How do I convert an integer to a javascript color?

Question

I have an integer which I need to convert to a color in javascript. I am using an MVC model and am trying to replicate a model in a software for a web interface. I have the color in integer format from the database. It needs to be converted to a color in javascript.

For example: integers like -12525360, -5952982

I have the code like this :

items[x].barStyle = "stroke: Black; fill = Red";

So instead of giving the fill:Red, I need to give it the exact color corresponding to the integer value.

This is the code I have written in C#. I need the same thing in javascript. Here resourcecolor= the integer input.

     var bytes = BitConverter.GetBytes(resourcecolor);
     ti.color = Color.FromArgb(bytes[3], bytes[2], bytes[1], bytes[0]);

Answer 1

In javascript, you express a ARGB color that is to be used with canvas or css as a string like "rgba(0-255,0-255,0-255,0-1)".

You can convert the integer to that string format with this function:

function toColor(num) {
    num >>>= 0;
    var b = num & 0xFF,
        g = (num & 0xFF00) >>> 8,
        r = (num & 0xFF0000) >>> 16,
        a = ( (num & 0xFF000000) >>> 24 ) / 255 ;
    return "rgba(" + [r, g, b, a].join(",") + ")";
}
toColor(-5952982)
//"rgba(165,42,42,1)"
toColor(-12525360)
//"rgba(64,224,208,1)"

Demo: http://jsfiddle.net/Ectpk/