change arrow keys (left, down, right) to letter keys (s, d, f) and arrow up to letter key 'k', because I think it is more comfortable

ffi/glfw-export.c

@@ -35,6 +35,10 @@ bool windowShouldClose(GLFWwindow *window) {
   glfwWindowShouldClose(window);
 }
 
+void pollEvents() {
+  glfwPollEvents();
+}
+
 void waitEvents() {
   glfwWaitEvents();
 }

ffi/glfw-import.sml

@@ -24,6 +24,7 @@ struct
   val terminate = _import "terminate" public : unit -> unit;
   val makeContextCurrent = _import "makeContextCurrent" public : window -> unit;
   val windowShouldClose = _import "windowShouldClose" public : window -> bool;
+  val pollEvents = _import "pollEvents" public reentrant : unit -> unit;
   val waitEvents = _import "waitEvents" public reentrant : unit -> unit;
   val swapBuffers = _import "swapBuffers" public : window -> unit;
   val setClipboardString = _import "setClipboardString" public : window * string -> unit;

ffi/glfw-input.c

@@ -6,6 +6,14 @@
 int PRESS = GLFW_PRESS;
 int RELEASE = GLFW_RELEASE;
 
+int KEY_S = GLFW_KEY_S;
+int KEY_D = GLFW_KEY_D;
+int KEY_F = GLFW_KEY_F;
+
+int KEY_J = GLFW_KEY_J;
+int KEY_K = GLFW_KEY_K;
+int KEY_L = GLFW_KEY_L;
+
 int ARROW_UP = GLFW_KEY_UP;
 int ARROW_DOWN = GLFW_KEY_DOWN;
 int ARROW_LEFT = GLFW_KEY_LEFT;

ffi/glfw-input.sml

@@ -27,6 +27,30 @@ struct
     _symbol "ARROW_RIGHT" public : ( unit -> int ) * ( int -> unit );
   val ARROW_RIGHT = ARROW_RIGHT ()
 
+  val (KEY_S, _) =
+    _symbol "KEY_S" public : ( unit -> int ) * ( int -> unit );
+  val KEY_S = KEY_S ()
+
+  val (KEY_D, _) =
+    _symbol "KEY_D" public : ( unit -> int ) * ( int -> unit );
+  val KEY_D = KEY_D ()
+
+  val (KEY_F, _) =
+    _symbol "KEY_F" public : ( unit -> int ) * ( int -> unit );
+  val KEY_F = KEY_F ()
+
+  val (KEY_J, _) =
+    _symbol "KEY_J" public : ( unit -> int ) * ( int -> unit );
+  val KEY_J = KEY_J ()
+
+  val (KEY_K, _) =
+    _symbol "KEY_K" public : ( unit -> int ) * ( int -> unit );
+  val KEY_K = KEY_K ()
+
+  val (KEY_L, _) =
+    _symbol "KEY_L" public : ( unit -> int ) * ( int -> unit );
+  val KEY_L = KEY_L ()
+
   val exportKeyCallback =
     _export "mltonKeyCallback" public : (int * int * int * int -> unit) -> unit;
   val setKeyCallback =

shell/gl-draw.sml

@@ -173,7 +173,7 @@ struct
           val _ = draw shellState
 
           val _ = Glfw.swapBuffers window
-          val _ = Glfw.waitEvents ()
+          val _ = Glfw.pollEvents ()
         in
           helpLoop (shellState, game)
         end

shell/input-state.sml

@@ -29,19 +29,19 @@ struct
   open Input
 
   fun handleKey (key, action) =
-    if key = ARROW_UP then
+    if key = KEY_K then
       if action = PRESS then (#upHeld state) := true
       else if action = RELEASE then (#upHeld state) := false
       else ()
-    else if key = ARROW_DOWN then
+    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 = ARROW_LEFT then
+    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 = ARROW_RIGHT then
+    else if key = KEY_F then
       if action = PRESS then (#rightHeld state) := true
       else if action = RELEASE then (#rightHeld state) := false
       else ()