A #PangoGlyphItemIter is an iterator over the clusters in a #PangoGlyphItem. The <firstterm>forward direction</firstterm> of the iterator is the logical direction of text. That is, with increasing @start_index and @start_char values. If @glyph_item is right-to-left (that is, if <literal>@glyph_item->item->analysis.level</literal> is odd), then @start_glyph decreases as the iterator moves forward. Moreover, in right-to-left cases, @start_glyph is greater than @end_glyph.