Posted by MarcoNL on Oct 27, 2021; 5:45pm
URL: https://forum.jogamp.org/Incorrect-context-on-GLCanvas-drawable-tp4041391p4041416.html

Hi all.
Today I think I've made some radical progress in the analysis of my issue.

First of all, I've built a simple test program:

JoglContextTestCase.java

This test program simply creates a JFrame on the default GraphicsConfiguration for my first screen, and adds an empty GLCanvas to this JFrame.
While creating the GUI, this test program enumerates all GraphicsDevice's available on my PC, and for each GraphicsDevice, all available GraphicsConfigurations.
Finally, in the init() callback of my GLEventListener, I simply print the GLVersion of my drawable.getContext().

On my Windows 10 development PC, which has two screens attached to a NVIDIA GeForce GTX 1060 6 GB graphics adapter, here is what I get on the stdout:

==============

Screen device # 0: \Display0
Screen device # 0, configuration # 0:
Screen device # 1: \Display1
Screen device # 1, configuration # 0:
NewFrame created in thread [15], isEDT: true
* Context GL version: 4.6 (Compat profile, arb, compat[ES2, ES3, ES31, ES32], FBO, hardware) - 4.6.0 NVIDIA 456.71

==============

So far, so good. In my init() callback, I get an OpenGL 4.6 context, and that's great. VTK would work fine with such a context.

However, if I just pass "-Dsun.java2d.noddraw=true" system property to my JVM (which is required to run both JOGL and my application smoothly), here is what I get:

==============

Screen device # 0: \Display0
Screen device # 0, configuration # 0:
Screen device # 0, configuration # 1:
Screen device # 0, configuration # 2:
Screen device # 0, configuration # 3:
Screen device # 0, configuration # 4:
Screen device # 0, configuration # 5:
Screen device # 1: \Display1
Screen device # 1, configuration # 0:
Screen device # 1, configuration # 1:
Screen device # 1, configuration # 2:
Screen device # 1, configuration # 3:
Screen device # 1, configuration # 4:
Screen device # 1, configuration # 5:
NewFrame created in thread [15], isEDT: true
* Context GL version: 1.1 (Compat profile, arb, compat[], FBO, hardware) - 1.1.0

==============

As you can see, with this system property, first of all I get 6 different GraphicsConfiguration per each screen (I am uncertain why, but this certainly doesn't depend on JOGL), and then the GLContext I get in my init() callback is an OpenGL 1.1 context (and I believe this depends on JOGL and shouldn't happen)!

Even stranger, if in my test case code I simply remove the call to GraphicsDevice.getConfigurations() (but always passing "-Dsun.java2d.noddraw=true"), then again I am getting a correct OpenGL 4.6 context. Here is the output I obtain in this last test configuration:

==============

NewFrame created in thread [15], isEDT: true
* Context GL version: 4.6 (Compat profile, arb, compat[ES2, ES3, ES31, ES32], FBO, hardware) - 4.6.0 NVIDIA 456.71

==============

I looks like the fact that I call "GraphicsDevice.getConfigurations()" (which apparently should do nothing) is changing something in the way JOGL creates its GLContext in the GLCanvas.

I would really appreciate your feedback, now that I've been able to put together a complete and very simple test case.

Thanks in advance for your time.
Best regards,

Marco Sambin