/* ************************************************************************

   qooxdoo - the new era of web development

   http://qooxdoo.org

   Copyright:
     2004-2006 by 1&1 Internet AG, Germany, http://www.1and1.org

   License:
     LGPL 2.1: http://www.gnu.org/licenses/lgpl.html

   Authors:
     * Sebastian Werner (wpbasti)
     * Andreas Ecker (ecker)

************************************************************************ */

/* ************************************************************************


************************************************************************ */

qx.OO.defineClass("qx.util.ColorUtil");

qx.Class.rgb2hsb = function(vRed, vGreen, vBlue)
{
  var vHue, vSaturation, vBrightness;

  vRed = parseFloat(vRed);
  vGreen = parseFloat(vGreen);
  vBlue = parseFloat(vBlue);

  var cmax = (vRed > vGreen) ? vRed : vGreen;
  if (vBlue > cmax) {
    cmax = vBlue;
  }

  var cmin = (vRed < vGreen) ? vRed : vGreen;
  if (vBlue < cmin) {
    cmin = vBlue;
  }

  vBrightness = cmax / 255.0;

  if (cmax != 0)
  {
    vSaturation = (cmax - cmin) / cmax;
  }
  else
  {
    vSaturation = 0;
  }

  if (vSaturation == 0)
  {
    vHue = 0;
  }
  else
  {
    var redc = (cmax - vRed) / (cmax - cmin);
    var greenc = (cmax - vGreen) / (cmax - cmin);
    var bluec = (cmax - vBlue) / (cmax - cmin);

    if (vRed == cmax)
    {
      vHue = bluec - greenc;
    }
    else if (vGreen == cmax)
    {
      vHue = 2.0 + redc - bluec;
    }
    else
    {
      vHue = 4.0 + greenc - redc;
    }

    vHue = vHue / 6.0;
    if (vHue < 0) vHue = vHue + 1.0;
  }

  return {
    hue : Math.round(vHue * 360),
    saturation : Math.round(vSaturation * 100),
    brightness : Math.round(vBrightness * 100)
  }
}

qx.Class.hsb2rgb = function(vHue, vSaturation, vBrightness)
{
  var i, f, p, q, t, vReturn;

  vHue = parseFloat(vHue/360);
  vSaturation = parseFloat(vSaturation/100);
  vBrightness = parseFloat(vBrightness/100);

  if(vHue >= 1.0) vHue %= 1.0;
  if(vSaturation > 1.0) vSaturation = 1.0;
  if(vBrightness > 1.0) vBrightness = 1.0;

  var tov = Math.floor(255 * vBrightness);

  var vReturn = {};

  if(vSaturation == 0.0)
  {
    vReturn.red = vReturn.green = vReturn.blue = tov;
  }
  else
  {
    vHue *= 6.0;

    i = Math.floor(vHue);

    f = vHue - i;

    p = Math.floor(tov * (1.0 - vSaturation));
    q = Math.floor(tov * (1.0 - (vSaturation * f)));
    t = Math.floor(tov * (1.0 - (vSaturation * (1.0  - f))));

    switch(i)
    {
      case 0:
        vReturn.red = tov;
        vReturn.green = t;
        vReturn.blue = p;
        break;

      case 1:
        vReturn.red = q;
        vReturn.green = tov;
        vReturn.blue = p;
        break;

      case 2:
        vReturn.red = p;
        vReturn.green = tov;
        vReturn.blue = t;
        break;

      case 3:
        vReturn.red = p;
        vReturn.green = q;
        vReturn.blue = tov;
        break;

      case 4:
        vReturn.red = t;
        vReturn.green = p;
        vReturn.blue = tov;
        break;

      case 5:
        vReturn.red = tov;
        vReturn.green = p;
        vReturn.blue = q;
        break;
    }
  }

  return vReturn;
}