biDirectional
This variable is set by mPDF when it detects characters from a script written in a right-to-left direction to allow processing of bidirectional text. It does not normally need to be defined by the user, but can be, in order to force the bidirectional algorithm to be applied.
Note: This variable originally started with an uppercase letter (≤ mPDF 2.2). Support for the uppercase version was removed in mPDF ≥ 6.0
bool $biDirectional
Default: false
