Maybe the scrolling could be set by the client program, so that each game could scroll the background as they liked. Plus that could allow a program to use the background to make clouds moving in the distance when the player stood still. It would make programming games for the engine much more programmer friendly. 

Does anyone have advice/code/pseudocode on how to do multiple height walls? I could use some guidance on how to optimize the feature (I think I have the math right now, but I haven't started implementing yet because it looks messy).

The casted ray must not stop at the 1st hitten wall. It has to go through it
With the ray, I'm building a list of objects to display.

Each time the ray hits a wall, I'm adding an object to the list.

Each object consists of its coordinates for the line() function and its color or texture tile.
If we are higher than the top of the wall(or if its texture is transparent), a 2nd object for drawing the top of the wall (floor) is added.
If we are lower than the bottom of the wall (or if its texture is transparent), an object for drawing the bottom of the wall (ceiling) is added
If the texture is transparent, a last object for drawing the back of the wall is added.

The ray stops at the end of the world.
If the world is too big, it may be much slower, when looking far away.

Then I'm drawing objects, from the farthest to the nearest.
So nearer objects are drawn over farther objects, which is natural.


You may then make some optimisations:
- stopping the ray when it is too far (but the effect is not "natural" if you don't add some shading-, fog- or water-effect)
- adding an object to the list, only if it is partially visible (not hidden completly by nearest objects)
- stopping the ray if nothing more can be visible (all pixels from the bottom to the top of the screen have been drawn)

Sorry to hear about the issues you got

However, this looks FRIGGIN AWESOME! Do you think you could be able to make the lower walls textures not squished vertically? It would look even better

Regardless, I'm saving this on my PC and trying ASAP!

Or you could simply have a tiling texture that only had a few bricks, and stretched it to fit. That way, it would still stretch a little, but not that bad. Or, you could have it simply cut off at the ends

Don't know how feasible this is...I haven't had much experience with this sort of thing! It Looks awesome, though! Will you be able to stand on lower portions eventually?

Or, you could have it simply cut off at the ends

Good call, that's what I'd suggest, since you're drawing wall slices as if they were vertical sprite slices of the wall, clipping in the space provided shouldn't be too much of an issue. You won't have to worry about coding a tiling routine for the textures, they would simply clip to the drawing space you calculated.

I'm pretty much blown away by the way. Quite impressive. I can't wait for this to be completed, my mind is already turning with things I want to do with this engine. *diabolical grin*

Yum! That screenie looks delicious!

Ah good, my suggestion wasn't stupid.

So far, the program looks excellent to me. One thing I'm a little confused on:
Mode7 is a floor rendering thing, right? And raycasting is for walls, so combining them gives textured walls, floors and ceilings. Is that right?

How much more power is used by Actual 3D than Raycasting?

Yeah. It was also used for Secret of Mana's Overworld map, I believe, as well as FF6's chocobo riding. It kind of gives the isometric feel, but a little better quality with rotation and all.