(PECL ps >= 1.1.0)
ps_setfont — Sets font to use for following output
Sets a font, which has to be loaded before with ps_findfont(). Outputting text without setting a font results in an error.
Resource identifier of the postscript file as returned by ps_new().
The font identifier as returned by ps_findfont().
The size of the font.
如果成功则返回 TRUE，失败则返回 FALSE。