From a6d91d28e858400bb44e47212d477da3cf31bb04 Mon Sep 17 00:00:00 2001
From: RealStickman <mrc@frm01.net>
Date: Wed, 31 May 2023 20:39:07 +0200
Subject: [PATCH] Set exact size for 120 dpi and add how to find it

---
 .../per-device/lupusregina/10-monitor.conf      |  2 +-
 arch-config/per-device/lupusregina/README.md    | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch-config/per-device/lupusregina/10-monitor.conf b/arch-config/per-device/lupusregina/10-monitor.conf
index f08012c7..102d08b8 100644
--- a/arch-config/per-device/lupusregina/10-monitor.conf
+++ b/arch-config/per-device/lupusregina/10-monitor.conf
@@ -1,5 +1,5 @@
 Section "Monitor"
     Identifier "DisplayPort-1"
     #DisplaySize 598 336 # In millimeters
-    DisplaySize 554 311 # In millimeters
+    DisplaySize 541 304 # In millimeters
 EndSection
diff --git a/arch-config/per-device/lupusregina/README.md b/arch-config/per-device/lupusregina/README.md
index c55fa031..61a3f784 100644
--- a/arch-config/per-device/lupusregina/README.md
+++ b/arch-config/per-device/lupusregina/README.md
@@ -5,3 +5,20 @@ The following parts are modified:
 - Polybar (.config/polybar/i3config.ini)
 - Xresources (.Xresources)
 - X11 (/etc/X11/xorg.conf.d/ _new files_)
+
+## Calculate Monitor size for desired DPI
+
+To get the exact monitor size xorg wants for a target dpi, execute this command.
+
+```sh
+xrandr --dpi [DPI]
+```
+
+Querying the set dpi now yields the exact monitor size you'd want to set.
+
+```
+$> xdpyinfo | grep -B 2 resolution
+screen #0:
+  dimensions:    2560x1440 pixels (541x304 millimeters)
+  resolution:    120x120 dots per inch
+```