This works a LOT better under Phosphorus: http://phosphorus.github.io/app.html?id=31815198&turbo=false&full-screen=false I had an idea that games like Wolfenstein could be implemented with fully-textured corridors by slicing hi-res images into vertical strips and then plotting those stripes scaled in a trapezium - it was meant to be fast and simple. Well, due to a combination of a scratch plotting bug, a scratch plotting 'design feature', and the cost of changing costumes, it turns out that it is neither fast nor particularly simple. Nevertheless, here is the code if anyone wants a chuckle, and if by any chance you're able to improve it (or if Scratch speeds up a lot at some point in the future) then a combination of this plus the "Painter's Algorithm" (as in http://scratch.mit.edu/projects/31569616/ ) ought to make for some flashy and relatively simply coded 3d games. The main use I had planned for this was to create a virtual walk-through art gallery, hence why I wanted high-res imagery on the walls.
Tip of the hat to @MegaApuTurkUltra for passing on the workaround that avoids the sprite scaling bug and big thanks to @SuperDoggy for speeding up the code by a factor of about 10! Still looking for any more optimisations that could significantly speed this up to the point that it's usable in a walk-through enviroment. So far the only way to make it usable is to compile it to an exe with procd's compiler or use Phosphorus!
