[PD] freehand drawing on video in GEM

[Spencer Russell]

I need to blob track a point of light in a video and use it to draw
freehand in the GEM window, possibly mixed with previously-recorded
video clips. I'd also like to connect the adjacent points with lines
so that the drawing is continuous.

I'm still pretty new to GEM, but I'm working on getting my head around
all the render order and buffering ideas, I'm just not sure what the
best approach is. I've tried using gemframebuffer going to a pix_snap,
but it takes up 100% CPU, so I figure there's got to be a better way.
Is there some sort of way I can just keep appending vertices to a list
and use something like [curve]?

Thanks,
spencer