if the font is not loaded then load it and make the required object else just make it the current font the encoding array can contain 'encoding'=> 'none','WinAnsiEncoding','MacRomanEncoding' or 'MacExpertEncoding' note that encoding='none' will need to be used for symbolic fonts and 'differences' => an array of mappings between numbers 0->255 and character names.
Signature
public function selectFont(
$fontName,
[string
$encoding = '',
[boolean
$set = true]] )