progress with resizing (triangle and button are always horizontally centred if windowWidth is greater than windowHeight, or windowHeight is greather than windowWidth)

functional-core/app-update.sml

@@ -2,18 +2,72 @@ structure AppUpdate =
 struct
   open AppType
 
+  (* This function adjusts the x position to be centre-aligned to the grid
+   * if windowWidth is greater than height 
+   * (where screen size does not have 1:1 aspect ratio). *)
+  fun calcRelativeX (x, windowWidth, windowHeight, halfWidth) =
+    if windowWidth > windowHeight then
+      let
+        val difference = windowWidth - windowHeight
+        val offset = Real32.fromInt (difference div 2)
+      in
+        x * (halfWidth - offset)
+      end
+    else
+      x * halfWidth
+
+  (* Similar to calcRelativeX, except it centre-aligns the y-point
+   * when windowHeight is greater than windowWidth. *)
+  fun calcRelativeY (y, windowWidth, windowHeight, halfHeight) =
+    if windowHeight > windowWidth then
+      let
+        val difference = windowHeight - windowWidth
+        val offset = Real32.fromInt (difference div 2)
+      in
+        y * (halfHeight - offset)
+      end
+    else
+      y * halfHeight
+
   local
-    fun helpGetTrianglesVector (lst, acc) =
+    fun helpGetTrianglesVector
+      (lst, acc, windowWidth, windowHeight, halfWidth, halfHeight) =
       case lst of
         {x1, y1, x2, y2, x3, y3} :: tl =>
-          let val vec = #[x1, y1, x2, y2, x3, y3]
-          in helpGetTrianglesVector (tl, vec :: acc)
+          let
+            val x1 = calcRelativeX (x1, windowWidth, windowHeight, halfWidth)
+            val x2 = calcRelativeX (x2, windowWidth, windowHeight, halfWidth)
+            val x3 = calcRelativeX (x3, windowWidth, windowHeight, halfWidth)
+
+            val y1 = calcRelativeY (y1, windowWidth, windowHeight, halfHeight)
+            val y2 = calcRelativeY (y2, windowWidth, windowHeight, halfHeight)
+            val y3 = calcRelativeY (y3, windowWidth, windowHeight, halfHeight)
+
+            val vec =
+             #[ x1 / halfWidth
+              , y1 / halfHeight
+              , x2 / halfWidth
+              , y2 / halfHeight
+              , x3 / halfWidth
+              , y3 / halfHeight
+              ]
+            val acc = vec :: acc
+          in
+            helpGetTrianglesVector
+              (tl, acc, windowWidth, windowHeight, halfWidth, halfHeight)
           end
       | [] => acc
   in
     fun getTrianglesVector (app: app_type) =
-      let val lst = helpGetTrianglesVector (#triangles app, [])
-      in Vector.concat lst
+      let
+        val windowWidth = #windowWidth app
+        val windowHeight = #windowHeight app
+        val halfWidth = Real32.fromInt (windowWidth div 2)
+        val halfHeight = Real32.fromInt (windowHeight div 2)
+        val lst = helpGetTrianglesVector
+          (#triangles app, [], windowWidth, windowHeight, halfWidth, halfHeight)
+      in
+        Vector.concat lst
       end
   end
 
@@ -29,8 +83,17 @@ struct
 
   local
     fun getVerticalClickPos
-      (yClickPoints, idx, horizontalPos, mouseX, mouseY, r, g, b, windowWidth,
-      windowHeight) =
+      ( yClickPoints
+      , idx
+      , horizontalPos
+      , mouseX
+      , mouseY
+      , r
+      , g
+      , b
+      , windowWidth
+      , windowHeight
+      ) =
       if idx = Vector.length yClickPoints then
         (#[], 0.0, 0.0)
       else
@@ -39,9 +102,18 @@ struct
         in
           if mouseY < curVerticalPos - 7.0 orelse mouseY > curVerticalPos + 7.0 then
             getVerticalClickPos
-              (yClickPoints, idx + 1, horizontalPos, mouseX, mouseY, r, g, b,
-              windowWidth, windowHeight)
-          else 
+              ( yClickPoints
+              , idx + 1
+              , horizontalPos
+              , mouseX
+              , mouseY
+              , r
+              , g
+              , b
+              , windowWidth
+              , windowHeight
+              )
+          else
             let
               (* calculate normalised device coordinates *)
               val halfWidth = Real32.fromInt (windowWidth div 2)
@@ -115,8 +187,18 @@ struct
             end
         end
 
-    fun getHorizontalClickPos (xClickPoints, yClickPoints, idx, mouseX, mouseY,
-      r, g, b, windowWidth, windowHeight) =
+    fun getHorizontalClickPos
+      ( xClickPoints
+      , yClickPoints
+      , idx
+      , mouseX
+      , mouseY
+      , r
+      , g
+      , b
+      , windowWidth
+      , windowHeight
+      ) =
       if idx = Vector.length xClickPoints then
         (#[], 0.0, 0.0)
       else
@@ -125,12 +207,30 @@ struct
         in
           if mouseX < curPos - 7.0 orelse mouseX > curPos + 7.0 then
             getHorizontalClickPos
-              (xClickPoints, yClickPoints, idx + 1, mouseX, mouseY, r, g, b,
-              windowWidth, windowHeight)
+              ( xClickPoints
+              , yClickPoints
+              , idx + 1
+              , mouseX
+              , mouseY
+              , r
+              , g
+              , b
+              , windowWidth
+              , windowHeight
+              )
           else
             getVerticalClickPos
-              (yClickPoints, 0, curPos, mouseX, mouseY, r, g, b, windowWidth,
-              windowHeight)
+              ( yClickPoints
+              , 0
+              , curPos
+              , mouseX
+              , mouseY
+              , r
+              , g
+              , b
+              , windowWidth
+              , windowHeight
+              )
         end
   in
     (*
@@ -140,8 +240,18 @@ struct
      * an empty vector is returned.
      *)
     fun getClickPos (mouseX, mouseY, r, g, b, model: app_type) =
-      getHorizontalClickPos (#xClickPoints model, #yClickPoints model, 0,
-      mouseX, mouseY, r, g, b, #windowWidth model, #windowHeight model)
+      getHorizontalClickPos
+        ( #xClickPoints model
+        , #yClickPoints model
+        , 0
+        , mouseX
+        , mouseY
+        , r
+        , g
+        , b
+        , #windowWidth model
+        , #windowHeight model
+        )
   end
 
   fun getFirstTriangleStageVector (x1, y1, drawVec, model) =
@@ -152,29 +262,11 @@ struct
       val halfWidth = Real32.fromInt (windowWidth div 2)
       val halfHeight = Real32.fromInt (windowHeight div 2)
 
-      val x1px = 
-        if windowWidth > windowHeight then
-          let
-            val difference = windowWidth - windowHeight
-            val offset = Real32.fromInt (difference div 2)
-          in
-            x1 * (halfWidth - offset)
-          end
-        else 
-          x1 * halfWidth
+      val x1px = calcRelativeX (x1, windowWidth, windowHeight, halfWidth)
       val left = (x1px - 5.0) / halfWidth
       val right = (x1px + 5.0) / halfWidth
 
-      val y1px = 
-        if windowHeight > windowWidth then
-          let
-            val difference = windowHeight - windowWidth
-            val offset = Real32.fromInt (difference div 2)
-          in
-            y1 * (halfHeight - offset)
-          end
-        else
-          y1 * halfHeight
+      val y1px = calcRelativeY (y1, windowWidth, windowHeight, halfHeight)
       val top = (y1px + 5.0) / halfHeight
       val bottom = (y1px - 5.0) / halfHeight
 
@@ -191,21 +283,22 @@ struct
       val halfWidth = Real32.fromInt (windowWidth div 2)
       val halfHeight = Real32.fromInt (windowHeight div 2)
 
-      val x1px = x1 * halfWidth
+
+      val x1px = calcRelativeX (x1, windowWidth, windowHeight, halfWidth)
       val left = (x1px - 5.0) / halfWidth
       val right = (x1px + 5.0) / halfWidth
 
-      val y1px = y1 * halfHeight
+      val y1px = calcRelativeY (y1, windowWidth, windowHeight, halfHeight)
       val top = (y1px + 5.0) / halfHeight
       val bottom = (y1px - 5.0) / halfHeight
 
       val firstVec = ltrbToVertex (left, top, right, bottom, 0.0, 0.0, 1.0)
 
-      val x2px = x2 * halfWidth
+      val x2px = calcRelativeX (x2, windowWidth, windowHeight, halfWidth)
       val left = (x2px - 5.0) / halfWidth
       val right = (x2px + 5.0) / halfWidth
 
-      val y2px = y2 * halfHeight
+      val y2px = calcRelativeY (y2, windowWidth, windowHeight, halfHeight)
       val top = (y2px + 5.0) / halfHeight
       val bottom = (y2px - 5.0) / halfHeight
 
@@ -227,9 +320,8 @@ struct
 
     fun mouseMoveOrRelease (model: app_type, mouseX, mouseY) =
       let
-        val {xClickPoints, yClickPoints, ...} = model 
-        val (drawVec, _, _) = getClickPos
-          (mouseX, mouseY, 1.0, 0.0, 0.0, model)
+        val {xClickPoints, yClickPoints, ...} = model
+        val (drawVec, _, _) = getClickPos (mouseX, mouseY, 1.0, 0.0, 0.0, model)
         val drawVec = getTriangleStageVector (model, drawVec)
         val drawMsg = DRAW_BUTTON drawVec
       in
@@ -238,7 +330,7 @@ struct
 
     fun mouseLeftClick (model: app_type, mouseX, mouseY) =
       let
-        val {xClickPoints, yClickPoints, ...} = model 
+        val {xClickPoints, yClickPoints, ...} = model
         val (buttonVec, hpos, vpos) = getClickPos
           (mouseX, mouseY, 0.0, 0.0, 1.0, model)
       in
@@ -256,8 +348,8 @@ struct
               end
           | FIRST {x1, y1} =>
               let
-                val drawVec = getFirstTriangleStageVector (x1, y1, buttonVec,
-                model)
+                val drawVec =
+                  getFirstTriangleStageVector (x1, y1, buttonVec, model)
                 val drawMsg = DRAW_BUTTON drawVec
 
                 val newTriangleStage = SECOND
@@ -282,28 +374,29 @@ struct
 
     fun resizeWindow (model, mouseX, mouseY, width, height) =
       let
-        val msg = String.concat [
-        "resized window. ",
-        "width = ",
-        Int.toString width,
-        " height = ",
-        Int.toString height,
-        "\n"
-                    ]
+        val msg = String.concat
+          [ "resized window. "
+          , "width = "
+          , Int.toString width
+          , " height = "
+          , Int.toString height
+          , "\n"
+          ]
         val _ = print msg
         val model = AppType.withWindowResize (model, width, height)
+
+        val drawVec = getTrianglesVector model
+        val drawMsg = DRAW_TRIANGLES_AND_RESET_BUTTONS drawVec
       in
-        (model, NO_DRAW, mouseX, mouseY)
+        (model, drawMsg, mouseX, mouseY)
       end
   in
     fun update (model: app_type, mouseX, mouseY, inputMsg) =
       case inputMsg of
         MOUSE_MOVE {x = mouseX, y = mouseY} =>
           mouseMoveOrRelease (model, mouseX, mouseY)
-      | MOUSE_LEFT_RELEASE => 
-          mouseMoveOrRelease (model, mouseX, mouseY)
-      | MOUSE_LEFT_CLICK => 
-          mouseLeftClick (model, mouseX, mouseY)
+      | MOUSE_LEFT_RELEASE => mouseMoveOrRelease (model, mouseX, mouseY)
+      | MOUSE_LEFT_CLICK => mouseLeftClick (model, mouseX, mouseY)
       | RESIZE_WINDOW {width, height} =>
           resizeWindow (model, mouseX, mouseY, width, height)
   end