slight refactoring (move pure parsing functions to functional core in a separate file)

functional-core/app/triangles.sml

@@ -0,0 +1,48 @@
+signature TRIANGLES =
+sig
+  val toVector: AppType.app_type -> Real32.real vector
+end
+
+structure Triangles :> TRIANGLES =
+struct
+  open AppType
+
+  fun helpToVector (lst, acc, windowWidth, windowHeight, halfWidth, halfHeight) =
+    case lst of
+      {x1, y1, x2, y2, x3, y3} :: tl =>
+        let
+          val x1 = Ndc.centreAlignX (x1, windowWidth, windowHeight, halfWidth)
+          val x2 = Ndc.centreAlignX (x2, windowWidth, windowHeight, halfWidth)
+          val x3 = Ndc.centreAlignX (x3, windowWidth, windowHeight, halfWidth)
+
+          val y1 = Ndc.centreAlignY (y1, windowWidth, windowHeight, halfHeight)
+          val y2 = Ndc.centreAlignY (y2, windowWidth, windowHeight, halfHeight)
+          val y3 = Ndc.centreAlignY (y3, windowWidth, windowHeight, halfHeight)
+
+          val vec =
+           #[ x1 / halfWidth
+            , y1 / halfHeight
+            , x2 / halfWidth
+            , y2 / halfHeight
+            , x3 / halfWidth
+            , y3 / halfHeight
+            ]
+          val acc = vec :: acc
+        in
+          helpToVector
+            (tl, acc, windowWidth, windowHeight, halfWidth, halfHeight)
+        end
+    | [] => acc
+
+  fun toVector (app: app_type) =
+    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 = helpToVector
+        (#triangles app, [], windowWidth, windowHeight, halfWidth, halfHeight)
+    in
+      Vector.concat lst
+    end
+end