Support Smaller terminal sizes using Sextants (with some color loss)

[jquast]

I've been experimenting with supporting smaller terminals, as low as 80x50 using Sextants.

Benefits,

• Works on most laymen terminals without resize, no need to "make the font smaller"
• ~50% less bandwidth for network servers
• With conditional removal of screen margins, this fits under 80 wide terminal which is pretty amazing!
• Still does the "full resolution" if it can fit

Problems,

• The unicode block itself is relatively new, I'd guess maybe 95% support half blocks and 80% sextants?
• Worse aspect ratio, "mostly circles" become "very ovular"
• There is still some flickering in some scrolling

https://www.jeffquast.com/gameboy-sextants.mp4
telnet 1984.ws 8063

If you're interested in this solution despite its issues, I'll do my best to clean it into a PR.

Also pictured is telnet support (via telnetlib3), let me know if you're interested, Telnet does NAWS (negotiate about window size), and, by using blessed I can "feed" it the raw input to detect key sequences without the use of a pty or curses or anything, so it is very low on resources.

[vxgmichel]

I love the idea, the demo looks great!

One question, you seem to be using the same source for both terminals, but the rendering looks different. In particular, when Link walks up the hallway there are light pixels artefacts that appear on the left window but not on the right window, why is that?

Also, if I understand correctly, you have to choose which two colors to use as foreground and background for each sextant, and then affect each of the 6 pixels to either one. So the bet is that having more than 2 colors in a 2x3 rectangle is such a rare occurrence in a game boy game that it will be barely noticeable?

For instance, that's the bleeding we can see here in your demo right?

[jquast]

So the bet is that having more than 2 colors in a 2x3 rectangle is such a rare occurrence in a game boy game that it will be barely noticeable?

That's pretty much correct, losing color fidelity, downsampling to just 2 colors means sometimes losing colors. It sometimes has strange effects, though I have improved it some since I took that video

[jquast]

One question, you seem to be using the same source for both terminals, but the rendering looks different. In particular, when Link walks up the hallway there are light pixels artefacts that appear on the left window but not on the right window, why is that?

There was a small bug in the blitter in that version, that specific artefact is fixed, but for example the carpet and the surrounding blocks in the top zelda room, as it is scrolled, has a strange "color warping" effect because they have well more than 2 colors

[jquast]

Also, just to mention, there are "Octants" in Unicode release 16 (Released September 2024), but I haven't yet found any terminal, web browser, and font on my system that yet supports them. But I think this could help with the aspect ratio