partially done coding key remapping functionality (what works: GLFW key code -> CoreKey.key_code, acting on CoreKey.key_code every frame; todo: load from config file on start up, have screen where we can remap keys, and save to config while when key mappings are changed)

shell/glfw-key-map.sml

@@ -1,7 +1,5 @@
 structure GlfwKeyMap =
 struct
-  open CoreKey
-
   structure KeyMap =
     MakeGapMap
       (struct
@@ -15,14 +13,9 @@ struct
          val maxNodeSize = 1024
        end)
 
-  val map = ref KeyMap.empty
-
-  fun codeFromKey (key: int) =
-    KeyMap.get (key, !map)
-
   fun helpInitKeyMap (pos, pairs, acc) =
     if pos = Vector.length pairs then
-      map := acc
+      acc
     else
       let
         val (code, key) = Vector.sub (pairs, pos)
@@ -33,6 +26,8 @@ struct
 
   fun initKeyMap () =
     let
+      open CoreKey
+
       (* vector of (glfw_key_code, Core.key_code) tuples. *)
       val pairs =
        #[ (32, KEY_SPACE)
@@ -157,6 +152,10 @@ struct
         , (348, KEY_MENU)
         ]
     in
-      KeyMap.empty
+      helpInitKeyMap (0, pairs, KeyMap.empty)
     end
+
+  val map = initKeyMap ()
+
+  fun codeFromKey (key: int) = KeyMap.get (key, map)
 end

shell/input-state.sml

@@ -1,5 +1,14 @@
 structure InputState =
 struct
+  val keyMappings = ref
+    { left = CoreKey.KEY_S
+    , right = CoreKey.KEY_F
+    , down = CoreKey.KEY_D
+    , up = CoreKey.KEY_E
+    , attack = CoreKey.KEY_J
+    , jump = CoreKey.KEY_K
+    }
+
   (* global state detecting button inputs *)
   val state =
     { leftHeld = ref false
@@ -19,6 +28,30 @@ struct
     , attackHeld = !(#attackHeld state)
     }
 
+  fun actionToBool action = action = Input.PRESS
+
+  fun handleKey (key, action) =
+    case GlfwKeyMap.codeFromKey key of
+      SOME code =>
+        let
+          val {left, right, down, up, attack, jump} = !keyMappings
+          val action = actionToBool action
+        in
+          if code = left then #leftHeld state := action
+          else if code = up then #upHeld state := action
+          else if code = right then #rightHeld state := action
+          else if code = down then #downHeld state := action
+          else if code = attack then #attackHeld state := action
+          else if code = jump then #upHeld state := action
+          else ()
+        end
+    | NONE => ()
+
+  fun keyCallback (key, scancode, action, mods) =
+    let open Input
+    in if mods = 0 then handleKey (key, action) else ()
+    end
+
   fun getWidth () =
     !(#width state)
 
@@ -28,37 +61,6 @@ struct
   fun sizeCallback (width, height) =
     (#width state := width; #height state := height)
 
-  open Input
-
-  fun handleKey (key, action) =
-    if key = KEY_K then
-      if action = PRESS then (#upHeld state) := true
-      else if action = RELEASE then (#upHeld state) := false
-      else ()
-    else if key = KEY_D then
-      if action = PRESS then (#downHeld state) := true
-      else if action = RELEASE then (#downHeld state) := false
-      else ()
-    else if key = KEY_S then
-      if action = PRESS then (#leftHeld state) := true
-      else if action = RELEASE then (#leftHeld state) := false
-      else ()
-    else if key = KEY_F then
-      if action = PRESS then (#rightHeld state) := true
-      else if action = RELEASE then (#rightHeld state) := false
-      else ()
-    else if key = KEY_J then
-      if action = PRESS then (#attackHeld state) := true
-      else if action = RELEASE then (#attackHeld state) := false
-      else ()
-    else
-      ()
-
-  fun keyCallback (key, scancode, action, mods) =
-    let open Input
-    in if mods = 0 then handleKey (key, action) else ()
-    end
-
   fun registerCallbacks window =
     let
       val () = Input.exportKeyCallback keyCallback