Function to calculate points on an equidistant star.

gistfile1.js

function CalculateStarPoints(centerX, centerY, arms, outerRadius, innerRadius)
{
   var results = "";

   var angle = Math.PI / arms;

   for (var i = 0; i < 2 * arms; i++)
   {
      // Use outer or inner radius depending on what iteration we are in.
      var r = (i & 1) == 0 ? outerRadius : innerRadius;
      
      var currX = centerX + Math.cos(i * angle) * r;
      var currY = centerY + Math.sin(i * angle) * r;

      // Our first time we simply append the coordinates, subsequet times
      // we append a ", " to distinguish each coordinate pair.
      if (i == 0)
      {
         results = currX + "," + currY;
      }
      else
      {
         results += ", " + currX + "," + currY;
      }
   }

   return results;
}