2 ms·

I think it's okay for glyph generation to be slow as long as it doesn't block redraw and immediate user feedback such as scrolling. While you can make that pro

by kragen 1y ago

I think it's okay for glyph generation to be slow as long as it doesn't block redraw and immediate user feedback such as scrolling. While you can make that problem easier by throwing more horsepower at the problem, I think that to actually solve it you need to design the software so that redraw doesn't wait for glyph generation. It's a case where late answers are worse than wrong answers. I had forgotten or didn't know that you'd also written a pure Ruby replacement for Xlib! That's pretty exciting! I'm inclined to regard X-Windows as a mistake, though. I think display servers and clients should communicate through the filesystem, by writing window images and input events to files where the other can find them. Inotify is also a botch of an API, but on Linux, inotify provides deep-submillisecond latency for filesystem change notification.

vidarh 1y ago
For the glyph regeneration, individual characters is more than fast enough - TrueType is actually quite simple to rasterize [1] (if you ignore things like hinting, which you increasingly might as well on 4k displays etc.; also: if you ignore emojis, which involve an embedded subset of SVG in the font file... eww). It's really just if you have a screenful of previously unseen glyphs you'd get a very brief slowdown. You could warm the cache if you wanted, but in practice I can increase/decrease the fontsize with a screenful of text in my terminal without it being slow enough to be worth optimizing more. > I had forgotten or didn't know that you'd also written a pure Ruby replacement for Xlib! That one is not all me. I've just filled in a bunch of blanks[2], mostly by specifying more packets after the original maintainer disappeared. I keep meaning to simplify it, as while it works well, I find it unnecessarily verbose. I'm also tempted to bite the bullet and write the code to auto-generate the packet handling from the XML files used for XCB. I think there's large parts of X11 that are broken, but the more I'm looking at my stack, and how little modern X clients use of X, the more tempted I am to try to write an X server as well, and see how much cruft I could strip away if I just implement what is needed to run the clients I care about (you could always run Xvnc or Xephyr or similar if you want to run some other app). That would make it plausible to then separate the rendering backend and the X protocol implementation, and toy with simpler/cleaner protocols... [1] https://github.com/vidarh/skrift https://github.com/vidarh/skrift [2] https://github.com/vidarh/ruby-x11 https://github.com/vidarh/ruby-x11
kragen 1y ago
> I think it's okay for glyph generation to be slow as long as it doesn't block redraw and immediate user feedback such as scrolling Incidentally, last night I loaded a page containing https://news.ycombinator.com/item?id=44061550 https://news.ycombinator.com/item?id=44061550 in Fennec on my phone, and at some point when I scrolled to where some superscripts were in view, they were briefly displayed as gray boxes. My inference is that Fennec had loaded the font metrics so it could do layout but didn't do glyph rasterization until the glyphs were in view or nearly so.

by kragen 1y ago

vidarh 1y ago

For the glyph regeneration, individual characters is more than fast enough - TrueType is actually quite simple to rasterize [1] (if you ignore things like hinting, which you increasingly might as well on 4k displays etc.; also: if you ignore emojis, which involve an embedded subset of SVG in the font file... eww). It's really just if you have a screenful of previously unseen glyphs you'd get a very brief slowdown. You could warm the cache if you wanted, but in practice I can increase/decrease the fontsize with a screenful of text in my terminal without it being slow enough to be worth optimizing more. > I had forgotten or didn't know that you'd also written a pure Ruby replacement for Xlib! That one is not all me. I've just filled in a bunch of blanks[2], mostly by specifying more packets after the original maintainer disappeared. I keep meaning to simplify it, as while it works well, I find it unnecessarily verbose. I'm also tempted to bite the bullet and write the code to auto-generate the packet handling from the XML files used for XCB. I think there's large parts of X11 that are broken, but the more I'm looking at my stack, and how little modern X clients use of X, the more tempted I am to try to write an X server as well, and see how much cruft I could strip away if I just implement what is needed to run the clients I care about (you could always run Xvnc or Xephyr or similar if you want to run some other app). That would make it plausible to then separate the rendering backend and the X protocol implementation, and toy with simpler/cleaner protocols... [1] https://github.com/vidarh/skrift https://github.com/vidarh/skrift [2] https://github.com/vidarh/ruby-x11 https://github.com/vidarh/ruby-x11

kragen 1y ago

> I think it's okay for glyph generation to be slow as long as it doesn't block redraw and immediate user feedback such as scrolling Incidentally, last night I loaded a page containing https://news.ycombinator.com/item?id=44061550 https://news.ycombinator.com/item?id=44061550 in Fennec on my phone, and at some point when I scrolled to where some superscripts were in view, they were briefly displayed as gray boxes. My inference is that Fennec had loaded the font metrics so it could do layout but didn't do glyph rasterization until the glyphs were in view or nearly so.