[Bf-committers] OSL Composite Node

[Dan Eicher]

Hi all,

During the Developer Meeting Ton suggested that someone look into creating
a comp node based on OSL so I've been (semi-)diligently working on that the
last couple of days. So far I have done all the plumbing and am ready to
tackle the trick bits of hooking into OSL.

>From what I can find on the interwebs the way to do it would be like in
OSL/testshade (
https://github.com/imageworks/OpenShadingLanguage/tree/master/src/testshade)
where you set up a 'fake' plane the size of the image (or tile I suppose)
and evaluate the x, y points on said plane after passing in the
input/output socket data as parameters.

While this is good and all for complex algorithms it does seem a bit
overkill for simple pixel filter functions (which the IRC discussion
proposed). Something like this would be super trivial using libjit (which
is the only other similar library I'm familiar with) so I'm hoping someone
knows a method to just call a function using OSL without having to setup a
shading context. Ton said he'd read on the OSL website that it is also
designed for stuff like this so I'm guessing that it must be possible
without too much trouble.

Anyhoo, off to plunge into the deep, dark depths of the OSL codebase.

Dan