feat: update flake.lock, add eye-protection.nix

home/linux/desktop/default.nix

@@ -7,6 +7,7 @@
     ./ssh.nix
     ./wallpaper.nix
     ./xdg.nix
+    ./eye-protection.nix
   ];
 
   home.packages = with pkgs; [

home/linux/desktop/eye-protection.nix

@@ -0,0 +1,41 @@
+{ pkgs, lib, ... }: {
+  # Adjust the color temperature(& brightness) of your screen according to
+  # your surroundings. This may help your eyes hurt less if you are
+  # working in front of the screen at night.
+  #
+  # works fine with both x11 & wayland(hyprland)
+  #
+  # https://gitlab.com/chinstrap/gammastep
+  services.gammastep = {
+    enable = true;
+    # add a gammastep icon in the system tray
+    # has problem with wayland, so disable it
+    tray = false;
+    temperature = {
+      day = 5700;
+      night = 4000;
+    };
+    # https://gitlab.com/chinstrap/gammastep/-/blob/master/gammastep.conf.sample?ref_type=heads
+    settings = {
+      general = {
+        fade = "1";  # gradually apply the new screen temperature/brightness over a couple of seconds.
+        # it is a fake brightness adjustment obtained by manipulating the gamma ramps,
+        # which means that it does not reduce the backlight　of the screen.
+        # Preferably only use it if your normal backlight adjustment is too coarse-grained.
+        brightness-day = "1.0";
+        brightness-night = "0.8";
+        location-provider = "manual";
+
+        # by default, Redshift will use the current elevation of the sun
+        # to determine whether it is daytime, night or in transition (dawn/dusk).
+        # dawn-time = "6:00-8:45";
+        # dusk-time = "18:35-20:15";
+      };
+      manual = {
+        # China, Shenzhen
+        lat = "22.5"; # latitude
+        lon = "114.1"; # longitude
+      };
+    };
+  };
+}