//returns an AABB that holds both a and v.
func Expand(a AABB, v vect.Vect) AABB {
return AABB{
vect.Min(a.Lower, v),
vect.Max(a.Upper, v),
}
}
//returns an AABB that holds both a and b.
func CombinePtr(a, b *AABB) AABB {
return AABB{
vect.Min(a.Lower, b.Lower),
vect.Max(a.Upper, b.Upper),
}
}