draw constellation lines with braille characters

[rumly111]

Using braille characters we can basically split each terminal cell to 2x8 "subpixels", and use those "dots" to draw lines etc.

Added param --braille (--unicode is also needed), here is the result:

[rumly111]

here is a better quality gif:

[da-luce]

This looks great! Have only done a brief skim so far but in about two weeks I'll have some more free time and will work to get this in :)

[da-luce]

Just skimming, but on large terminals, would a buff overflow be possible here?

Since we're always rendering constant number of constellation lines each frame, it might be safer to dynamically allocate a buffer based on the current terminal size. Doing that each frame might be expensive but then again I'm not sure without bench marking

[rumly111]

well that's what google gpt recommended me for safe big numbers :) Even with font size 10 px you need 10000x10000 display resolution, which is way above 4k monitors. dynamic allocation just complicates things.

[da-luce]

Thinking about how the flags will work here; technically enabling braille is displaying some unicode characters, which one might expect to find under the unicode flag.

I think a better solution for the future will be to have distinct flags for different element styles, e.g.:

• Constellation style: ASCII, smooth, braille
• Star style: ASCII, circle, braille

Seems out of scope for this PR, just noting to self.

[rumly111]

hmm, I just wanted something to work, so didn't bother with args logic. for example if I set --braille, it could automatically enables --unicode etc, but the user should think of it himself. anyway, your idea of having a separate "braille" rendering mode is not bad, and here is a library for C that works with "braille graphics" : https://github.com/Huulivoide/libdrawille . I looked at the bresenham line drawing algorithm there.