pango:context-base-dir (context)

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

Gets or sets the base direction for the Pango context. 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.