Revert "cogl: Pick glReadPixels format by target, not source"
This reverts commit 981b0454.
Fixes #418 (closed)
I'd like to ask for a freeze break for this one. It affects window animations, therefore being highly visible.
On IRC:
(17:42:28) halfline: it might cause a big performance regression for some dual gpu set ups
(17:42:59) halfline: but reverting the swizzle operation might cause a performance regression for all setups so...
(17:43:19) halfline: i think your MR is probably the most conservative near term solution