dwarf-fortress.dfhack: make overridable

Currently, it is quite hard to override anything about dfhack (for
example, to add plugins at build time), because

1. it is not exposed anywhere, so you have to do something like
   `dwarf-fortress.override (oldArgs: { dfhack = oldArgs.dfhack.override...; })`
2. the final `dfhack` derivation is a `buildEnv`, so `overrideAttrs`
   doesn't work as expected.

This fixes 1 by adding `dfhack` to the wrapper's `passthru`, and 2 by
moving `twbt.lib` (which is the only reason for the dfhack `buildEnv`)
into the wrapper.

Also adds an `extraPackages` argument to the wrapper, and copies `*.init`
files from the env to the DF directory so that we can easily add a
`dfhack.init`.

With these changes, I was able to build dfhack with the dfplex plugin.

pkgs/games/dwarf-fortress/default.nix

@@ -69,7 +69,7 @@ let
 
           dfhack = callPackage ./dfhack {
             inherit (perlPackages) XMLLibXML XMLLibXSLT;
-            inherit dfVersion twbt;
+            inherit dfVersion;
             stdenv = gccStdenv;
           };
 

pkgs/games/dwarf-fortress/dfhack/default.nix

@@ -13,8 +13,6 @@
 , allegro5
 , libGLU
 , libGL
-, enableTWBT ? true
-, twbt
 , SDL
 , dfVersion
 }:
@@ -115,9 +113,9 @@ let
       exit 1
     fi
   '';
-
-  dfhack = stdenv.mkDerivation {
-    pname = "dfhack-base";
+in
+  stdenv.mkDerivation {
+    pname = "dfhack";
     inherit version;
 
     # Beware of submodules
@@ -166,21 +164,13 @@ let
       ln -s ${ruby}/lib/libruby-*.so $out/hack/libruby.so
     '';
 
-  };
-in
+    passthru = { inherit dfVersion; };
 
-buildEnv {
-  name = "dfhack-${version}";
-
-  passthru = { inherit version dfVersion; };
-
-  paths = [ dfhack ] ++ lib.optionals enableTWBT [ twbt.lib ];
-
-  meta = with lib; {
-    description = "Memory hacking library for Dwarf Fortress and a set of tools that use it";
-    homepage = "https://github.com/DFHack/dfhack/";
-    license = licenses.zlib;
-    platforms = [ "x86_64-linux" "i686-linux" ];
-    maintainers = with maintainers; [ robbinch a1russell abbradar numinit ];
-  };
-}
+    meta = with lib; {
+      description = "Memory hacking library for Dwarf Fortress and a set of tools that use it";
+      homepage = "https://github.com/DFHack/dfhack/";
+      license = licenses.zlib;
+      platforms = [ "x86_64-linux" "i686-linux" ];
+      maintainers = with maintainers; [ robbinch a1russell abbradar numinit ];
+    };
+  }

pkgs/games/dwarf-fortress/wrapper/default.nix

@@ -16,6 +16,7 @@
 , twbt
 , themes ? { }
 , theme ? null
+, extraPackages ? [ ]
   # General config options:
 , enableIntro ? true
 , enableTruetype ? true
@@ -27,7 +28,6 @@
 let
   dfhack_ = dfhack.override {
     inherit enableStoneSense;
-    inherit enableTWBT;
   };
 
   ptheme =
@@ -38,16 +38,16 @@ let
   unBool = b: if b then "YES" else "NO";
 
   # These are in inverse order for first packages to override the next ones.
-  themePkg = lib.optional (theme != null) ptheme;
+  themePkgs = lib.optional (theme != null) ptheme;
   pkgs = lib.optional enableDFHack dfhack_
     ++ lib.optional enableSoundSense soundSense
-    ++ lib.optional enableTWBT twbt.art
+    ++ lib.optionals enableTWBT [ twbt.lib twbt.art ]
     ++ [ dwarf-fortress ];
 
-  fixup = lib.singleton (runCommand "fixup" { } (''
+  config = runCommand "dwarf-fortress-config" { } (''
     mkdir -p $out/data/init
   '' + (if (theme != null) then ''
-    cp ${lib.head themePkg}/data/init/init.txt $out/data/init/init.txt
+    cp ${ptheme}/data/init/init.txt $out/data/init/init.txt
   '' else ''
     cp ${dwarf-fortress}/data/init/init.txt $out/data/init/init.txt
   '') + lib.optionalString enableDFHack ''
@@ -76,21 +76,24 @@ let
   '' + ''
     substituteInPlace $out/data/init/init.txt \
       --replace '[INTRO:YES]' '[INTRO:${unBool enableIntro}]' \
-      --replace '[TRUETYPE:YES]' '[TRUETYPE:${unBool enableTruetype}]' \
+      --replace '[TRUETYPE:24]' '[TRUETYPE:${unBool enableTruetype}]' \
       --replace '[FPS:NO]' '[FPS:${unBool enableFPS}]' \
       --replace '[SOUND:YES]' '[SOUND:${unBool enableSound}]'
-  ''));
+  '');
 
   env = buildEnv {
     name = "dwarf-fortress-env-${dwarf-fortress.dfVersion}";
 
-    paths = fixup ++ themePkg ++ pkgs;
-    pathsToLink = [ "/" "/hack" "/hack/scripts" ];
+    paths = extraPackages ++ [ config ] ++ themePkgs ++ pkgs;
 
     ignoreCollisions = true;
   };
 in
 
+lib.throwIf (enableTWBT && !enableDFHack) "dwarf-fortress: TWBT requires DFHack to be enabled"
+lib.throwIf (enableStoneSense && !enableDFHack) "dwarf-fortress: StoneSense requires DFHack to be enabled"
+lib.throwIf (enableTextMode && enableTWBT) "dwarf-fortress: text mode and TWBT are mutually exclusive"
+
 stdenv.mkDerivation {
   pname = "dwarf-fortress";
   version = dwarf-fortress.dfVersion;
@@ -114,7 +117,10 @@ stdenv.mkDerivation {
   runDFHack = ./dfhack.in;
   runSoundSense = ./soundSense.in;
 
-  passthru = { inherit dwarf-fortress dwarf-therapist; };
+  passthru = {
+    inherit dwarf-fortress dwarf-therapist twbt;
+    dfhack = dfhack_;
+  };
 
   buildCommand = ''
     mkdir -p $out/bin

pkgs/games/dwarf-fortress/wrapper/dfhack.in

@@ -2,8 +2,8 @@
 
 source @dfInit@
 
-for i in dfhack.init-example dfhack-config/default hack/* stonesense/*; do
-  update_path "$i"
+for i in *.init *.init-example dfhack-config/default dfhack-config/init hack/* stonesense/*; do
+  if [ -e "$i" ]; then update_path "$i"; fi
 done
 
 cd "$DF_DIR"