Typically, when I talk to Jitter users about writing one's own shader programs for use with jit.gl.slab, I usually get glazed-over eyes and this sort of distant look of wonder. When I try to explain how easy it is, that look typically turns to one of annoyed disbelief. So, for a long time now I've been thinking about writing an article to de-mystify the process of writing your own GLSL shaders, and to help everyone avoid some common frustrations.
In this installment, we'll be working on some more advanced ninja tricks - creating the beginnings of a control/preset structure with assignable LFOs, and building a GPU-based video delay effect. These two parts will bring our system to a much more usable level, and allow for much more complex and interesting results. Ironically, most of what we are really doing in this installment is just an extension of bread-and-butter Max message passing stuff.