A perspective projection and solid color 3d demo with a rotation and matrix math and stuff done in a supremely manual way. I'll try to make some kind of 3d game with it soon.
X/O to change cam distance
up/down to rotate on X axis
left/right to rotate on Y axis
I stole a polygon fill function from @zovirl 's Perspective-correct texture mapping cart.
Ok I finally got it right.
This is pretty much a prism command that draws a rectangle as well as lines to connect it to another rectange that's a little larger.