LYGIA Shader Library

Use:

<vec3\vec4> rgb2oklab(<vec3|vec4> srgb)

Check it on Github

#ifndef FNC_RGB2OKLAB
#define FNC_RGB2OKLAB

const mat3 inv_oklab_A = mat3(  0.2104542553, 1.9779984951, 0.0259040371,
                                0.7936177850, -2.4285922050, 0.7827717662,
                                -0.0040720468, 0.4505937099, -0.8086757660);

const mat3 inv_oklab_B = mat3(  0.4121656120, 0.2118591070, 0.0883097947,
                                0.5362752080, 0.6807189584, 0.2818474174,
                                0.0514575653, 0.1074065790, 0.6302613616);

vec3 rgb2oklab(vec3 linear) {
    vec3 lms = inv_oklab_B * linear;
    return inv_oklab_A * (sign(lms)*pow(abs(lms), vec3(0.3333333333333)));

}

vec4 rgb2oklab(vec4 linear) {
    return vec4(rgb2oklab(linear.rgb), linear.a);
}
#endif

Use:

<float3\float4> rgb2oklab(<float3|float4> srgb)

Check it on Github

#ifndef FNC_RGB2OKLAB
#define FNC_RGB2OKLAB

const float3x3 inv_oklab_A = float3x3(  0.2104542553, 1.9779984951, 0.0259040371,
                                        0.7936177850, -2.4285922050, 0.7827717662,
                                        -0.0040720468, 0.4505937099, -0.8086757660);

const float3x3 inv_oklab_B = float3x3(  0.4121656120, 0.2118591070, 0.0883097947,
                                        0.5362752080, 0.6807189584, 0.2818474174,
                                        0.0514575653, 0.1074065790, 0.6302613616);

float3 rgb2oklab(float3 rgb) {
    float3 lms = mul(inv_oklab_B, rgb);
    return mul(inv_oklab_A, sign(lms)*pow(abs(lms), float3(0.3333333333333)));

}

float4 rgb2oklab(float4 rgb) {
    return float4(rgb2oklab(rgb.rgb), rgb.a);
}
#endif

Check it on Github

const inv_oklab_A : mat3x3<f32>  = mat3x3<f32>( vec3<f32>(0.2104542553, 1.9779984951, 0.0259040371), 
                                                vec3<f32>(0.7936177850, -2.4285922050, 0.7827717662), 
                                                vec3<f32>(-0.0040720468, 0.4505937099, -0.8086757660) );

const inv_oklab_B : mat3x3<f32>  = mat3x3<f32>( vec3<f32>(0.4121656120, 0.2118591070, 0.0883097947), 
                                                vec3<f32>(0.5362752080, 0.6807189584, 0.2818474174), 
                                                vec3<f32>(0.0514575653, 0.1074065790, 0.6302613616) );

fn rgb2oklab(linear: vec3<f32>) -> vec3<f32> {
    let lms = inv_oklab_B * linear;
    return inv_oklab_A * (sign(lms) * pow(abs(lms), vec3<f32>(0.3333333333333)));
}