Posted by Christophe LAFOLET on Feb 06, 2020; 10:17am
URL: https://forum.jogamp.org/Frame-with-transparent-background-tp4040332p4040341.html

Hello

The problem is in file sun/java2d/opengl/GLXGraphicsConfig.c
In the method GLXGC_InitFBConfig(), a score is computed to select a visual with the minimal Vram usage but it do not take into account the alpha.
According to the list of visuals, if the visuals with alpha are at the beginning of the list, they can be selected, if they are at the end of the list (our case), they are never selected.

Christophe