done with handling for gamepad's face buttons; next, handle r2 and l2 buttons

shell/glfw-gamepad.sml

@@ -5,7 +5,7 @@ struct
   fun isInDeadZone (x, y) =
     x < 0.1 andalso x > ~0.1 andalso y < 0.1 andalso y > ~0.1
 
-  (* todo: query L2 and R2, and handle them *)
+  (* todo: also query L2 and R2, and handle them *)
   fun axisToDir (x, y) =
     if isInDeadZone (x, y) then CENTRE
     else if abs x > abs y then if x > 0.0 then RIGHT else LEFT
@@ -22,10 +22,24 @@ struct
     orelse Input.getGamepadState 12 <> 0 orelse Input.getGamepadState 13 <> 0
     orelse Input.getGamepadState 14 <> 0 orelse Input.getGamepadState 15 <> 0
 
-  local open InputMsg
+  local
-  in
+    val state =
+      { crossPressed = ref false
+      , circlePressed = ref false
+      , squarePressed = ref false
+      , trianglePressed = ref false
+      , r1Pressed = ref false
+      , l1Pressed = ref false
+      }
+
+    open InputMsg
+
     fun handleTrianglePressed (x, y) =
+      if !(#trianglePressed state) then
+        ()
+      else
         let
+          val () = #trianglePressed state := true
           val chr =
             case axisToDir (x, y) of
               CENTRE => #"a"
@@ -40,7 +54,11 @@ struct
         end
 
     fun handleCirclePressed (x, y) =
+      if !(#circlePressed state) then
+        ()
+      else
         let
+          val () = #circlePressed state := true
           val chr =
             case axisToDir (x, y) of
               CENTRE => #"b"
@@ -55,6 +73,12 @@ struct
         end
 
     fun handleCrossPressed (x, y) =
+      if !(#crossPressed state) then
+        ()
+      else
+        let
+          val () = #crossPressed state := true
+        in
           case axisToDir (x, y) of
             CENTRE => InputMailbox.append (CHAR_EVENT #"c")
           | UP => InputMailbox.append (CHAR_EVENT #"g")
@@ -65,8 +89,15 @@ struct
           | R2 =>
               (* todo: either shift or enter *)
               raise Fail "glfw-gamepad.sml: 77\n"
+        end
 
     fun handleSquarePressed (x, y) =
+      if !(#squarePressed state) then
+        ()
+      else
+        let
+          val () = #squarePressed state := true
+        in
           case axisToDir (x, y) of
             CENTRE => InputMailbox.append (CHAR_EVENT #"d")
           | UP => InputMailbox.append (CHAR_EVENT #"h")
@@ -78,39 +109,57 @@ struct
               (* todo: either shift or enter *)
               raise Fail "glfw-gamepad.sml: 87\n"
         end
-
+  in
     fun handleIfJoystickIsPresent () =
       let
         open InputMsg
 
+        (* query possible events for information *)
         val xAxis = Input.getLeftJoystickXAxisState ()
         val yAxis = Input.getLeftJoystickYAxisState ()
 
-      val crossPrressed = Input.isCrossButtonPressed ()
+        val crossPressed = Input.isCrossButtonPressed ()
         val circlePressed = Input.isCircleButtonPressed ()
         val squarePressed = Input.isSquareButtonPressed ()
         val trianglePressed = Input.isTriangleButtonPressed ()
 
         val r1Pressed = Input.isR1ButtonPressed ()
         val l1Pressed = Input.isL1ButtonPressed ()
-    in
+
-      if crossPrressed <> 0 then
+        (* handle button events *)
-        (* pressing two buttons at the same time is a no-op *)
+        val () =
-        if
+          if crossPressed = 0 then #crossPressed state := false
-          circlePressed <> 0 orelse squarePressed <> 0
+          else if !(#crossPressed state) then ()
-          orelse trianglePressed <> 0 orelse r1Pressed <> 0
-          orelse l1Pressed <> 0
-        then ()
           else handleCrossPressed (xAxis, yAxis)
-      else if circlePressed <> 0 then
+
-        if
+        val () =
-          squarePressed <> 0 orelse trianglePressed <> 0 orelse r1Pressed <> 0
+          if circlePressed = 0 then #circlePressed state := false
-          orelse l1Pressed <> 0
+          else if !(#circlePressed state) then ()
-        then ()
           else handleCirclePressed (xAxis, yAxis)
-      else
+
+        val () =
+          if squarePressed = 0 then #squarePressed state := false
+          else if !(#squarePressed state) then ()
+          else handleSquarePressed (xAxis, yAxis)
+
+        val () =
+          if trianglePressed = 0 then #trianglePressed state := false
+          else if !(#trianglePressed state) then ()
+          else handleTrianglePressed (xAxis, yAxis)
+
+        val () =
+          if r1Pressed = 0 then #r1Pressed state := false
+          else if !(#r1Pressed state) then ()
+          else InputMailbox.append (CHAR_EVENT #" ")
+
+        val () =
+          if l1Pressed = 0 then #l1Pressed state := false
+          else if !(#l1Pressed state) then ()
+          else InputMailbox.append KEY_BACKSPACE
+      in
         ()
       end
+  end
 
   fun query () =
     if getGamepadState () then handleIfJoystickIsPresent ()