Posted by Bricksnspace on Sep 23, 2014; 10:47am
URL: https://forum.jogamp.org/GLOffscreenAutoDrawable-problem-with-OSX-Mavericks-tp4032763p4033204.html

A workaround for who face this problem (it is present even in normal GLDrawable, not only in OffScreen GLDrawable): do NOT use AWTGLReadBufferUtil but use a "raw" read with glReadPixels with GL_BGR (do NOT read Alpha channel, the problem in AWT/Mavericks is there).
Here you can see a test program with broken image and correct image:
http://pastebin.com/hspvitwA

HTH
Thank you

Mario