well thats an eye opener.

[Brian Beuken]

yeah, is pretty standard posting on linux or raspbery forums, though the advice I was given was not actually the advice I asked for it did lead me to ask question that helped me to get my eyes opened, I'm not following convention, and they simply don't understand why I would want to be doing OpenGLES when they've done a prefectly good OpenGL and SDL, QT and whatever libs are around...which no one appreciates I don't use... And good as their OpenGL is, its not 100% compliant and has performance issues in some situations. I will only do OpenGL on fully compliant systems otherwise I just focus on getting the best out of the systems, ie OpenGLES2

It does seem everytime I post on those forums, there's a combination of why do you want to do that, and no, you need to do this, and some noob comments. But hey, thats why I'm here

DispmanX does not work on Pi4, that much I have worked out some time ago, its now intended to be only for X11 or other display systems, I'm not sure it even works now? The issue mainly is that depending on what you want to do, and what system yo have you need to use different drivers.. but its not documented at all well. X11 on any version, needs mesa libs... DispmanX needs the onboard static libs and Pi4 only runs X11 (at the moment), so the onboard libs it has are useless. Also you need to set the raspi-config to default libs for OpenGLES, or KMS libs for OpenGL/x11 on rasp.
And on Pi, use the KMS libs, but use Mesa and either OpenGLES or openGL....

yeah... not confusing at all.