ecmascript:

function initialize()
{
   numOfPoints = 100;

   if (radius < 0)
   {
      Browser.print ('[Arc2D] Warning:  invalid value, radius=' + value + ' must instead be >= 0');
   }

   if ((startAngle < 0) || (startAngle >= 2 * Math.PI))
   {
      Browser.print ('[Arc2D] Warning: startAngle=' + startAngle + ' must be within range [0..2pi)');
   }

   if ((endAngle < 0) || (endAngle >= 2 * Math.PI))
   {
      Browser.print ('[Arc2D] Warning: endAngle=' + endAngle + ' must be within range [0..2pi)');
   }

   // equal startAngle, endAngle means draw full circle.
   // high out-of-range endAngle is OK for local computation.
   if (startAngle >= endAngle)
      endAngle += (2 * Math.PI);

   differAng = Math.abs((endAngle - startAngle))/numOfPoints;

   for (i = 0; i <= numOfPoints; i++)
   {
      arcSet3d[i] = new SFVec3f (radius * Math.cos(startAngle + i * differAng), radius * Math.sin(startAngle + i * differAng), 0.0);
      arcIndexSet3d[i] = i;
   }

} // initialize