a little refactoring

functional-core/app-update.sml

@@ -137,79 +137,81 @@ struct
     | SECOND {x1, y1, x2, y2} =>
         getSecondTriangleStageVector (x1, y1, x2, y2, drawVec)
 
-  fun update (model, mouseX, mouseY, inputMsg) =
-    let
-      open DrawMessage
-      open InputMessage
-    in
+  local
+    open DrawMessage
+    open InputMessage
+
+    fun mouseMoveOrRelease (model, mouseX, mouseY) =
+      let
+        val (drawVec, _, _) = getClickPos
+          (#clickPoints model, mouseX, mouseY, 1.0, 0.0, 0.0)
+        val drawVec = getTriangleStageVector (model, drawVec)
+        val drawMsg = DRAW_BUTTON drawVec
+      in
+        (model, drawMsg, mouseX, mouseY)
+      end
+
+    fun mouseLeftClick (model, mouseX, mouseY) =
+      let
+        val (buttonVec, hpos, vpos) = getClickPos
+          (#clickPoints model, mouseX, mouseY, 0.0, 0.0, 1.0)
+      in
+        if Vector.length buttonVec > 0 then
+          case #triangleStage model of
+            NO_TRIANGLE =>
+              let
+                val drawVec = getTriangleStageVector (model, buttonVec)
+                val drawMsg = DRAW_BUTTON drawVec
+
+                val newTriangleStage = FIRST {x1 = hpos, y1 = vpos}
+                val model = AppType.withTriangleStage (model, newTriangleStage)
+              in
+                (model, drawMsg, mouseX, mouseY)
+              end
+          | FIRST {x1, y1} =>
+              let
+                val drawVec = getFirstTriangleStageVector (x1, y1, buttonVec)
+                val drawMsg = DRAW_BUTTON drawVec
+
+                val newTriangleStage = SECOND
+                  {x1 = x1, y1 = y1, x2 = hpos, y2 = vpos}
+                val model = AppType.withTriangleStage (model, newTriangleStage)
+              in
+                (model, drawMsg, mouseX, mouseY)
+              end
+          | SECOND {x1, y1, x2, y2} =>
+              let
+                val model = AppType.addTriangleAndResetStage
+                  (model, x1, y1, x2, y2, hpos, vpos)
+
+                val drawVec = getTrianglesVector model
+                val drawMsg = DRAW_TRIANGLES_AND_RESET_BUTTONS drawVec
+              in
+                (model, drawMsg, mouseX, mouseY)
+              end
+        else
+          (model, NO_DRAW, mouseX, mouseY)
+      end
+
+    fun resizeWindow (model, mouseX, mouseY, width, height) =
+      let
+        val low = Int.min (width, height)
+        val high = Int.min (width, height)
+
+        val difference = high - low
+        val offset = difference div 2
+        val _ = print "resized window \n"
+      in
+        (model, NO_DRAW, mouseX, mouseY)
+      end
+  in
+    fun update (model, mouseX, mouseY, inputMsg) =
       case inputMsg of
         MOUSE_MOVE {x = mouseX, y = mouseY} =>
-          let
-            val (drawVec, _, _) = getClickPos
-              (#clickPoints model, mouseX, mouseY, 1.0, 0.0, 0.0)
-            val drawVec = getTriangleStageVector (model, drawVec)
-            val drawMsg = DRAW_BUTTON drawVec
-          in
-            (model, drawMsg, mouseX, mouseY)
-          end
-      | MOUSE_LEFT_RELEASE =>
-          let
-            val (drawVec, _, _) = getClickPos
-              (#clickPoints model, mouseX, mouseY, 1.0, 0.0, 0.0)
-            val drawVec = getTriangleStageVector (model, drawVec)
-            val drawMsg = DRAW_BUTTON drawVec
-          in
-            (model, drawMsg, mouseX, mouseY)
-          end
-      | MOUSE_LEFT_CLICK =>
-          let
-            val (buttonVec, hpos, vpos) = getClickPos
-              (#clickPoints model, mouseX, mouseY, 0.0, 0.0, 1.0)
-          in
-            if Vector.length buttonVec > 0 then
-              (case #triangleStage model of
-                 NO_TRIANGLE =>
-                   let
-                     val drawVec = getTriangleStageVector (model, buttonVec)
-                     val drawMsg = DRAW_BUTTON drawVec
-
-                     val newTriangleStage = FIRST {x1 = hpos, y1 = vpos}
-                     val model =
-                       AppType.withTriangleStage (model, newTriangleStage)
-                   in
-                     (model, drawMsg, mouseX, mouseY)
-                   end
-               | FIRST {x1, y1} =>
-                   let
-                     val drawVec =
-                       getFirstTriangleStageVector (x1, y1, buttonVec)
-                     val drawMsg = DRAW_BUTTON drawVec
-
-                     val newTriangleStage = SECOND
-                       {x1 = x1, y1 = y1, x2 = hpos, y2 = vpos}
-                     val model =
-                       AppType.withTriangleStage (model, newTriangleStage)
-                   in
-                     (model, drawMsg, mouseX, mouseY)
-                   end
-               | SECOND {x1, y1, x2, y2} =>
-                   let
-                     val model = AppType.addTriangleAndResetStage
-                       (model, x1, y1, x2, y2, hpos, vpos)
-
-                     val drawVec = getTrianglesVector model
-                     val drawMsg = DRAW_TRIANGLES_AND_RESET_BUTTONS drawVec
-                   in
-                     (model, drawMsg, mouseX, mouseY)
-                   end)
-            else
-              (model, NO_DRAW, mouseX, mouseY)
-          end
+          mouseMoveOrRelease (model, mouseX, mouseY)
+      | MOUSE_LEFT_RELEASE => mouseMoveOrRelease (model, mouseX, mouseY)
+      | MOUSE_LEFT_CLICK => mouseLeftClick (model, mouseX, mouseY)
       | RESIZE_WINDOW {width, height} =>
-          let
-            val _ = print "resized window \n"
-          in
-            (model, NO_DRAW, mouseX, mouseY)
-          end
-    end
+          resizeWindow (model, mouseX, mouseY, width, height)
+  end
 end

imperative-shell/app-draw.sml

@@ -94,18 +94,21 @@ struct
     end
 
   fun drawButton (buttonDrawObject: draw_object, buttonDrawLength) =
-    let
-      val {vertexBuffer, program, ...} = buttonDrawObject
-      val _ = Gles3.bindBuffer vertexBuffer
-      val _ = Gles3.vertexAttribPointer (0, 2, 5, 0)
-      val _ = Gles3.enableVertexAttribArray 0
-      val _ = Gles3.vertexAttribPointer (1, 3, 5, 8)
-      val _ = Gles3.enableVertexAttribArray 1
-      val _ = Gles3.useProgram program
-      val _ = Gles3.drawArrays (Gles3.TRIANGLES (), 0, buttonDrawLength)
-    in
+    if buttonDrawLength > 0 then
+      let
+        val {vertexBuffer, program, ...} = buttonDrawObject
+        val _ = Gles3.bindBuffer vertexBuffer
+        val _ = Gles3.vertexAttribPointer (0, 2, 5, 0)
+        val _ = Gles3.enableVertexAttribArray 0
+        val _ = Gles3.vertexAttribPointer (1, 3, 5, 8)
+        val _ = Gles3.enableVertexAttribArray 1
+        val _ = Gles3.useProgram program
+        val _ = Gles3.drawArrays (Gles3.TRIANGLES (), 0, buttonDrawLength)
+      in
+        ()
+      end
+    else
       ()
-    end
 
   fun initTriangles () =
     let
@@ -114,12 +117,7 @@ struct
       val {vertexBuffer, program, ...} = triangleDrawObject
 
       val _ = Gles3.bindBuffer vertexBuffer
-      val _ =
-        Gles3.bufferData
-          ( #[]
-          , 0
-          , Gles3.STATIC_DRAW ()
-          )
+      val _ = Gles3.bufferData (#[], 0, Gles3.STATIC_DRAW ())
       val _ = Gles3.vertexAttribPointer (0, 2, 2, 0)
       val _ = Gles3.enableVertexAttribArray 0
     in
@@ -136,15 +134,17 @@ struct
     end
 
   fun drawTriangles (triangleDrawObject: draw_object, triangleDrawLength) =
-    let
-      val {vertexBuffer, program, ...} = triangleDrawObject
-      val _ = Gles3.bindBuffer vertexBuffer
-      val _ = Gles3.vertexAttribPointer (0, 2, 2, 0)
-      val _ = Gles3.enableVertexAttribArray 0
-      val _ = Gles3.useProgram program
-      val _ = Gles3.drawArrays
-        (Gles3.TRIANGLES (), 0, triangleDrawLength)
-    in
+    if triangleDrawLength > 0 then
+      let
+        val {vertexBuffer, program, ...} = triangleDrawObject
+        val _ = Gles3.bindBuffer vertexBuffer
+        val _ = Gles3.vertexAttribPointer (0, 2, 2, 0)
+        val _ = Gles3.enableVertexAttribArray 0
+        val _ = Gles3.useProgram program
+        val _ = Gles3.drawArrays (Gles3.TRIANGLES (), 0, triangleDrawLength)
+      in
+        ()
+      end
+    else
       ()
-    end
 end