Kitty: macOS font smoothing

[slice]

Is there a way to change how fonts are smoothed while using kitty on macOS?

iTerm2 is on the left, and kitty is on the right.

Is there a way to accomplish the same smoothing as iTerm?

[kovidgoyal]

No, you will never get the same rendering between iterm2 and kitty as kitty does not use CoreText to render fonts. The next kitty release will however include support for subpixel antialiasing, which IIRC iterm2 uses as well (although personally, I find sub-pixel antialiasing to be sub-optimal on high resolution displays).

[slice]

Thank you for the quick response! :+1:

[kovidgoyal]

Actually, I should say that I am currently investigating getting kitty to use CoreText on macOS, if I succeed, this should be automatically fixed.

[kovidgoyal]

I managed to get CoreText rendering working (in the ct branch)

[slice]

I built a fresh version of kitty and there appears to be no effect, how strange. I tried messing around with the render context in the render_glyphs function and couldn't figure out how to make the text appear to my liking.

I guess it's not a big deal, though.

[kovidgoyal]

Make sure you are using the same font variant, i.e. the thick/thin/medium/book style. Use kitty list-fonts to get a list.

[slice]

Some recent changes caused the font rendering to change substantially for me:

Old on the left, new on the right. Thanks for this, it looks much better now!

NOTE: Both instances are using identical configuration.

[kovidgoyal]

That's likely the effect of https://github.com/kovidgoyal/kitty/commit/b9d0ec0d4cc4e35b805f5dd3b8e9342926051673

[slice]

Hmm...

I know this issue is closed and it has been a while, but font smoothing is still "thin" despite terminal glyphs being rendered with CoreText.

[kovidgoyal]

The remaining difference between kitty and most other terminals is kitty does not do sub-pixel AA as it is an unnecessary waste of resources on modern retina displays, see other bug reports for full explanation.