## Vertical Text Vertical Text — Laying text out in vertical directions |

## Synopsis

    enum        PangoGravity;
    #define     PANGO_TYPE_GRAVITY
    enum        PangoGravityHint;
    #define     PANGO_TYPE_GRAVITY_HINT
    #define     PANGO_GRAVITY_IS_VERTICAL       (gravity)
    PangoGravity pango_gravity_get_for_matrix   (const PangoMatrix *matrix);
    PangoGravity pango_gravity_get_for_script   (PangoScript script,
                                                 PangoGravity base_gravity,
                                                 PangoGravityHint hint);

## Description

Since 1.16, Pango is able to correctly lay vertical text out. In fact, it can set layouts of mixed vertical and non-vertical text. This section describes the types used for setting vertical text parameters.

## Details

### enum PangoGravity

    typedef enum {
      PANGO_GRAVITY_SOUTH,
      PANGO_GRAVITY_EAST,
      PANGO_GRAVITY_NORTH,
      PANGO_GRAVITY_WEST,
      PANGO_GRAVITY_AUTO
    } PangoGravity;

The PangoGravity type represents the orientation of glyphs in a segment of text. This is useful when rendering vertical text layouts. In those situations, the layout is rotated using a non-identity PangoMatrix, and then glyph orientation is controlled using PangoGravity. Not every value in this enumeration makes sense for every usage of PangoGravity; for example, `PANGO_GRAVITY_AUTO` only can be passed to `pango_context_set_base_gravity()` and can only be returned by `pango_context_get_base_gravity()`.

See also: PangoGravityHint

`PANGO_GRAVITY_SOUTH` | Glyphs stand upright (default)
`PANGO_GRAVITY_EAST` | Glyphs are rotated 90 degrees clockwise
`PANGO_GRAVITY_NORTH` | Glyphs are upside-down
`PANGO_GRAVITY_WEST` | Glyphs are rotated 90 degrees counter-clockwise
`PANGO_GRAVITY_AUTO` | Gravity is resolved from the context matrix

Since 1.16

### PANGO_TYPE_GRAVITY

    #define PANGO_TYPE_GRAVITY (pango_gravity_get_type())

The GObject type for PangoGravity.

### enum PangoGravityHint

    typedef enum {
      PANGO_GRAVITY_HINT_NATURAL,
      PANGO_GRAVITY_HINT_STRONG,
      PANGO_GRAVITY_HINT_LINE
    } PangoGravityHint;

The PangoGravityHint defines how horizontal scripts should behave in a vertical context. That is, English excerpt in a vertical paragraph for example.

See PangoGravity.

`PANGO_GRAVITY_HINT_NATURAL` | scripts will take their natural gravity based on the base gravity and the script. This is the default.
`PANGO_GRAVITY_HINT_STRONG` | always use the base gravity set, regardless of the script.
`PANGO_GRAVITY_HINT_LINE` | for scripts not in their natural direction (eg. Latin in East gravity), choose per-script gravity such that every script respects the line progression. This means, Latin and Arabic will take opposite gravities and both flow top-to-bottom for example.

Since 1.16

### PANGO_TYPE_GRAVITY_HINT

    #define PANGO_TYPE_GRAVITY_HINT (pango_gravity_hint_get_type())

The GObject type for PangoGravity.

### PANGO_GRAVITY_IS_VERTICAL()

    #define     PANGO_GRAVITY_IS_VERTICAL(gravity)

Whether a PangoGravity represents vertical writing directions.

`gravity` : | the PangoGravity to check

Since 1.16

### pango_gravity_get_for_matrix ()

    PangoGravity pango_gravity_get_for_matrix   (const PangoMatrix *matrix);

Finds the gravity that best matches the rotation component in a PangoMatrix.

`matrix` : | a PangoMatrix
Returns : | the gravity of `matrix`, which will never be `PANGO_GRAVITY_AUTO`, or `PANGO_GRAVITY_SOUTH` if `matrix` is `NULL`

Since 1.16

### pango_gravity_get_for_script ()

    PangoGravity pango_gravity_get_for_script   (PangoScript script,
                                                 PangoGravity base_gravity,
                                                 PangoGravityHint hint);

Based on the script, base gravity, and hint, returns actual gravity to use in laying out a single PangoItem.

If `base_gravity` is `PANGO_GRAVITY_AUTO`, it is first replaced with the preferred gravity of `script`. To get the preferred gravity of a script, pass `PANGO_GRAVITY_AUTO` and `PANGO_GRAVITY_HINT_STRONG` in.

`script` : | PangoScript to query
`base_gravity` : | base gravity of the paragraph
`hint` : | orientation hint
Returns : | resolved gravity suitable to use for a run of text

Since 1.16