Hello,

I’m trying to create a DCTL to use as an IDT for footage with the rec2020 gamut and the rec2100-hlg transfer function. I used http://acesidtdctl.tcolorscience.com/ as a starting point, and then used Apps (Colour - Dash) | Colour Science for the Rec2020 → AP0 matrix with the Bradford CAT. For the transfer function, I referenced https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.2100-2-201807-I!!PDF-E.pdf on page 9 (HLG Reference EOTF).

From all of that, I ended up with the following DCTL code:

```
// ACES DIT rec2020 rec2100-hlg to ACES(AP0) DCTL
#if (__RESOLVE_VER_MAJOR__ >= 17)
DEFINE_ACES_PARAM(IS_PARAMETRIC_ACES_TRANSFORM: 0)
#endif
__DEVICE__ inline float Log_to_linear(float inv)
{
float outv;
float aspec = 0.17883277f;
float bspec = 1.0f - 4.0f * aspec;
float cspec = 0.5f - aspec * _logf(4.0f * aspec);
if (inv > 0.5f)
{
outv = (_expf((inv - cspec) / aspec) + bspec) / 12.0f;
}
else
{
outv = _powf(inv, 2.0f) / 3.0f;
}
return outv;
}
__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 mtx[9] = {0.6790856347f, 0.1577009146f, 0.1632134507f, 0.0460020031f, 0.8590546730f, 0.0949433240f, -0.0005739432f, 0.0284677684f, 0.9721061748f};
float r1 = Log_to_linear(p_R);
float g1 = Log_to_linear(p_G);
float b1 = Log_to_linear(p_B);
float r2 = r1 * mtx[0] + g1 * mtx[1] + b1 * mtx[2];
float g2 = r1 * mtx[3] + g1 * mtx[4] + b1 * mtx[5];
float b2 = r1 * mtx[6] + g1 * mtx[7] + b1 * mtx[8];
return make_float3(r2, g2, b2);
}
```

To me, this all looks correct, however when used as an IDT in Resolve, it results in a broken image with lots of hot pixels (I blacked out the faces of the subjects in the below image):

Looking for some pointers on how I can get a correct Rec2020 Rec2100-hlg → AP0 DCTL working.