vec3 rgb2hsb(vec3 c) {
    vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
    vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
    vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
    float d = q.x - min(q.w, q.y);
    float e = 1.0e-10;
    return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
}

// Function from Iñigo Quiles
// https://www.shadertoy.com/view/MsS3Wc
vec3 hsb2rgb(vec3 c){
    vec3 rgb = clamp(abs(mod(c.x * 6.0 + vec3(0.0, 4.0, 2.0), 6.0) - 3.0) - 1.0, 0.0, 1.0);
    rgb = rgb * rgb * (3.0 - 2.0 * rgb);
    return c.z * mix(vec3(1.0), rgb, c.y);
}

float getVisualBrightness(vec3 color) {
	return color.r*0.2989+color.g*0.5870+color.b*0.1140;
}

vec3 getGrayscaledColor(vec3 color) {
	float br = getVisualBrightness(color);
	return vec3(br, br, br);
}