cpdf-source/cpdftexttopdf.ml

98 lines
3.5 KiB
OCaml

open Pdfutil
open Cpdferror
let of_utf8_with_newlines fontpack fontsize t =
let items = ref [] in
let currfont = ref ~-1 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) ->
begin if n <> !currfont then
begin
if !currtext <> [] then items := Cpdftype.Text (rev !currtext)::!items;
currtext := [];
currfont := n;
items := Cpdftype.Font (string_of_int n, 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;
currtext := [];
buf := []
| 13 (*'\r'*) -> ()
| x ->
buf := x::!buf)
codepoints;
(* Do last one *)
let c = rev !buf in
if c <> [] then process_codepoints c;
rev !items
(* Post process, adding Tag / EndTag around paragraphs *)
let rec tag_paragraphs = function
| Cpdftype.NewLine::Cpdftype.NewLine::t ->
Cpdftype.EndTag::Cpdftype.NewLine::Cpdftype.NewLine::Cpdftype.Tag "P"::tag_paragraphs t
| x::t -> x::tag_paragraphs t
| [] -> [Cpdftype.EndTag]
let tag_paragraphs l =
Cpdftype.Tag "P"::tag_paragraphs l
let typeset ~process_struct_tree ?subformat ?title ~papersize ~font ~fontsize text =
let process_struct_tree =
process_struct_tree || subformat = Some Cpdfua.PDFUA1 || subformat = Some Cpdfua.PDFUA2
in
let pdf, title =
match subformat with
| None -> Pdf.empty (), begin match title with Some x -> x | None -> "" end
| Some Cpdfua.PDFUA1 ->
begin match title with
| None -> error "no -title given"
| Some title -> Cpdfua.create_pdfua1 title papersize 1, title
end
| Some Cpdfua.PDFUA2 ->
begin match title with
| None -> error "no -title given"
| Some title -> Cpdfua.create_pdfua2 title papersize 1, title
end
in
let codepoints = setify (Pdftext.codepoints_of_utf8 (Pdfio.string_of_bytes text)) in
let fontpack =
match font with
| Cpdfembed.PreMadeFontPack t -> t
| Cpdfembed.EmbedInfo {fontfile; fontname; encoding} ->
Cpdfembed.embed_truetype pdf ~fontfile ~fontname ~codepoints ~encoding
| 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
flprint (Cpdftype.to_string instrs);
flprint "------------------------------";
let tagged = tag_paragraphs instrs in
flprint (Cpdftype.to_string tagged);
let margin = Pdfunits.points (Pdfpaper.width papersize) (Pdfpaper.unit papersize) /. 15. in
let instrs =
if tagged = [] then [] else
let firstfont = hd (keep (function Cpdftype.Font _ -> true | _ -> false) tagged) in
[firstfont; Cpdftype.BeginDocument] @ instrs
in
let pages = Cpdftype.typeset ~process_struct_tree margin margin margin margin papersize pdf instrs in
let pdf, pageroot = Pdfpage.add_pagetree pages pdf in
Pdfpage.add_root pageroot [] pdf