javascript - Philips hue, convert xy from api to HEX or RGB -

i making web interface manage hue lamps, struggling when comes color handling..

the api of lamps provides me x , y coordinates http://en.wikipedia.org/wiki/cie_1931_color_space

but not z value.

i think must calculate z brightness value or saturation value (0 255).

but terrible @ colors, , math :p.

i tried use thoses functions https://github.com/eikeon/hue-color-converter/blob/master/colorconverter.ts

but saw in comments, thoses functions not provide correct values...

could me here please ? ☺

ps : need javascript function.

okay manage make working of : how convert rgb value xy value phillips hue bulb

function xybritorgb(x, y, bri){             z = 1.0 - x - y;             y = bri / 255.0; // brightness of lamp             x = (y / y) * x;             z = (y / y) * z;             r = x * 1.612 - y * 0.203 - z * 0.302;             g = -x * 0.509 + y * 1.412 + z * 0.066;             b = x * 0.026 - y * 0.072 + z * 0.962;             r = r <= 0.0031308 ? 12.92 * r : (1.0 + 0.055) * math.pow(r, (1.0 / 2.4)) - 0.055;             g = g <= 0.0031308 ? 12.92 * g : (1.0 + 0.055) * math.pow(g, (1.0 / 2.4)) - 0.055;             b = b <= 0.0031308 ? 12.92 * b : (1.0 + 0.055) * math.pow(b, (1.0 / 2.4)) - 0.055;             maxvalue = math.max(r,g,b);             r /= maxvalue;             g /= maxvalue;             b /= maxvalue;             r = r * 255;   if (r < 0) { r = 255 };             g = g * 255;   if (g < 0) { g = 255 };             b = b * 255;   if (b < 0) { b = 255 };             return {                 r :r,                 g :g,                 b :b             }         } 

its not very precise, works quite well. if manage make better, please post here, thanks.