in rico.js [709:749]
Rico.Color.RGBtoHSB = function(r, g, b) {
var hue;
var saturation;
var brightness;
var cmax = (r > g) ? r : g;
if (b > cmax)
cmax = b;
var cmin = (r < g) ? r : g;
if (b < cmin)
cmin = b;
brightness = cmax / 255.0;
if (cmax != 0)
saturation = (cmax - cmin)/cmax;
else
saturation = 0;
if (saturation == 0)
hue = 0;
else {
var redc = (cmax - r)/(cmax - cmin);
var greenc = (cmax - g)/(cmax - cmin);
var bluec = (cmax - b)/(cmax - cmin);
if (r == cmax)
hue = bluec - greenc;
else if (g == cmax)
hue = 2.0 + redc - bluec;
else
hue = 4.0 + greenc - redc;
hue = hue / 6.0;
if (hue < 0)
hue = hue + 1.0;
}
return { h : hue, s : saturation, b : brightness };
}