(PHP 4 >= 4.0.5, PHP 5, PECL ming SVN)
ming_setcubicthreshold — Set cubic threshold
Sets the threshold error for drawing cubic beziers.
The Threshold. Lower is more accurate, hence larger file size.
Es wird kein Wert zurückgegeben.
Reading that document on Macromedia's site gives me light.
http://www.macromedia.com/support/flash/ts/documents/beziers.htm
It says, swf format only supports quadratic beziers, what less accurate than cubic beziers, but easy to render fast. I think, in swf file's beziers are quadratic interpolation of better looking quadratic beziers. Threshold value drives this accuracy (more control nodes, bigger files)