It isn’t an open problem for text editors or terminals, which is the point Casey made in his videos.
Unfortunately it's not this simple. Unicode and multilingual support means you can't possibly generate a single bitmap to contain all possible characters. Modern UIs (including text editors and terminals) generally support various zoom levels, which requires re-rasterizing glyphs at different zoom levels. This means you typically have to rasterize vector graphics (your font) on the fly as needed and then update your bitmap.
Edit: Also, emojis and certain scripts require composting multiple glyphs together. This means you have to figure out which glyphs are required for your codepoint and use your font metrics to composite the glyphs appropriately. Then throw in mathematical notation and all bets are off.
My point is, rendering text is not a simple done deal, but it's also not an impossible feat and it can be done efficiently.
vector graphics are not rendered directly to the screen. fonts are rasterized first, then the rasterization is what the GPU receives.
What difference does it make if you're caching the rasterization or not? You're still rendering vector graphics. And you're not just rasterizing once.
Modern font renderers can't get away with rasterizing glyphs once and reusing them anymore than arbitrary vector graphics renderers can. I sure hope my vector graphics editors cache the rasterizations instead of re-rasterizing needlessly.
it's not every frame. that's my point. that you missed twice because you can't see past details to the point of the statement.
lmao welcome to HN, if you don't enjoy that experience I don't recommend you try to argue here.
> figure out which glyphs are required for your codepoint and use your font metrics to composite the glyphs appropriately.
this is all done in shaping though, the renderers just see "put this thing there" and (at least in GTK) we just maintain texture atlases that are updated on the fly.
you're correct that it doesn't solve the same glyph at lots of scales though. but glyphy does (and at high FPS too).
To be clear, I'm not bashing on GTK. I'm saying that it definitely isn't as simple as the above comment implies ;)
the bitmap stuff still has major drawbacks though, like maintaining grid alignments and pixel boundaries where as this stuff (mostly) goes away using glyphy.
still work to be done around hinting though (hence not merged).