(PHP 4, PECL pdflib >= 1.0.0)
PDF_setgray_fill — Set fill color to gray [deprecated]
Sets the current fill color to a gray value between 0 and 1 inclusive. 성공할 경우 TRUE를, 실패할 경우 FALSE를 반환합니다.
This function is deprecated since PDFlib version 4, use PDF_setcolor() instead.