Nice! As an idea, maybe detecting the fixed-point to use before the actual graphing? Might get complicated, though...

That looks really cool. I thought you could do inequalities with the TI-OS though, I might be thinking of Piecewise Functions though. Though you could probably mix that and the shading thing together to get the desired effect (on the TI-OS). Only issue though is that the shading looks like crap on it (again, the TI-OS, I didn't mean you program, yours looks amazing ).

Ya, that's what I thought. Well glad to see this

I think one of the issue is that grayscale in ASM and BASIC (Doors CS/xLIB/Celtic/Omnicalc) can be hard to implement, while in Axe it's pretty much a joke

The hardest part gotta be in BASIC with 4 level grayscale. 3 level is not too bad but with 4 level you need to pre-render each frame of grayscale, meaning for a 8x8 sprite, for example, you need to manually draw the dithering and store each copy of the sprite in pictures. Not only in the end you got 4 pictures instead of 2 (including the one containing the black), but also it takes a ridiculous amount of effort to draw one single 8x8 sprite (about 30 minutes per sprite). Fortunately there is a tool to edit 4 and 5 level grayscale but it's still annoying because then you end up having to archive/unarchive stuff since the tool takes a lot of RAM (although you can use Doors CS)