simondev.Shaders_Clouds1/shaders/oklab.glsl

// https://bottosson.github.io/posts/oklab/


float cbrtf(float x) {
  return pow(x, 1.0 / 3.0);
}

vec3 rgbToOklab(vec3 c) 
{
  float l = 0.4122214708 * c.r + 0.5363325363 * c.g + 0.0514459929 * c.b;
	float m = 0.2119034982 * c.r + 0.6806995451 * c.g + 0.1073969566 * c.b;
	float s = 0.0883024619 * c.r + 0.2817188376 * c.g + 0.6299787005 * c.b;

    float l_ = cbrtf(l);
    float m_ = cbrtf(m);
    float s_ = cbrtf(s);

    return vec3(
        0.2104542553*l_ + 0.7936177850*m_ - 0.0040720468*s_,
        1.9779984951*l_ - 2.4285922050*m_ + 0.4505937099*s_,
        0.0259040371*l_ + 0.7827717662*m_ - 0.8086757660*s_
    );
}

vec3 oklabToRGB(vec3 c) 
{
    float l_ = c.x + 0.3963377774 * c.y + 0.2158037573 * c.z;
    float m_ = c.x - 0.1055613458 * c.y - 0.0638541728 * c.z;
    float s_ = c.x - 0.0894841775 * c.y - 1.2914855480 * c.z;

    float l = l_*l_*l_;
    float m = m_*m_*m_;
    float s = s_*s_*s_;

    return vec3(
        +4.0767416621 * l - 3.3077115913 * m + 0.2309699292 * s,
        -1.2684380046 * l + 2.6097574011 * m - 0.3413193965 * s,
        -0.0041960863 * l - 0.7034186147 * m + 1.7076147010 * s
    );
}


#ifndef USE_OKLAB
#define col3 vec3
#else
vec3 col3(float r, float g, float b) {
  return rgbToOklab(vec3(r, g, b));
}

vec3 col3(vec3 v) {
  return rgbToOklab(v);
}

vec3 col3(float v) {
  return rgbToOklab(vec3(v));
}
#endif