Is there a documents I can read to educate myself about what this code is doing?
How do we know what to do with .safetensors file to make a cat picture?
Why exactly do we need stuff like this:

float sigma_up = std::min(sigmas[i + 1], std::sqrt(sigmas[i + 1] * sigmas[i + 1] * (sigmas[i] * sigmas[i] - sigmas[i + 1] * sigmas[i + 1]) / (sigmas[i] * sigmas[i])));