cpdf-source/cpdftexttopdf.ml

72 lines
2.6 KiB
OCaml

open Pdfutil
(* Return set of unicode characters in this text *)
let used_characters t =
let codepoints = Pdftext.codepoints_of_utf8 t in
setify codepoints
let rec of_utf8_with_newlines fontpack fontsize t =
let items = ref [] in
let currfont = ref 0 in
let codepoints = Pdftext.codepoints_of_utf8 t in
let currtext = ref [] in
let process_codepoints cs =
iter
(fun u ->
match Cpdfembed.get_char fontpack u with
| Some (c, n, f) ->
Printf.printf "Charcode %i, font number %i\n" c n;
begin if n <> !currfont then
begin
if !currtext <> [] then items := Cpdftype.Text (rev !currtext)::!items;
currtext := [];
currfont := n;
items := Cpdftype.Font (f, fontsize)::!items;
currtext := char_of_int c::!currtext;
end
else
currtext := char_of_int c::!currtext
end
| None -> Printf.printf "No glyph for unicode U+%04X in this font\n" u)
cs;
items := Cpdftype.Text (rev !currtext)::!items
in
let buf = ref [] in
List.iter
(function
| 10 (*'\n'*) ->
let c = rev !buf in
if c <> [] then process_codepoints c;
items := Cpdftype.NewLine::!items;
buf := []
| 13 (*'\r'*) -> ()
| x ->
buf := x::!buf)
codepoints;
(* Do last one *)
let c = rev !buf in
if c <> [] then process_codepoints c;
rev !items
let typeset ~papersize ~font ~fontsize text =
let pdf = Pdf.empty () in
let codepoints = used_characters (Pdfio.string_of_bytes text) in
let font, fontpack =
match font with
| Cpdfembed.PreMadeFontPack t -> (hd (fst t), t)
| Cpdfembed.EmbedInfo {fontfile; fontname; encoding} ->
let embedded = Cpdfembed.embed_truetype pdf ~fontfile ~fontname ~codepoints ~encoding in
(hd (fst embedded), embedded)
| Cpdfembed.ExistingNamedFont -> raise (Pdf.PDFError "Can't use existing named font for text-to-PDF")
in
let instrs = of_utf8_with_newlines fontpack fontsize (Pdfio.string_of_bytes text) in
let margin =
Pdfunits.convert
72. (Pdfpaper.unit papersize) (Pdfunits.PdfPoint) (Pdfpaper.width papersize) /. 15.
in
let instrs = [Cpdftype.Font (font, fontsize); Cpdftype.BeginDocument] @ instrs in
Printf.printf "to_string: %s\n" (Cpdftype.to_string instrs);
let pages = Cpdftype.typeset margin margin margin margin papersize pdf instrs in
let pdf, pageroot = Pdfpage.add_pagetree pages pdf in
Pdfpage.add_root pageroot [] pdf