(PECL ps >= 1.1.0)
ps_setlinecap — Sets appearance of line ends
$psdoc, int $type): boolSets how line ends look like.
psdocResource identifier of the postscript file as returned by ps_new().
type
The type of line ends. Possible values are
PS_LINECAP_BUTT,
PS_LINECAP_ROUND, or
PS_LINECAP_SQUARED.
成功时返回 true， 或者在失败时返回 false。