Ubuntu – Trying to get opengl 2 shaders to work glxinfo says I have 4.20 installed

Ok, I finally fixed this by removing the closed-source proprietary driver, and using the open source Radeon driver. See https://help.ubuntu.com/community/RadeonDriver

The open source driver fully supports my ATI card CEDAR Radeon HD 5430/5450/6330/6350/6370

To install the open source driver it is enough to fully remove the closed-source one (more details at https://wiki.ubuntu.com/X/Troubleshooting/VideoDriverDetection#Problem:_Need_to_purge_-fglrx). This is what I used:

sudo apt-get remove --purge fglrx*
sudo apt-get remove --purge xserver-xorg-video-ati xserver-xorg-video-radeon
sudo apt-get install xserver-xorg-video-ati
sudo apt-get install --reinstall libgl1-mesa-glx libgl1-mesa-dri xserver-xorg-core
sudo dpkg-reconfigure xserver-xorg
sudo shutdown -r now

After restart both laptop screen and my external monitor screen worked. To set the resolution for the two monitors I used arandr tool.

To check all is ok:

sudo lshw -c video

should show ... configuration: driver=radeon latency=0

Hope this will be of help.

OpenGL ES is a subset of the original OpenGL specification and is designed for embedded systems such as smart phones. I'm not 100% sure why the version numbers do not correspond, but they don't. The latest version is 4.5 for OpenGL and 3.2 for OpenGL ES. This explains the reason for the OpenGL ES part of your output. In your case, you have support for the latest versions of both OpenGL and OpenGL ES.

You will note that the OpenGL and OpenGL ES entries have a version string and a shading language version string. Prior to OpenGL 3.3, the OpenGL version number and the shading language version number did not match. I believe this is the reason they have separate entries in the output (as they can obviously be different for older hardware). As seen in your output, the version number (4.5) matches the shading language version (also 4.5).

The hardest part (and the part that I'm not 100% sure about) is the "OpenGL version string".

From what I have seen on several completely different machines, this appears to be capped at version 3.0. The shading language version for 3.0 is 1.3 so the shading language version string makes sense for this OpenGL version. However, why is version capped at 3.0? My thoughts are as follows:

Version 3.0 introduced deprecation (see this link). This is also where the two separate profiles came from, "Core" and "Compatibility". Any implementation of OpenGL only has to implement the "core" specification to be valid.

If you read the Mesa release notes for a particular version you will see a statement relating to this core/compatibility profile issue. The following was taken from the release notes for the latest version 17.0.0 here:

Mesa 17.0.0 implements the OpenGL 4.5 API, but the version reported by glGetString(GL_VERSION) or glGetIntegerv(GL_MAJOR_VERSION) / glGetIntegerv(GL_MINOR_VERSION) depends on the particular driver being used. Some drivers don't support all the features required in OpenGL 4.5. OpenGL 4.5 is only available if requested at context creation because compatibility contexts are not supported.

Note the last part "OpenGL 4.5 is only available if requested at context creation because compatibility contexts are not supported". Therefore, I think the "OpenGL version string" is the supported version for a "compatibility" profile context (or in other words, for support of any deprecated feature prior to version 3.0).