From 766933ef75c719748ef3035c1e316be05e080f3d Mon Sep 17 00:00:00 2001
From: John Whitington <john@coherentgraphics.co.uk>
Date: Mon, 22 Nov 2021 14:44:14 -0800
Subject: [PATCH] newlines done

---
 cpdfcommand.ml | 24 ++++++++++++++++++++----
 cpdftype.ml    | 47 ++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 56 insertions(+), 15 deletions(-)

diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index 82e05f1..b80d221 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -2921,15 +2921,31 @@ let of_utf8 (f, fontsize) t =
 let of_pdfdocencoding (f, fontsize) t =
   of_utf8 (f, fontsize) (Pdftext.utf8_of_pdfdocstring t)
 
+let rec of_utf8_with_newlines t =
+  let items = ref [] in
+  let buf = Buffer.create 256 in
+    String.iter
+      (function
+       | '\n' ->
+           let c = Buffer.contents buf in
+             if c <> "" then items := Cpdftype.Text c::!items;
+             items := Cpdftype.NewLine::!items;
+             Buffer.clear buf
+       | x ->
+           Buffer.add_char buf x)
+      t;
+    (* Do last one *)
+    let c = Buffer.contents buf in
+      if c <> "" then items := Text c::!items;
+    rev !items
+
 let typeset text =
   let pdf = Pdf.empty () in
   let f = (Pdftext.StandardFont (Pdftext.Courier, Pdftext.WinAnsiEncoding), 12.) in
   let pages =
     Cpdftype.typeset
-      20. 20. 20. 20. Pdfpaper.a4 pdf
-      [Cpdftype.Font f;
-       Text (of_utf8 f (string_of_bytes text))]
- in
+      20. 20. 20. 20. Pdfpaper.a4 pdf ([Cpdftype.Font f] @ of_utf8_with_newlines (string_of_bytes text))
+  in
     let pdf, pageroot = Pdfpage.add_pagetree pages pdf in
       Pdfpage.add_root pageroot [] pdf
 
diff --git a/cpdftype.ml b/cpdftype.ml
index 6f404c2..d290966 100644
--- a/cpdftype.ml
+++ b/cpdftype.ml
@@ -97,11 +97,31 @@ let font_widths f fontsize =
    on one long page. Words longer than a whole line just fall off the margin.
    Turn text newlines into real newlines. *)
 let width_of_string ws s =
-  fold_left ( +. ) 0. (map (fun s -> ws.(int_of_char s)) (explode s))
+  fold_left ( +. ) 0. (map (fun s -> ws.(int_of_char s)) s) (* FIXME efficiency *)
 
-(* Takes ws, the width table and text, and returns (this_line, needs_newline, remaining_text) *)
-let split_text space_left ws t =
-  (t, false, "")
+(* Split into words on spaces. Find how many words (at least one, to make
+   progress) fit into the available space. We set needs_newline if the next
+   word would overflow. Return (text, needs_newline, remaining_text) *)
+(* FIXME efficiency *)
+let split_text space_left widths t =
+  let chars = ref (explode t) in
+  let words = ref [] in
+  let space_left = ref space_left in
+  let return needs_newline =
+    (implode (flatten (rev !words)), needs_newline, implode !chars)
+  in
+    try
+      while !chars <> [] do
+        let word, rest = cleavewhile (neq ' ') !chars in
+          let w = width_of_string widths word in 
+          if !words = [] || w < !space_left
+            then (words := (word @ [' '])::!words; space_left := !space_left -. w -. width_of_string widths [' '])
+            else raise Exit;
+          chars := if rest = [] then [] else tl rest;
+      done;
+      return false
+    with
+      Exit -> return true
 
 let layout lmargin rmargin papersize i =
   let width =
@@ -116,13 +136,16 @@ let layout lmargin rmargin papersize i =
         s.width_table <- font_widths f fontsize;
         o := Font (f, fontsize) :: !o
     | Text text ->
-        let this_line, needs_newline, remaining_text =
-          split_text (xpos_max -. s.xpos) s.width_table text
-        in
-          o := Text this_line :: !o;
-          s.xpos <- s.xpos +. width_of_string s.width_table this_line;
-          if needs_newline then layout_element NewLine;
-          if remaining_text <> "" then layout_element (Text remaining_text)
+        if text = "" then () else
+          begin
+            let this_line, needs_newline, remaining_text =
+              split_text (xpos_max -. s.xpos) s.width_table text
+            in
+              o := Text this_line :: !o;
+              s.xpos <- s.xpos +. width_of_string s.width_table (explode this_line);
+              if needs_newline then layout_element NewLine;
+              if remaining_text <> "" then layout_element (Text remaining_text)
+          end
     | HGlue {glen} as glue ->
         s.xpos <- s.xpos +. glen;
         o := glue :: !o;
@@ -148,6 +171,8 @@ let make_resources fontobjnums =
    dictionaries. New page only
    creates a page when that page has content. *)
 let typeset lmargin rmargin tmargin bmargin papersize pdf i =
+  print_endline "***input:\n\n";
+  print_endline (to_string i);
   let i = layout lmargin rmargin papersize i in
   print_endline "***after layout:\n\n";
   print_endline (to_string i);