class Surface {
    public float ir, ig, ib;        // surface's intrinsic color
    public float ka, kd, ks, ns;    // constants for phong model
    public float kt, kr, nt;
    private static final float TINY = 0.001f;
    private static final float I255 = 0.00392156f;  // 1/255

    // constructor
    public Surface(
        float rval, float gval, float bval, // surface color
        float a,                            // ambient coefficient
        float d,                            // diffuse coefficient
        float s,                            // specular coefficient
        float n,                            // phong shineiness
        float r,                            // reflectance
        float t,                            // transmission
        float index                         // index of refraction
    ) {
        ir = rval; ig = gval; ib = bval;
        ka = a; kd = d; ks = s; ns = n;
        kr = r*I255; kt = t; nt = index;
    }