jtBaseApp/node_modules/@cesium/engine/Source/Shaders/Builtin/Functions/HSLToRGB.glsl

/**
 * Converts an HSL color (hue, saturation, lightness) to RGB
 * HSL <-> RGB conversion: {@link http://www.chilliant.com/rgb2hsv.html}
 *
 * @name czm_HSLToRGB
 * @glslFunction
 * 
 * @param {vec3} rgb The color in HSL.
 *
 * @returns {vec3} The color in RGB.
 *
 * @example
 * vec3 hsl = czm_RGBToHSL(rgb);
 * hsl.z *= 0.1;
 * rgb = czm_HSLToRGB(hsl);
 */

vec3 hueToRGB(float hue)
{
    float r = abs(hue * 6.0 - 3.0) - 1.0;
    float g = 2.0 - abs(hue * 6.0 - 2.0);
    float b = 2.0 - abs(hue * 6.0 - 4.0);
    return clamp(vec3(r, g, b), 0.0, 1.0);
}

vec3 czm_HSLToRGB(vec3 hsl)
{
    vec3 rgb = hueToRGB(hsl.x);
    float c = (1.0 - abs(2.0 * hsl.z - 1.0)) * hsl.y;
    return (rgb - 0.5) * c + hsl.z;
}