DOKK / manpages / debian 12 / libfcft-doc / fcft_kerning.3.en
fcft_kerning(3) fcft fcft_kerning(3)

fcft_kerning - calculate kerning distance between two wide characters

#include <fcft/fcft.h>

bool fcft_kerning(

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

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.

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.

See fcft_from_name()

2022-12-01 3.1.5