Implements generation of monitor section

README.md

@@ -4,8 +4,6 @@ Simple application VM's based on Nix package manager.
 
 Designed primarily for full screen usage without guest additions.
 
-By default uses 3840x2160, so you need to change `appvm/nix/base.nix` monitorSection. Autodetection based on host resolution will be done after.
-
 It's a proof-of-concept, but you can still use it. Also there is a lot of strange things inside, don't afraid of :)
 
 ## Install Nix package manager
@@ -23,9 +21,17 @@ It's a proof-of-concept, but you can still use it. Also there is a lot of strang
 
 (if you clone appvm to home directory)
 
+## Generate resolution
+
+By default uses 3840x2160. If you need to regenerate `appvm/nix/monitor.nix`:
+
+    $ appvm/appvm.sh generate-resolution 1920 1080 > appvm/nix/monitor.nix
+
+Autodetection is a bash-spaghetti, so you need to check results. BTW it's just a X.org monitor section.
+
 ## Create VM
 
-    $ $HOME/appvm/appvm.sh chromium
+    $ $HOME/appvm/appvm.sh build chromium
 
 ## Run application
 

appvm.sh

@@ -19,6 +19,17 @@ if [[ "$1" == "build" && "$2" != "" ]]; then
     chmod +x ${VM_BIN_PATH}
     chmod +x bin/appvm.${2}
     unlink result
+elif [[ "$1" == "generate-resolution" && "$2" != "" && "$3" != "" ]]; then
+    MONITOR_SIZE="$(xrandr | grep mm | head -n 1 | awk '{ print $(NF-2) " " $(NF) }' | sed 's/mm//g')"
+    CVT="$(cvt ${2} ${3} | grep Modeline)"
+    echo "{"
+    echo "  services.xserver.monitorSection = ''"
+    echo "    " ${CVT}
+    echo "    " Option '"PreferredMode"' $(echo ${CVT} | awk '{ print $2 }')
+    echo "    " DisplaySize ${MONITOR_SIZE} # In millimeters
+    echo "  '';"
+    echo "}"
 else
-    echo "Usage: $0 build APPLICATION"
+    echo -e "Usage:\t$0 build APPLICATION"
+    echo -e "or:\t$0 generate-resolution X Y"
 fi

nix/base.nix

@@ -1,4 +1,8 @@
 {
+  imports = [
+    <nix/monitor.nix>
+  ];
+
   system.nixos.stateVersion = "18.03";
 
   services.xserver = {

nix/monitor.nix

@@ -0,0 +1,7 @@
+{
+  services.xserver.monitorSection = ''
+     Modeline "3840x2160_60.00" 712.75 3840 4160 4576 5312 2160 2163 2168 2237 -hsync +vsync
+     Option "PreferredMode" "3840x2160_60.00"
+     DisplaySize 610 350
+  '';
+}