Is there any way to identify the color of other sources from a shader?

[Eindacor_DS]

I'm essentially trying to turn sources into masks that modify the coloration of other sources, but I can't see an obvious way to fetch that kind of data. Is this currently possible? Is there any way to customize draw order and maybe fetch colors from a buffer of some sort?

 

[FerretBomb]

Shaders only operate on the source they're applied to, and only with the current frame, and no external buffering available.
Apparently you can set up more complex effects (including buffering) with a LUA script module, but it's definitely not newbie-friendly.

 

[Eindacor_DS]

Ok thanks. I'm actually a graphics programmer by trade, so I might take a look at the LUA stuff and see what I can come up with.