local void walktree(nodeptr *aptr, nodeptr *nptr, cellptr cptr, cellptr bptr,
nodeptr p, real psize, vector pmid)
{
nodeptr *np, *ap, q;
int actsafe;
matrix trQM;
if (Update(p)) { // new forces needed in node?
np = nptr; // start new active list
actsafe = actmax - NSUB; // leave room for NSUB more
for (ap = aptr; ap < nptr; ap++) { // loop over active nodes
if (Type(*ap) == CELL) { // is this node a cell?
if (accept(*ap, psize, pmid)) { // does it pass the test?
if (Mass(*ap) > 0.0) { // and contribute to field?
Mass(cptr) = Mass(*ap); // copy to interaction list
SETV(Pos(cptr), Pos(*ap));
#if defined(SOFTCORR)
TRACEM(Trace(cptr), Quad(*ap)); // save trace in copy
SETMI(trQM);
MULMS(trQM, trQM, Trace(cptr)/3);
SUBM(Quad(cptr), Quad(*ap), trQM); // store traceless moment
#else
SETM(Quad(cptr), Quad(*ap)); // copy traceless moment
#endif
cptr++; // and bump cell array ptr
}
} else { // this cell fails the test
if (np - active >= actsafe) // make sure list has room
fatal("%s.walktree: active list overflow\n", getprog());
for (q = More(*ap); q != Next(*ap); q = Next(q))
// loop over all subcells
*np++= q; // put them on active list
}
} else // else this node is a body
if (*ap != p && Mass(*ap) > 0.0) { // not self-interaction?
--bptr; // bump body array ptr
Mass(bptr) = Mass(*ap); // and copy data to array
SETV(Pos(bptr), Pos(*ap));
}
}
acttot = MAX(acttot, np - active); // keep track of max active
if (np != nptr) { // if new actives were added
walksub(nptr, np, cptr, bptr, p, psize, pmid);
// then visit next level
} else { // else no actives left
if (Type(p) != BODY) // make sure we got a body
fatal("%s.walktree: recursion terminated with cell\n"
" p = 0x%x psize = %.8f Mass(p) = %g\n"
" pmid = (%.8f,%.8f,%.8f)\n Pos(p) = (%.8f,%.8f,%.8f)\n",
getprog(), (int) p, psize, Mass(p),
pmid[0], pmid[1], pmid[2], Pos(p)[0], Pos(p)[1], Pos(p)[2]);
gravsum((bodyptr) p, cptr, bptr); // sum force on this body
}
}
}
void snaprect(bodyptr btab, int nbody)
{
matrix qmat, tmpm;
bodyptr bp;
vector frame[3], tmpv;
static vector oldframe[3] =
{ { 1.0, 0.0, 0.0, }, { 0.0, 1.0, 0.0, }, { 0.0, 0.0, 1.0, }, };
int i;
snapcenter(btab, nbody, WeightField.offset);
CLRM(qmat);
for (bp = btab; bp < NthBody(btab, nbody); bp = NextBody(bp)) {
OUTVP(tmpm, Pos(bp), Pos(bp));
MULMS(tmpm, tmpm, Weight(bp));
ADDM(qmat, qmat, tmpm);
}
eigenvect(frame[0], frame[1], frame[2], qmat);
if (dotvp(oldframe[0], frame[0]) < 0.0)
MULVS(frame[0], frame[0], -1.0);
if (dotvp(oldframe[2], frame[2]) < 0.0)
MULVS(frame[2], frame[2], -1.0);
CROSSVP(frame[1], frame[2], frame[0]);
printvect("e_x:", frame[0]);
printvect("e_y:", frame[1]);
printvect("e_z:", frame[2]);
for (bp = btab; bp < NthBody(btab, nbody); bp = NextBody(bp)) {
if (PosField.offset != BadOffset) {
for (i = 0; i < NDIM; i++)
tmpv[i] = dotvp(Pos(bp), frame[i]);
SETV(Pos(bp), tmpv);
}
if (VelField.offset != BadOffset) {
for (i = 0; i < NDIM; i++)
tmpv[i] = dotvp(Vel(bp), frame[i]);
SETV(Vel(bp), tmpv);
}
if (AccField.offset != BadOffset) {
for (i = 0; i < NDIM; i++)
tmpv[i] = dotvp(Acc(bp), frame[i]);
SETV(Acc(bp), tmpv);
}
if (AuxVecField.offset != BadOffset) {
for (i = 0; i < NDIM; i++)
tmpv[i] = dotvp(AuxVec(bp), frame[i]);
SETV(AuxVec(bp), tmpv);
}
}
for (i = 0; i < NDIM; i++)
SETV(oldframe[i], frame[i]);
}
