LYGIA Shader Library

Dependencies:

• lygia/math/mmin.glsl
• lygia/math/saturate.glsl

Use:

rgb2cmyk(<vec3|vec4> rgba)

Check it on Github

#ifndef FNC_RGB2CMYK
#define FNC_RGB2CMYK
vec4 rgb2cmyk(const in vec3 rgb) {
    float k = mmin(1.0 - rgb);
    float invK = 1.0 - k;
    vec3 cmy = (1.0 - rgb - k) / invK;
    cmy *= step(0.0, invK);
    return saturate(vec4(cmy, k));
}
#endif

Dependencies:

• lygia/math/mmin.glsl

Use:

rgb2cmyk(<float3|float4> rgba)

Check it on Github

#ifndef FNC_RGB2CMYK
#define FNC_RGB2CMYK
float4 rgb2cmyk(float3 rgb) {
    float k = mmin(1.0 - rgb);
    float invK = 1.0 - k;
    float3 cmy = (1.0 - rgb - k) / invK;
    cmy *= step(0.0, invK);
    return saturate(float4(cmy, k));
}
#endif

Check it on Github

fn rgb2cmyk(rgb: vec3f) -> vec4f {
    let k = min(1.0 - rgb.r, min(1.0 - rgb.g, 1.0 - rgb.b));
    let invK = 1.0 - k;
    var cmy = (1.0 - rgb - k) / invK;
    cmy *= step(0.0, invK);
    return saturate(vec4f(cmy, k));
}