Make rail examples freely rotatable

Makefile

@@ -25,8 +25,10 @@ $(TARGET): src/Main.elm $(SRC) elm-package.json
 clean:
 	rm -f $(TARGET)
 
-INSTALL_SSH=uber:html/p/rails/
-INSTALL_HTTP=http://thorsten-wissmann.de/p/rails/
+#INSTALL_SSH=uber:html/p/rails/
+#INSTALL_HTTP=http://thorsten-wissmann.de/p/rails/
+INSTALL_SSH=i8:web/rails/
+INSTALL_HTTP=https://www8.cs.fau.de/ext/thorsten/rails
 install: $(CSS) rails.html $(IMG) $(wildcard *.js)
 	rsync -Pravdtze ssh $^ $(INSTALL_SSH)
 	@echo $(INSTALL_HTTP)/rails.html

src/Main.elm

@@ -69,7 +69,7 @@ init =
     (smv, initial_cmd) = NuSmvInput.init
   in
   ( { rails =
-        RailPuzzle.init ex.car_positions ex.rail_net
+        RailPuzzle.init ex.car_positions ex.rail_net ex.rotation
         |> RailPuzzle.runCommand initial_cmd
         |> RailPuzzle.runCommand initial_query
     , network_index = initial_network_index
@@ -159,7 +159,7 @@ update msg model =
                       ))
 
             , rails =
-                RailPuzzle.init rail_example.car_positions rail_example.rail_net
+                RailPuzzle.init rail_example.car_positions rail_example.rail_net rail_example.rotation
                 |> RailPuzzle.runCommand (RPCmd.SetQuery new_query)
                 |> RailPuzzle.importHistory new_hist
                 |> RailPuzzle.importOptions (RailPuzzle.exportOptions model.rails)

src/RailExample.elm

@@ -13,6 +13,7 @@ type alias RailExample =
   , rail_net : RailTree (Has RT.Hint ()) (Has RT.Angles ())
   , car_positions : List RT.Path
   , queries : List (List Int) -- 0-indexed query
+  , rotation : Float -- the initial angle
   }
 
 {-| permute the cars on a rail example
@@ -83,6 +84,7 @@ big =
           ]
         ]
   , queries = []
+  , rotation = -40
   }
 
 type alias Shunt =
@@ -137,6 +139,7 @@ one_junction head subs =
       |> List.map ((++) head_prefix)
     )
   , queries = []
+  , rotation = 0
   }
 
 inglenook_422 =
@@ -158,6 +161,7 @@ inglenook_422 =
     , [ RT.Further, RT.Further, RT.Choose 1, RT.Choose 0, RT.Further ]
     ]
   , queries = []
+  , rotation = -20
   }
 
 inglenook_533 =
@@ -181,6 +185,7 @@ inglenook_533 =
     , [ RT.Further, RT.Further, RT.Further, RT.Choose 1, RT.Choose 0, RT.Further, RT.Further ]
     ]
   , queries = []
+  , rotation = -20
   }
 
 merge_sort n =

src/RailPuzzle.elm

@@ -51,6 +51,7 @@ import Debug
 type alias RawModel render_cache =
   { rt : RT.LayoutedRailTree (Has RT.Path ()) ()
   , cars : Array C.Carriage
+  , rotation : Float -- the rotation of the entire network in degrees
   , initial_car_positions : Array RT.Path
   , car_selected : Int
     -- the train to be built, refering to indices in the cars array
@@ -93,8 +94,11 @@ type alias Options = -- Some gui options
 cmd : RPCmd.Command -> Msg
 cmd = Command
 
-init : List RT.Path -> RailTree (Has RT.Hint ()) (Has RT.Angles ()) -> Model
-init car_positions rail_net =
+{-|
+  The float is an angle [0,360] denoting the rotation of the rail net
+ -}
+init : List RT.Path -> RailTree (Has RT.Hint ()) (Has RT.Angles ()) -> Float -> Model
+init car_positions rail_net rotation =
   let
     new_car idx =
       let f = C.defaultFlags in
@@ -105,7 +109,7 @@ init car_positions rail_net =
         }
     layouted_rail_net =
       rail_net
-      |> RT.layoutRailTree
+      |> RT.layoutRailTreeAt  (P2D.Angled rotation (P2D.P2D 0.0 0.0))
       |> RT.indexify
       |> RT.map Has.swap identity
     cars = Array.indexedMap new_car <| Array.fromList car_positions
@@ -121,6 +125,7 @@ init car_positions rail_net =
       , show_shunt_labels = False
       , history = RPHistory.init
       , render_cache = ()
+      , rotation = rotation
       }
   in
   fillRenderCache model
@@ -386,7 +391,7 @@ fillRenderCache model =
     root_bumper =
       RT.Junction (Has.unit RT.AutoAngles) [] -- take a simple bumper
       -- layout it at the root but with the reversed angle
-      |> RT.layoutRailTreeAt (P2D.Angled -180 (P2D.P2D 0.0 0.0))
+      |> RT.layoutRailTreeAt (P2D.Angled (model.rotation-180) (P2D.P2D 0.0 0.0))
 
     root_bumper_svg : List (Svg.Svg Msg)
     root_bumper_svg =