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cpdfembed.ml

@@ -1,26 +1,16 @@
 (* Truetype font embedding example *)
 open Pdfutil
 
-(* For the first stage of our embedder, we are only allowing standard encodings, and we don't actually subset.
+(* For the first stage of our embedder, we are only allowing Latin, and we don't actually subset.
   a) Get a list of Unicode codepoints;
   b) See which of them are in the glyph list;
   c) See which of those are in (StdEncoding|MacRomanEncoding|WinAnsiEncoding), and get their codes;
   d) Build a font to do just those;
-  e) We put question marks for any character not in the encoding
+  e) We put missing glyph or similar for any character not in the encoding
   (* FUTURE *)
   1) Actually subset the font to save size
   2) Allow characters not in the standard encodings by builing one or more secondary subsets *)
 
-(* UTF8 Input text *)
-let text = "Noto Sans Black Àë"
-let encoding = Pdftext.MacRomanEncoding
-
-let unicodepoints = Pdftext.codepoints_of_utf8 text
-
-let glyphlist_table = Pdfglyphlist.reverse_glyph_hashes ()
-  
-let encoding_table = Pdftext.reverse_table_of_encoding encoding
-
 (*let () =
   iter
     (fun u ->
@@ -29,117 +19,68 @@ let encoding_table = Pdftext.reverse_table_of_encoding encoding
          Printf.printf "glyph name %s --> " glyphname;
          let pdfcode = Hashtbl.find encoding_table glyphname in
          Printf.printf "pdf code %i\n" pdfcode)
-    unicodepoints
+    unicodepoints *)
 
-let pdfcode_of_unicode_codepoint u =
+let pdfcode_of_unicode_codepoint encoding_table glyphlist_table u =
   try
     Some (Hashtbl.find encoding_table (Hashtbl.find glyphlist_table [u]))
   with
     Not_found -> None
 
-let tj_text =
+let calc_accepted_unicodepoints encoding_table glyphlist_table codepoints =
-  implode
-    (map
-      (fun x -> match pdfcode_of_unicode_codepoint x with Some c -> char_of_int c | None -> '?')
-      unicodepoints)
-
-let calc_accepted_unicodepoints codepoints =
   setify
     (option_map
-       (fun u -> match pdfcode_of_unicode_codepoint u with Some _ -> Some u | None -> None)
+       (fun u -> match pdfcode_of_unicode_codepoint encoding_table glyphlist_table u with Some _ -> Some u | None -> None)
        codepoints)
 
-let accepted_unicodepoints =
-  map
-    (fun u -> (u, pdfcode_of_unicode_codepoint u))
-    (calc_accepted_unicodepoints unicodepoints)
-
-let contents_of_file filename =
-  let ch = open_in_bin filename in
-  let s = really_input_string ch (in_channel_length ch) in
-    close_in ch;
-    s
-
-let fontname = "NotoSans-Black"
-let fontstr = contents_of_file (fontname ^ ".ttf")
-
-let f =
-  Cpdftruetype.parse ~subset:accepted_unicodepoints (Pdfio.bytes_of_string fontstr)
-
-let contents =
-  "1 0 0 1 50 770 cm BT/TT1 36 Tf(" ^ tj_text ^ ")Tj ET"
-
-let widths =
-  Pdf.Array (map (fun x -> Pdf.Integer x) (Array.to_list f.Cpdftruetype.widths))
-
 let fontnum = ref 0
 
 let basename () =
   incr fontnum;
   "AAAAA" ^ string_of_char (char_of_int (!fontnum + 65))
 
-let name_1 = basename ()
-
 let string_of_encoding = function
   | Pdftext.WinAnsiEncoding -> "/WinAnsiEncoding"
   | Pdftext.MacRomanEncoding -> "/MacRomanEncoding"
   | Pdftext.StandardEncoding -> "/StandardEncoding"
   | _ -> failwith "unknown encoding"
 
-let font =
+let embed_truetype pdf ~fontfile ~fontname ~text ~encoding =
-  Pdf.add_dict_entry
+  let unicodepoints = Pdftext.codepoints_of_utf8 text in
-    (Pdfread.parse_single_object
+  let glyphlist_table = Pdfglyphlist.reverse_glyph_hashes () in 
-      (Printf.sprintf "<</Type/Font/Subtype/TrueType/BaseFont/%s+%s/FontDescriptor 6 0 R/Encoding%s/FirstChar %i/LastChar %i>>" name_1 fontname (string_of_encoding encoding) f.Cpdftruetype.firstchar f.Cpdftruetype.lastchar))
+  let encoding_table = Pdftext.reverse_table_of_encoding encoding in
-    "/Widths"
+  let accepted_unicodepoints =
-    widths
+    map
-
+      (fun u -> (u, pdfcode_of_unicode_codepoint encoding_table glyphlist_table u))
-let fontdescriptor =
+      (calc_accepted_unicodepoints encoding_table glyphlist_table unicodepoints)
-  Pdfread.parse_single_object
+  in
-    (Printf.sprintf "<</Type/FontDescriptor/FontName/%s+%s/Flags %i/FontBBox[%i %i %i %i]/ItalicAngle %i/Ascent %i/Descent %i/CapHeight %i/StemV %i/XHeight %i/AvgWidth %i/MaxWidth %i/FontFile2 7 0 R>>"
+  let f =
-    name_1 fontname f.Cpdftruetype.flags f.Cpdftruetype.minx f.Cpdftruetype.miny f.Cpdftruetype.maxx f.Cpdftruetype.maxy f.Cpdftruetype.italicangle
+    Cpdftruetype.parse ~subset:accepted_unicodepoints fontfile
-    f.Cpdftruetype.ascent f.Cpdftruetype.descent f.Cpdftruetype.capheight f.Cpdftruetype.stemv f.Cpdftruetype.xheight f.Cpdftruetype.avgwidth f.Cpdftruetype.maxwidth)
+  in
-
+  let widths =
-let fontfile =
+    Pdf.Array (map (fun x -> Pdf.Integer x) (Array.to_list f.Cpdftruetype.widths))
-  let len = String.length fontstr in
+  in
+  let name_1 = basename () in
+  let fontfile =
+    let len = Pdfio.bytes_size fontfile in
     Pdf.Stream
       {contents =
          (Pdf.Dictionary [("/Length", Pdf.Integer len); ("/Length1", Pdf.Integer len)],
-        Pdf.Got (Pdfio.bytes_of_string fontstr))}
+          Pdf.Got fontfile)}
-*)
-
-(*let objects =
-  [(1, Pdfread.parse_single_object "<</Type/Catalog/Pages 2 0 R>>");
-   (2, Pdfread.parse_single_object "<</Type/Pages/Kids[3 0 R]/Count 1>>");
-   (3, Pdfread.parse_single_object "<</Type/Page/Resources<</Font <</TT1 5 0 R>>>>/Parent 2 0 R/MediaBox[0 0 595 842]/Rotate 0/Contents[4 0 R]>>");
-   (4, Pdf.Stream
-         {contents = (Pdf.Dictionary [("/Length", Pdf.Integer (String.length contents))],
-                     (Pdf.Got (Pdfio.bytes_of_string contents)))});
-   (5, font);
-   (6, fontdescriptor);
-   (7, fontfile);
-  ]
-
-let root = 1
-
-let trailerdict =
-  Pdfread.parse_single_object (Printf.sprintf "<</Root 1 0 R/Size %i>>" (length objects + 1))
-
-let pdf =
-  let pdf =
-   {Pdf.major = 2;
-    Pdf.minor = 0;
-    Pdf.root = root;
-    Pdf.objects =
-      {Pdf.maxobjnum = 0;
-       Pdf.parse = None;
-       Pdf.pdfobjects = Pdf.pdfobjmap_empty ();
-       Pdf.object_stream_ids = null_hash ()};
-    Pdf.trailerdict = trailerdict;
-    Pdf.was_linearized = false;
-    Pdf.saved_encryption = None}
   in
-    iter (Pdf.addobj_given_num pdf) objects;
+  let fontfile_num = Pdf.addobj pdf fontfile in
-    pdf
+  let fontdescriptor =
-
+    Pdfread.parse_single_object
-let () =
+      (Printf.sprintf "<</Type/FontDescriptor/FontName/%s+%s/Flags %i/FontBBox[%i %i %i %i]/ItalicAngle %i/Ascent %i/Descent %i/CapHeight %i/StemV %i/XHeight %i/AvgWidth %i/MaxWidth %i/FontFile2 %i 0 R>>"
-  Pdfwrite.pdf_to_file pdf "subset.pdf"*)
+      name_1 fontname f.Cpdftruetype.flags f.Cpdftruetype.minx f.Cpdftruetype.miny f.Cpdftruetype.maxx f.Cpdftruetype.maxy f.Cpdftruetype.italicangle
+      f.Cpdftruetype.ascent f.Cpdftruetype.descent f.Cpdftruetype.capheight f.Cpdftruetype.stemv f.Cpdftruetype.xheight f.Cpdftruetype.avgwidth f.Cpdftruetype.maxwidth fontfile_num)
+  in
+  let fontdesc_num = Pdf.addobj pdf fontdescriptor in
+  let font =
+    Pdf.add_dict_entry
+      (Pdfread.parse_single_object
+        (Printf.sprintf "<</Type/Font/Subtype/TrueType/BaseFont/%s+%s/FontDescriptor %i 0 R/Encoding%s/FirstChar %i/LastChar %i>>" name_1 fontname fontdesc_num (string_of_encoding encoding) f.Cpdftruetype.firstchar f.Cpdftruetype.lastchar))
+      "/Widths"
+      widths
+  in
+    Pdf.addobj pdf font

cpdfembed.mli

@@ -1 +1,4 @@
-(* *)
+(* Embed a TrueType font for the given set of UTF8 characters in the given
+   encoding, adding it as an object to the PDF, and returning the number of
+   that object. *)
+val embed_truetype : Pdf.t -> fontfile:Pdfio.bytes -> fontname:string -> text:string -> encoding:Pdftext.encoding -> int