on different testcomputers i manage to use --transform to avoid stretching a 4:3 image to a 16:9 screen.. it properly moves the image to the left edge and displays a black bar on the right side. --set 'scaling mode' Center is not working in these cases because the option is not recognized on external screens .. this only works on laptops (embedded displays for me) therefore i use --transform! i testet it on a new pc in our school with an intel skylake cpu and it made the screen flash like crazy once and most of the time it properly scales plasma and the area where i can move my mouse but i can still maximize all my windows to the whole sceenarea it looks really weird - everything is contained to the correct rectangle, i see a black bar on the right sight but windows can cover this area nevertheless... this is the line i am using and i don't think the line is the problem - as i said it works on all the other computers: echo "exec xrandr --output $DISPLAY1 --mode $RESOLUTION --primary $TRANSFORM --output $DISPLAY2 --mode $RESOLUTION --same-as $DISPLAY1 &" where TRANSFORM="--transform 1.3330078125,0,0,0,1,0,0,0,1" for example in order to scale the image proportionally to a 1024x768 image on a full hd screen i tried several other transformations and the result is always the same.
what makes you think that this is a bug in KWin?
good question.. it was just a hunch.. because plasma resized accordingly, the mouse area (where i can move my mouse) did resize too.. but my windows are drawn over the whole screen when maximized - therefore i thought that the windowmanager probably is a good start to search for a reason / bug
Please provide the output of qdbus org.kde.KWin /KWin supportInformation and of xrandr.
If you can provide the information requested in comment #3, please add it.
To further investigate this issue, KDE developers need the information requested in comment #3. If you can provide it, or need help with finding that information, please add a comment.
qdbus org.kde.KWin /KWin supportInformation -------------------------------------------------- KWin-Unterstützungsinformationen: Benutzen Sie die folgenden Informationen, wenn Sie nach Unterstützung fragen, z. B. auf http://forum .kde.org. Sie enthalten Informationen über die momentan laufende Instanz, welche Optionen verwendet werden, welcher OpenGL-Treiber verwendet wird und welche Effekte laufen. Bitte geben Sie die unten stehenden Informationen bei einem Pastebin-Dienst wie http://paste.kde.org ein, anstatt sie direkt in die Hilfediskussionen zu schreiben. ========================== Version ======= KWin version: 5.9.2 Qt Version: 5.7.1 Qt compile version: 5.7.1 XCB compile version: 1.11.1 Operation Mode: X11 only Build Options ============= KWIN_BUILD_DECORATIONS: yes KWIN_BUILD_TABBOX: yes KWIN_BUILD_ACTIVITIES: yes HAVE_INPUT: yes HAVE_DRM: yes HAVE_GBM: yes HAVE_X11_XCB: yes HAVE_EPOXY_GLX: yes HAVE_WAYLAND_EGL: yes X11 === Vendor: The X.Org Foundation Vendor Release: 11804000 Protocol Version/Revision: 11/0 SHAPE: yes; Version: 0x11 RANDR: yes; Version: 0x14 DAMAGE: yes; Version: 0x11 Composite: yes; Version: 0x4 RENDER: yes; Version: 0xb XFIXES: yes; Version: 0x50 SYNC: yes; Version: 0x31 GLX: yes; Version: 0x0 Decoration ========== Plugin: org.kde.breeze Theme: Blur: 0 onAllDesktopsAvailable: false alphaChannelSupported: false closeOnDoubleClickOnMenu: false decorationButtonsLeft: 9 decorationButtonsRight: 3, 4, 5 borderSize: 3 gridUnit: 10 font: Noto Sans,10,-1,5,50,0,0,0,0,0 smallSpacing: 2 largeSpacing: 10 Options ======= focusPolicy: 0 nextFocusPrefersMouse: false clickRaise: true autoRaise: false autoRaiseInterval: 0 delayFocusInterval: 0 shadeHover: false shadeHoverInterval: 250 separateScreenFocus: false placement: 4 focusPolicyIsReasonable: true borderSnapZone: 10 windowSnapZone: 10 centerSnapZone: 0 snapOnlyWhenOverlapping: false rollOverDesktops: true focusStealingPreventionLevel: 1 legacyFullscreenSupport: false operationTitlebarDblClick: 5000 operationMaxButtonLeftClick: 5000 operationMaxButtonMiddleClick: 5015 operationMaxButtonRightClick: 5014 commandActiveTitlebar1: 0 commandActiveTitlebar2: 30 commandActiveTitlebar3: 2 commandInactiveTitlebar1: 4 commandInactiveTitlebar2: 30 commandInactiveTitlebar3: 2 commandWindow1: 7 commandWindow2: 8 commandWindow3: 8 commandWindowWheel: 31 commandAll1: 10 commandAll2: 3 commandAll3: 14 keyCmdAllModKey: 16777251 showGeometryTip: false condensedTitle: false electricBorderMaximize: true electricBorderTiling: true electricBorderCornerRatio: 0.10000000149011612 borderlessMaximizedWindows: false killPingTimeout: 5000 hideUtilityWindowsForInactive: true inactiveTabsSkipTaskbar: false autogroupSimilarWindows: false autogroupInForeground: true compositingMode: 2 useCompositing: false compositingInitialized: false hiddenPreviews: 1 glSmoothScale: 2 xrenderSmoothScale: false maxFpsInterval: 16666666 refreshRate: 0 vBlankTime: 6000000 glStrictBinding: true glStrictBindingFollowsDriver: true glCoreProfile: false glPreferBufferSwap: 97 glPlatformInterface: 1 windowsBlockCompositing: true Screen Edges ============ desktopSwitching: false desktopSwitchingMovingClients: false cursorPushBackDistance: 1x1 timeThreshold: 150 reActivateThreshold: 350 actionTopLeft: 0 actionTop: 0 actionTopRight: 0 actionRight: 0 actionBottomRight: 0 actionBottom: 0 actionBottomLeft: 0 actionLeft: 0 Screens ======= Multi-Head: no Active screen follows mouse: no Number of Screens: 2 Screen 0: --------- Name: HDMI-1 Geometry: 0,0,1024x768 Refresh Rate: 75.0286 Screen 1: --------- Name: DP-2 Geometry: 0,0,1024x768 Refresh Rate: 60.0038 Compositing =========== Compositing is not active xrandr ----------------------------------------- Screen 0: minimum 320 x 200, current 1024 x 768, maximum 8192 x 8192 DP-1 disconnected (normal left inverted right x axis y axis) HDMI-1 connected primary 1024x768+0+0 (normal left inverted right x axis y axis) 521mm x 293mm 1920x1080 60.00 + 1680x1050 59.88 1280x1024 75.02 60.02 1440x900 59.90 1280x960 60.00 1280x720 60.00 1024x768 75.03* 70.07 60.00 832x624 74.55 800x600 72.19 75.00 60.32 56.25 640x480 75.00 72.81 66.67 59.94 720x400 70.08 DP-2 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm 1024x768 60.00* 800x600 60.32 56.25 848x480 60.00 640x480 59.94 HDMI-2 disconnected (normal left inverted right x axis y axis) DP-3 disconnected (normal left inverted right x axis y axis) HDMI-3 disconnected (normal left inverted right x axis y axis)
According to the output KWin gets the right resolution. What KWin detects is what xrandr reports. The maximize area is based on the information xrandr provides. We cannot do much when the information provided is wrong. What I find strange in the output is that it contains two overlapping displays which are not cloned. I don't think it's relevant, but it's something which could cause issues.