blitImage is part of __DRIimageExtension Mesa internal API.
It is used to blit from a surface to another (I don't expect it would be difficult to implement for an intel dev).
The extension is required for the secondary card for DRI_PRIME on egl/wayland, glx dri3 (and soon egl/x11 dri3).
While if you are on a dedicated card it doesn't make a lot of sense to use DRI_PRIME to render on the integrated gpu (thus explaining the current low interest to implement the function), we could imagine it be used by future wayland compositors when enabling the use of several displays connected to different cards (one of the big things wayland is supposed to solve).
As Wayland compositors begin to be more and more ready, I suggest to implement that function soon, so that when wayland compositors become ready enough to begin to implement advanced functionnalities, blitImage would be ready for intel as well for Mesa stable.
*** Bug 97853 has been marked as a duplicate of this bug. ***
I want to run applications on the integrated instead of the dedicated GPU (because I don't want to use proprietary Nvidia Linux drivers) and this missing feature is blocking me from it.