Support for COLRv1 fonts about kitty HOT 7 CLOSED

You are welcome. If there is ever a reasonably widely used font that supports only COLRv1 without COLRv0 fallbacks we can reconsider, but as it stands I dont think the performance hit is worth it. Using pre-rendered bitmaps for emoji works fine.

from kitty.

Works fine for me with Segoe UI Emoji which uses COLRv1

kitty --config=None --debug-font-fallback -o 'symbol_map U+1f63a Segoe UI Emoji' sh -c 'printf "\U1f63a"; read'

from kitty.

Thanks for so prompt reply!

It indeed works with Segoe UI Emoji, but no luck with COLRv1 variant Noto Color Emoji:

kitty --config=None --debug-font-fallback -o 'symbol_map U+1f63a Noto Color Emoji' sh -c 'printf "\U1f63a"; read'

Also I noticed that the Segoe UI Emoji displayed by Kitty (left) is different from the one in GTK (right):

This is most likely because the Segoe UI Emoji is a hybrid font that supports both COLRv1 and COLRv0, and Kitty actual displayed COLRv0 glyphs.

from kitty.

Works fine with Noto Color Emoji as well

kitty --config=None --debug-font-fallback -o 'symbol_map U+1f63a Noto Color Emoji' sh -c 'printf "\U1f63a"; read'

Presumably that has bitmap fallbacks too?

from kitty.

Maybe the COLRv1 version share the same font name Noto Color Emoji with the CDBT version packaged by most distros (assuming your system has the both installed).
Anyway, I suppose we could simply try to scale the interface large enough to determine if it is in CBDT or COLR format:
CBDT (packaged by Archlinux):

pkgname=noto-color-emoji
pkgver=2.042
pkgrel=1
epoch=1
pkgdesc='Google Noto color emoji font using COLRv1'
arch=(any)
url='https://www.google.com/get/noto/'
license=(custom:OFL)
provides=(noto-fonts-emoji emoji-font)
conflicts=(noto-fonts-emoji)
source=(
    NotoColorEmoji.ttf::https://github.com/googlefonts/noto-emoji/raw/v$pkgver/fonts/Noto-COLRv1.ttf
    LICENSE::https://github.com/googlefonts/noto-emoji/raw/v$pkgver/LICENSE
)
sha256sums=('d5ce808f06f4776023202c22441d03d7e57f8980091d2107404438592f2b62f6'
            'c71d239df91726fc519c6eb72d318ec65820627232b2f796219e87dcf35d0ab4')

package() {
  mkdir -p "$pkgdir"/usr/share/fonts/noto
  install -m644 NotoColorEmoji.ttf "$pkgdir"/usr/share/fonts/noto/
  install -Dm644 LICENSE "$pkgdir"/usr/share/licenses/$pkgname/LICENSE
}

from kitty.

Well given that the distro packaged fonts include color bitmaps, whats the motivation for supporting rendering of SVG? It's much slower/wasteful of CPU cycles.

from kitty.

Well, I would have thought that with FreeType supporting COLRv1, Kitty could easily support it like COLRv0.
Since the harms outweigh the benefits, it doesn't count as an enhancement and duplicates #2691.

Thanks for your hard work!

from kitty.