The PangoDirection type represents a direction in the Unicode bidirectional algorithm; not every value in this enumeration makes sense for every usage of PangoDirection; for example, the return value of pango_unichar_direction() and pango_find_base_dir() cannot be Pango::DIRECTION_WEAK_LTR or Pango::DIRECTION_WEAK_RTL, since every character is either neutral or has a strong direction; on the other hand Pango::DIRECTION_NEUTRAL doesn't make sense to pass to pango_log2vis_get_embedding_levels().
The Pango::DIRECTION_TTB_LTR, Pango::DIRECTION_TTB_RTL values come from an earlier interpretation of this enumeration as the writing direction of a block of text and are no longer used; see the Text module of the CSS3 spec for how vertical text is planned to be handled in a future version of Pango. The explanation of why Pango::DIRECTION_TTB_LTR is treated as PANGO_DIRECTION_RTL can be found there as well.
Value | Symbolic name | Description |
| 0 | Pango::DIRECTION_LTR | A strong left-to-right direction. |
| 1 | Pango::DIRECTION_RTL | A strong right-to-left direction. |
| 2 | Pango::DIRECTION_TTB_LTR | Deprecated value; treated the same as Pango::DIRECTION_RTL. |
| 3 | Pango::DIRECTION_TTB_RTL | Deprecated value; treated the same as Pango::DIRECTION_LTR. |
| 4 | Pango::DIRECTION_WEAK_LTR | A weak left-to-right direction. |
| 5 | Pango::DIRECTION_WEAK_RTL | A weak right-to-left direction. |
| 6 | Pango::DIRECTION_NEUTRAL | No direction specified. |