gistfile1.java

sealed case class Sphere      (center:Vector3d   , radius: Double)     extends Geometry
{
    def intersect (r:Ray, h:Hit, range:Range,material:Color3f): Option [(Hit,Range)]=
    {

      var v = new Vector3d ( r.origin.x - center.x , r.origin.y - center.y,r.origin.z - center.z);
      var discriminant = pow (v.dot (r.direction),2.0) - (pow (v.dot(v),2) - pow (radius,2));
      if (discriminant >= 0 )
        {
          //var t1 = -(v.dot(r.direction)) + sqrt (discriminant);
          var t = -(v.dot(r.direction)) - sqrt (discriminat);
          
          if (t >= range.minT  && t < range.maxT )
            {
              var h = new Hit (t,material);
              range.maxT = t;
              
              return Some (h,range);              
            }
          return None;
          
        }
      else              
        return None;
    }
}