Returns the width of text using the parameters font and size. Please note that font is a font handle returned by pdf_findfont(). Parameters font and size are optional before PHP 4.3.5 or with PDFlib less than 5. If they are not specified, the font set by pdf_setfont() is used.
注: Both the font and size parameters must be used together.
See also pdf_setfont() and pdf_findfont().