Fix desktop file and move directories around

packages/nix/polymc/default.nix

@@ -0,0 +1,49 @@
+{ lib, mkDerivation, fetchFromGitHub, cmake, jdk8, jdk, zlib, file, makeWrapper, xorg, libpulseaudio, qtbase, libGL, msaClientID ? "" }:
+
+let
+  libpath = with xorg; lib.makeLibraryPath [ libX11 libXext libXcursor libXrandr libXxf86vm libpulseaudio libGL ];
+in 
+mkDerivation rec {
+  pname = "polymc";
+  version = "1.0.4";
+  src = fetchFromGitHub {
+    owner = "PolyMC";
+    repo = "PolyMC";
+    rev = "${version}";
+    sha256 = "sha256-8aya0KfV9F+i2qBpweWcR9hwyTSQkqn2wHdtkCEeNvk=";
+    fetchSubmodules = true;
+  };
+  nativeBuildInputs = [ cmake file makeWrapper ];
+  buildInputs = [ qtbase jdk8 zlib ];
+
+  patches = [ ./0001-pick-latest-java-first.patch ];
+
+  postPatch = ''
+    # hardcode jdk paths
+    substituteInPlace launcher/java/JavaUtils.cpp \
+      --replace 'scanJavaDir("/usr/lib/jvm")' 'javas.append("${jdk}/lib/openjdk/bin/java")' \
+      --replace 'scanJavaDir("/usr/lib32/jvm")' 'javas.append("${jdk8}/lib/openjdk/bin/java")'
+  '';
+
+  cmakeFlags = [ "-DLauncher_LAYOUT=lin-system" ];
+
+  postInstall = ''
+    # xorg.xrandr needed for LWJGL [2.9.2, 3) https://github.com/LWJGL/lwjgl/issues/128
+    wrapProgram $out/bin/polymc \
+      --set GAME_LIBRARY_PATH /run/opengl-driver/lib:${libpath} \
+      --prefix PATH : ${lib.makeBinPath [ xorg.xrandr ]}
+
+    substituteInPlace $out/share/applications/org.polymc.PolyMC.desktop --replace 'Exec=' 'Exec=${placeholder "out"}/bin/polymc'
+  '';
+
+  meta = with lib; {
+    homepage = "https://github.com/PolyMC/PolyMC";
+    description = "A free, open source launcher for Minecraft";
+    longDescription = ''
+      Allows you to have multiple, separate instances of Minecraft (each with their own mods, texture packs, saves, etc) and helps you manage them and their associated options with a simple interface.
+    '';
+    platforms = platforms.linux;
+    license = licenses.gpl3;
+    maintainers = with maintainers; [ cidkid ];
+  };
+}