Creating a 3D LUT from a set of cubic splines, obtained from an acv file

acv_to_lut.cpp

const size_t CUBE_SIZE = 16;
std::vector<float> red(CUBE_SIZE);
std::vector<float> green(CUBE_SIZE);
std::vector<float> blue(CUBE_SIZE);

for (size_t i = 0; i < CUBE_SIZE; ++i)
{
	float input = (float)i / (float)(CUBE_SIZE - 1);
	float input255 = input * 255.0f;

	float redValue   = clamp(cubicSplines[1].ComputeAtPoint(input255), 0.0f, 255.0f);
	float greenValue = clamp(cubicSplines[2].ComputeAtPoint(input255), 0.0f, 255.0f);
	float blueValue  = clamp(cubicSplines[3].ComputeAtPoint(input255), 0.0f, 255.0f);

	red[i]   = saturate(cubicSplines[0].ComputeAtPoint(redValue) / 255.0f);
	green[i] = saturate(cubicSplines[0].ComputeAtPoint(greenValue) / 255.0f);
	blue[i]  = saturate(cubicSplines[0].ComputeAtPoint(blueValue) / 255.0f);
}