initialise app with a file path, for the functionality of loading different files from the terminal

fcore/app-init.sml

@@ -1,6 +1,7 @@
 signature APP_INIT =
 sig
-  val fromWindowWidthAndHeight: int * int * int * int -> AppType.app_type
+  val fromWindowWidthAndHeight: int * int * int * int * string
+                                -> AppType.app_type
 end
 
 structure AppInit :> APP_INIT =
@@ -16,6 +17,7 @@ struct
     , hFinish
     , canvasWidth
     , canvasHeight
+    , filepath
     ) : app_type =
     let
       val (xClickPoints, yClickPoints) =
@@ -38,7 +40,7 @@ struct
       , showGraph = true
       , arrowX = 0
       , arrowY = 0
-      , openFilePath = ""
+      , openFilePath = filepath
       , r = 0
       , g = 0
       , b = 0
@@ -50,7 +52,7 @@ struct
     end
 
   fun fromWindowWidthAndHeight
-    (windowWidth, windowHeight, canvasWidth, canvasHeight) =
+    (windowWidth, windowHeight, canvasWidth, canvasHeight, filepath) =
     if windowWidth > windowHeight then
       let
         val difference = windowWidth - windowHeight
@@ -66,6 +68,7 @@ struct
           , windowHeight
           , canvasWidth
           , canvasHeight
+          , filepath
           )
       end
     else
@@ -83,6 +86,7 @@ struct
           , hFinish
           , canvasWidth
           , canvasHeight
+          , filepath
           )
       end
 end