fcft_kerning(3)

fcft_kerning3

Calculate kerning distance between two wide characters

Usage

#include <fcft/fcft.h>

bool fcft_kerning(

struct fcft_font *font, uint32_t left, uint32_t right, long *restrict x, long *restrict y);

Overview

fcft_kerning() calculates the kerning distances x (horizontal) and y (vertical) between the two wide characters left and right, in pixels.

Both characters must exist in the primary font.

fcft_kerning() is just a convenience function around FT_Get_Kerning() and as such, it only supports legacy kern tables. In particular, OpenType fonts' GPOS tables are not supported. fcft is not a text shaping library.

Return value

On success, fcft_kerning() returns true, and x and y are updated with the kerning distance, in pixels.

On error, false is returned. This may happen for several reasons:

•

The primary font does not have any kerning information.

•

One, or both, of the two characters have no corresponding glyph in the primary font.

•

There is no kerning information for this character combination.

Examples

See fcft_from_name()

Releases

4 releases since Debian 11 (Bullseye); the text changed 3 times.

  1. 11
  2. 12
  3. 13
  4. Arch

From fcft 3.3.3-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.