After finding out that the vanilla fisheye shader for some inexplicable
reason does not work here, I set out to learn glsl. In process of doing so,
I stumbled across Libero Spagnolini's cool PhotoBooth demystified website
which has greatly helped me facilitate learning more about shader language.
As a result, I am sharing this collection of semi-useful shaders, some of
which mimic PhotoBooth behavior (Mac users already have jit.gl.imageunit
object to access those, so they will likely be more useful for Windows
users), other that are reproducible using jitter tricks (although in the
case of a dedicated GPU with hw shaders, this implementation should
theoretically offload computing to the GPU), and finally a few that are
likely less common.
FWIW, I think the greatest value (apart from the working fisheye shader ;-)
comes from the fact that algorithms are self-contained, terse, and have
adequate (albeit not necessarily consistent) comments, all of which will
hopefully facilitate learning of shaders. That being said, there are some
cool effects that can be created using extreme values, so make sure to mess
with input values...
OK, enough of ranting, you can get "shaders ahoy!" from the following URL:
NB: not all filters take both values, so if you see no difference while
scratching one of the input Max number boxes, that is probably why.