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

Since 1.16

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.

Since 1.16

PANGO_GRAVITY_IS_VERTICAL()

#define             PANGO_GRAVITY_IS_VERTICAL(gravity)

Whether a PangoGravity represents vertical writing directions.

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.

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.

Since 1.16

pango_gravity_get_for_script_and_width ()

PangoGravity        pango_gravity_get_for_script_and_width
                                                        (PangoScript script,
                                                         gboolean wide,
                                                         PangoGravity base_gravity,
                                                         PangoGravityHint hint);

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

This function is similar to pango_gravity_get_for_script() except that this function makes a distinction between narrow/half-width and wide/full-width characters also. Wide/full-width characters always stand <emph>upright</emph>, that is, they always take the base gravity, whereas narrow/full-width characters are always rotated in vertical context.

If base_gravity is PANGO_GRAVITY_AUTO, it is first replaced with the preferred gravity of script.

Since 1.26

pango_gravity_to_rotation ()

double              pango_gravity_to_rotation           (PangoGravity gravity);

Converts a PangoGravity value to its natural rotation in radians. gravity should not be PANGO_GRAVITY_AUTO.

Note that pango_matrix_rotate() takes angle in degrees, not radians. So, to call pango_matrix_rotate() with the output of this function you should multiply it by (180. / G_PI).

Since 1.16