libraries moved to opensim-libs, a new repository

1 files changed, 0 insertions, 1139 deletions

diff --git a/libraries/ode-0.9/ode/src/stepfast.cpp b/libraries/ode-0.9/ode/src/stepfast.cpp
deleted file mode 100755
index 35c45db..0000000
--- a/libraries/ode-0.9/ode/src/stepfast.cpp
+++ /dev/null
@@ -1,1139 +0,0 @@
-/*************************************************************************
- *                                                                       *
- * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith.       *
- * All rights reserved.  Email: russ@q12.org   Web: www.q12.org          *
- *                                                                       *
- * Fast iterative solver, David Whittaker. Email: david@csworkbench.com  *
- *                                                                       *
- * 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.                     *
- *                                                                       *
- *************************************************************************/
-
-// This is the StepFast code by David Whittaker. This code is faster, but
-// sometimes less stable than, the original "big matrix" code.
-// Refer to the user's manual for more information.
-// Note that this source file duplicates a lot of stuff from step.cpp,
-// eventually we should move the common code to a third file.
-
-#include "objects.h"
-#include "joint.h"
-#include <ode/config.h>
-#include <ode/objects.h>
-#include <ode/odemath.h>
-#include <ode/rotation.h>
-#include <ode/timer.h>
-#include <ode/error.h>
-#include <ode/matrix.h>
-#include <ode/misc.h>
-#include "lcp.h"
-#include "step.h"
-#include "util.h"
-
-
-// misc defines
-
-#define ALLOCA dALLOCA16
-
-#define RANDOM_JOINT_ORDER
-//#define FAST_FACTOR   //use a factorization approximation to the LCP solver (fast, theoretically less accurate)
-#define SLOW_LCP      //use the old LCP solver
-//#define NO_ISLANDS    //does not perform island creation code (3~4% of simulation time), body disabling doesn't work
-//#define TIMING
-
-
-static int autoEnableDepth = 2;
-
-void dWorldSetAutoEnableDepthSF1 (dxWorld *world, int autodepth)
-{
-        if (autodepth > 0)
-                autoEnableDepth = autodepth;
-        else
-                autoEnableDepth = 0;
-}
-
-int dWorldGetAutoEnableDepthSF1 (dxWorld *world)
-{
-        return autoEnableDepth;
-}
-
-//little bit of math.... the _sym_ functions assume the return matrix will be symmetric
-static void
-Multiply2_sym_p8p (dReal * A, dReal * B, dReal * C, int p, int Askip)
-{
-        int i, j;
-        dReal sum, *aa, *ad, *bb, *cc;
-        dIASSERT (p > 0 && A && B && C);
-        bb = B;
-        for (i = 0; i < p; i++)
-        {
-                //aa is going accross the matrix, ad down
-                aa = ad = A;
-                cc = C;
-                for (j = i; j < p; j++)
-                {
-                        sum = bb[0] * cc[0];
-                        sum += bb[1] * cc[1];
-                        sum += bb[2] * cc[2];
-                        sum += bb[4] * cc[4];
-                        sum += bb[5] * cc[5];
-                        sum += bb[6] * cc[6];
-                        *(aa++) = *ad = sum;
-                        ad += Askip;
-                        cc += 8;
-                }
-                bb += 8;
-                A += Askip + 1;
-                C += 8;
-        }
-}
-
-static void
-MultiplyAdd2_sym_p8p (dReal * A, dReal * B, dReal * C, int p, int Askip)
-{
-        int i, j;
-        dReal sum, *aa, *ad, *bb, *cc;
-        dIASSERT (p > 0 && A && B && C);
-        bb = B;
-        for (i = 0; i < p; i++)
-        {
-                //aa is going accross the matrix, ad down
-                aa = ad = A;
-                cc = C;
-                for (j = i; j < p; j++)
-                {
-                        sum = bb[0] * cc[0];
-                        sum += bb[1] * cc[1];
-                        sum += bb[2] * cc[2];
-                        sum += bb[4] * cc[4];
-                        sum += bb[5] * cc[5];
-                        sum += bb[6] * cc[6];
-                        *(aa++) += sum;
-                        *ad += sum;
-                        ad += Askip;
-                        cc += 8;
-                }
-                bb += 8;
-                A += Askip + 1;
-                C += 8;
-        }
-}
-
-
-// this assumes the 4th and 8th rows of B are zero.
-
-static void
-Multiply0_p81 (dReal * A, dReal * B, dReal * C, int p)
-{
-        int i;
-        dIASSERT (p > 0 && A && B && C);
-        dReal sum;
-        for (i = p; i; i--)
-        {
-                sum = B[0] * C[0];
-                sum += B[1] * C[1];
-                sum += B[2] * C[2];
-                sum += B[4] * C[4];
-                sum += B[5] * C[5];
-                sum += B[6] * C[6];
-                *(A++) = sum;
-                B += 8;
-        }
-}
-
-
-// this assumes the 4th and 8th rows of B are zero.
-
-static void
-MultiplyAdd0_p81 (dReal * A, dReal * B, dReal * C, int p)
-{
-        int i;
-        dIASSERT (p > 0 && A && B && C);
-        dReal sum;
-        for (i = p; i; i--)
-        {
-                sum = B[0] * C[0];
-                sum += B[1] * C[1];
-                sum += B[2] * C[2];
-                sum += B[4] * C[4];
-                sum += B[5] * C[5];
-                sum += B[6] * C[6];
-                *(A++) += sum;
-                B += 8;
-        }
-}
-
-
-// this assumes the 4th and 8th rows of B are zero.
-
-static void
-Multiply1_8q1 (dReal * A, dReal * B, dReal * C, int q)
-{
-        int k;
-        dReal sum;
-        dIASSERT (q > 0 && A && B && C);
-        sum = 0;
-        for (k = 0; k < q; k++)
-                sum += B[k * 8] * C[k];
-        A[0] = sum;
-        sum = 0;
-        for (k = 0; k < q; k++)
-                sum += B[1 + k * 8] * C[k];
-        A[1] = sum;
-        sum = 0;
-        for (k = 0; k < q; k++)
-                sum += B[2 + k * 8] * C[k];
-        A[2] = sum;
-        sum = 0;
-        for (k = 0; k < q; k++)
-                sum += B[4 + k * 8] * C[k];
-        A[4] = sum;
-        sum = 0;
-        for (k = 0; k < q; k++)
-                sum += B[5 + k * 8] * C[k];
-        A[5] = sum;
-        sum = 0;
-        for (k = 0; k < q; k++)
-                sum += B[6 + k * 8] * C[k];
-        A[6] = sum;
-}
-
-//****************************************************************************
-// body rotation
-
-// return sin(x)/x. this has a singularity at 0 so special handling is needed
-// for small arguments.
-
-static inline dReal
-sinc (dReal x)
-{
-        // if |x| < 1e-4 then use a taylor series expansion. this two term expansion
-        // is actually accurate to one LS bit within this range if double precision
-        // is being used - so don't worry!
-        if (dFabs (x) < 1.0e-4)
-                return REAL (1.0) - x * x * REAL (0.166666666666666666667);
-        else
-                return dSin (x) / x;
-}
-
-
-// given a body b, apply its linear and angular rotation over the time
-// interval h, thereby adjusting its position and orientation.
-
-static inline void
-moveAndRotateBody (dxBody * b, dReal h)
-{
-        int j;
-
-        // handle linear velocity
-        for (j = 0; j < 3; j++)
-                b->posr.pos[j] += h * b->lvel[j];
-
-        if (b->flags & dxBodyFlagFiniteRotation)
-        {
-                dVector3 irv;                   // infitesimal rotation vector
-                dQuaternion q;                  // quaternion for finite rotation
-
-                if (b->flags & dxBodyFlagFiniteRotationAxis)
-                {
-                        // split the angular velocity vector into a component along the finite
-                        // rotation axis, and a component orthogonal to it.
-                        dVector3 frv, irv;      // finite rotation vector
-                        dReal k = dDOT (b->finite_rot_axis, b->avel);
-                        frv[0] = b->finite_rot_axis[0] * k;
-                        frv[1] = b->finite_rot_axis[1] * k;
-                        frv[2] = b->finite_rot_axis[2] * k;
-                        irv[0] = b->avel[0] - frv[0];
-                        irv[1] = b->avel[1] - frv[1];
-                        irv[2] = b->avel[2] - frv[2];
-
-                        // make a rotation quaternion q that corresponds to frv * h.
-                        // compare this with the full-finite-rotation case below.
-                        h *= REAL (0.5);
-                        dReal theta = k * h;
-                        q[0] = dCos (theta);
-                        dReal s = sinc (theta) * h;
-                        q[1] = frv[0] * s;
-                        q[2] = frv[1] * s;
-                        q[3] = frv[2] * s;
-                }
-                else
-                {
-                        // make a rotation quaternion q that corresponds to w * h
-                        dReal wlen = dSqrt (b->avel[0] * b->avel[0] + b->avel[1] * b->avel[1] + b->avel[2] * b->avel[2]);
-                        h *= REAL (0.5);
-                        dReal theta = wlen * h;
-                        q[0] = dCos (theta);
-                        dReal s = sinc (theta) * h;
-                        q[1] = b->avel[0] * s;
-                        q[2] = b->avel[1] * s;
-                        q[3] = b->avel[2] * s;
-                }
-
-                // do the finite rotation
-                dQuaternion q2;
-                dQMultiply0 (q2, q, b->q);
-                for (j = 0; j < 4; j++)
-                        b->q[j] = q2[j];
-
-                // do the infitesimal rotation if required
-                if (b->flags & dxBodyFlagFiniteRotationAxis)
-                {
-                        dReal dq[4];
-                        dWtoDQ (irv, b->q, dq);
-                        for (j = 0; j < 4; j++)
-                                b->q[j] += h * dq[j];
-                }
-        }
-        else
-        {
-                // the normal way - do an infitesimal rotation
-                dReal dq[4];
-                dWtoDQ (b->avel, b->q, dq);
-                for (j = 0; j < 4; j++)
-                        b->q[j] += h * dq[j];
-        }
-
-        // normalize the quaternion and convert it to a rotation matrix
-        dNormalize4 (b->q);
-        dQtoR (b->q, b->posr.R);
-
-        // notify all attached geoms that this body has moved
-        for (dxGeom * geom = b->geom; geom; geom = dGeomGetBodyNext (geom))
-                dGeomMoved (geom);
-}
-
-//****************************************************************************
-//This is an implementation of the iterated/relaxation algorithm.
-//Here is a quick overview of the algorithm per Sergi Valverde's posts to the
-//mailing list:
-//
-//  for i=0..N-1 do
-//      for c = 0..C-1 do
-//          Solve constraint c-th
-//          Apply forces to constraint bodies
-//      next
-//  next
-//  Integrate bodies
-
-void
-dInternalStepFast (dxWorld * world, dxBody * body[2], dReal * GI[2], dReal * GinvI[2], dxJoint * joint, dxJoint::Info1 info, dxJoint::Info2 Jinfo, dReal stepsize)
-{
-        int i, j, k;
-# ifdef TIMING
-        dTimerNow ("constraint preprocessing");
-# endif
-
-        dReal stepsize1 = dRecip (stepsize);
-
-        int m = info.m;
-        // nothing to do if no constraints.
-        if (m <= 0)
-                return;
-
-        int nub = 0;
-        if (info.nub == info.m)
-                nub = m;
-
-        // compute A = J*invM*J'. first compute JinvM = J*invM. this has the same
-        // format as J so we just go through the constraints in J multiplying by
-        // the appropriate scalars and matrices.
-#   ifdef TIMING
-        dTimerNow ("compute A");
-#   endif
-        dReal JinvM[2 * 6 * 8];
-        //dSetZero (JinvM, 2 * m * 8);
-
-        dReal *Jsrc = Jinfo.J1l;
-        dReal *Jdst = JinvM;
-        if (body[0])
-        {
-                for (j = m - 1; j >= 0; j--)
-                {
-                        for (k = 0; k < 3; k++)
-                                Jdst[k] = Jsrc[k] * body[0]->invMass;
-                        dMULTIPLY0_133 (Jdst + 4, Jsrc + 4, GinvI[0]);
-                        Jsrc += 8;
-                        Jdst += 8;
-                }
-        }
-        if (body[1])
-        {
-                Jsrc = Jinfo.J2l;
-                Jdst = JinvM + 8 * m;
-                for (j = m - 1; j >= 0; j--)
-                {
-                        for (k = 0; k < 3; k++)
-                                Jdst[k] = Jsrc[k] * body[1]->invMass;
-                        dMULTIPLY0_133 (Jdst + 4, Jsrc + 4, GinvI[1]);
-                        Jsrc += 8;
-                        Jdst += 8;
-                }
-        }
-
-
-        // now compute A = JinvM * J'.
-        int mskip = dPAD (m);
-        dReal A[6 * 8];
-        //dSetZero (A, 6 * 8);
-
-        if (body[0]) {
-                Multiply2_sym_p8p (A, JinvM, Jinfo.J1l, m, mskip);
-                if (body[1])
-                        MultiplyAdd2_sym_p8p (A, JinvM + 8 * m, Jinfo.J2l,
-                                              m, mskip);
-        } else {
-                if (body[1])
-                        Multiply2_sym_p8p (A, JinvM + 8 * m, Jinfo.J2l,
-                                           m, mskip);
-        }
-
-        // add cfm to the diagonal of A
-        for (i = 0; i < m; i++)
-                A[i * mskip + i] += Jinfo.cfm[i] * stepsize1;
-
-        // compute the right hand side `rhs'
-#   ifdef TIMING
-        dTimerNow ("compute rhs");
-#   endif
-        dReal tmp1[16];
-        //dSetZero (tmp1, 16);
-        // put v/h + invM*fe into tmp1
-        for (i = 0; i < 2; i++)
-        {
-                if (!body[i])
-                        continue;
-                for (j = 0; j < 3; j++)
-                        tmp1[i * 8 + j] = body[i]->facc[j] * body[i]->invMass + body[i]->lvel[j] * stepsize1;
-                dMULTIPLY0_331 (tmp1 + i * 8 + 4, GinvI[i], body[i]->tacc);
-                for (j = 0; j < 3; j++)
-                        tmp1[i * 8 + 4 + j] += body[i]->avel[j] * stepsize1;
-        }
-        // put J*tmp1 into rhs
-        dReal rhs[6];
-        //dSetZero (rhs, 6);
-
-        if (body[0]) {
-                Multiply0_p81 (rhs, Jinfo.J1l, tmp1, m);
-                if (body[1])
-                        MultiplyAdd0_p81 (rhs, Jinfo.J2l, tmp1 + 8, m);
-        } else {
-                if (body[1])
-                        Multiply0_p81 (rhs, Jinfo.J2l, tmp1 + 8, m);
-        }
-
-        // complete rhs
-        for (i = 0; i < m; i++)
-                rhs[i] = Jinfo.c[i] * stepsize1 - rhs[i];
-
-#ifdef SLOW_LCP
-        // solve the LCP problem and get lambda.
-        // this will destroy A but that's okay
-#       ifdef TIMING
-        dTimerNow ("solving LCP problem");
-#       endif
-        dReal *lambda = (dReal *) ALLOCA (m * sizeof (dReal));
-        dReal *residual = (dReal *) ALLOCA (m * sizeof (dReal));
-        dReal lo[6], hi[6];
-        memcpy (lo, Jinfo.lo, m * sizeof (dReal));
-        memcpy (hi, Jinfo.hi, m * sizeof (dReal));
-        dSolveLCP (m, A, lambda, rhs, residual, nub, lo, hi, Jinfo.findex);
-#endif
-
-        // LCP Solver replacement:
-        // This algorithm goes like this:
-        // Do a straightforward LDLT factorization of the matrix A, solving for
-        // A*x = rhs
-        // For each x[i] that is outside of the bounds of lo[i] and hi[i],
-        //    clamp x[i] into that range.
-        //    Substitute into A the now known x's
-        //    subtract the residual away from the rhs.
-        //    Remove row and column i from L, updating the factorization
-        //    place the known x's at the end of the array, keeping up with location in p
-        // Repeat until all constraints have been clamped or all are within bounds
-        //
-        // This is probably only faster in the single joint case where only one repeat is
-        // the norm.
-
-#ifdef FAST_FACTOR
-        // factorize A (L*D*L'=A)
-#       ifdef TIMING
-        dTimerNow ("factorize A");
-#       endif
-        dReal d[6];
-        dReal L[6 * 8];
-        memcpy (L, A, m * mskip * sizeof (dReal));
-        dFactorLDLT (L, d, m, mskip);
-
-        // compute lambda
-#       ifdef TIMING
-        dTimerNow ("compute lambda");
-#       endif
-
-        int left = m;                           //constraints left to solve.
-        int remove[6];
-        dReal lambda[6];
-        dReal x[6];
-        int p[6];
-        for (i = 0; i < 6; i++)
-                p[i] = i;
-        while (true)
-        {
-                memcpy (x, rhs, left * sizeof (dReal));
-                dSolveLDLT (L, d, x, left, mskip);
-
-                int fixed = 0;
-                for (i = 0; i < left; i++)
-                {
-                        j = p[i];
-                        remove[i] = false;
-                        // This isn't the exact same use of findex as dSolveLCP.... since x[findex]
-                        // may change after I've already clamped x[i], but it should be close
-                        if (Jinfo.findex[j] > -1)
-                        {
-                                dReal f = fabs (Jinfo.hi[j] * x[p[Jinfo.findex[j]]]);
-                                if (x[i] > f)
-                                        x[i] = f;
-                                else if (x[i] < -f)
-                                        x[i] = -f;
-                                else
-                                        continue;
-                        }
-                        else
-                        {
-                                if (x[i] > Jinfo.hi[j])
-                                        x[i] = Jinfo.hi[j];
-                                else if (x[i] < Jinfo.lo[j])
-                                        x[i] = Jinfo.lo[j];
-                                else
-                                        continue;
-                        }
-                        remove[i] = true;
-                        fixed++;
-                }
-                if (fixed == 0 || fixed == left)        //no change or all constraints solved
-                        break;
-
-                for (i = 0; i < left; i++)      //sub in to right hand side.
-                        if (remove[i])
-                                for (j = 0; j < left; j++)
-                                        if (!remove[j])
-                                                rhs[j] -= A[j * mskip + i] * x[i];
-
-                for (int r = left - 1; r >= 0; r--)     //eliminate row/col for fixed variables
-                {
-                        if (remove[r])
-                        {
-                                //dRemoveLDLT adapted for use without row pointers.
-                                if (r == left - 1)
-                                {
-                                        left--;
-                                        continue;       // deleting last row/col is easy
-                                }
-                                else if (r == 0)
-                                {
-                                        dReal a[6];
-                                        for (i = 0; i < left; i++)
-                                                a[i] = -A[i * mskip];
-                                        a[0] += REAL (1.0);
-                                        dLDLTAddTL (L, d, a, left, mskip);
-                                }
-                                else
-                                {
-                                        dReal t[6];
-                                        dReal a[6];
-                                        for (i = 0; i < r; i++)
-                                                t[i] = L[r * mskip + i] / d[i];
-                                        for (i = 0; i < left - r; i++)
-                                                a[i] = dDot (L + (r + i) * mskip, t, r) - A[(r + i) * mskip + r];
-                                        a[0] += REAL (1.0);
-                                        dLDLTAddTL (L + r * mskip + r, d + r, a, left - r, mskip);
-                                }
-
-                                dRemoveRowCol (L, left, mskip, r);
-                                //end dRemoveLDLT
-
-                                left--;
-                                if (r < (left - 1))
-                                {
-                                        dReal tx = x[r];
-                                        memmove (d + r, d + r + 1, (left - r) * sizeof (dReal));
-                                        memmove (rhs + r, rhs + r + 1, (left - r) * sizeof (dReal));
-                                        //x will get written over by rhs anyway, no need to move it around
-                                        //just store the fixed value we just discovered in it.
-                                        x[left] = tx;
-                                        for (i = 0; i < m; i++)
-                                                if (p[i] > r && p[i] <= left)
-                                                        p[i]--;
-                                        p[r] = left;
-                                }
-                        }
-                }
-        }
-
-        for (i = 0; i < m; i++)
-                lambda[i] = x[p[i]];
-#       endif
-        // compute the constraint force `cforce'
-#       ifdef TIMING
-        dTimerNow ("compute constraint force");
-#endif
-
-        // compute cforce = J'*lambda
-        dJointFeedback *fb = joint->feedback;
-        dReal cforce[16];
-        //dSetZero (cforce, 16);
-
-        if (fb)
-        {
-                // the user has requested feedback on the amount of force that this
-                // joint is applying to the bodies. we use a slightly slower
-                // computation that splits out the force components and puts them
-                // in the feedback structure.
-                dReal data1[8], data2[8];
-                if (body[0])
-                {
-                        Multiply1_8q1 (data1, Jinfo.J1l, lambda, m);
-                        dReal *cf1 = cforce;
-                        cf1[0] = (fb->f1[0] = data1[0]);
-                        cf1[1] = (fb->f1[1] = data1[1]);
-                        cf1[2] = (fb->f1[2] = data1[2]);
-                        cf1[4] = (fb->t1[0] = data1[4]);
-                        cf1[5] = (fb->t1[1] = data1[5]);
-                        cf1[6] = (fb->t1[2] = data1[6]);
-                }
-                if (body[1])
-                {
-                        Multiply1_8q1 (data2, Jinfo.J2l, lambda, m);
-                        dReal *cf2 = cforce + 8;
-                        cf2[0] = (fb->f2[0] = data2[0]);
-                        cf2[1] = (fb->f2[1] = data2[1]);
-                        cf2[2] = (fb->f2[2] = data2[2]);
-                        cf2[4] = (fb->t2[0] = data2[4]);
-                        cf2[5] = (fb->t2[1] = data2[5]);
-                        cf2[6] = (fb->t2[2] = data2[6]);
-                }
-        }
-        else
-        {
-                // no feedback is required, let's compute cforce the faster way
-                if (body[0])
-                        Multiply1_8q1 (cforce, Jinfo.J1l, lambda, m);
-                if (body[1])
-                        Multiply1_8q1 (cforce + 8, Jinfo.J2l, lambda, m);
-        }
-
-        for (i = 0; i < 2; i++)
-        {
-                if (!body[i])
-                        continue;
-                for (j = 0; j < 3; j++)
-                {
-                        body[i]->facc[j] += cforce[i * 8 + j];
-                        body[i]->tacc[j] += cforce[i * 8 + 4 + j];
-                }
-        }
-}
-
-void
-dInternalStepIslandFast (dxWorld * world, dxBody * const *bodies, int nb, dxJoint * const *_joints, int nj, dReal stepsize, int maxiterations)
-{
-#   ifdef TIMING
-        dTimerNow ("preprocessing");
-#   endif
-        dxBody *bodyPair[2], *body;
-        dReal *GIPair[2], *GinvIPair[2];
-        dxJoint *joint;
-        int iter, b, j, i;
-        dReal ministep = stepsize / maxiterations;
-
-        // make a local copy of the joint array, because we might want to modify it.
-        // (the "dxJoint *const*" declaration says we're allowed to modify the joints
-        // but not the joint array, because the caller might need it unchanged).
-        dxJoint **joints = (dxJoint **) ALLOCA (nj * sizeof (dxJoint *));
-        memcpy (joints, _joints, nj * sizeof (dxJoint *));
-
-        // get m = total constraint dimension, nub = number of unbounded variables.
-        // create constraint offset array and number-of-rows array for all joints.
-        // the constraints are re-ordered as follows: the purely unbounded
-        // constraints, the mixed unbounded + LCP constraints, and last the purely
-        // LCP constraints. this assists the LCP solver to put all unbounded
-        // variables at the start for a quick factorization.
-        //
-        // joints with m=0 are inactive and are removed from the joints array
-        // entirely, so that the code that follows does not consider them.
-        // also number all active joints in the joint list (set their tag values).
-        // inactive joints receive a tag value of -1.
-
-        int m = 0;
-        dxJoint::Info1 * info = (dxJoint::Info1 *) ALLOCA (nj * sizeof (dxJoint::Info1));
-        int *ofs = (int *) ALLOCA (nj * sizeof (int));
-        for (i = 0, j = 0; j < nj; j++)
-        {       // i=dest, j=src
-                joints[j]->vtable->getInfo1 (joints[j], info + i);
-                dIASSERT (info[i].m >= 0 && info[i].m <= 6 && info[i].nub >= 0 && info[i].nub <= info[i].m);
-                if (info[i].m > 0)
-                {
-                        joints[i] = joints[j];
-                        joints[i]->tag = i;
-                        i++;
-                }
-                else
-                {
-                        joints[j]->tag = -1;
-                }
-        }
-        nj = i;
-
-        // the purely unbounded constraints
-        for (i = 0; i < nj; i++)
-        {
-                ofs[i] = m;
-                m += info[i].m;
-        }
-        dReal *c = NULL;
-        dReal *cfm = NULL;
-        dReal *lo = NULL;
-        dReal *hi = NULL;
-        int *findex = NULL;
-
-        dReal *J = NULL;
-        dxJoint::Info2 * Jinfo = NULL;
-
-        if (m)
-        {
-        // create a constraint equation right hand side vector `c', a constraint
-        // force mixing vector `cfm', and LCP low and high bound vectors, and an
-        // 'findex' vector.
-                c = (dReal *) ALLOCA (m * sizeof (dReal));
-                cfm = (dReal *) ALLOCA (m * sizeof (dReal));
-                lo = (dReal *) ALLOCA (m * sizeof (dReal));
-                hi = (dReal *) ALLOCA (m * sizeof (dReal));
-                findex = (int *) ALLOCA (m * sizeof (int));
-        dSetZero (c, m);
-        dSetValue (cfm, m, world->global_cfm);
-        dSetValue (lo, m, -dInfinity);
-        dSetValue (hi, m, dInfinity);
-        for (i = 0; i < m; i++)
-                findex[i] = -1;
-
-        // get jacobian data from constraints. a (2*m)x8 matrix will be created
-        // to store the two jacobian blocks from each constraint. it has this
-        // format:
-        //
-        //   l l l 0 a a a 0  \    .
-        //   l l l 0 a a a 0   }-- jacobian body 1 block for joint 0 (3 rows)
-        //   l l l 0 a a a 0  /
-        //   l l l 0 a a a 0  \    .
-        //   l l l 0 a a a 0   }-- jacobian body 2 block for joint 0 (3 rows)
-        //   l l l 0 a a a 0  /
-        //   l l l 0 a a a 0  }--- jacobian body 1 block for joint 1 (1 row)
-        //   l l l 0 a a a 0  }--- jacobian body 2 block for joint 1 (1 row)
-        //   etc...
-        //
-        //   (lll) = linear jacobian data
-        //   (aaa) = angular jacobian data
-        //
-#   ifdef TIMING
-        dTimerNow ("create J");
-#   endif
-                J = (dReal *) ALLOCA (2 * m * 8 * sizeof (dReal));
-                dSetZero (J, 2 * m * 8);
-                Jinfo = (dxJoint::Info2 *) ALLOCA (nj * sizeof (dxJoint::Info2));
-        for (i = 0; i < nj; i++)
-        {
-                Jinfo[i].rowskip = 8;
-                Jinfo[i].fps = dRecip (stepsize);
-                Jinfo[i].erp = world->global_erp;
-                Jinfo[i].J1l = J + 2 * 8 * ofs[i];
-                Jinfo[i].J1a = Jinfo[i].J1l + 4;
-                Jinfo[i].J2l = Jinfo[i].J1l + 8 * info[i].m;
-                Jinfo[i].J2a = Jinfo[i].J2l + 4;
-                Jinfo[i].c = c + ofs[i];
-                Jinfo[i].cfm = cfm + ofs[i];
-                Jinfo[i].lo = lo + ofs[i];
-                Jinfo[i].hi = hi + ofs[i];
-                Jinfo[i].findex = findex + ofs[i];
-                //joints[i]->vtable->getInfo2 (joints[i], Jinfo+i);
-        }
-
-        }
-
-        dReal *saveFacc = (dReal *) ALLOCA (nb * 4 * sizeof (dReal));
-        dReal *saveTacc = (dReal *) ALLOCA (nb * 4 * sizeof (dReal));
-        dReal *globalI = (dReal *) ALLOCA (nb * 12 * sizeof (dReal));
-        dReal *globalInvI = (dReal *) ALLOCA (nb * 12 * sizeof (dReal));
-        for (b = 0; b < nb; b++)
-        {
-                for (i = 0; i < 4; i++)
-                {
-                        saveFacc[b * 4 + i] = bodies[b]->facc[i];
-                        saveTacc[b * 4 + i] = bodies[b]->tacc[i];
-                }
-                bodies[b]->tag = b;
-        }
-
-        for (iter = 0; iter < maxiterations; iter++)
-        {
-#       ifdef TIMING
-                dTimerNow ("applying inertia and gravity");
-#       endif
-                dReal tmp[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
-
-                for (b = 0; b < nb; b++)
-                {
-                        body = bodies[b];
-
-                        // for all bodies, compute the inertia tensor and its inverse in the global
-                        // frame, and compute the rotational force and add it to the torque
-                        // accumulator. I and invI are vertically stacked 3x4 matrices, one per body.
-                        // @@@ check computation of rotational force.
-
-                        // compute inertia tensor in global frame
-                        dMULTIPLY2_333 (tmp, body->mass.I, body->posr.R);
-                        dMULTIPLY0_333 (globalI + b * 12, body->posr.R, tmp);
-                        // compute inverse inertia tensor in global frame
-                        dMULTIPLY2_333 (tmp, body->invI, body->posr.R);
-                        dMULTIPLY0_333 (globalInvI + b * 12, body->posr.R, tmp);
-
-                        for (i = 0; i < 4; i++)
-                                body->tacc[i] = saveTacc[b * 4 + i];
-#ifdef dGYROSCOPIC
-                        // compute rotational force
-                        dMULTIPLY0_331 (tmp, globalI + b * 12, body->avel);
-                        dCROSS (body->tacc, -=, body->avel, tmp);
-#endif
-
-                        // add the gravity force to all bodies
-                        if ((body->flags & dxBodyNoGravity) == 0)
-                        {
-                                body->facc[0] = saveFacc[b * 4 + 0] + body->mass.mass * world->gravity[0];
-                                body->facc[1] = saveFacc[b * 4 + 1] + body->mass.mass * world->gravity[1];
-                                body->facc[2] = saveFacc[b * 4 + 2] + body->mass.mass * world->gravity[2];
-                                body->facc[3] = 0;
-                        } else {
-                                body->facc[0] = saveFacc[b * 4 + 0];
-                                body->facc[1] = saveFacc[b * 4 + 1];
-                                body->facc[2] = saveFacc[b * 4 + 2];
-                                body->facc[3] = 0;
-                        }
-
-                }
-
-#ifdef RANDOM_JOINT_ORDER
-#ifdef TIMING
-                dTimerNow ("randomizing joint order");
-#endif
-                //randomize the order of the joints by looping through the array
-                //and swapping the current joint pointer with a random one before it.
-                for (j = 0; j < nj; j++)
-                {
-                        joint = joints[j];
-                        dxJoint::Info1 i1 = info[j];
-                        dxJoint::Info2 i2 = Jinfo[j];
-                        const int r = dRandInt(j+1);
-                        dIASSERT (r < nj);
-                        joints[j] = joints[r];
-                        info[j] = info[r];
-                        Jinfo[j] = Jinfo[r];
-                        joints[r] = joint;
-                        info[r] = i1;
-                        Jinfo[r] = i2;
-                }
-#endif
-
-                //now iterate through the random ordered joint array we created.
-                for (j = 0; j < nj; j++)
-                {
-#ifdef TIMING
-                        dTimerNow ("setting up joint");
-#endif
-                        joint = joints[j];
-                        bodyPair[0] = joint->node[0].body;
-                        bodyPair[1] = joint->node[1].body;
-
-                        if (bodyPair[0] && (bodyPair[0]->flags & dxBodyDisabled))
-                                bodyPair[0] = 0;
-                        if (bodyPair[1] && (bodyPair[1]->flags & dxBodyDisabled))
-                                bodyPair[1] = 0;
-                        
-                        //if this joint is not connected to any enabled bodies, skip it.
-                        if (!bodyPair[0] && !bodyPair[1])
-                                continue;
-                        
-                        if (bodyPair[0])
-                        {
-                                GIPair[0] = globalI + bodyPair[0]->tag * 12;
-                                GinvIPair[0] = globalInvI + bodyPair[0]->tag * 12;
-                        }
-                        if (bodyPair[1])
-                        {
-                                GIPair[1] = globalI + bodyPair[1]->tag * 12;
-                                GinvIPair[1] = globalInvI + bodyPair[1]->tag * 12;
-                        }
-
-                        joints[j]->vtable->getInfo2 (joints[j], Jinfo + j);
-
-                        //dInternalStepIslandFast is an exact copy of the old routine with one
-                        //modification: the calculated forces are added back to the facc and tacc
-                        //vectors instead of applying them to the bodies and moving them.
-                        if (info[j].m > 0)
-                        {
-                        dInternalStepFast (world, bodyPair, GIPair, GinvIPair, joint, info[j], Jinfo[j], ministep);
-                        }               
-                }
-                //  }
-#       ifdef TIMING
-                dTimerNow ("moving bodies");
-#       endif
-                //Now we can simulate all the free floating bodies, and move them.
-                for (b = 0; b < nb; b++)
-                {
-                        body = bodies[b];
-
-                        for (i = 0; i < 4; i++)
-                        {
-                                body->facc[i] *= ministep;
-                                body->tacc[i] *= ministep;
-                        }
-
-                        //apply torque
-                        dMULTIPLYADD0_331 (body->avel, globalInvI + b * 12, body->tacc);
-
-                        //apply force
-                        for (i = 0; i < 3; i++)
-                                body->lvel[i] += body->invMass * body->facc[i];
-
-                        //move It!
-                        moveAndRotateBody (body, ministep);
-                }
-        }
-        for (b = 0; b < nb; b++)
-                for (j = 0; j < 4; j++)
-                        bodies[b]->facc[j] = bodies[b]->tacc[j] = 0;
-}
-
-
-#ifdef NO_ISLANDS
-
-// Since the iterative algorithm doesn't care about islands of bodies, this is a
-// faster algorithm that just sends it all the joints and bodies in one array.
-// It's downfall is it's inability to handle disabled bodies as well as the old one.
-static void
-processIslandsFast (dxWorld * world, dReal stepsize, int maxiterations)
-{
-        // nothing to do if no bodies
-        if (world->nb <= 0)
-                return;
-
-        dInternalHandleAutoDisabling (world,stepsize);
-
-#       ifdef TIMING
-        dTimerStart ("creating joint and body arrays");
-#       endif
-        dxBody **bodies, *body;
-        dxJoint **joints, *joint;
-        joints = (dxJoint **) ALLOCA (world->nj * sizeof (dxJoint *));
-        bodies = (dxBody **) ALLOCA (world->nb * sizeof (dxBody *));
-
-        int nj = 0;
-        for (joint = world->firstjoint; joint; joint = (dxJoint *) joint->next)
-                joints[nj++] = joint;
-
-        int nb = 0;
-        for (body = world->firstbody; body; body = (dxBody *) body->next)
-                bodies[nb++] = body;
-
-        dInternalStepIslandFast (world, bodies, nb, joints, nj, stepsize, maxiterations);
-#       ifdef TIMING
-        dTimerEnd ();
-        dTimerReport (stdout, 1);
-#       endif
-}
-
-#else
-
-//****************************************************************************
-// island processing
-
-// this groups all joints and bodies in a world into islands. all objects
-// in an island are reachable by going through connected bodies and joints.
-// each island can be simulated separately.
-// note that joints that are not attached to anything will not be included
-// in any island, an so they do not affect the simulation.
-//
-// this function starts new island from unvisited bodies. however, it will
-// never start a new islands from a disabled body. thus islands of disabled
-// bodies will not be included in the simulation. disabled bodies are
-// re-enabled if they are found to be part of an active island.
-
-static void
-processIslandsFast (dxWorld * world, dReal stepsize, int maxiterations)
-{
-#ifdef TIMING
-        dTimerStart ("Island Setup");
-#endif
-        dxBody *b, *bb, **body;
-        dxJoint *j, **joint;
-
-        // nothing to do if no bodies
-        if (world->nb <= 0)
-                return;
-
-        dInternalHandleAutoDisabling (world,stepsize);
-
-        // make arrays for body and joint lists (for a single island) to go into
-        body = (dxBody **) ALLOCA (world->nb * sizeof (dxBody *));
-        joint = (dxJoint **) ALLOCA (world->nj * sizeof (dxJoint *));
-        int bcount = 0;                         // number of bodies in `body'
-        int jcount = 0;                         // number of joints in `joint'
-        int tbcount = 0;
-        int tjcount = 0;
-        
-        // set all body/joint tags to 0
-        for (b = world->firstbody; b; b = (dxBody *) b->next)
-                b->tag = 0;
-        for (j = world->firstjoint; j; j = (dxJoint *) j->next)
-                j->tag = 0;
-
-        // allocate a stack of unvisited bodies in the island. the maximum size of
-        // the stack can be the lesser of the number of bodies or joints, because
-        // new bodies are only ever added to the stack by going through untagged
-        // joints. all the bodies in the stack must be tagged!
-        int stackalloc = (world->nj < world->nb) ? world->nj : world->nb;
-        dxBody **stack = (dxBody **) ALLOCA (stackalloc * sizeof (dxBody *));
-        int *autostack = (int *) ALLOCA (stackalloc * sizeof (int));
-
-        for (bb = world->firstbody; bb; bb = (dxBody *) bb->next)
-        {
-#ifdef TIMING
-                dTimerNow ("Island Processing");
-#endif
-                // get bb = the next enabled, untagged body, and tag it
-                if (bb->tag || (bb->flags & dxBodyDisabled))
-                        continue;
-                bb->tag = 1;
-
-                // tag all bodies and joints starting from bb.
-                int stacksize = 0;
-                int autoDepth = autoEnableDepth;
-                b = bb;
-                body[0] = bb;
-                bcount = 1;
-                jcount = 0;
-                goto quickstart;
-                while (stacksize > 0)
-                {
-                        b = stack[--stacksize]; // pop body off stack
-                        autoDepth = autostack[stacksize];
-                        body[bcount++] = b;     // put body on body list
-                  quickstart:
-
-                        // traverse and tag all body's joints, add untagged connected bodies
-                        // to stack
-                        for (dxJointNode * n = b->firstjoint; n; n = n->next)
-                        {
-                                if (!n->joint->tag)
-                                {
-                                        int thisDepth = autoEnableDepth;
-                                        n->joint->tag = 1;
-                                        joint[jcount++] = n->joint;
-                                        if (n->body && !n->body->tag)
-                                        {
-                                                if (n->body->flags & dxBodyDisabled)
-                                                        thisDepth = autoDepth - 1;
-                                                if (thisDepth < 0)
-                                                        continue;
-                                                n->body->flags &= ~dxBodyDisabled;
-                                                n->body->tag = 1;
-                                                autostack[stacksize] = thisDepth;
-                                                stack[stacksize++] = n->body;
-                                        }
-                                }
-                        }
-                        dIASSERT (stacksize <= world->nb);
-                        dIASSERT (stacksize <= world->nj);
-                }
-
-                // now do something with body and joint lists
-                dInternalStepIslandFast (world, body, bcount, joint, jcount, stepsize, maxiterations);
-
-                // what we've just done may have altered the body/joint tag values.
-                // we must make sure that these tags are nonzero.
-                // also make sure all bodies are in the enabled state.
-                int i;
-                for (i = 0; i < bcount; i++)
-                {
-                        body[i]->tag = 1;
-                        body[i]->flags &= ~dxBodyDisabled;
-                }
-                for (i = 0; i < jcount; i++)
-                        joint[i]->tag = 1;
-                
-                tbcount += bcount;
-                tjcount += jcount;
-        }
-        
-#ifdef TIMING
-        dMessage(0, "Total joints processed: %i, bodies: %i", tjcount, tbcount);
-#endif
-
-        // if debugging, check that all objects (except for disabled bodies,
-        // unconnected joints, and joints that are connected to disabled bodies)
-        // were tagged.
-# ifndef dNODEBUG
-        for (b = world->firstbody; b; b = (dxBody *) b->next)
-        {
-                if (b->flags & dxBodyDisabled)
-                {
-                        if (b->tag)
-                                dDebug (0, "disabled body tagged");
-                }
-                else
-                {
-                        if (!b->tag)
-                                dDebug (0, "enabled body not tagged");
-                }
-        }
-        for (j = world->firstjoint; j; j = (dxJoint *) j->next)
-        {
-                if ((j->node[0].body && (j->node[0].body->flags & dxBodyDisabled) == 0) || (j->node[1].body && (j->node[1].body->flags & dxBodyDisabled) == 0))
-                {
-                        if (!j->tag)
-                                dDebug (0, "attached enabled joint not tagged");
-                }
-                else
-                {
-                        if (j->tag)
-                                dDebug (0, "unattached or disabled joint tagged");
-                }
-        }
-# endif
-
-#       ifdef TIMING
-        dTimerEnd ();
-        dTimerReport (stdout, 1);
-#       endif
-}
-
-#endif
-
-
-void dWorldStepFast1 (dWorldID w, dReal stepsize, int maxiterations)
-{
-        dUASSERT (w, "bad world argument");
-        dUASSERT (stepsize > 0, "stepsize must be > 0");
-        processIslandsFast (w, stepsize, maxiterations);
-}