Posted by gouessej on Jan 17, 2018; 10:20am
URL: https://forum.jogamp.org/JOGL-Swing-Multiple-viewports-tp4038537p4038550.html

Thank you for the feedback. It's a side effect of this feature, it's mentioned in the documentation:
http://jogamp.org/deployment/jogamp-next/javadoc/jogl/javadoc/com/jogamp/opengl/awt/GLJPanel.html#bug842

P.S: I use jogl.gljpanel.noglsl in JogAmp's Ardor3D Continuation, that's why I don't reproduce this problem but the vertical flipping has a lower memory footprint when it's performed by the build-in GLSL shader.