pango:context-base-dir (context)

context -- a pango:context
direction -- a pango:direction value with the base direction

The pango:context-base-dir function retrieves the base direction for the Pango context. The (setf pango:context-base-dir) function sets the base direction.

The base direction is used in applying the Unicode bidirectional algorithm. If the direction is :ltr or :rtl, then the value will be used as the paragraph direction in the Unicode bidirectional algorithm. A :weak-ltr value or :weak-rtl value is used only for paragraphs that do not contain any strong characters themselves.