protected boolean intersection(Cell cell) {
double k = box.k;
double vz = box.viewZone;
double x1 = cell.getSpace().getLoAnchor().x;
double y1 = cell.getSpace().getLoAnchor().y;
double z1 = cell.getSpace().getLoAnchor().z;
double x2 = cell.getSpace().getHiAnchor().x;
double y2 = cell.getSpace().getHiAnchor().y;
double z2 = cell.getSpace().getHiAnchor().z;
double X1 = pos.x - (k * vz);
double Y1 = pos.y - (k * vz);
double Z1 = pos.z - (k * vz);
double X2 = pos.x + (k * vz);
double Y2 = pos.y + (k * vz);
double Z2 = pos.z + (k * vz);
// Only when the area is before or after the cell there cannot
// exist an intersection (case a and b). Else there must be an
// intersection (cases c, d, e and f).
//
// |-a-| +---------+ |-b-|
// | |
// |-c-| |-d-|
// | |
// | |-e-| |
// | |
// |-+----f----+-|
// | |
// +---------+
//
// (04/21/11) here lies my beautiful comment. Sorry if it is
// no more readable, barbarians ruined it.
if (X2 < x1 || X1 > x2) return false;
if (Y2 < y1 || Y1 > y2) return false;
if (Z2 < z1 || Z1 > z2) return false;
return true;
}
protected void recurseRepulsion(Cell cell, Vector3 delta) {
if (intersection(cell)) {
if (cell.isLeaf()) {
Iterator<? extends Particle> i = cell.getParticles();
while (i.hasNext()) {
NodeParticle node = (NodeParticle) i.next();
if (node != this) {
delta.set(node.pos.x - pos.x, node.pos.y - pos.y, box.is3D ? node.pos.z - pos.z : 0);
double len = delta.normalize();
if (len > 0) // && len < ( box.k * box.viewZone ) )
{
if (len < box.k) len = box.k; // XXX NEW To prevent infinite
// repulsion.
double factor = len != 0 ? ((box.K2 / (len * len)) * node.weight) : 0.00001;
box.energies.accumulateEnergy(factor); // TODO check
// this
repE += factor;
delta.scalarMult(-factor);
disp.add(delta);
}
}
}
} else {
int div = cell.getSpace().getDivisions();
for (int i = 0; i < div; i++) recurseRepulsion(cell.getSub(i), delta);
}
} else {
if (cell != this.cell) {
BarycenterCellData bary = (BarycenterCellData) cell.getData();
double dist = bary.distanceFrom(pos);
double size = cell.getSpace().getSize();
if ((!cell.isLeaf()) && ((size / dist) > box.theta)) {
int div = cell.getSpace().getDivisions();
for (int i = 0; i < div; i++) recurseRepulsion(cell.getSub(i), delta);
} else {
if (bary.weight != 0) {
// System.err.printf(
// "applying bary %s [depth=%d weight=%d]%n",
// cell.getId(), cell.getDepth(), (int)bary.weight );
delta.set(
bary.center.x - pos.x, bary.center.y - pos.y, box.is3D ? bary.center.z - pos.z : 0);
double len = delta.normalize();
if (len > 0) {
if (len < box.k) len = box.k; // XXX NEW To prevent infinite
// repulsion.
double factor = len != 0 ? ((box.K2 / (len * len)) * (bary.weight)) : 0.00001f;
box.energies.accumulateEnergy(factor);
delta.scalarMult(-factor);
repE += factor;
disp.add(delta);
}
}
}
}
}
}