Provide a way to set (or auto-detect) physical screen size (diagonal or DPI). I am proposing this feature due to the fact that different screens have different DPI, which means that the previews shown in kcm cannot match what is actually observed when we look at our monitors. Take it as an example having a laptop with a retina-like screen connected to an external monitor with a low-res "big" screen (let's say, 17" 1024x768). The kcm preview would be absurd and we would have a very hard time adjusting the screens' positions in order to properly extend the desktop between them while making sure the mouse cursor crosses the "shared edge" perfectly in the middle of it. I have also attached an image that further demonstrates the problem. The bluish gradient inside the LVDS1 screen is an example of the real screen size relatively to the VGA1 screen. The objective of the feature would be to scale the LVDS1 screen preview down to the bluish gradient size. In order to do so, kscreen could either autodetect DPI/diagonal or have a way to input DPI/diagonal, or both. I believe this would be a useful feature for many multi-screen users. I've never seen anything like it on other display configuration utilities, so it would continue KDE's uniqueness and customizability. Reproducible: Always Steps to Reproduce: 1. Open kscreen Actual Results: kscreen is shown, but I see that the ratio of the areas of the screens is not the same as the ratio of the areas of my physical monitors' screens. I also don't see any option to scale the screens according to their DPI/diagonal sizes. Expected Results: kscreen is shown, and I see that the ratio of the areas of the screens is the same as the ratio of the areas of my physical monitors' screens.
this is still valid for 5.21 i think the physical size is quite easy to get but I have no idea how to implement it cat /var/log/Xorg.0.log |grep -i size [ 2578.124] (II) modeset(0): Max Image Size [cm]: horiz.: 37 vert.: 23 [ 2578.124] (II) modeset(0): clock: 592.5 MHz Image Size: 366 x 229 mm [ 2578.124] (II) modeset(0): clock: 474.0 MHz Image Size: 366 x 229 mm [ 2578.155] (II) modeset(0): Max Image Size [cm]: horiz.: 60 vert.: 34 [ 2578.155] (II) modeset(0): #0: hsize: 1280 vsize 1024 refresh: 60 vid: 32897 [ 2578.155] (II) modeset(0): #1: hsize: 1440 vsize 900 refresh: 60 vid: 149 [ 2578.155] (II) modeset(0): #2: hsize: 1680 vsize 1050 refresh: 60 vid: 179 [ 2578.155] (II) modeset(0): #3: hsize: 1920 vsize 1080 refresh: 60 vid: 49361 [ 2578.155] (II) modeset(0): #4: hsize: 1920 vsize 1200 refresh: 60 vid: 209 [ 2578.155] (II) modeset(0): clock: 241.5 MHz Image Size: 597 x 336 mm [ 2578.155] (II) modeset(0): clock: 74.2 MHz Image Size: 597 x 336 mm [ 2578.155] (II) modeset(0): clock: 27.0 MHz Image Size: 597 x 336 mm [ 2578.155] (II) modeset(0): clock: 27.0 MHz Image Size: 597 x 336 mm [ 2579.985] (II) NVIDIA(G0): Virtual screen size determined to be 640 x 480 [ 2580.279] (II) modeset(0): Setting screen physical size to 1693 x 635
We already do some autodetection on Wayland, to set the scale to 200% when appropriate. We could do more though.
>I am proposing this feature due to the fact that different screens have different DPI, which means that the previews shown in kcm cannot match what is actually observed when we look at our monitors. On wayland we show things in logical size in order to approximately do this.