DCTLs/LogC_AWG_to_Linear_Rec709.dctl at master · rodrigomas/DCTLs · GitHub

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// LogC Alexa Wide Gamut to Linear (Rec709 Primaries)

__DEVICE__ float3 transform(int p_Width, int p_Height, int p_X, int p_Y, float p_R, float p_G, float p_B)
{
    const float Lr = p_R > 0.1496582f ? (_powf(10.0f, (p_R - 0.385537f) / 0.2471896f) - 0.052272f) / 5.555556f : (p_R - 0.092809f) / 5.367655f;

    const float Lg = p_G > 0.1496582f ? (_powf(10.0f, (p_G - 0.385537f) / 0.2471896f) - 0.052272f) / 5.555556f : (p_G - 0.092809f) / 5.367655f;

    const float Lb = p_B > 0.1496582f ? (_powf(10.0f, (p_B - 0.385537f) / 0.2471896f) - 0.052272f) / 5.555556f : (p_B - 0.092809f) / 5.367655f;

    const float Mr = ((Lr) * 1.617523f) + ((Lg) * -0.537287f) + ((Lb) * -0.080237f);

    const float Mg = ((Lr) * -0.070573f) + ((Lg) * 1.334613f) + ((Lb) * -0.26404f);

    const float Mb = ((Lr) * -0.021102f) + ((Lg) * -0.226954f) + ((Lb) * 1.248056f);

    const float r = (Mr);

    const float g = (Mg);

    const float b = (Mb);

    return make_float3(r, g, b);
}