One of the best things about the original Splatoon was its wonderful Miiverse functionality. Players were encouraged to create elaborate doodles using the Wii U's GamePad touchscreen, which would then be displayed—via the wonders of the console's built-in social media platform—in Splatoon's hub area for everyone to see. The best posts would also appear on billboards in-game, or emblazoned across the sky in an explosion of fireworks during Splatfests. It was great.
Nintendo has attempted to mimic this functionality for Splatoon 2 on Switch, but without the built-in stylus support seen on Wii U, people are finding it just a little bit harder to create the kind of artistic masterpieces frequently seen in the first game. That hasn't stopped eager fans from trying to find creative work-arounds to the problem though.
Over on Reddit there are several discussions on this very issue, but most people seem to agree that the best option for creating more elaborate artwork is to ignore the Switch's touchscreen completely. Instead, creatives prefer to blow up a 320x120 image so that the pixels are clearly visible, then painstakingly input each dot individually, using the Switch's D-pad and buttons. It's effective but, as you can probably imagine, incredibly tedious.
Enterprising modder Shiny Quagsire has gone one considerable step further, however, creating a far more hi-tech solution. Using a combination of hardware and software hacks, Shiny Quagsire has managed to automate the process with a program that will take an image, convert it into the D-pad and button presses that artists would ordinarily do manually, then input them into the Switch one by one—essentially 'printing' the image onto Splatoon 2's drawing input screen.
As my technologically inept brain understands it, Shiny Quagsire has used a USB development board to emulate the Pokken Tournament Controller which, thanks to a recent Switch firmware update, is then recognised by the console as a Pro Controller. This last bit is important because Pro Controllers are compatible with—and can be used in—all Switch games, including Splatoon 2.
That's the crucial connectivity sorted then. From here, the program running on the USB board is then able to take a supplied image, convert it into bits, then convert that information into D-Pad and button presses. Those inputs are then automatically performed on Splatoon 2's image drawing screen using the Pokken controller interface as the middle man. Science!
It's an ingenious solution to a fun problem, even if it's not quite as artistically satisfying as doing the whole thing by hand. For those that prize speed over personal accomplishment, however, the full details of Shiny Quagsire's project can be found over on GitHub, and you'll find a few handy breakdowns of the fundamentals (as written by people smarter than I) over on Reddit.