cpdf-source/cpdfdraw.ml

269 lines
9.2 KiB
OCaml

open Pdfutil
type colspec =
NoCol
| RGB of float * float * float
| Grey of float
| CYMK of float * float * float * float
type image =
JPEG
type drawops =
| Rect of float * float * float * float
| Bezier of float * float * float * float * float * float
| To of float * float
| Line of float * float
| ClosePath
| SetFill of colspec
| SetStroke of colspec
| SetLineThickness of float
| SetLineCap of int
| SetLineJoin of int
| SetMiterLimit of float
| SetDashPattern of float list * float
| Matrix of Pdftransform.transform_matrix
| Push
| Pop
| Fill
| FillEvenOdd
| Stroke
| FillStroke
| FillStrokeEvenOdd
| Clip
| ClipEvenOdd
| FormXObject of float * float * float * float * string * drawops list
| Use of string
| ImageXObject of string * Pdf.pdfobject
| Image of string
| NewPage
| Opacity of float
| SOpacity of float
| Font of Pdftext.standard_font * float
| BT
| ET
| Text of string
| SpecialText of string
| Newline
| Leading of float
| CharSpace of float
| WordSpace of float
| TextScale of float
| RenderMode of int
| Rise of float
| URL of string
| EndURL
(* Per page resources *)
type res =
{images : (string, (string * int)) Hashtbl.t; (* (name, (pdf name, objnum)) *)
extgstates : (string, Pdf.pdfobject) Hashtbl.t; (* pdf name, pdf object *)
fonts : (string, int) Hashtbl.t; (* (pdf name, objnum)) *)
form_xobjects : (string, int) Hashtbl.t; (* (pdf name, objnum)) *)
mutable time : Cpdfstrftime.t;
mutable current_url : string option;
mutable current_font : Pdftext.font;
mutable num : int}
let res =
{images = null_hash ();
extgstates = null_hash ();
fonts = null_hash ();
form_xobjects = null_hash ();
time = Cpdfstrftime.dummy;
current_url = None;
current_font = Pdftext.StandardFont (Pdftext.TimesRoman, Pdftext.WinAnsiEncoding);
num = 0}
let fresh_name s =
res.num <- res.num + 1;
s ^ string_of_int res.num
(* At end of page, we keep things for which we have indirects - we may use them on another page. *)
let reset_state () =
Hashtbl.clear res.extgstates
let process_specials pdf endpage filename bates batespad num page s =
let pairs =
Cpdfaddtext.replace_pairs pdf endpage None filename bates batespad num page
in
Cpdfaddtext.process_text res.time s pairs
let rec ops_of_drawop pdf endpage filename bates batespad num page = function
| Push -> [Pdfops.Op_q]
| Pop -> [Pdfops.Op_Q]
| Matrix m -> [Pdfops.Op_cm m]
| Rect (x, y, w, h) -> [Pdfops.Op_re (x, y, w, h)]
| Bezier (a, b, c, d, e, f) -> [Pdfops.Op_c (a, b, c, d, e, f)]
| To (x, y) -> [Pdfops.Op_m (x, y)]
| Line (x, y) -> [Pdfops.Op_l (x, y)]
| SetFill x ->
begin match x with
| RGB (r, g, b) -> [Op_rg (r, g, b)]
| Grey g -> [Op_g g]
| CYMK (c, y, m, k) -> [Op_k (c, y, m, k)]
| NoCol -> []
end
| SetStroke x ->
begin match x with
| RGB (r, g, b) -> [Op_RG (r, g, b)]
| Grey g -> [Op_G g]
| CYMK (c, y, m, k) -> [Op_K (c, y, m, k)]
| NoCol -> []
end
| ClosePath
| Fill -> [Pdfops.Op_f]
| FillEvenOdd -> [Pdfops.Op_f']
| Stroke -> [Pdfops.Op_S]
| FillStroke -> [Pdfops.Op_B]
| FillStrokeEvenOdd -> [Pdfops.Op_B']
| Clip -> [Pdfops.Op_W; Pdfops.Op_n]
| ClipEvenOdd -> [Pdfops.Op_W']
| SetLineThickness t -> [Pdfops.Op_w t; Pdfops.Op_n]
| SetLineCap c -> [Pdfops.Op_J c]
| SetLineJoin j -> [Pdfops.Op_j j]
| SetMiterLimit m -> [Pdfops.Op_M m]
| SetDashPattern (x, y) -> [Pdfops.Op_d (x, y)]
| FormXObject (a, b, c, d, n, ops) -> create_form_xobject a b c d pdf endpage filename bates batespad num page n ops; []
| Use n -> [Pdfops.Op_Do n]
| Image s -> [Pdfops.Op_Do (try fst (Hashtbl.find res.images s) with _ -> Cpdferror.error ("Image not found: " ^ s))]
| ImageXObject (s, obj) ->
Hashtbl.add res.images s (fresh_name "/XObj", Pdf.addobj pdf obj);
[]
| NewPage -> Pdfe.log ("NewPage remaining in graphic stream"); assert false
| Opacity v ->
let n = fresh_name "/gs" in
Hashtbl.add res.extgstates n (Pdf.Dictionary [("/ca", Pdf.Real v)]);
[Pdfops.Op_gs n]
| SOpacity v ->
let n = fresh_name "/gs" in
Hashtbl.add res.extgstates n (Pdf.Dictionary [("/CA", Pdf.Real v)]);
[Pdfops.Op_gs n]
| URL s ->
res.current_url <- Some s;
[]
| EndURL ->
res.current_url <- None;
[]
| Font (s, f) ->
let o = Pdftext.write_font pdf (Pdftext.StandardFont (s, Pdftext.WinAnsiEncoding)) in
let n = fresh_name "/F" in
Hashtbl.add res.fonts n o;
res.current_font <- (Pdftext.StandardFont (s, Pdftext.WinAnsiEncoding));
[Pdfops.Op_Tf (n, f)]
| BT -> [Pdfops.Op_BT]
| ET -> [Pdfops.Op_ET]
| Text s ->
let charcodes =
implode (map char_of_int (option_map (Pdftext.charcode_extractor_of_font_real res.current_font) (Pdftext.codepoints_of_utf8 s)))
in
[Pdfops.Op_Tj charcodes]
| SpecialText s ->
let s = process_specials pdf endpage filename bates batespad num page s in
let charcodes =
implode (map char_of_int (option_map (Pdftext.charcode_extractor_of_font_real res.current_font) (Pdftext.codepoints_of_utf8 s)))
in
[Pdfops.Op_Tj charcodes]
| Leading f -> [Pdfops.Op_TL f]
| CharSpace f -> [Pdfops.Op_Tc f]
| WordSpace f -> [Pdfops.Op_Tw f]
| TextScale f -> [Pdfops.Op_Tz f]
| RenderMode i -> [Pdfops.Op_Tr i]
| Rise f -> [Pdfops.Op_Ts f]
| Newline -> [Pdfops.Op_T']
and ops_of_drawops pdf endpage filename bates batespad num page drawops =
flatten (map (ops_of_drawop pdf endpage filename bates batespad num page) drawops)
and create_form_xobject a b c d pdf endpage filename bates batespad num page n ops =
let data =
Pdfio.bytes_of_string (Pdfops.string_of_ops (ops_of_drawops pdf endpage filename bates batespad num page ops))
in
let obj =
Pdf.Stream
{contents =
(Pdf.Dictionary
[("/Length", Pdf.Integer (Pdfio.bytes_size data));
("/Subtype", Pdf.Name "/Form");
("/BBox", Pdf.Array [Pdf.Real a; Pdf.Real b; Pdf.Real c; Pdf.Real d])
],
Pdf.Got data)}
in
Hashtbl.add res.form_xobjects n (Pdf.addobj pdf obj)
(* Draw all the accumulated operators. *)
let draw_single ~filename ~bates ~batespad fast range pdf drawops =
let endpage = Pdfpage.endpage pdf in
let pages = Pdfpage.pages_of_pagetree pdf in
let ss =
map2
(fun n p -> Pdfops.string_of_ops (ops_of_drawops pdf endpage filename bates batespad n p drawops))
(ilist 1 endpage)
pages
in
let pdf = ref pdf in
iter2
(fun n s ->
if mem n range then pdf := Cpdftweak.append_page_content s false fast [n] !pdf)
(ilist 1 endpage)
ss;
let pdf = !pdf in
let images = list_of_hashtbl res.images in
let image_resources = map (fun (_, (n, o)) -> (n, Pdf.Indirect o)) images in
let gss_resources = list_of_hashtbl res.extgstates in
let font_resources = map (fun (n, o) -> (n, Pdf.Indirect o)) (list_of_hashtbl res.fonts) in
let form_resources = map (fun (n, o) -> (n, Pdf.Indirect o)) (list_of_hashtbl res.form_xobjects) in
match images, gss_resources, font_resources, form_resources with [], [], [], [] -> pdf | _ ->
let pages = Pdfpage.pages_of_pagetree pdf in
let pages =
map
(fun p ->
let new_resources =
let existing_xobjects =
match Pdf.lookup_direct pdf "/XObject" p.Pdfpage.resources with
| Some (Pdf.Dictionary d) -> d
| _ -> []
in
let existing_gss =
match Pdf.lookup_direct pdf "/ExtGState" p.Pdfpage.resources with
| Some (Pdf.Dictionary d) -> d
| _ -> []
in
let existing_fonts =
match Pdf.lookup_direct pdf "/Font" p.Pdfpage.resources with
| Some (Pdf.Dictionary d) -> d
| _ -> []
in
let new_xobjects = fold_right (fun (k, v) d -> add k v d) (form_resources @ image_resources) existing_xobjects in
let new_gss = fold_right (fun (k, v) d -> add k v d) gss_resources existing_gss in
let new_fonts = fold_right (fun (k, v) d -> add k v d) font_resources existing_fonts in
Pdf.add_dict_entry
(Pdf.add_dict_entry
(Pdf.add_dict_entry p.Pdfpage.resources "/XObject" (Pdf.Dictionary new_xobjects))
"/ExtGState"
(Pdf.Dictionary new_gss))
"/Font"
(Pdf.Dictionary new_fonts)
in
{p with resources = new_resources})
pages
in
Pdfpage.change_pages true pdf pages
let draw ~filename ~bates ~batespad fast range pdf drawops =
res.time <- Cpdfstrftime.current_time ();
let pdf = ref pdf in
let range = ref range in
let chunks = ref (split_around (eq NewPage) drawops) in
while !chunks <> [] do
reset_state ();
pdf := draw_single ~filename ~bates ~batespad fast !range !pdf (hd !chunks);
chunks := tl !chunks;
if !chunks <> [] then begin
let endpage = Pdfpage.endpage !pdf in
pdf := Cpdfpad.padafter [endpage] !pdf;
range := [endpage + 1]
end
done;
!pdf