[PD] GEM and single buffer mode

[Adrian]

I hope somebody at least can introduce me to the difference between
single and double layer buffer mode, some additional material on the
net would be cool as well.

I want to do some duplicates in space, in examples copy a rectangle 10
times with altered position.

My idea was to draw the rect 10 times a frame and then clear the
buffer. So i can then rotate the cam around it. But that idea was
built out of fragments of info i have in my head. So a
clear statement on single/double mode buffer would be so helpful.

thx in advance
adi