[Development] Question regarding commit: Fix transformation in eglfs backingstore

[Jon Trulson]

Commit 12491f35bbea7008b15fb0ba0ee7ea5bf6eb6b6c from Laszlo Agocs:

     Fix transformation in eglfs backingstore

     While not visible with forced-fullscreen windows, the formula used
     to set up positioning on the Y axis is wrong. (with the GL
     coordinate system Y goes 1..-1 when moving top-to-bottom)

     Taken from kms' version of the backingstore which had the formulas
     corrected.

I am crosscompiling qt5 for a Raspberry Pi board using eglfs, and the
latest raspbian (2012-08-16-wheezy-raspbian).  It has gone well
with the most recent git masters, pulled today.

I noticed though that while running various qtbase widget examples
(scribble, sliders, etc) that the Y axis is inverted.

Those opengl examples that work, do show up properly regardless of
this patch (paintedwindow).

The commit above seems to be responsible.  If I revert it, then the
apps display properly (though opening menus, etc still cause crashes,
but that's another issue.)

OpenGL apps, including qml via qmlscene still look correct.

I suspect that Y inversion is already being handled elsewhere within
Qt, so I am curious as to what problem was actually seen that required
this change?

Should it be reverted?

-- 
Jon Trulson

Atoms are what make us matter.