How do I generate an EPS or a vector based PDF from an SWF?
Well, you don’t. Nowadays it’s very well possible to generate a JPG or other pixel-based format with an SWF, and with some server-side scripting to turn it in to a PDF. But all the images will still be pixel-based.
But after some surfing, I found out the way to vectors is SVG (Scalable Vector Graphics). And after some more surfing, I found Degrafa. This is an open source declarative graphics framework in Flex. And with it, it looks relatively easy to generate a SVG image from Flex (example). And an SVG image can be converted to a PDF serverside or clientside, or edited in programs like Adobe Illustrator.
So, no (vector based) PDF from an SWF, but an SVG from Flex; that’s pretty close.
Status: Didn’t test it yet, but looks promising