From a07cf335efba505c7a770631d693590d261666fb Mon Sep 17 00:00:00 2001
From: Stefan Kempinger <kempinger@ins.jku.at>
Date: Wed, 28 Jan 2026 23:40:35 +0100
Subject: [PATCH] Add libinput and udev calibration rule

Set LIBINPUT_CALIBRATION_MATRIX via a udev rule to "-1 0 1 0 -1 1"
to apply input calibration/inversion for libinput devices
---
 mum/configuration.nix | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mum/configuration.nix b/mum/configuration.nix
index e3afaf9..c833500 100644
--- a/mum/configuration.nix
+++ b/mum/configuration.nix
@@ -86,6 +86,7 @@
     nixd
     wlr-randr
     kmsxx
+    libinput
   ];
   programs.firefox = {
     enable = true;
@@ -118,7 +119,9 @@
     ''}/bin/start-cage-app";
   };
   services.getty.loginProgram = "${pkgs.coreutils}/bin/true";
-
+  services.udev.extraRules = ''
+    ENV{LIBINPUT_CALIBRATION_MATRIX}="-1 0 1 0 -1 1"
+    '';
   # Some programs need SUID wrappers, can be configured further or are
   # started in user sessions.
   # programs.mtr.enable = true;