I suggest some simple glReadPixels is sufficient :)
Mir's current screen{shot,cast} infrastructure is a bit complicated and designed on the assumption that rendering everything twice is faster than rendering everything once with a glReadPixels in the loop. I think that assumption may yet be proven false. So a simple glReadPixels could work (even from inside QtMir).
I suggest some simple glReadPixels is sufficient :)
Mir's current screen{shot,cast} infrastructure is a bit complicated and designed on the assumption that rendering everything twice is faster than rendering everything once with a glReadPixels in the loop. I think that assumption may yet be proven false. So a simple glReadPixels could work (even from inside QtMir).