SetDefaultTTFont — Set the default TrueType font
$plot->SetDefaultTTFont($font)
SetDefaultTTFont sets the default TrueType font,
resets all text elements to use that font, and enables TrueType fonts.
$fontName of the TrueType font file to use as default. Specify either a filename in the default TrueType font directory, or a full pathname to the font file.
Starting at PHPlot-5.0rc3, the behavior of this function changed. It now accepts either a filename (which must be in the default TrueType font directory as set with SetTTFPath), or a full pathname. In addition, it automatically enables TrueType font usage as if SetUseTTF(True) was called.
This function resets all elements to use the named font and default sizes, so it undoes all prior SetFont calls.
Change the font used by individual text elements with SetFont after using SetDefaultTTFont.