(PHP 5 <= 5.3.0, PECL ming SVN)
SWFFill::skewYTo — Sets fill y-skew
$y
   )This function is EXPERIMENTAL. The behaviour of this function, its name, and surrounding documentation may change without notice in a future release of PHP. This function should be used at your own risk.
   Sets the fill y-skew to y.
  
y
       When y is 1.0, it is a 45-degree upward slant.
       More is more upward, less is more downward. 
      
No value is returned.