shader a_u_b_v (output vector cout = 0, output vector mcout = 0) 
{
    int a = 2;
    int b = int(P[0])*10;
    
    int c = a<<b;
    
    cout = vector(tan(v), tan(P[1]/c), v-u);
    vector mcout_ = cout;
    
    if(int(P[0]*32)%2)
    {
        a = raytype("camera") * 6;
        b = int(v) *4;
        c = a<<b;
        mcout_ = vector(tan(P[2]/c), tan(v/u), v);
    }
    
    mcout = mcout_;
}
