2,t1); + } + // set right hand side + if (j->contact.surface.mode & dContactMotion1) { + info->c[1] = j->contact.surface.motion1; + } + // set LCP bounds and friction index. this depends on the approximation + // mode + info->lo[1] = -j->contact.surface.mu; + info->hi[1] = j->contact.surface.mu; + if (j->contact.surface.mode & dContactApprox1_1) info->findex[1] = 0; + + // set slip (constraint force mixing) + if (j->contact.surface.mode & dContactSlip1) + info->cfm[1] = j->contact.surface.slip1; + } + + // second friction direction + if (j->the_m >= 3) { + info->J1l[s2+0] = t2[0]; + info->J1l[s2+1] = t2[1]; + info->J1l[s2+2] = t2[2]; + dCROSS (info->J1a+s2,=,c1,t2); + if (j->node[1].body) { + info->J2l[s2+0] = -t2[0]; + info->J2l[s2+1] = -t2[1]; + info->J2l[s2+2] = -t2[2]; + dCROSS (info->J2a+s2,= -,c2,t2); + } + // set right hand side + if (j->contact.surface.mode & dContactMotion2) { + info->c[2] = j->contact.surface.motion2; + } + // set LCP bounds and friction index. this depends on the approximation + // mode + if (j->contact.surface.mode & dContactMu2) { + info->lo[2] = -j->contact.surface.mu2; + info->hi[2] = j->contact.surface.mu2; + } + else { + info->lo[2] = -j->contact.surface.mu; + info->hi[2] = j->contact.surface.mu; + } + if (j->contact.surface.mode & dContactApprox1_2) info->findex[2] = 0; + + // set slip (constraint force mixing) + if (j->contact.surface.mode & dContactSlip2) + info->cfm[2] = j->contact.surface.slip2; + } +} + + +dxJoint::Vtable __dcontact_vtable = { + sizeof(dxJointContact), + (dxJoint::init_fn*) contactInit, + (dxJoint::getInfo1_fn*) contactGetInfo1, + (dxJoint::getInfo2_fn*) contactGetInfo2, + dJointTypeContact}; + +//**************************************************************************** +// hinge 2. note that this joint must be attached to two bodies for it to work + +static dReal measureHinge2Angle (dxJointHinge2 *joint) +{ + dVector3 a1,a2; + dMULTIPLY0_331 (a1,joint->node[1].body->posr.R,joint->axis2); + dMULTIPLY1_331 (a2,joint->node[0].body->posr.R,a1); + dReal x = dDOT(joint->v1,a2); + dReal y = dDOT(joint->v2,a2); + return -dArcTan2 (y,x); +} + + +static void hinge2Init (dxJointHinge2 *j) +{ + dSetZero (j->anchor1,4); + dSetZero (j->anchor2,4); + dSetZero (j->axis1,4); + j->axis1[0] = REAL(1.0); + dSetZero (j->axis2,4); + j->axis2[1] = REAL(1.0); + j->c0 = 0; + j->s0 = 0; + + dSetZero (j->v1,4); + j->v1[0] = REAL(1.0); + dSetZero (j->v2,4); + j->v2[1] = REAL(1.0); + + j->limot1.init (j->world); + j->limot2.init (j->world); + + j->susp_erp = j->world->global_erp; + j->susp_cfm = j->world->global_cfm; + + j->flags |= dJOINT_TWOBODIES; +} + + +static void hinge2GetInfo1 (dxJointHinge2 *j, dxJoint::Info1 *info) +{ + info->m = 4; + info->nub = 4; + + // see if we're powered or at a joint limit for axis 1 + int atlimit=0; + if ((j->limot1.lostop >= -dPI || j->limot1.histop <= dPI) && + j->limot1.lostop <= j->limot1.histop) { + dReal angle = measureHinge2Angle (j); + if (j->limot1.testRotationalLimit (angle)) atlimit = 1; + } + if (atlimit || j->limot1.fmax > 0) info->m++; + + // see if we're powering axis 2 (we currently never limit this axis) + j->limot2.limit = 0; + if (j->limot2.fmax > 0) info->m++; +} + + +// macro that computes ax1,ax2 = axis 1 and 2 in global coordinates (they are +// relative to body 1 and 2 initially) and then computes the constrained +// rotational axis as the cross product of ax1 and ax2. +// the sin and cos of the angle between axis 1 and 2 is computed, this comes +// from dot and cross product rules. + +#define HINGE2_GET_AXIS_INFO(axis,sin_angle,cos_angle) \ + dVector3 ax1,ax2; \ + dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); \ + dMULTIPLY0_331 (ax2,joint->node[1].body->posr.R,joint->axis2); \ + dCROSS (axis,=,ax1,ax2); \ + sin_angle = dSqrt (dMUL(axis[0],axis[0]) + dMUL(axis[1],axis[1]) + dMUL(axis[2],axis[2])); \ + cos_angle = dDOT (ax1,ax2); + + +static void hinge2GetInfo2 (dxJointHinge2 *joint, dxJoint::Info2 *info) +{ + // get information we need to set the hinge row + dReal s,c; + dVector3 q; + HINGE2_GET_AXIS_INFO (q,s,c); + dNormalize3 (q); // @@@ quicker: divide q by s ? + + // set the three ball-and-socket rows (aligned to the suspension axis ax1) + setBall2 (joint,info,joint->anchor1,joint->anchor2,ax1,joint->susp_erp); + + // set the hinge row + int s3=3*info->rowskip; + info->J1a[s3+0] = q[0]; + info->J1a[s3+1] = q[1]; + info->J1a[s3+2] = q[2]; + if (joint->node[1].body) { + info->J2a[s3+0] = -q[0]; + info->J2a[s3+1] = -q[1]; + info->J2a[s3+2] = -q[2]; + } + + // compute the right hand side for the constrained rotational DOF. + // axis 1 and axis 2 are separated by an angle `theta'. the desired + // separation angle is theta0. sin(theta0) and cos(theta0) are recorded + // in the joint structure. the correcting angular velocity is: + // |angular_velocity| = angle/time = erp*(theta0-theta) / stepsize + // = (erp*fps) * (theta0-theta) + // (theta0-theta) can be computed using the following small-angle-difference + // approximation: + // theta0-theta ~= tan(theta0-theta) + // = sin(theta0-theta)/cos(theta0-theta) + // = (c*s0 - s*c0) / (c*c0 + s*s0) + // = c*s0 - s*c0 assuming c*c0 + s*s0 ~= 1 + // where c = cos(theta), s = sin(theta) + // c0 = cos(theta0), s0 = sin(theta0) + + dReal k = dMUL(info->fps,info->erp); + info->c[3] = dMUL(k,(dMUL(joint->c0,s) - dMUL(joint->s0,c))); + + // if the axis1 hinge is powered, or has joint limits, add in more stuff + int row = 4 + joint->limot1.addLimot (joint,info,4,ax1,1); + + // if the axis2 hinge is powered, add in more stuff + joint->limot2.addLimot (joint,info,row,ax2,1); + + // set parameter for the suspension + info->cfm[0] = joint->susp_cfm; +} + + +// compute vectors v1 and v2 (embedded in body1), used to measure angle +// between body 1 and body 2 + +static void makeHinge2V1andV2 (dxJointHinge2 *joint) +{ + if (joint->node[0].body) { + // get axis 1 and 2 in global coords + dVector3 ax1,ax2,v; + dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); + dMULTIPLY0_331 (ax2,joint->node[1].body->posr.R,joint->axis2); + + // don't do anything if the axis1 or axis2 vectors are zero or the same + if ((ax1[0]==0 && ax1[1]==0 && ax1[2]==0 || + (ax2[0]==0) && ax2[1]==0 && ax2[2]==0) || + (ax1[0]==ax2[0] && ax1[1]==ax2[1] && ax1[2]==ax2[2])) return; + + // modify axis 2 so it's perpendicular to axis 1 + dReal k = dDOT(ax1,ax2); + for (int i=0; i<3; i++) ax2[i] -= dMUL(k,ax1[i]); + dNormalize3 (ax2); + + // make v1 = modified axis2, v2 = axis1 x (modified axis2) + dCROSS (v,=,ax1,ax2); + dMULTIPLY1_331 (joint->v1,joint->node[0].body->posr.R,ax2); + dMULTIPLY1_331 (joint->v2,joint->node[0].body->posr.R,v); + } +} + + +EXPORT_C void dJointSetHinge2Anchor (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + setAnchors (joint,x,y,z,joint->anchor1,joint->anchor2); + makeHinge2V1andV2 (joint); +} + + +EXPORT_C void dJointSetHinge2Axis1 (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->node[0].body) { + dReal q[4]; + q[0] = x; + q[1] = y; + q[2] = z; + q[3] = 0; + dNormalize3 (q); + dMULTIPLY1_331 (joint->axis1,joint->node[0].body->posr.R,q); + joint->axis1[3] = 0; + + // compute the sin and cos of the angle between axis 1 and axis 2 + dVector3 ax; + HINGE2_GET_AXIS_INFO(ax,joint->s0,joint->c0); + } + makeHinge2V1andV2 (joint); +} + + +EXPORT_C void dJointSetHinge2Axis2 (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->node[1].body) { + dReal q[4]; + q[0] = x; + q[1] = y; + q[2] = z; + q[3] = 0; + dNormalize3 (q); + dMULTIPLY1_331 (joint->axis2,joint->node[1].body->posr.R,q); + joint->axis1[3] = 0; + + // compute the sin and cos of the angle between axis 1 and axis 2 + dVector3 ax; + HINGE2_GET_AXIS_INFO(ax,joint->s0,joint->c0); + } + makeHinge2V1andV2 (joint); +} + + +EXPORT_C void dJointSetHinge2Param (dJointID j, int parameter, dReal value) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if ((parameter & 0xff00) == 0x100) { + joint->limot2.set (parameter & 0xff,value); + } + else { + if (parameter == dParamSuspensionERP) joint->susp_erp = value; + else if (parameter == dParamSuspensionCFM) joint->susp_cfm = value; + else joint->limot1.set (parameter,value); + } +} + + +EXPORT_C void dJointGetHinge2Anchor (dJointID j, dVector3 result) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->flags & dJOINT_REVERSE) + getAnchor2 (joint,result,joint->anchor2); + else + getAnchor (joint,result,joint->anchor1); +} + + +EXPORT_C void dJointGetHinge2Anchor2 (dJointID j, dVector3 result) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->flags & dJOINT_REVERSE) + getAnchor (joint,result,joint->anchor1); + else + getAnchor2 (joint,result,joint->anchor2); +} + + +EXPORT_C void dJointGetHinge2Axis1 (dJointID j, dVector3 result) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->node[0].body) { + dMULTIPLY0_331 (result,joint->node[0].body->posr.R,joint->axis1); + } +} + + +EXPORT_C void dJointGetHinge2Axis2 (dJointID j, dVector3 result) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->node[1].body) { + dMULTIPLY0_331 (result,joint->node[1].body->posr.R,joint->axis2); + } +} + + +EXPORT_C dReal dJointGetHinge2Param (dJointID j, int parameter) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if ((parameter & 0xff00) == 0x100) { + return joint->limot2.get (parameter & 0xff); + } + else { + if (parameter == dParamSuspensionERP) return joint->susp_erp; + else if (parameter == dParamSuspensionCFM) return joint->susp_cfm; + else return joint->limot1.get (parameter); + } +} + + +EXPORT_C dReal dJointGetHinge2Angle1 (dJointID j) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->node[0].body) return measureHinge2Angle (joint); + else return 0; +} + + +EXPORT_C dReal dJointGetHinge2Angle1Rate (dJointID j) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->node[0].body) { + dVector3 axis; + dMULTIPLY0_331 (axis,joint->node[0].body->posr.R,joint->axis1); + dReal rate = dDOT(axis,joint->node[0].body->avel); + if (joint->node[1].body) rate -= dDOT(axis,joint->node[1].body->avel); + return rate; + } + else return 0; +} + + +EXPORT_C dReal dJointGetHinge2Angle2Rate (dJointID j) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + + if (joint->node[0].body && joint->node[1].body) { + dVector3 axis; + dMULTIPLY0_331 (axis,joint->node[1].body->posr.R,joint->axis2); + dReal rate = dDOT(axis,joint->node[0].body->avel); + if (joint->node[1].body) rate -= dDOT(axis,joint->node[1].body->avel); + return rate; + } + else return 0; +} + + +EXPORT_C void dJointAddHinge2Torques (dJointID j, dReal torque1, dReal torque2) +{ + dxJointHinge2* joint = (dxJointHinge2*)j; + dVector3 axis1, axis2; + + + if (joint->node[0].body && joint->node[1].body) { + dMULTIPLY0_331 (axis1,joint->node[0].body->posr.R,joint->axis1); + dMULTIPLY0_331 (axis2,joint->node[1].body->posr.R,joint->axis2); + axis1[0] = dMUL(axis1[0],torque1) + dMUL(axis2[0],torque2); + axis1[1] = dMUL(axis1[1],torque1) + dMUL(axis2[1],torque2); + axis1[2] = dMUL(axis1[2],torque1) + dMUL(axis2[2],torque2); + dBodyAddTorque (joint->node[0].body,axis1[0],axis1[1],axis1[2]); + dBodyAddTorque(joint->node[1].body, -axis1[0], -axis1[1], -axis1[2]); + } +} + + +dxJoint::Vtable __dhinge2_vtable = { + sizeof(dxJointHinge2), + (dxJoint::init_fn*) hinge2Init, + (dxJoint::getInfo1_fn*) hinge2GetInfo1, + (dxJoint::getInfo2_fn*) hinge2GetInfo2, + dJointTypeHinge2}; + +//**************************************************************************** +// universal + +// I just realized that the universal joint is equivalent to a hinge 2 joint with +// perfectly stiff suspension. By comparing the hinge 2 implementation to +// the universal implementation, you may be able to improve this +// implementation (or, less likely, the hinge2 implementation). + +static void universalInit (dxJointUniversal *j) +{ + dSetZero (j->anchor1,4); + dSetZero (j->anchor2,4); + dSetZero (j->axis1,4); + j->axis1[0] = REAL(1.0); + dSetZero (j->axis2,4); + j->axis2[1] = REAL(1.0); + dSetZero(j->qrel1,4); + dSetZero(j->qrel2,4); + j->limot1.init (j->world); + j->limot2.init (j->world); +} + + +static void getUniversalAxes(dxJointUniversal *joint, dVector3 ax1, dVector3 ax2) +{ + // This says "ax1 = joint->node[0].body->posr.R * joint->axis1" + dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); + + if (joint->node[1].body) { + dMULTIPLY0_331 (ax2,joint->node[1].body->posr.R,joint->axis2); + } + else { + ax2[0] = joint->axis2[0]; + ax2[1] = joint->axis2[1]; + ax2[2] = joint->axis2[2]; + } +} + +static void getUniversalAngles(dxJointUniversal *joint, dReal *angle1, dReal *angle2) +{ + if (joint->node[0].body) + { + // length 1 joint axis in global coordinates, from each body + dVector3 ax1, ax2; + dMatrix3 R; + dQuaternion qcross, qq, qrel; + + getUniversalAxes (joint,ax1,ax2); + + // It should be possible to get both angles without explicitly + // constructing the rotation matrix of the cross. Basically, + // orientation of the cross about axis1 comes from body 2, + // about axis 2 comes from body 1, and the perpendicular + // axis can come from the two bodies somehow. (We don't really + // want to assume it's 90 degrees, because in general the + // constraints won't be perfectly satisfied, or even very well + // satisfied.) + // + // However, we'd need a version of getHingeAngleFromRElativeQuat() + // that CAN handle when its relative quat is rotated along a direction + // other than the given axis. What I have here works, + // although it's probably much slower than need be. + + dRFrom2Axes (R, ax1[0], ax1[1], ax1[2], ax2[0], ax2[1], ax2[2]); + + dRtoQ (R, qcross); + + + // This code is essentialy the same as getHingeAngle(), see the comments + // there for details. + + // get qrel = relative rotation between node[0] and the cross + dQMultiply1 (qq, joint->node[0].body->q, qcross); + dQMultiply2 (qrel, qq, joint->qrel1); + + *angle1 = getHingeAngleFromRelativeQuat(qrel, joint->axis1); + + // This is equivalent to + // dRFrom2Axes(R, ax2[0], ax2[1], ax2[2], ax1[0], ax1[1], ax1[2]); + // You see that the R is constructed from the same 2 axis as for angle1 + // but the first and second axis are swapped. + // So we can take the first R and rapply a rotation to it. + // The rotation is around the axis between the 2 axes (ax1 and ax2). + // We do a rotation of 180deg. + + dQuaternion qcross2; + // Find the vector between ax1 and ax2 (i.e. in the middle) + // We need to turn around this vector by 180deg + + // The 2 axes should be normalize so to find the vector between the 2. + // Add and devide by 2 then normalize or simply normalize + // ax2 + // ^ + // | + // | + /// *------------> ax1 + // We want the vector a 45deg + // + // N.B. We don't need to normalize the ax1 and ax2 since there are + // normalized when we set them. + + // We set the quaternion q = [cos(theta), dir*sin(theta)] = [w, x, y, Z] + qrel[0] = 0; // equivalent to cos(Pi/2) + qrel[1] = ax1[0] + ax2[0]; // equivalent to x*sin(Pi/2); since sin(Pi/2) = 1 + qrel[2] = ax1[1] + ax2[1]; + qrel[3] = ax1[2] + ax2[2]; + + dReal l = dRecip(dSqrt(dMUL(qrel[1],qrel[1]) + dMUL(qrel[2],qrel[2]) + dMUL(qrel[3],qrel[3]))); + qrel[1] = dMUL(qrel[1],l); + qrel[2] = dMUL(qrel[2],l); + qrel[3] = dMUL(qrel[3],l); + + dQMultiply0 (qcross2, qrel, qcross); + + if (joint->node[1].body) { + dQMultiply1 (qq, joint->node[1].body->q, qcross2); + dQMultiply2 (qrel, qq, joint->qrel2); + } + else { + // pretend joint->node[1].body->q is the identity + dQMultiply2 (qrel, qcross2, joint->qrel2); + } + + *angle2 = - getHingeAngleFromRelativeQuat(qrel, joint->axis2); + + } + else + { + *angle1 = 0; + *angle2 = 0; + } +} + +static dReal getUniversalAngle1(dxJointUniversal *joint) +{ + if (joint->node[0].body) { + // length 1 joint axis in global coordinates, from each body + dVector3 ax1, ax2; + dMatrix3 R; + dQuaternion qcross, qq, qrel; + + getUniversalAxes (joint,ax1,ax2); + + // It should be possible to get both angles without explicitly + // constructing the rotation matrix of the cross. Basically, + // orientation of the cross about axis1 comes from body 2, + // about axis 2 comes from body 1, and the perpendicular + // axis can come from the two bodies somehow. (We don't really + // want to assume it's 90 degrees, because in general the + // constraints won't be perfectly satisfied, or even very well + // satisfied.) + // + // However, we'd need a version of getHingeAngleFromRElativeQuat() + // that CAN handle when its relative quat is rotated along a direction + // other than the given axis. What I have here works, + // although it's probably much slower than need be. + + dRFrom2Axes(R, ax1[0], ax1[1], ax1[2], ax2[0], ax2[1], ax2[2]); + dRtoQ (R,qcross); + + // This code is essential the same as getHingeAngle(), see the comments + // there for details. + + // get qrel = relative rotation between node[0] and the cross + dQMultiply1 (qq,joint->node[0].body->q,qcross); + dQMultiply2 (qrel,qq,joint->qrel1); + + return getHingeAngleFromRelativeQuat(qrel, joint->axis1); + } + return 0; +} + + +static dReal getUniversalAngle2(dxJointUniversal *joint) +{ + if (joint->node[0].body) { + // length 1 joint axis in global coordinates, from each body + dVector3 ax1, ax2; + dMatrix3 R; + dQuaternion qcross, qq, qrel; + + getUniversalAxes (joint,ax1,ax2); + + // It should be possible to get both angles without explicitly + // constructing the rotation matrix of the cross. Basically, + // orientation of the cross about axis1 comes from body 2, + // about axis 2 comes from body 1, and the perpendicular + // axis can come from the two bodies somehow. (We don't really + // want to assume it's 90 degrees, because in general the + // constraints won't be perfectly satisfied, or even very well + // satisfied.) + // + // However, we'd need a version of getHingeAngleFromRElativeQuat() + // that CAN handle when its relative quat is rotated along a direction + // other than the given axis. What I have here works, + // although it's probably much slower than need be. + + dRFrom2Axes(R, ax2[0], ax2[1], ax2[2], ax1[0], ax1[1], ax1[2]); + dRtoQ(R, qcross); + + if (joint->node[1].body) { + dQMultiply1 (qq, joint->node[1].body->q, qcross); + dQMultiply2 (qrel,qq,joint->qrel2); + } + else { + // pretend joint->node[1].body->q is the identity + dQMultiply2 (qrel,qcross, joint->qrel2); + } + + return - getHingeAngleFromRelativeQuat(qrel, joint->axis2); + } + return 0; +} + + +static void universalGetInfo1 (dxJointUniversal *j, dxJoint::Info1 *info) +{ + info->nub = 4; + info->m = 4; + + // see if we're powered or at a joint limit. + bool constraint1 = j->limot1.fmax > 0; + bool constraint2 = j->limot2.fmax > 0; + + bool limiting1 = (j->limot1.lostop >= -dPI || j->limot1.histop <= dPI) && + j->limot1.lostop <= j->limot1.histop; + bool limiting2 = (j->limot2.lostop >= -dPI || j->limot2.histop <= dPI) && + j->limot2.lostop <= j->limot2.histop; + + // We need to call testRotationLimit() even if we're motored, since it + // records the result. + if (limiting1 || limiting2) { + dReal angle1, angle2; + getUniversalAngles (j, &angle1, &angle2); + if (limiting1 && j->limot1.testRotationalLimit (angle1)) constraint1 = true; + if (limiting2 && j->limot2.testRotationalLimit (angle2)) constraint2 = true; + } + if (constraint1) + info->m++; + if (constraint2) + info->m++; +} + + +static void universalGetInfo2 (dxJointUniversal *joint, dxJoint::Info2 *info) +{ + // set the three ball-and-socket rows + setBall (joint,info,joint->anchor1,joint->anchor2); + + // set the universal joint row. the angular velocity about an axis + // perpendicular to both joint axes should be equal. thus the constraint + // equation is + // p*w1 - p*w2 = 0 + // where p is a vector normal to both joint axes, and w1 and w2 + // are the angular velocity vectors of the two bodies. + + // length 1 joint axis in global coordinates, from each body + dVector3 ax1, ax2; + dVector3 ax2_temp; + // length 1 vector perpendicular to ax1 and ax2. Neither body can rotate + // about this. + dVector3 p; + dReal k; + + getUniversalAxes(joint, ax1, ax2); + k = dDOT(ax1, ax2); + ax2_temp[0] = ax2[0] - dMUL(k,ax1[0]); + ax2_temp[1] = ax2[1] - dMUL(k,ax1[1]); + ax2_temp[2] = ax2[2] - dMUL(k,ax1[2]); + dCROSS(p, =, ax1, ax2_temp); + dNormalize3(p); + + int s3=3*info->rowskip; + + info->J1a[s3+0] = p[0]; + info->J1a[s3+1] = p[1]; + info->J1a[s3+2] = p[2]; + + if (joint->node[1].body) { + info->J2a[s3+0] = -p[0]; + info->J2a[s3+1] = -p[1]; + info->J2a[s3+2] = -p[2]; + } + + // compute the right hand side of the constraint equation. set relative + // body velocities along p to bring the axes back to perpendicular. + // If ax1, ax2 are unit length joint axes as computed from body1 and + // body2, we need to rotate both bodies along the axis p. If theta + // is the angle between ax1 and ax2, we need an angular velocity + // along p to cover the angle erp * (theta - Pi/2) in one step: + // + // |angular_velocity| = angle/time = erp*(theta - Pi/2) / stepsize + // = (erp*fps) * (theta - Pi/2) + // + // if theta is close to Pi/2, + // theta - Pi/2 ~= cos(theta), so + // |angular_velocity| ~= (erp*fps) * (ax1 dot ax2) + + info->c[3] = dMUL(info->fps,dMUL(info->erp,- dDOT(ax1, ax2))); + + // if the first angle is powered, or has joint limits, add in the stuff + int row = 4 + joint->limot1.addLimot (joint,info,4,ax1,1); + + // if the second angle is powered, or has joint limits, add in more stuff + joint->limot2.addLimot (joint,info,row,ax2,1); +} + + +static void universalComputeInitialRelativeRotations (dxJointUniversal *joint) +{ + if (joint->node[0].body) { + dVector3 ax1, ax2; + dMatrix3 R; + dQuaternion qcross; + + getUniversalAxes(joint, ax1, ax2); + + // Axis 1. + dRFrom2Axes(R, ax1[0], ax1[1], ax1[2], ax2[0], ax2[1], ax2[2]); + dRtoQ(R, qcross); + dQMultiply1 (joint->qrel1, joint->node[0].body->q, qcross); + + // Axis 2. + dRFrom2Axes(R, ax2[0], ax2[1], ax2[2], ax1[0], ax1[1], ax1[2]); + dRtoQ(R, qcross); + if (joint->node[1].body) { + dQMultiply1 (joint->qrel2, joint->node[1].body->q, qcross); + } + else { + // set joint->qrel to qcross + for (int i=0; i<4; i++) joint->qrel2[i] = qcross[i]; + } + } +} + + +EXPORT_C void dJointSetUniversalAnchor (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + setAnchors (joint,x,y,z,joint->anchor1,joint->anchor2); + universalComputeInitialRelativeRotations(joint); +} + + +EXPORT_C void dJointSetUniversalAxis1 (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + setAxes (joint,x,y,z,NULL,joint->axis2); + else + setAxes (joint,x,y,z,joint->axis1,NULL); + universalComputeInitialRelativeRotations(joint); +} + + +EXPORT_C void dJointSetUniversalAxis2 (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + setAxes (joint,x,y,z,joint->axis1,NULL); + else + setAxes (joint,x,y,z,NULL,joint->axis2); + universalComputeInitialRelativeRotations(joint); +} + + +EXPORT_C void dJointGetUniversalAnchor (dJointID j, dVector3 result) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + getAnchor2 (joint,result,joint->anchor2); + else + getAnchor (joint,result,joint->anchor1); +} + + +EXPORT_C void dJointGetUniversalAnchor2 (dJointID j, dVector3 result) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + getAnchor (joint,result,joint->anchor1); + else + getAnchor2 (joint,result,joint->anchor2); +} + + +EXPORT_C void dJointGetUniversalAxis1 (dJointID j, dVector3 result) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + getAxis2 (joint,result,joint->axis2); + else + getAxis (joint,result,joint->axis1); +} + + +EXPORT_C void dJointGetUniversalAxis2 (dJointID j, dVector3 result) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + getAxis (joint,result,joint->axis1); + else + getAxis2 (joint,result,joint->axis2); +} + + +EXPORT_C void dJointSetUniversalParam (dJointID j, int parameter, dReal value) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if ((parameter & 0xff00) == 0x100) { + joint->limot2.set (parameter & 0xff,value); + } + else { + joint->limot1.set (parameter,value); + } +} + + +EXPORT_C dReal dJointGetUniversalParam (dJointID j, int parameter) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if ((parameter & 0xff00) == 0x100) { + return joint->limot2.get (parameter & 0xff); + } + else { + return joint->limot1.get (parameter); + } +} + +EXPORT_C void dJointGetUniversalAngles (dJointID j, dReal *angle1, dReal *angle2) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + return getUniversalAngles (joint, angle2, angle1); + else + return getUniversalAngles (joint, angle1, angle2); +} + + +EXPORT_C dReal dJointGetUniversalAngle1 (dJointID j) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + return getUniversalAngle2 (joint); + else + return getUniversalAngle1 (joint); +} + + +EXPORT_C dReal dJointGetUniversalAngle2 (dJointID j) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + if (joint->flags & dJOINT_REVERSE) + return getUniversalAngle1 (joint); + else + return getUniversalAngle2 (joint); +} + + +EXPORT_C dReal dJointGetUniversalAngle1Rate (dJointID j) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + + if (joint->node[0].body) { + dVector3 axis; + + if (joint->flags & dJOINT_REVERSE) + getAxis2 (joint,axis,joint->axis2); + else + getAxis (joint,axis,joint->axis1); + + dReal rate = dDOT(axis, joint->node[0].body->avel); + if (joint->node[1].body) rate -= dDOT(axis, joint->node[1].body->avel); + return rate; + } + return 0; +} + + +EXPORT_C dReal dJointGetUniversalAngle2Rate (dJointID j) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + + + if (joint->node[0].body) { + dVector3 axis; + + if (joint->flags & dJOINT_REVERSE) + getAxis (joint,axis,joint->axis1); + else + getAxis2 (joint,axis,joint->axis2); + + dReal rate = dDOT(axis, joint->node[0].body->avel); + if (joint->node[1].body) rate -= dDOT(axis, joint->node[1].body->avel); + return rate; + } + return 0; +} + + +EXPORT_C void dJointAddUniversalTorques (dJointID j, dReal torque1, dReal torque2) +{ + dxJointUniversal* joint = (dxJointUniversal*)j; + dVector3 axis1, axis2; + + + if (joint->flags & dJOINT_REVERSE) { + dReal temp = torque1; + torque1 = - torque2; + torque2 = - temp; + } + + getAxis (joint,axis1,joint->axis1); + getAxis2 (joint,axis2,joint->axis2); + axis1[0] = dMUL(axis1[0],torque1) + dMUL(axis2[0],torque2); + axis1[1] = dMUL(axis1[1],torque1) + dMUL(axis2[1],torque2); + axis1[2] = dMUL(axis1[2],torque1) + dMUL(axis2[2],torque2); + + if (joint->node[0].body != 0) + dBodyAddTorque (joint->node[0].body,axis1[0],axis1[1],axis1[2]); + if (joint->node[1].body != 0) + dBodyAddTorque(joint->node[1].body, -axis1[0], -axis1[1], -axis1[2]); +} + + + + + +dxJoint::Vtable __duniversal_vtable = { + sizeof(dxJointUniversal), + (dxJoint::init_fn*) universalInit, + (dxJoint::getInfo1_fn*) universalGetInfo1, + (dxJoint::getInfo2_fn*) universalGetInfo2, + dJointTypeUniversal}; + + + +//**************************************************************************** +// Prismatic and Rotoide + +static void PRInit (dxJointPR *j) +{ + // Default Position + // Z^ + // | Body 1 P R Body2 + // |+---------+ _ _ +-----------+ + // || |----|----(_)--------+ | + // |+---------+ - +-----------+ + // | + // X.-----------------------------------------> Y + // N.B. X is comming out of the page + dSetZero (j->anchor2,4); + + dSetZero (j->axisR1,4); + j->axisR1[0] = REAL(1.0); + dSetZero (j->axisR2,4); + j->axisR2[0] = REAL(1.0); + + dSetZero (j->axisP1,4); + j->axisP1[1] = REAL(1.0); + dSetZero (j->qrel,4); + dSetZero (j->offset,4); + + j->limotR.init (j->world); + j->limotP.init (j->world); +} + + +EXPORT_C dReal dJointGetPRPosition (dJointID j) +{ + dxJointPR* joint = (dxJointPR*)j; + + + dVector3 q; + // get the offset in global coordinates + dMULTIPLY0_331 (q,joint->node[0].body->posr.R,joint->offset); + + if (joint->node[1].body) { + dVector3 anchor2; + + // get the anchor2 in global coordinates + dMULTIPLY0_331 (anchor2,joint->node[1].body->posr.R,joint->anchor2); + + q[0] = ( (joint->node[0].body->posr.pos[0] + q[0]) - + (joint->node[1].body->posr.pos[0] + anchor2[0]) ); + q[1] = ( (joint->node[0].body->posr.pos[1] + q[1]) - + (joint->node[1].body->posr.pos[1] + anchor2[1]) ); + q[2] = ( (joint->node[0].body->posr.pos[2] + q[2]) - + (joint->node[1].body->posr.pos[2] + anchor2[2]) ); + + } + else { + //N.B. When there is no body 2 the joint->anchor2 is already in + // global coordinates + + q[0] = ( (joint->node[0].body->posr.pos[0] + q[0]) - + (joint->anchor2[0]) ); + q[1] = ( (joint->node[0].body->posr.pos[1] + q[1]) - + (joint->anchor2[1]) ); + q[2] = ( (joint->node[0].body->posr.pos[2] + q[2]) - + (joint->anchor2[2]) ); + + } + + dVector3 axP; + // get prismatic axis in global coordinates + dMULTIPLY0_331 (axP,joint->node[0].body->posr.R,joint->axisP1); + + return dDOT(axP, q); +} + + +EXPORT_C dReal dJointGetPRPositionRate (dJointID j) +{ + dxJointPR* joint = (dxJointPR*)j; + + + if (joint->node[0].body) { + // We want to find the rate of change of the prismatic part of the joint + // We can find it by looking at the speed difference between body1 and the + // anchor point. + + // r will be used to find the distance between body1 and the anchor point + dVector3 r; + if (joint->node[1].body) { + // Find joint->anchor2 in global coordinates + dVector3 anchor2; + dMULTIPLY0_331 (anchor2,joint->node[1].body->posr.R,joint->anchor2); + + r[0] = joint->node[0].body->posr.pos[0] - anchor2[0]; + r[1] = joint->node[0].body->posr.pos[1] - anchor2[1]; + r[2] = joint->node[0].body->posr.pos[2] - anchor2[2]; + } + else { + //N.B. When there is no body 2 the joint->anchor2 is already in + // global coordinates + r[0] = joint->node[0].body->posr.pos[0] - joint->anchor2[0]; + r[1] = joint->node[0].body->posr.pos[1] - joint->anchor2[1]; + r[2] = joint->node[0].body->posr.pos[2] - joint->anchor2[2]; + } + + // The body1 can have velocity coming from the rotation of + // the rotoide axis. We need to remove this. + + // Take only the angular rotation coming from the rotation + // of the rotoide articulation + // N.B. Body1 and Body2 should have the same rotation along axis + // other than the rotoide axis. + dVector3 angular; + dMULTIPLY0_331 (angular,joint->node[0].body->posr.R,joint->axisR1); + dReal omega = dDOT(angular, joint->node[0].body->avel); + angular[0] = dMUL(angular[0],omega); + angular[1] = dMUL(angular[1],omega); + angular[2] = dMUL(angular[2],omega); + + // Find the contribution of the angular rotation to the linear speed + // N.B. We do vel = r X w instead of vel = w x r to have vel negative + // since we want to remove it from the linear velocity of the body + dVector3 lvel1; + dCROSS(lvel1, =, r, angular); + + lvel1[0] += joint->node[0].body->lvel[0]; + lvel1[1] += joint->node[0].body->lvel[1]; + lvel1[2] += joint->node[0].body->lvel[2]; + + // Since we want rate of change along the prismatic axis + // get axisP1 in global coordinates and get the component + // along this axis only + dVector3 axP1; + dMULTIPLY0_331 (axP1,joint->node[0].body->posr.R,joint->axisP1); + return dDOT(axP1, lvel1); + } + + return REAL(0.0); +} + + + +static void PRGetInfo1 (dxJointPR *j, dxJoint::Info1 *info) +{ + info->m = 4; + info->nub = 4; + + bool added = false; + + added = false; + // see if the prismatic articulation is powered + if (j->limotP.fmax > 0) + { + added = true; + (info->m)++; // powered needs an extra constraint row + } + + // see if we're at a joint limit. + j->limotP.limit = 0; + if ((j->limotP.lostop > -dInfinity || j->limotP.histop < dInfinity) && + j->limotP.lostop <= j->limotP.histop) { + // measure joint position + dReal pos = dJointGetPRPosition (j); + if (pos <= j->limotP.lostop) { + j->limotP.limit = 1; + j->limotP.limit_err = pos - j->limotP.lostop; + if (!added) + (info->m)++; + } + + if (pos >= j->limotP.histop) { + j->limotP.limit = 2; + j->limotP.limit_err = pos - j->limotP.histop; + if (!added) + (info->m)++; + } + } + +} + + + +static void PRGetInfo2 (dxJointPR *joint, dxJoint::Info2 *info) +{ + int s = info->rowskip; + int s2= 2*s; + int s3= 3*s; + int s4= 4*s; + + dReal k = dMUL(info->fps,info->erp); + + + dVector3 q; // plane space of axP and after that axR + + // pull out pos and R for both bodies. also get the `connection' + // vector pos2-pos1. + + dReal *pos1,*pos2 = 0,*R1,*R2 = 0; + pos1 = joint->node[0].body->posr.pos; + R1 = joint->node[0].body->posr.R; + if (joint->node[1].body) { + pos2 = joint->node[1].body->posr.pos; + R2 = joint->node[1].body->posr.R; + } + else { + // pos2 = 0; // N.B. We can do that to be safe but it is no necessary + // R2 = 0; // N.B. We can do that to be safe but it is no necessary + } + + + dVector3 axP; // Axis of the prismatic joint in global frame + dMULTIPLY0_331 (axP, R1, joint->axisP1); + + // distance between the body1 and the anchor2 in global frame + // Calculated in the same way as the offset + dVector3 dist; + + if (joint->node[1].body) + { + dMULTIPLY0_331 (dist, R2, joint->anchor2); + dist[0] += pos2[0] - pos1[0]; + dist[1] += pos2[1] - pos1[1]; + dist[2] += pos2[2] - pos1[2]; + } + else { + dist[0] = joint->anchor2[0] - pos1[0]; + dist[1] = joint->anchor2[1] - pos1[1]; + dist[2] = joint->anchor2[2] - pos1[2]; + } + + + // ====================================================================== + // Work on the Rotoide part (i.e. row 0, 1 and maybe 4 if rotoide powered + + // Set the two rotoide rows. The rotoide axis should be the only unconstrained + // rotational axis, the angular velocity of the two bodies perpendicular to + // the rotoide 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 rotoide axis, and w1 and w2 + // are the angular velocity vectors of the two bodies. + dVector3 ax1; + dMULTIPLY0_331 (ax1, joint->node[0].body->posr.R, joint->axisR1); + dCROSS(q , =, ax1, axP); + + info->J1a[0] = axP[0]; + info->J1a[1] = axP[1]; + info->J1a[2] = axP[2]; + info->J1a[s+0] = q[0]; + info->J1a[s+1] = q[1]; + info->J1a[s+2] = q[2]; + + if (joint->node[1].body) { + info->J2a[0] = -axP[0]; + info->J2a[1] = -axP[1]; + info->J2a[2] = -axP[2]; + info->J2a[s+0] = -q[0]; + info->J2a[s+1] = -q[1]; + info->J2a[s+2] = -q[2]; + } + + + // Compute the right hand side of the constraint equation set. Relative + // body velocities along p and q to bring the rotoide back into alignment. + // ax1,ax2 are the unit length rotoide axes of body1 and body2 in world frame. + // 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. + + dVector3 ax2; + if (joint->node[1].body) { + dMULTIPLY0_331 (ax2, R2, joint->axisR2); + } + else { + ax2[0] = joint->axisR2[0]; + ax2[1] = joint->axisR2[1]; + ax2[2] = joint->axisR2[2]; + } + + dVector3 b; + dCROSS (b,=,ax1, ax2); + info->c[0] = dMUL(k,dDOT(b, axP)); + info->c[1] = dMUL(k,dDOT(b, q)); + + + + // ========================== + // Work on the Prismatic part (i.e row 2,3 and 4 if only the prismatic is powered + // or 5 if rotoide and prismatic powered + + // two rows. we want: vel2 = vel1 + w1 x c ... but this would + // result in three equations, so we project along the planespace vectors + // so that sliding along the prismatic axis is disregarded. for symmetry we + // also substitute (w1+w2)/2 for w1, as w1 is supposed to equal w2. + + // p1 + R1 dist' = p2 + R2 anchor2' ## OLD ## p1 + R1 anchor1' = p2 + R2 dist' + // v1 + w1 x R1 dist' + v_p = v2 + w2 x R2 anchor2'## OLD v1 + w1 x R1 anchor1' = v2 + w2 x R2 dist' + v_p + // v_p is speed of prismatic joint (i.e. elongation rate) + // Since the constraints are perpendicular to v_p we have: + // p dot v_p = 0 and q dot v_p = 0 + // ax1 dot ( v1 + w1 x dist = v2 + w2 x anchor2 ) + // q dot ( v1 + w1 x dist = v2 + w2 x anchor2 ) + // == + // ax1 . v1 + ax1 . w1 x dist = ax1 . v2 + ax1 . w2 x anchor2 ## OLD ## ax1 . v1 + ax1 . w1 x anchor1 = ax1 . v2 + ax1 . w2 x dist + // since a . (b x c) = - b . (a x c) = - (a x c) . b + // and a x b = - b x a + // ax1 . v1 - ax1 x dist . w1 - ax1 . v2 - (- ax1 x anchor2 . w2) = 0 + // ax1 . v1 + dist x ax1 . w1 - ax1 . v2 - anchor2 x ax1 . w2 = 0 + // Coeff for 1er line of: J1l => ax1, J2l => -ax1 + // Coeff for 2er line of: J1l => q, J2l => -q + // Coeff for 1er line of: J1a => dist x ax1, J2a => - anchor2 x ax1 + // Coeff for 2er line of: J1a => dist x q, J2a => - anchor2 x q + + + dCROSS ((info->J1a)+s2, = , dist, ax1); + + dCROSS ((info->J1a)+s3, = , dist, q); + + + info->J1l[s2+0] = ax1[0]; + info->J1l[s2+1] = ax1[1]; + info->J1l[s2+2] = ax1[2]; + + info->J1l[s3+0] = q[0]; + info->J1l[s3+1] = q[1]; + info->J1l[s3+2] = q[2]; + + if (joint->node[1].body) { + dVector3 anchor2; + + // Calculate anchor2 in world coordinate + dMULTIPLY0_331 (anchor2, R2, joint->anchor2); + + // ax2 x anchor2 instead of anchor2 x ax2 since we want the negative value + dCROSS ((info->J2a)+s2, = , ax2, anchor2); // since ax1 == ax2 + + // The cross product is in reverse order since we want the negative value + dCROSS ((info->J2a)+s3, = , q, anchor2); + + info->J2l[s2+0] = -ax1[0]; + info->J2l[s2+1] = -ax1[1]; + info->J2l[s2+2] = -ax1[2]; + + info->J2l[s3+0] = -q[0]; + info->J2l[s3+1] = -q[1]; + info->J2l[s3+2] = -q[2]; + } + + + // We want to make correction for motion not in the line of the axisP + // We calculate the displacement w.r.t. the anchor pt. + // + // compute the elements 2 and 3 of right hand side. + // we want to align the offset point (in body 2's frame) with the center of body 1. + // The position should be the same when we are not along the prismatic axis + dVector3 err; + dMULTIPLY0_331 (err, R1, joint->offset); + err[0] += dist[0]; + err[1] += dist[1]; + err[2] += dist[2]; + info->c[2] = dMUL(k,dDOT(ax1, err)); + info->c[3] = dMUL(k,dDOT(q, err)); + + // Here we can't use addLimot because of some assumption in the function + int powered = joint->limotP.fmax > 0; + if (powered || joint->limotP.limit) { + info->J1l[s4+0] = axP[0]; + info->J1l[s4+1] = axP[1]; + info->J1l[s4+2] = axP[2]; + if (joint->node[1].body) { + info->J2l[s4+0] = -axP[0]; + info->J2l[s4+1] = -axP[1]; + info->J2l[s4+2] = -axP[2]; + } + // linear limot torque decoupling step: + // + // if this is a linear limot (e.g. from a slider), 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 powered or limited slider-jointed free + // bodies from gaining angular momentum. + // the solution used here is to apply the constraint forces at the point + // halfway between the body centers. there is no penalty (other than an + // extra tiny bit of computation) in doing this adjustment. note that we + // only need to do this if the constraint connects two bodies. + + dVector3 ltd = {}; // Linear Torque Decoupling vector (a torque) + if (joint->node[1].body) { + dVector3 c; + c[0]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[0]-joint->node[0].body->posr.pos[0])); + c[1]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[1]-joint->node[0].body->posr.pos[1])); + c[2]=dMUL(REAL(0.5),(joint->node[1].body->posr.pos[2]-joint->node[0].body->posr.pos[2])); + dReal val = dDOT(q, c); + c[0] -= dMUL(val,c[0]); + c[1] -= dMUL(val,c[1]); + c[2] -= dMUL(val,c[2]); + + dCROSS (ltd,=,c,axP); + info->J1a[s4+0] = ltd[0]; + info->J1a[s4+1] = ltd[1]; + info->J1a[s4+2] = ltd[2]; + info->J2a[s4+0] = ltd[0]; + info->J2a[s4+1] = ltd[1]; + info->J2a[s4+2] = ltd[2]; + } + + // if we're limited low and high simultaneously, the joint motor is + // ineffective + if (joint->limotP.limit && (joint->limotP.lostop == joint->limotP.histop)) + powered = 0; + + int row = 4; + if (powered) { + info->cfm[row] = joint->limotP.normal_cfm; + if (!joint->limotP.limit) { + info->c[row] = joint->limotP.vel; + info->lo[row] = -joint->limotP.fmax; + info->hi[row] = joint->limotP.fmax; + } + else { + // the joint is at a limit, AND is being powered. if the joint is + // being powered into the limit then we apply the maximum motor force + // in that direction, because the motor is working against the + // immovable limit. if the joint is being powered away from the limit + // then we have problems because actually we need *two* lcp + // constraints to handle this case. so we fake it and apply some + // fraction of the maximum force. the fraction to use can be set as + // a fudge factor. + + dReal fm = joint->limotP.fmax; + dReal vel = joint->limotP.vel; + int limit = joint->limotP.limit; + if ((vel > 0) || (vel==0 && limit==2)) fm = -fm; + + // if we're powering away from the limit, apply the fudge factor + if ((limit==1 && vel > 0) || (limit==2 && vel < 0)) + fm = dMUL(fm,joint->limotP.fudge_factor); + + + dBodyAddForce (joint->node[0].body,-dMUL(fm,axP[0]),-dMUL(fm,axP[1]),-dMUL(fm,axP[2])); + + if (joint->node[1].body) { + dBodyAddForce (joint->node[1].body,dMUL(fm,axP[0]),dMUL(fm,axP[1]),dMUL(fm,axP[2])); + + // linear limot torque decoupling step: refer to above discussion + dBodyAddTorque (joint->node[0].body,-dMUL(fm,ltd[0]),-dMUL(fm,ltd[1]), + -dMUL(fm,ltd[2])); + dBodyAddTorque (joint->node[1].body,-dMUL(fm,ltd[0]),-dMUL(fm,ltd[1]), + -dMUL(fm,ltd[2])); + } + } + } + + if (joint->limotP.limit) { + dReal k = dMUL(info->fps,joint->limotP.stop_erp); + info->c[row] = -dMUL(k,joint->limotP.limit_err); + info->cfm[row] = joint->limotP.stop_cfm; + + if (joint->limotP.lostop == joint->limotP.histop) { + // limited low and high simultaneously + info->lo[row] = -dInfinity; + info->hi[row] = dInfinity; + } + else { + if (joint->limotP.limit == 1) { + // low limit + info->lo[row] = 0; + info->hi[row] = dInfinity; + } + else { + // high limit + info->lo[row] = -dInfinity; + info->hi[row] = 0; + } + + // deal with bounce + if (joint->limotP.bounce > 0) { + // calculate joint velocity + dReal vel; + vel = dDOT(joint->node[0].body->lvel, axP); + if (joint->node[1].body) + vel -= dDOT(joint->node[1].body->lvel, axP); + + // only apply bounce if the velocity is incoming, and if the + // resulting c[] exceeds what we already have. + if (joint->limotP.limit == 1) { + // low limit + if (vel < 0) { + dReal newc = -dMUL(joint->limotP.bounce,vel); + if (newc > info->c[row]) info->c[row] = newc; + } + } + else { + // high limit - all those computations are reversed + if (vel > 0) { + dReal newc = -dMUL(joint->limotP.bounce,vel); + if (newc < info->c[row]) info->c[row] = newc; + } + } + } + } + } + } +} + + +// compute initial relative rotation body1 -> body2, or env -> body1 +static void PRComputeInitialRelativeRotation (dxJointPR *joint) +{ + if (joint->node[0].body) { + if (joint->node[1].body) { + dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); + } + else { + // set joint->qrel to the transpose of the first body q + joint->qrel[0] = joint->node[0].body->q[0]; + for (int i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; + // WARNING do we need the - in -joint->node[0].body->q[i]; or not + } + } +} + +EXPORT_C void dJointSetPRAnchor (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointPR* joint = (dxJointPR*)j; + + + dVector3 dummy; + setAnchors (joint,x,y,z,dummy,joint->anchor2); +} + + +EXPORT_C void dJointSetPRAxis1 (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointPR* joint = (dxJointPR*)j; + //int i; + + + setAxes (joint,x,y,z,joint->axisP1, 0); + + PRComputeInitialRelativeRotation (joint); + + // compute initial relative rotation body1 -> body2, or env -> body1 + // also compute distance between anchor of body1 w.r.t center of body 2 + dVector3 c; + if (joint->node[1].body) { + dVector3 anchor2; + dMULTIPLY0_331 (anchor2,joint->node[1].body->posr.R, joint->anchor2); + + c[0] = ( joint->node[1].body->posr.pos[0] + anchor2[0] - + joint->node[0].body->posr.pos[0] ); + c[1] = ( joint->node[1].body->posr.pos[1] + anchor2[1] - + joint->node[0].body->posr.pos[1] ); + c[2] = ( joint->node[1].body->posr.pos[2] + anchor2[2] - + joint->node[0].body->posr.pos[2] ); + } + else if (joint->node[0].body) { + c[0] = joint->anchor2[0] - joint->node[0].body->posr.pos[0]; + c[1] = joint->anchor2[1] - joint->node[0].body->posr.pos[1]; + c[2] = joint->anchor2[2] - joint->node[0].body->posr.pos[2]; + } + else + { + joint->offset[0] = joint->anchor2[0]; + joint->offset[1] = joint->anchor2[1]; + joint->offset[2] = joint->anchor2[2]; + + return; + } + + + dMULTIPLY1_331 (joint->offset,joint->node[0].body->posr.R,c); +} + + +EXPORT_C void dJointSetPRAxis2 (dJointID j, dReal x, dReal y, dReal z) +{ + dxJointPR* joint = (dxJointPR*)j; + + setAxes (joint,x,y,z,joint->axisR1,joint->axisR2); + PRComputeInitialRelativeRotation (joint); +} + + +EXPORT_C void dJointSetPRParam (dJointID j, int parameter, dReal value) +{ + dxJointPR* joint = (dxJointPR*)j; + + if ((parameter & 0xff00) == 0x100) { + joint->limotR.set (parameter,value); + } + else { + joint->limotP.set (parameter & 0xff,value); + } +} + +EXPORT_C void dJointGetPRAnchor (dJointID j, dVector3 result) +{ + dxJointPR* joint = (dxJointPR*)j; + + + if (joint->node[1].body) + getAnchor2 (joint,result,joint->anchor2); + else + { + result[0] = joint->anchor2[0]; + result[1] = joint->anchor2[1]; + result[2] = joint->anchor2[2]; + } + +} + +EXPORT_C void dJointGetPRAxis1 (dJointID j, dVector3 result) +{ + dxJointPR* joint = (dxJointPR*)j; + + getAxis(joint, result, joint->axisP1); +} + +EXPORT_C void dJointGetPRAxis2 (dJointID j, dVector3 result) +{ + dxJointPR* joint = (dxJointPR*)j; + + getAxis(joint, result, joint->axisR1); +} + +EXPORT_C dReal dJointGetPRParam (dJointID j, int parameter) +{ + dxJointPR* joint = (dxJointPR*)j; + + if ((parameter & 0xff00) == 0x100) { + return joint->limotR.get (parameter & 0xff); + } + else { + return joint->limotP.get (parameter); + } +} + +EXPORT_C void dJointAddPRTorque (dJointID j, dReal torque) +{ + dxJointPR* joint = (dxJointPR*)j; + dVector3 axis; + + + if (joint->flags & dJOINT_REVERSE) + torque = -torque; + + getAxis (joint,axis,joint->axisR1); + axis[0] = dMUL(axis[0],torque); + axis[1] = dMUL(axis[1],torque); + axis[2] = dMUL(axis[2],torque); + + if (joint->node[0].body != 0) + dBodyAddTorque (joint->node[0].body, axis[0], axis[1], axis[2]); + if (joint->node[1].body != 0) + dBodyAddTorque(joint->node[1].body, -axis[0], -axis[1], -axis[2]); +} + + +dxJoint::Vtable __dPR_vtable = { + sizeof(dxJointPR), + (dxJoint::init_fn*) PRInit, + (dxJoint::getInfo1_fn*) PRGetInfo1, + (dxJoint::getInfo2_fn*) PRGetInfo2, + dJointTypePR +}; + + +//**************************************************************************** +// angular motor + +static void amotorInit (dxJointAMotor *j) +{ + int i; + j->num = 0; + j->mode = dAMotorUser; + for (i=0; i<3; i++) { + j->rel[i] = 0; + dSetZero (j->axis[i],4); + j->limot[i].init (j->world); + j->angle[i] = 0; + } + dSetZero (j->reference1,4); + dSetZero (j->reference2,4); +} + + +// compute the 3 axes in global coordinates + +static void amotorComputeGlobalAxes (dxJointAMotor *joint, dVector3 ax[3]) +{ + if (joint->mode == dAMotorEuler) { + // special handling for euler mode + dMULTIPLY0_331 (ax[0],joint->node[0].body->posr.R,joint->axis[0]); + if (joint->node[1].body) { + dMULTIPLY0_331 (ax[2],joint->node[1].body->posr.R,joint->axis[2]); + } + else { + ax[2][0] = joint->axis[2][0]; + ax[2][1] = joint->axis[2][1]; + ax[2][2] = joint->axis[2][2]; + } + dCROSS (ax[1],=,ax[2],ax[0]); + dNormalize3 (ax[1]); + } + else { + for (int i=0; i < joint->num; i++) { + if (joint->rel[i] == 1) { + // relative to b1 + dMULTIPLY0_331 (ax[i],joint->node[0].body->posr.R,joint->axis[i]); + } + else if (joint->rel[i] == 2) { + // relative to b2 + if (joint->node[1].body) { // jds: don't assert, just ignore + dMULTIPLY0_331 (ax[i],joint->node[1].body->posr.R,joint->axis[i]); + } + } + else { + // global - just copy it + ax[i][0] = joint->axis[i][0]; + ax[i][1] = joint->axis[i][1]; + ax[i][2] = joint->axis[i][2]; + } + } + } +} + + +static void amotorComputeEulerAngles (dxJointAMotor *joint, dVector3 ax[3]) +{ + // assumptions: + // global axes already calculated --> ax + // axis[0] is relative to body 1 --> global ax[0] + // axis[2] is relative to body 2 --> global ax[2] + // ax[1] = ax[2] x ax[0] + // original ax[0] and ax[2] are perpendicular + // reference1 is perpendicular to ax[0] (in body 1 frame) + // reference2 is perpendicular to ax[2] (in body 2 frame) + // all ax[] and reference vectors are unit length + + // calculate references in global frame + dVector3 ref1,ref2; + dMULTIPLY0_331 (ref1,joint->node[0].body->posr.R,joint->reference1); + if (joint->node[1].body) { + dMULTIPLY0_331 (ref2,joint->node[1].body->posr.R,joint->reference2); + } + else { + ref2[0] = joint->reference2[0]; + ref2[1] = joint->reference2[1]; + ref2[2] = joint->reference2[2]; + } + + // get q perpendicular to both ax[0] and ref1, get first euler angle + dVector3 q; + dCROSS (q,=,ax[0],ref1); + joint->angle[0] = -dArcTan2 (dDOT(ax[2],q),dDOT(ax[2],ref1)); + + // get q perpendicular to both ax[0] and ax[1], get second euler angle + dCROSS (q,=,ax[0],ax[1]); + joint->angle[1] = -dArcTan2 (dDOT(ax[2],ax[0]),dDOT(ax[2],q)); + + // get q perpendicular to both ax[1] and ax[2], get third euler angle + dCROSS (q,=,ax[1],ax[2]); + joint->angle[2] = -dArcTan2 (dDOT(ref2,ax[1]), dDOT(ref2,q)); +} + + +// set the reference vectors as follows: +// * reference1 = current axis[2] relative to body 1 +// * reference2 = current axis[0] relative to body 2 +// this assumes that: +// * axis[0] is relative to body 1 +// * axis[2] is relative to body 2 + +static void amotorSetEulerReferenceVectors (dxJointAMotor *j) +{ + if (j->node[0].body && j->node[1].body) { + dVector3 r; // axis[2] and axis[0] in global coordinates + dMULTIPLY0_331 (r,j->node[1].body->posr.R,j->axis[2]); + dMULTIPLY1_331 (j->reference1,j->node[0].body->posr.R,r); + dMULTIPLY0_331 (r,j->node[0].body->posr.R,j->axis[0]); + dMULTIPLY1_331 (j->reference2,j->node[1].body->posr.R,r); + } + + else { // jds + // else if (j->node[0].body) { + // dMULTIPLY1_331 (j->reference1,j->node[0].body->posr.R,j->axis[2]); + // dMULTIPLY0_331 (j->reference2,j->node[0].body->posr.R,j->axis[0]); + + // We want to handle angular motors attached to passive geoms + dVector3 r; // axis[2] and axis[0] in global coordinates + r[0] = j->axis[2][0]; r[1] = j->axis[2][1]; r[2] = j->axis[2][2]; r[3] = j->axis[2][3]; + dMULTIPLY1_331 (j->reference1,j->node[0].body->posr.R,r); + dMULTIPLY0_331 (r,j->node[0].body->posr.R,j->axis[0]); + j->reference2[0] += r[0]; j->reference2[1] += r[1]; + j->reference2[2] += r[2]; j->reference2[3] += r[3]; + } +} + + +static void amotorGetInfo1 (dxJointAMotor *j, dxJoint::Info1 *info) +{ + info->m = 0; + info->nub = 0; + + // compute the axes and angles, if in euler mode + if (j->mode == dAMotorEuler) { + dVector3 ax[3]; + amotorComputeGlobalAxes (j,ax); + amotorComputeEulerAngles (j,ax); + } + + // see if we're powered or at a joint limit for each axis + for (int i=0; i < j->num; i++) { + if (j->limot[i].testRotationalLimit (j->angle[i]) || + j->limot[i].fmax > 0) { + info->m++; + } + } +} + + +static void amotorGetInfo2 (dxJointAMotor *joint, dxJoint::Info2 *info) +{ + int i; + + // compute the axes (if not global) + dVector3 ax[3]; + amotorComputeGlobalAxes (joint,ax); + + // in euler angle mode we do not actually constrain the angular velocity + // along the axes axis[0] and axis[2] (although we do use axis[1]) : + // + // to get constrain w2-w1 along ...not + // ------ --------------------- ------ + // d(angle[0])/dt = 0 ax[1] x ax[2] ax[0] + // d(angle[1])/dt = 0 ax[1] + // d(angle[2])/dt = 0 ax[0] x ax[1] ax[2] + // + // constraining w2-w1 along an axis 'a' means that a'*(w2-w1)=0. + // to prove the result for angle[0], write the expression for angle[0] from + // GetInfo1 then take the derivative. to prove this for angle[2] it is + // easier to take the euler rate expression for d(angle[2])/dt with respect + // to the components of w and set that to 0. + + dVector3 *axptr[3]; + axptr[0] = &ax[0]; + axptr[1] = &ax[1]; + axptr[2] = &ax[2]; + + dVector3 ax0_cross_ax1; + dVector3 ax1_cross_ax2; + if (joint->mode == dAMotorEuler) { + dCROSS (ax0_cross_ax1,=,ax[0],ax[1]); + axptr[2] = &ax0_cross_ax1; + dCROSS (ax1_cross_ax2,=,ax[1],ax[2]); + axptr[0] = &ax1_cross_ax2; + } + + int row=0; + for (i=0; i < joint->num; i++) { + row += joint->limot[i].addLimot (joint,info,row,*(axptr[i]),1); + } +} + + +EXPORT_C void dJointSetAMotorNumAxes (dJointID j, int num) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + if (joint->mode == dAMotorEuler) { + joint->num = 3; + } + else { + if (num < 0) num = 0; + if (num > 3) num = 3; + joint->num = num; + } +} + + +EXPORT_C void dJointSetAMotorAxis (dJointID j, int anum, int rel, dReal x, dReal y, dReal z) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + + // adjust rel to match the internal body order + if (!joint->node[1].body && rel==2) rel = 1; + + joint->rel[anum] = rel; + + // x,y,z is always in global coordinates regardless of rel, so we may have + // to convert it to be relative to a body + dVector3 r; + r[0] = x; + r[1] = y; + r[2] = z; + r[3] = 0; + if (rel > 0) { + if (rel==1) { + dMULTIPLY1_331 (joint->axis[anum],joint->node[0].body->posr.R,r); + } + else { + // don't assert; handle the case of attachment to a bodiless geom + if (joint->node[1].body) { // jds + dMULTIPLY1_331 (joint->axis[anum],joint->node[1].body->posr.R,r); + } + else { + joint->axis[anum][0] = r[0]; joint->axis[anum][1] = r[1]; + joint->axis[anum][2] = r[2]; joint->axis[anum][3] = r[3]; + } + } + } + else { + joint->axis[anum][0] = r[0]; + joint->axis[anum][1] = r[1]; + joint->axis[anum][2] = r[2]; + } + dNormalize3 (joint->axis[anum]); + if (joint->mode == dAMotorEuler) amotorSetEulerReferenceVectors (joint); +} + + +EXPORT_C void dJointSetAMotorAngle (dJointID j, int anum, dReal angle) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + if (joint->mode == dAMotorUser) { + if (anum < 0) anum = 0; + if (anum > 3) anum = 3; + joint->angle[anum] = angle; + } +} + + +EXPORT_C void dJointSetAMotorParam (dJointID j, int parameter, dReal value) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + int anum = parameter >> 8; + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + parameter &= 0xff; + joint->limot[anum].set (parameter, value); +} + + +EXPORT_C void dJointSetAMotorMode (dJointID j, int mode) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + joint->mode = mode; + if (joint->mode == dAMotorEuler) { + joint->num = 3; + amotorSetEulerReferenceVectors (joint); + } +} + + +EXPORT_C int dJointGetAMotorNumAxes (dJointID j) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + return joint->num; +} + + +EXPORT_C void dJointGetAMotorAxis (dJointID j, int anum, dVector3 result) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + if (joint->rel[anum] > 0) { + if (joint->rel[anum]==1) { + dMULTIPLY0_331 (result,joint->node[0].body->posr.R,joint->axis[anum]); + } + else { + if (joint->node[1].body) { // jds + dMULTIPLY0_331 (result,joint->node[1].body->posr.R,joint->axis[anum]); + } + else { + result[0] = joint->axis[anum][0]; result[1] = joint->axis[anum][1]; + result[2] = joint->axis[anum][2]; result[3] = joint->axis[anum][3]; + } + } + } + else { + result[0] = joint->axis[anum][0]; + result[1] = joint->axis[anum][1]; + result[2] = joint->axis[anum][2]; + } +} + + +EXPORT_C int dJointGetAMotorAxisRel (dJointID j, int anum) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + return joint->rel[anum]; +} + + +EXPORT_C dReal dJointGetAMotorAngle (dJointID j, int anum) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + if (anum < 0) anum = 0; + if (anum > 3) anum = 3; + return joint->angle[anum]; +} + + +EXPORT_C dReal dJointGetAMotorAngleRate (dJointID /*j*/, int /*anum*/) +{ + // @@@ + return 0; +} + + +EXPORT_C dReal dJointGetAMotorParam (dJointID j, int parameter) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + int anum = parameter >> 8; + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + parameter &= 0xff; + return joint->limot[anum].get (parameter); +} + + +EXPORT_C int dJointGetAMotorMode (dJointID j) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + + return joint->mode; +} + + +EXPORT_C void dJointAddAMotorTorques (dJointID j, dReal torque1, dReal torque2, dReal torque3) +{ + dxJointAMotor* joint = (dxJointAMotor*)j; + dVector3 axes[3]; + + + if (joint->num == 0) + return; + + + amotorComputeGlobalAxes (joint,axes); + axes[0][0] = dMUL(axes[0][0],torque1); + axes[0][1] = dMUL(axes[0][1],torque1); + axes[0][2] = dMUL(axes[0][2],torque1); + if (joint->num >= 2) { + axes[0][0] += dMUL(axes[1][0],torque2); + axes[0][1] += dMUL(axes[1][1],torque2); + axes[0][2] += dMUL(axes[1][2],torque2); + if (joint->num >= 3) { + axes[0][0] += dMUL(axes[2][0],torque3); + axes[0][1] += dMUL(axes[2][1],torque3); + axes[0][2] += dMUL(axes[2][2],torque3); + } + } + + if (joint->node[0].body != 0) + dBodyAddTorque (joint->node[0].body,axes[0][0],axes[0][1],axes[0][2]); + if (joint->node[1].body != 0) + dBodyAddTorque(joint->node[1].body, -axes[0][0], -axes[0][1], -axes[0][2]); +} + + +dxJoint::Vtable __damotor_vtable = { + sizeof(dxJointAMotor), + (dxJoint::init_fn*) amotorInit, + (dxJoint::getInfo1_fn*) amotorGetInfo1, + (dxJoint::getInfo2_fn*) amotorGetInfo2, + dJointTypeAMotor}; + + + +//**************************************************************************** +// lmotor joint +static void lmotorInit (dxJointLMotor *j) +{ + int i; + j->num = 0; + for (i=0;i<3;i++) { + dSetZero(j->axis[i],4); + j->limot[i].init(j->world); + } +} + +static void lmotorComputeGlobalAxes (dxJointLMotor *joint, dVector3 ax[3]) +{ + for (int i=0; i< joint->num; i++) { + if (joint->rel[i] == 1) { + dMULTIPLY0_331 (ax[i],joint->node[0].body->posr.R,joint->axis[i]); + } + else if (joint->rel[i] == 2) { + if (joint->node[1].body) { // jds: don't assert, just ignore + dMULTIPLY0_331 (ax[i],joint->node[1].body->posr.R,joint->axis[i]); + } + } else { + ax[i][0] = joint->axis[i][0]; + ax[i][1] = joint->axis[i][1]; + ax[i][2] = joint->axis[i][2]; + } + } +} + +static void lmotorGetInfo1 (dxJointLMotor *j, dxJoint::Info1 *info) +{ + info->m = 0; + info->nub = 0; + for (int i=0; i < j->num; i++) { + if (j->limot[i].fmax > 0) { + info->m++; + } + } +} + +static void lmotorGetInfo2 (dxJointLMotor *joint, dxJoint::Info2 *info) +{ + int row=0; + dVector3 ax[3]; + lmotorComputeGlobalAxes(joint, ax); + + for (int i=0;inum;i++) { + row += joint->limot[i].addLimot(joint,info,row,ax[i], 0); + } +} + +EXPORT_C void dJointSetLMotorAxis (dJointID j, int anum, int rel, dReal x, dReal y, dReal z) +{ + dxJointLMotor* joint = (dxJointLMotor*)j; +//for now we are ignoring rel! + + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + + if (!joint->node[1].body && rel==2) rel = 1; //ref 1 + + joint->rel[anum] = rel; + + dVector3 r; + r[0] = x; + r[1] = y; + r[2] = z; + r[3] = 0; + if (rel > 0) { + if (rel==1) { + dMULTIPLY1_331 (joint->axis[anum],joint->node[0].body->posr.R,r); + } else { + //second body has to exists thanks to ref 1 line + dMULTIPLY1_331 (joint->axis[anum],joint->node[1].body->posr.R,r); + } + } else { + joint->axis[anum][0] = r[0]; + joint->axis[anum][1] = r[1]; + joint->axis[anum][2] = r[2]; + } + + dNormalize3 (joint->axis[anum]); +} + +EXPORT_C void dJointSetLMotorNumAxes (dJointID j, int num) +{ + dxJointLMotor* joint = (dxJointLMotor*)j; + + if (num < 0) num = 0; + if (num > 3) num = 3; + joint->num = num; +} + +EXPORT_C void dJointSetLMotorParam (dJointID j, int parameter, dReal value) +{ + dxJointLMotor* joint = (dxJointLMotor*)j; + + int anum = parameter >> 8; + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + parameter &= 0xff; + joint->limot[anum].set (parameter, value); +} + +EXPORT_C int dJointGetLMotorNumAxes (dJointID j) +{ + dxJointLMotor* joint = (dxJointLMotor*)j; + + return joint->num; +} + + +EXPORT_C void dJointGetLMotorAxis (dJointID j, int anum, dVector3 result) +{ + dxJointLMotor* joint = (dxJointLMotor*)j; + + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + result[0] = joint->axis[anum][0]; + result[1] = joint->axis[anum][1]; + result[2] = joint->axis[anum][2]; +} + +EXPORT_C dReal dJointGetLMotorParam (dJointID j, int parameter) +{ + dxJointLMotor* joint = (dxJointLMotor*)j; + + int anum = parameter >> 8; + if (anum < 0) anum = 0; + if (anum > 2) anum = 2; + parameter &= 0xff; + return joint->limot[anum].get (parameter); +} + +dxJoint::Vtable __dlmotor_vtable = { + sizeof(dxJointLMotor), + (dxJoint::init_fn*) lmotorInit, + (dxJoint::getInfo1_fn*) lmotorGetInfo1, + (dxJoint::getInfo2_fn*) lmotorGetInfo2, + dJointTypeLMotor +}; + + +//**************************************************************************** +// fixed joint + +static void fixedInit (dxJointFixed *j) +{ + dSetZero (j->offset,4); + dSetZero (j->qrel,4); +} + + +static void fixedGetInfo1 (dxJointFixed */*j*/, dxJoint::Info1 *info) +{ + info->m = 6; + info->nub = 6; +} + + +static void fixedGetInfo2 (dxJointFixed *joint, dxJoint::Info2 *info) +{ + int s = info->rowskip; + + // Three rows for orientation + setFixedOrientation(joint, info, joint->qrel, 3); + + // Three rows for position. + // set jacobian + info->J1l[0] = REAL(1.0); + info->J1l[s+1] = REAL(1.0); + info->J1l[2*s+2] = REAL(1.0); + + dVector3 ofs; + dMULTIPLY0_331 (ofs,joint->node[0].body->posr.R,joint->offset); + if (joint->node[1].body) { + dCROSSMAT (info->J1a,ofs,s,+,-); + info->J2l[0] = REAL(-1.0); + info->J2l[s+1] = REAL(-1.0); + info->J2l[2*s+2] = REAL(-1.0); + } + + // set right hand side for the first three rows (linear) + dReal k = dMUL(info->fps,info->erp); + if (joint->node[1].body) { + for (int j=0; j<3; j++) + info->c[j] = dMUL(k,(joint->node[1].body->posr.pos[j] - + joint->node[0].body->posr.pos[j] + ofs[j])); + } + else { + for (int j=0; j<3; j++) + info->c[j] = dMUL(k,(joint->offset[j] - joint->node[0].body->posr.pos[j])); + } +} + + +EXPORT_C void dJointSetFixed (dJointID j) +{ + dxJointFixed* joint = (dxJointFixed*)j; + + int i; + + // This code is taken from sJointSetSliderAxis(), we should really put the + // common code in its own function. + // compute the offset between the bodies + if (joint->node[0].body) { + if (joint->node[1].body) { + dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); + dReal ofs[4]; + for (i=0; i<4; i++) ofs[i] = joint->node[0].body->posr.pos[i]; + for (i=0; i<4; i++) ofs[i] -= joint->node[1].body->posr.pos[i]; + dMULTIPLY1_331 (joint->offset,joint->node[0].body->posr.R,ofs); + } + else { + // set joint->qrel to the transpose of the first body's q + joint->qrel[0] = joint->node[0].body->q[0]; + for (i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; + for (i=0; i<4; i++) joint->offset[i] = joint->node[0].body->posr.pos[i]; + } + } +} + + +dxJoint::Vtable __dfixed_vtable = { + sizeof(dxJointFixed), + (dxJoint::init_fn*) fixedInit, + (dxJoint::getInfo1_fn*) fixedGetInfo1, + (dxJoint::getInfo2_fn*) fixedGetInfo2, + dJointTypeFixed}; + +//**************************************************************************** +// null joint + +static void nullGetInfo1 (dxJointNull */*j*/, dxJoint::Info1 *info) +{ + info->m = 0; + info->nub = 0; +} + + +static void nullGetInfo2 (dxJointNull */*joint*/, dxJoint::Info2 */*info*/) +{ + +} + + +dxJoint::Vtable __dnull_vtable = { + sizeof(dxJointNull), + (dxJoint::init_fn*) 0, + (dxJoint::getInfo1_fn*) nullGetInfo1, + (dxJoint::getInfo2_fn*) nullGetInfo2, + dJointTypeNull}; + + + + +/* + This code is part of the Plane2D ODE joint + by psero@gmx.de + Wed Apr 23 18:53:43 CEST 2003 + + Add this code to the file: ode/src/joint.cpp +*/ + + +# define VoXYZ(v1, o1, x, y, z) \ + ( \ + (v1)[0] o1 (x), \ + (v1)[1] o1 (y), \ + (v1)[2] o1 (z) \ + ) + +static const dReal Midentity[3][3] = + { + { REAL(1.0), 0, 0 }, + { 0, REAL(1.0), 0 }, + { 0, 0, REAL(1.0), } + }; + + + +static void plane2dInit (dxJointPlane2D *j) +/*********************************************/ +{ + /* MINFO ("plane2dInit ()"); */ + j->motor_x.init (j->world); + j->motor_y.init (j->world); + j->motor_angle.init (j->world); +} + + + +static void plane2dGetInfo1 (dxJointPlane2D *j, dxJoint::Info1 *info) +/***********************************************************************/ +{ + /* MINFO ("plane2dGetInfo1 ()"); */ + + info->nub = 3; + info->m = 3; + + if (j->motor_x.fmax > 0) + j->row_motor_x = info->m ++; + if (j->motor_y.fmax > 0) + j->row_motor_y = info->m ++; + if (j->motor_angle.fmax > 0) + j->row_motor_angle = info->m ++; +} + + + +static void plane2dGetInfo2 (dxJointPlane2D *joint, dxJoint::Info2 *info) +/***************************************************************************/ +{ + int r0 = 0, + r1 = info->rowskip, + r2 = 2 * r1; + dReal eps = dMUL(info->fps,info->erp); + + /* MINFO ("plane2dGetInfo2 ()"); */ + +/* + v = v1, w = omega1 + (v2, omega2 not important (== static environment)) + + constraint equations: + xz = 0 + wx = 0 + wy = 0 + + <=> ( 0 0 1 ) (vx) ( 0 0 0 ) (wx) ( 0 ) + ( 0 0 0 ) (vy) + ( 1 0 0 ) (wy) = ( 0 ) + ( 0 0 0 ) (vz) ( 0 1 0 ) (wz) ( 0 ) + J1/J1l Omega1/J1a +*/ + + // fill in linear and angular coeff. for left hand side: + + VoXYZ (&info->J1l[r0], =, 0, 0, REAL(1.0)); + VoXYZ (&info->J1l[r1], =, 0, 0, 0); + VoXYZ (&info->J1l[r2], =, 0, 0, 0); + + VoXYZ (&info->J1a[r0], =, 0, 0, 0); + VoXYZ (&info->J1a[r1], =, REAL(1.0), 0, 0); + VoXYZ (&info->J1a[r2], =, 0, REAL(1.0), 0); + + // error correction (against drift): + + // a) linear vz, so that z (== pos[2]) == 0 + info->c[0] = dMUL(eps,-joint->node[0].body->posr.pos[2]); + + + // if the slider is powered, or has joint limits, add in the extra row: + + if (joint->row_motor_x > 0) + joint->motor_x.addLimot ( + joint, info, joint->row_motor_x, Midentity[0], 0); + + if (joint->row_motor_y > 0) + joint->motor_y.addLimot ( + joint, info, joint->row_motor_y, Midentity[1], 0); + + if (joint->row_motor_angle > 0) + joint->motor_angle.addLimot ( + joint, info, joint->row_motor_angle, Midentity[2], 1); +} + + + +dxJoint::Vtable __dplane2d_vtable = +{ + sizeof (dxJointPlane2D), + (dxJoint::init_fn*) plane2dInit, + (dxJoint::getInfo1_fn*) plane2dGetInfo1, + (dxJoint::getInfo2_fn*) plane2dGetInfo2, + dJointTypePlane2D +}; + + +EXPORT_C void dJointSetPlane2DXParam (dxJoint *joint, + int parameter, dReal value) +{ + + dxJointPlane2D* joint2d = (dxJointPlane2D*)( joint ); + joint2d->motor_x.set (parameter, value); +} + + +EXPORT_C void dJointSetPlane2DYParam (dxJoint *joint, + int parameter, dReal value) +{ + + dxJointPlane2D* joint2d = (dxJointPlane2D*)( joint ); + joint2d->motor_y.set (parameter, value); +} + + + +EXPORT_C void dJointSetPlane2DAngleParam (dxJoint *joint, + int parameter, dReal value) +{ + + dxJointPlane2D* joint2d = (dxJointPlane2D*)( joint ); + joint2d->motor_angle.set (parameter, value); +} + + +