Created attachment 117488 [details]
Attempt to force EGL-based OpenGL compositing
I have an old laptop with ATI RS480 graphics (Radeon Xpress 200M), and I've
been testing KDE Plasma 5.x in KUbuntu 15.04 (currently version 5.3 from the
backports PPA). In all the versions I've tried, OpenGL compositing fails. For
the GLX API, I assume this is because r300 *almost* supports OpenGL 2.1, but
falls short on NPOT texture support.
After some reading
(http://blog.martin-graesslin.com/blog/2011/07/running-kwin-with-opengl-es-2-0/),
I thought I might try the EGL API for OpenGL ES compositing. The GUI wouldn't
let me select EGL, so I forced it using environment variables
(https://community.kde.org/KWin/Environment_Variables) as follows:
KWIN_OPENGL_INTERFACE=egl
KWIN_COMPOSE=O1 (I also tried O2, same result)
Unfortunately, the (truncated) result is:
kwin_core: OpenGL driver recommends XRender based compositing. Falling back to
XRender.
...
kwin_core: Failed to initialize compositing, compositing disabled
>>From what I've read, the r300 should have full OpenGL ES 2.0 support, so is the
driver blocking EGL compositing unnecessarily?
The full log of my attempt to force EGL-based compositing is attached.