Newer
Older
qd_cnooc_front / static / Cesium / Shaders / Builtin / Functions / HSBToRGB.glsl
[wangxitong] on 27 Nov 2021 651 bytes first commit
/**
 * Converts an HSB color (hue, saturation, brightness) to RGB
 * HSB <-> RGB conversion with minimal branching: {@link http://lolengine.net/blog/2013/07/27/rgb-to-hsv-in-glsl}
 *
 * @name czm_HSBToRGB
 * @glslFunction
 * 
 * @param {vec3} hsb The color in HSB.
 *
 * @returns {vec3} The color in RGB.
 *
 * @example
 * vec3 hsb = czm_RGBToHSB(rgb);
 * hsb.z *= 0.1;
 * rgb = czm_HSBToRGB(hsb);
 */

const vec4 K_HSB2RGB = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);

vec3 czm_HSBToRGB(vec3 hsb)
{
    vec3 p = abs(fract(hsb.xxx + K_HSB2RGB.xyz) * 6.0 - K_HSB2RGB.www);
    return hsb.z * mix(K_HSB2RGB.xxx, clamp(p - K_HSB2RGB.xxx, 0.0, 1.0), hsb.y);
}