3bgl-shader alpha release

One of the things I have been working on off and on for the last few years is a DSL for translating something resembling Common Lisp to GLSL. Recently, I finally got around to combining the various pieces into something approximately usable, and the result is 3bgl-shader.

It is still a bit rough, in particular most of the error messages are pretty bad. The main features (type-inference, dependency tracking, and interactive usage) seem to be working reasonably well though.

The video also shows something else I've been working on recently, which is a hack to show an xterm within a 3d scene, using the X Composite extension. That part is even rougher, to the point it doesn't even start up reliably. When it does start, it works reasonably well, and I even managed to get a nested draw loop working on *debugger-hook* so it can be used to debug code running in an emacs displayed on the xterm from within the code being debugged.