void WorldEditorSelection::offset( const Point3F& offset, F32 gridSnap )
{
   for( iterator iter = begin(); iter != end(); ++ iter )
   {
      SceneObject* obj = dynamic_cast<SceneObject*>( *iter );
      if( !obj )
         continue;

      MatrixF mat = obj->getTransform();
      Point3F wPos;
      mat.getColumn(3, &wPos);

      // adjust
      wPos += offset;

      if( gridSnap != 0.f )
      {
         wPos.x = _snapFloat(wPos.x, gridSnap);
         wPos.y = _snapFloat(wPos.y, gridSnap);
         wPos.z = _snapFloat(wPos.z, gridSnap);
      }

      mat.setColumn(3, wPos);
      obj->setTransform(mat);
   }

   mCentroidValid = false;
}

F32 WorldEditorSelection::_snapFloat(const F32 &val, const F32 &snap) const
{
   if (snap == 0.0f)
      return val;

   F32 a = mFmod(val, snap);

   F32 temp = val;

   if (mFabs(a) > (snap / 2))
      val < 0.0f ? temp -= snap : temp += snap;

   return(temp - a);
}