make sure that drawn text is scaled + centered to middle of screen, if window size doesn't match expected ratio of 16:9

fcore/title/title-vec.sml

@@ -1,23 +1,80 @@
 structure TitleVec =
 struct
-  val fontSpace = Constants.fontSpace
+  fun helpGetTextVec
-  val fontSize = Constants.fontSize
+    (x, y, fontSize, fontSpace, windowWidth, windowHeight, pos, str, acc) =
-
-  fun getTextVec (x, y, windowWidth, windowHeight, pos, str, acc) =
     if pos = String.size str then
       Vector.concat acc
     else
       let
         val chr = String.sub (str, pos)
         val chrFun = Vector.sub (CozetteAscii.asciiTable, Char.ord chr)
+
         val hd = chrFun
           (x, y, fontSize, fontSize, windowWidth, windowHeight, 0.0, 0.0, 0.0)
         val acc = hd :: acc
       in
-        getTextVec
+        helpGetTextVec
-          (x + fontSpace, y, windowWidth, windowHeight, pos + 1, str, acc)
+          ( x + fontSpace
+          , y
+          , fontSize
+          , fontSpace
+          , windowWidth
+          , windowHeight
+          , pos + 1
+          , str
+          , acc
+          )
       end
 
+  fun getTextVec (x, y, width, height, str) =
+    let
+      val wratio = width / Constants.worldWidthReal
+      val hratio = height / Constants.worldHeightReal
+    in
+      if wratio < hratio then
+        let
+          val scale = Constants.worldHeightReal * wratio
+          val yOffset =
+            if height > scale then (height - scale) / 2.0
+            else if height < scale then (scale - height) / 2.0
+            else 0.0
+
+          val x = Real32.fromInt x * wratio
+          val y = Real32.fromInt y * wratio + yOffset
+
+          val x = Real32.toInt IEEEReal.TO_NEAREST x
+          val y = Real32.toInt IEEEReal.TO_NEAREST y
+
+          val fontSize = Constants.fontSize * wratio
+
+          val fontSpace = Real32.fromInt Constants.fontSpace * wratio
+          val fontSpace = Real32.toInt IEEEReal.TO_NEAREST fontSpace
+        in
+          helpGetTextVec (x, y, fontSize, fontSpace, width, height, 0, str, [])
+        end
+      else
+        let
+          val scale = Constants.worldWidthReal * hratio
+          val xOffset =
+            if width > scale then (width - scale) / 2.0
+            else if width < scale then (scale - width) / 2.0
+            else 0.0
+
+          val x = Real32.fromInt x * hratio + xOffset
+          val y = Real32.fromInt y * hratio
+
+          val x = Real32.toInt IEEEReal.TO_NEAREST x
+          val y = Real32.toInt IEEEReal.TO_NEAREST y
+
+          val fontSize = Constants.fontSize * hratio
+
+          val fontSpace = Real32.fromInt Constants.fontSpace * hratio
+          val fontSpace = Real32.toInt IEEEReal.TO_NEAREST fontSpace
+        in
+          helpGetTextVec (x, y, fontSize, fontSpace, width, height, 0, str, [])
+        end
+    end
+
   fun getDrawVec (title: TitleType.title_type, width, height) =
-    getTextVec (555, 55, width, height, 0, "hello world", [])
+    getTextVec (0, 0, width, height, "hello world")
 end