done for the moment with text rendering

fcore/buffer.sml

@@ -4,14 +4,12 @@ struct
    * char-wrap is a similar concept to word-wrap, 
    * but it breaks on character in the middle of a word.
    * Todo: 
-   * - Let caller know which termination case was reached.
-   *   Did we reach the end of the string or did we exhaust the screen space?
    * - Possibly add visual horizontal indentation when char-wrap occurs
    *   on an indented line *)
   fun buildTextString
     ( pos, str, acc, posX, posY, startX
     , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-    , r, g, b
+    , r, g, b, tl
     ) =
     if pos < String.size str then
       case String.sub (str, pos) of
@@ -19,18 +17,18 @@ struct
           (* if space, then proceed forward one char 
            * without adding to acc *)
           buildTextString
-            ( pos + 1, str, acc, posX + 25, posY, startX
-            , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-            , r, g, b
-            )
+           ( pos + 1, str, acc, posX + 25, posY, startX
+           , windowWidth, windowHeight, fWindowWidth, fWindowHeight
+           , r, g, b, tl
+           )
       | #"\t" =>
           (* if tab, proceed forward one char,
            * and jump visually forwards three chars *)
           buildTextString
-            ( pos + 1, str, acc, posX + 75, posY, startX
-            , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-            , r, g, b
-            )
+           ( pos + 1, str, acc, posX + 75, posY, startX
+           , windowWidth, windowHeight, fWindowWidth, fWindowHeight
+           , r, g, b, tl
+           )
       | #"\n" =>
           (* if \n, move down vertically, and move to start horizontally
            * assuming we have not exceeded the window's height.
@@ -39,9 +37,10 @@ struct
             buildTextString
               ( pos + 1, str, acc, startX, posY + 25, startX
               , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-              , r, g, b
+              , r, g, b, tl
               )
           else
+            (* return if there is no more vertical space after line break *)
             acc
       | #"\r" =>
           (* same as \n, except we also check if we are in a \r\n pair,
@@ -50,19 +49,20 @@ struct
             if
               pos < String.size str - 1
               andalso String.sub (str, pos + 1) = #"\n"
-            then
+            then 
               buildTextString
                 ( pos + 2, str, acc, startX, posY + 25, startX
                 , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-                , r, g, b
+                , r, g, b, tl
                 )
-            else
+            else 
               buildTextString
                 ( pos + 1, str, acc, startX, posY + 25, startX
                 , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-                , r, g, b
+                , r, g, b, tl
                 )
           else
+            (* return if there is no more vertical space after line break *)
             acc
       | chr =>
           (* for any other character, add it to acc if there is space,
@@ -80,7 +80,7 @@ struct
                 buildTextString
                   ( pos + 1, str, acc, posX + 25, posY, startX
                   , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-                  , r, g, b
+                  , r, g, b, tl
                   )
               end
             else if posY + 25 < windowHeight then
@@ -96,13 +96,51 @@ struct
                 buildTextString
                   ( pos + 1, str, acc, startX + 25, posY + 25, startX
                   , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-                  , r, g, b
+                  , r, g, b, tl
                   )
               end
             else
-              (* if no space horizontally or vertically, just return *)
+              (* return if no space horizontally or vertically *)
               acc
           end
     else
-      acc
+      (* if we reached the end of the string, 
+       * call function to build next string *)
+      continueBuildTextLineGap
+        ( tl, acc, posX, posY, startX
+        , windowWidth, windowHeight, fWindowWidth, fWindowWidth
+        , r, g, b
+        )
+
+  and continueBuildTextLineGap
+    ( strList, acc, posX, posY, startX
+    , windowWidth, windowHeight, fWindowWidth, fWindowHeight
+    , r, g, b
+    ) =
+    case strList of
+      hd :: tl =>
+        buildTextString
+          ( 0, hd, acc, posX, posY, startX
+          , windowWidth, windowHeight, fWindowWidth, fWindowHeight
+          , r, g, b, tl
+          )
+    | [] => acc
+
+  (* todo: 
+   * before calling continueBuildTextLineGap, 
+   * find start position inside LineGap 
+   * to start building from *)
+  fun startBuildTextLineGap (startLine, lineGap: LineGap.t, windowWidth, windowHeight) =
+    let
+      val acc =
+        continueBuildTextLineGap 
+          ( #rightStrings lineGap, [], 10, 10, 10
+          , windowWidth, windowHeight
+          , Real32.fromInt windowWidth
+          , Real32.fromInt windowHeight
+          , 0.0, 0.0, 0.0
+          )
+    in
+      Vector.concat acc
+    end
 end