public void relax() {
if (p1.inv_mass == 0 && p2.inv_mass == 0) return;
Vec displacement = get_displacement();
if (displacement.equals(new Vec(0, 0))) return;
double prop1, prop2;
if (p1.inv_mass == 0) {
prop1 = 0;
prop2 = 1;
} else if (p2.inv_mass == 0) {
prop1 = 1;
prop2 = 0;
} else {
double imass_total = p1.inv_mass + p2.inv_mass;
prop1 = p1.inv_mass / imass_total;
prop2 = p2.inv_mass / imass_total;
}
p1.pos.iadd(displacement.mul(prop1));
p2.pos.isub(displacement.mul(prop2));
}
public int find(Vec vec) {
for (int i = 0; i < _vecs.length; i++) if (vec.equals(_vecs[i])) return i;
return -1;
}
