On Wed, 17 Jan 2018 20:26:04 +0000 Peter Flynn <pe...@silmaril.ie> said:
> On 17/01/18 04:47, Carsten Haitzler wrote: > > On Tue, 16 Jan 2018 20:23:02 +0000 Peter Flynn <pe...@silmaril.ie> said: > > > >> This is (seemingly) not an Enlightenment-specific problem; it's just > >> that I was running E when it happened. It appears to happen with XFCE > >> and Cinnamon as well, but if anyone has a clue, please email me off-list. > >> > >> My Dell XPS 15 plugged into a classroom projector only displays the > >> wallpaper background: no icons, no menus, no windows, no bryce, nothing, > >> just the wallpaper. I've used this classroom and projector for years > >> with a lot of machines, this is the first time with this laptop. > >> > >> Details at https://forums.linuxmint.com/viewtopic.php?f=147&t=261862 > > > > That is truly odd. E and XFCE are quite different beasts. E draws its > > wallpaper within the compositor using textures and OpenGL as part of > > redrawing the scene graph (Or maybe using the CPU and shm buffers). What is > > and is not drawn is controlled client-side (not in the Xserver at all). > > What you have is really odd. > > I thought so too. I've been plugging in laptops to overheads since they > were invented, and while projectors are notorious for screwing up on > resolution and aspect ratio (and in not detecting the computer), I've > never seen one that didn't display what it was given. I can only > conclude that somehow the XPS15 is feeding only part of the display down > the wire. I get what you mean. sometimes signal doesn't work (cable too long and your laptop produces a weaker signal than other devices so it isn't received), or sometimes sparkles or errors as some bits are messed up. Yes sizing can be an issue too. But magically displaying your wallpaper and "nothing else" (not even a mouse cursor ... did you try move the mouse off the edge of your screen just in case its extending not cloning? so the cursor goes over there?). > > Are you sure the wallpaper is set by E? > > Yes, positive. I installed a completely different wallpaper in XFCE. You set it with e's wallpaper dialog... right? > > you haven't run other gnome, xfce or > > other tools to set a background pixmap on the root window? E never sets one > > (it just sets bg color to black of the root window). > > I actually don't know or understand how stuff gets onto the display, and > at my time of life there are other things to do :-) hahahahah. > > The forum indicates you have clone mode enabled which means E won't be > > rendering 2 screens of content, and only one. > > I'm not familiar with clone mode. clone is just displaying the exact same screen on 2 outputs. it clones the output. so you have only 1 screen from software's point of view, but the hardware is configured to pump out that 1 screen set of pixels to 2 outputs. that's all clone mode is. > > E's randr (screen setup) stuff > > will just configure 2 outputs to point to the same region on the root > > window, and that's it. The Xserver should configure the scanouts/CRTC's to > > produce a display signal for those pixels for both outputs (LCD panel and > > VGA). If one output produces different content... The logical assumption is > > that one output is NOT pointing to the same region or memory. One idea > > might be that somehow by pure luck it's pointing to the texture memory for > > the bg pixmap and they just happen to line up perfectly... normally if this > > happened i'd expect it to point to random garbage in video memory. > > Interesting analysis, thank you. > > > Does the mouse cursor appear at all on that screen? > > No, nothing but the wallpaper. When I get a chance to go back into that > room again I will remove the wallpaper first, so that E goes back to its > default black background. even if you move the mouse off the screen to the left/right (maybe even above/below)... it doesn't go onto the projector screen? > And find some time to try it on other projectors... ]TBH it's not really different to E or X if it's a projector or not. it may as well be multiple monitors. it's some display on the VGA output (or hdmi, or displayport or dvi or whatever). i certainly use multiple screens all day, every day, so i know it tends to work. :) you have some odd case there... -- ------------- Codito, ergo sum - "I code, therefore I am" -------------- Carsten Haitzler - ras...@rasterman.com ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ enlightenment-users mailing list enlightenment-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-users
