stbtt_GetFontVMetrics function
computes a scale factor to produce a font whose EM size is mapped to 'pixels' tall. This is probably what traditional APIs compute, but I'm not positive.
Implementation
@ffi.Native<
ffi.Void Function(
ffi.Pointer<stbtt_fontinfo>,
ffi.Pointer<ffi.Int>,
ffi.Pointer<ffi.Int>,
ffi.Pointer<ffi.Int>,
)
>()
external void stbtt_GetFontVMetrics(
ffi.Pointer<stbtt_fontinfo> info,
ffi.Pointer<ffi.Int> ascent,
ffi.Pointer<ffi.Int> descent,
ffi.Pointer<ffi.Int> lineGap,
);