void ReflectiveBox::process(Candidate *c) const {
Vector3d cur = (c->current.getPosition() - origin) / size; // current position in cell units
Vector3d n = cur.floor();
if ((n.x == 0) and (n.y == 0) and (n.z == 0))
return; // do nothing if candidate is inside the box
// flip direction
Vector3d nReflect(pow(-1, n.x), pow(-1, n.y), pow(-1, n.z));
c->current.setDirection(c->current.getDirection() * nReflect);
c->previous.setDirection(c->previous.getDirection() * nReflect);
c->created.setDirection(c->created.getDirection() * nReflect);
c->source.setDirection(c->source.getDirection() * nReflect);
Vector3d src = (c->source.getPosition() - origin) / size; // initial position in cell units
Vector3d cre = (c->created.getPosition() - origin) / size; // initial position in cell units
Vector3d prv = (c->previous.getPosition() - origin) / size; // previous position in cell units
// repeatedly translate until the current position is inside the cell
while ((cur.x < 0) or (cur.x > 1)) {
double t = 2 * (cur.x > 1);
src.x = t - src.x;
cre.x = t - cre.x;
prv.x = t - prv.x;
cur.x = t - cur.x;
}
while ((cur.y < 0) or (cur.y > 1)) {
double t = 2 * (cur.y > 1);
src.y = t - src.y;
cre.y = t - cre.y;
prv.y = t - prv.y;
cur.y = t - cur.y;
}
while ((cur.z < 0) or (cur.z > 1)) {
double t = 2 * (cur.z > 1);
src.z = t - src.z;
cre.z = t - cre.z;
prv.z = t - prv.z;
cur.z = t - cur.z;
}
c->current.setPosition(cur * size + origin);
c->source.setPosition(src * size + origin);
c->created.setPosition(cre * size + origin);
c->previous.setPosition(prv * size + origin);
}
