mx_normalmap.osl

void mx_normalmap_vector2(vector value, vector2 normal_scale, vector N, vector T, vector B, output vector result)
{
    if (value == vector(0.0))
    {
        result = N;
    }
    else
    {
        // The OSL backend uses dPdu and dPdv for tangents and bitangents, but these vectors are not
        // guaranteed to be orthonormal.
        //
        // Orthogonalize the tangent frame using Gram-Schmidt, unlike in the other backends.
        //
        vector v = value * 2.0 - 1.0;
        vector Tn = normalize(T - dot(T, N) * N);
        vector Bn = normalize(B - dot(B, N) * N - dot(B, Tn) * Tn);
        result = normalize(Tn * v[0] * normal_scale.x + Bn * v[1] * normal_scale.y + N * v[2]);
    }
}

void mx_normalmap_float(vector value, float normal_scale, vector N, vector T, vector B, output vector result)
{
    mx_normalmap_vector2(value, vector2(normal_scale, normal_scale), N, T, B, result);
}