From: spamtrap42@jacob21819.net   
      
   On 2025-12-26, John-Paul Stewart  wrote:   
   > On 2025-12-24 11:15 p.m., Robert Riches wrote:   
   >>   
   >> Does anyone have favorite tutorials or other helps for dealing   
   >> with a high-DPI transition?   
   >>   
   >> I'm Running Devuan (currently Daedalus, hopefully soon Excalibur)   
   >> using plain X and fvwm2, no DE as such with 1920x1200 monitors.   
   >> Just purchased a round of 4k monitors, so I'll be needing to   
   >> adjust xterm fonts, web browser issues, other GUI application   
   >> issues, etc.   
   >   
   > It's been a couple years since made a similar switch.  But as far as I   
   > recall, there's not much to do other than configuring X.  I had to   
   > manually specify the monitors' physical size (in millimetres) in my   
   > xorg.conf so that X could calculate the correct DPI.  Then everything   
   > that's measured in points just kind of fell into place.  (E.g., there   
   > was nothing to be done for LibreOffice, etc.)   
   >   
   > You'll need to switch your window manager to a high-DPI theme (easy with   
   > my choice, xfwm4) since that's all laid out in pixels and you'll have   
   > tiny icons and title bars if you don't change.   
   >   
   > There were very few apps that required any tweaking once X and the   
   > window manager were correctly configured.  The venerable 'gv' is the   
   > only one I can think of that required its own DPI setting (in   
   > ~/.Xresources) rather than using X's own.   
   >   
   >> For web browser issues, I anticipate a lot of fun with websites   
   >> and web apps that use (n)px directives for some of their margins   
   >> and spacing.  If the browser interprets those at face value,   
   >> mixed with other directives in units of text elements and such,   
   >> things could end up looking somewhat different from how the   
   >> developers intended.   
   > That's actually not an issue.  HTML/CSS "px" are NOT device pixels but   
   > units of 1/96 inches.[1]  In other words, HTML/CSS "px" are standardized   
   > at 96 DPI regardless of actual screen resolution.  So if something   
   > specifies 24px it actually means 1/4 inch.  On my 4K displays that ends   
   > up being more like 40 device pixels.  So websites will still work more   
   > or less as expected.   
   >   
   > [1] https://www.w3schools.com/css/css_units.asp   
      
   For anyone finding this thread in the future, there's another   
   trick for Firefox.  In about:config, set   
      
           layout.css.devPixelsPerPx   
      
   to a value greater than 1.  For a 27" 4K monitor, the monitor's   
   device DPI is 163, and a value of 1.6 makes the Firefox UI   
   elements (menu bar, dialogs, etc.) a reasonable size.  YMMV on   
   the value for your situation.   
      
   --   
   Robert Riches   
   spamtrap42@jacob21819.net   
   (Yes, that is one of my email addresses.)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)