cpdf-source/cpdfpage.ml

848 lines
33 KiB
OCaml

open Pdfutil
open Cpdferror
(* When we transfor a page by wrapping in an [Op_cm], we must also
invert any /Matrix entries in pattern dictionaries, including inside xobjects *)
let rec change_pattern_matrices_resources pdf tr resources =
try
begin match Pdf.lookup_direct pdf "/XObject" resources with
| Some (Pdf.Dictionary elts) ->
iter
(fun (k, v) ->
match v with
| Pdf.Indirect i -> change_pattern_matrices_xobject pdf tr k v i
| _ -> raise (Pdf.PDFError "change_pattern_matrices_page"))
elts
| _ -> ()
end;
begin match Pdf.lookup_direct pdf "/Pattern" resources with
| Some (Pdf.Dictionary patterns) ->
let entries =
map
(fun (name, p) ->
Printf.printf "Changing matrices of pattern %s\n" name;
let old_pattern = Pdf.direct pdf p in
let new_pattern =
let existing_tr = Pdf.parse_matrix pdf "/Matrix" old_pattern in
let new_tr = Pdftransform.matrix_compose (Pdftransform.matrix_invert tr) existing_tr in
Pdf.add_dict_entry old_pattern "/Matrix" (Pdf.make_matrix new_tr)
in
name, Pdf.Indirect (Pdf.addobj pdf new_pattern))
patterns
in
Pdf.add_dict_entry resources "/Pattern" (Pdf.Dictionary entries)
| _ -> resources
end
with
Pdftransform.NonInvertable ->
Printf.eprintf "Warning: noninvertible matrix\n%!";
resources
and change_pattern_matrices_xobject pdf tr k v i =
match Pdf.lookup_direct pdf "/Subtype" v with
| Some (Pdf.Name "/Form") ->
Printf.printf "Processing form xobject %s for patterns\n" k;
let form_xobject = Pdf.lookup_obj pdf i in
begin match Pdf.lookup_direct pdf "/Resources" form_xobject with
| Some resources ->
let form_xobject' =
Pdf.add_dict_entry form_xobject "/Resources" (change_pattern_matrices_resources pdf tr resources)
in
Pdf.addobj_given_num pdf (i, form_xobject')
| _ -> ()
end
| _ -> ()
let change_pattern_matrices_page pdf tr page =
let page =
{page with Pdfpage.resources = change_pattern_matrices_resources pdf tr page.Pdfpage.resources}
in
match Pdf.lookup_direct pdf "/XObject" page.Pdfpage.resources with
| Some (Pdf.Dictionary elts) ->
iter
(fun (k, v) ->
match v with
| Pdf.Indirect i -> change_pattern_matrices_xobject pdf tr k v i
| _ -> raise (Pdf.PDFError "change_pattern_matrices_page"))
elts;
page
| _ -> page
(* Output information for each page *)
let output_page_info pdf range =
let pages = Pdfpage.pages_of_pagetree pdf
and labels = Pdfpagelabels.read pdf in
let getbox page box =
if box = "/MediaBox" then
match page.Pdfpage.mediabox with
| Pdf.Array [a; b; c; d] ->
Printf.sprintf "%f %f %f %f"
(Pdf.getnum pdf a) (Pdf.getnum pdf b) (Pdf.getnum pdf c) (Pdf.getnum pdf d)
| _ -> ""
else
match Pdf.lookup_direct pdf box page.Pdfpage.rest with
| Some (Pdf.Array [a; b; c; d]) ->
Printf.sprintf "%f %f %f %f"
(Pdf.getnum pdf a) (Pdf.getnum pdf b) (Pdf.getnum pdf c) (Pdf.getnum pdf d)
| _ -> ""
and rotation page =
Pdfpage.int_of_rotation page.Pdfpage.rotate
in
iter
(fun pnum ->
let page = select pnum pages in
Printf.printf "Page %i:\n" pnum;
Printf.printf "Label: %s\n"
(try Pdfpagelabels.pagelabeltext_of_pagenumber pnum labels with Not_found -> "");
Printf.printf "MediaBox: %s\n" (getbox page "/MediaBox");
Printf.printf "CropBox: %s\n" (getbox page "/CropBox");
Printf.printf "BleedBox: %s\n" (getbox page "/BleedBox");
Printf.printf "TrimBox: %s\n" (getbox page "/TrimBox");
Printf.printf "ArtBox: %s\n" (getbox page "/ArtBox");
Printf.printf "Rotation: %i\n" (rotation page))
range
let process_pages f pdf range =
let pages = Pdfpage.pages_of_pagetree pdf in
let pages', pagenumbers, matrices = (* new page objects, page number, matrix *)
split3
(map2
(fun n p -> if mem n range then f n p else (p, n, Pdftransform.i_matrix))
(ilist 1 (length pages))
pages)
in
Pdfpage.change_pages ~matrices:(combine pagenumbers matrices) true pdf pages'
let iter_pages f pdf range =
let pages = Pdfpage.pages_of_pagetree pdf in
iter2
(fun n p -> if mem n range then f n p)
(ilist 1 (length pages))
pages
let map_pages f pdf range =
let pages = Pdfpage.pages_of_pagetree pdf in
option_map2
(fun n p -> if mem n range then Some (f n p) else None)
(ilist 1 (length pages))
pages
(* Clip a page to one of its boxes, or the media box if that box is not
* present. This is a hard clip, done by using a clipping rectangle, so that
* the page may then be used as a stamp without extraneous material reapearing.
* *)
let hard_box pdf range boxname mediabox_if_missing fast =
process_pages
(Pdfpage.ppstub (fun pagenum page ->
let minx, miny, maxx, maxy =
if boxname = "/MediaBox" then
Pdf.parse_rectangle pdf page.Pdfpage.mediabox
else
match Pdf.lookup_direct pdf boxname page.Pdfpage.rest with
| Some a -> Pdf.parse_rectangle pdf a
| _ ->
if mediabox_if_missing
then Pdf.parse_rectangle pdf page.Pdfpage.mediabox
else error (Printf.sprintf "hard_box: box %s not found" boxname)
in
let ops = [Pdfops.Op_re (minx, miny, maxx -. minx, maxy -. miny); Pdfops.Op_W; Pdfops.Op_n] in
Pdfpage.prepend_operators pdf ops ~fast page))
pdf
range
let shift_page ?(fast=false) dxdylist pdf pnum page =
let dx, dy = List.nth dxdylist (pnum - 1) in
let transform_op =
Pdfops.Op_cm (Pdftransform.matrix_of_op (Pdftransform.Translate (dx, dy)))
in
let page =
change_pattern_matrices_page pdf (Pdftransform.mktranslate ~-.dx ~-.dy) page
in
Pdfannot.transform_annotations pdf (Pdftransform.mktranslate dx dy) page.Pdfpage.rest;
(Pdfpage.prepend_operators pdf [transform_op] ~fast page, pnum, Pdftransform.mktranslate dx dy)
let shift_pdf ?(fast=false) dxdylist pdf range =
process_pages (shift_page ~fast dxdylist pdf) pdf range
(* Shift page data *)
let make_mediabox (xmin, ymin, xmax, ymax) =
Pdf.Array
[Pdf.Real xmin; Pdf.Real ymin; Pdf.Real xmax; Pdf.Real ymax]
(* Change the media box and other known boxes by the function [f] which takes
xmin, xmax, ymin, ymax as input. *)
let change_boxes f pdf page =
let names = ["/TrimBox"; "/ArtBox"; "/CropBox"; "/BleedBox"]
in let getbox n =
Pdf.lookup_direct pdf n page.Pdfpage.rest
in
let boxes = combine names (map getbox names) in
let toreplace = lose (function (_, None) -> true | _ -> false) boxes in
let toreplace =
map
(function (name, Some value) -> (name, value) | _ -> assert false)
toreplace
in
let rest' =
fold_left
(fun e (k, v) ->
let v =
make_mediabox (f (Pdf.parse_rectangle pdf v))
in
Pdf.replace_dict_entry e k v)
page.Pdfpage.rest
toreplace
in
{page with
Pdfpage.mediabox =
make_mediabox (f (Pdf.parse_rectangle pdf page.Pdfpage.mediabox));
Pdfpage.rest = rest'}
(* Scale contents *)
let scale_page_contents ?(fast=false) scale position pdf pnum page =
let (minx, miny, maxx, maxy) as box =
(* Use cropbox if available *)
Pdf.parse_rectangle
pdf
(match Pdf.lookup_direct pdf "/CropBox" page.Pdfpage.rest with
| Some r -> r
| None -> page.Pdfpage.mediabox)
in
let sx, sy, _ = Cpdfposition.calculate_position true 0. box position in
let tx, ty =
let open Cpdfposition in
match position with
| Top t -> 0., -.t
| TopLeft t -> t, -.t
| TopRight t -> -.t, -.t
| Left t -> t, 0.
| BottomLeft t -> t, t
| Bottom t -> 0., t
| BottomRight t -> -.t, t
| Right t -> -.t, 0.
| _ -> 0., 0. (* centre it... FIXME: We will add a center position, eventually, for text and this... *)
in
let transform =
Pdftransform.matrix_of_transform
[Pdftransform.Translate (tx, ty);
Pdftransform.Scale ((sx, sy), scale, scale)]
in
let transform_op = Pdfops.Op_cm transform in
let page = change_pattern_matrices_page pdf (Pdftransform.matrix_invert transform) page in
Pdfannot.transform_annotations pdf transform page.Pdfpage.rest;
(Pdfpage.prepend_operators pdf [transform_op] ~fast page, pnum, transform)
let scale_contents ?(fast=false) position scale pdf range =
process_pages (scale_page_contents ~fast scale position pdf) pdf range
(* Set media box *)
let set_mediabox xywhlist pdf range =
let crop_page pnum page =
let x, y, w, h = List.nth xywhlist (pnum - 1) in
{page with
Pdfpage.mediabox =
(Pdf.Array
[Pdf.Real x; Pdf.Real y;
Pdf.Real (x +. w); Pdf.Real (y +. h)])}
in
process_pages (Pdfpage.ppstub crop_page) pdf range
(* If a cropbox exists, make it the mediabox. If not, change nothing. *)
let copy_cropbox_to_mediabox pdf range =
process_pages
(Pdfpage.ppstub (fun _ page ->
match Pdf.lookup_direct pdf "/CropBox" page.Pdfpage.rest with
| Some pdfobject -> {page with Pdfpage.mediabox = Pdf.direct pdf pdfobject}
| None -> page))
pdf
range
let remove_cropping_pdf pdf range =
let remove_cropping_page _ page =
{page with
Pdfpage.rest =
(Pdf.remove_dict_entry page.Pdfpage.rest "/CropBox")}
in
process_pages (Pdfpage.ppstub remove_cropping_page) pdf range
let remove_trim_pdf pdf range =
let remove_trim_page _ page =
{page with
Pdfpage.rest =
(Pdf.remove_dict_entry page.Pdfpage.rest "/TrimBox")}
in
process_pages (Pdfpage.ppstub remove_trim_page) pdf range
let remove_art_pdf pdf range =
let remove_art_page _ page =
{page with
Pdfpage.rest =
(Pdf.remove_dict_entry page.Pdfpage.rest "/ArtBox")}
in
process_pages (Pdfpage.ppstub remove_art_page) pdf range
let remove_bleed_pdf pdf range =
let remove_bleed_page _ page =
{page with
Pdfpage.rest =
(Pdf.remove_dict_entry page.Pdfpage.rest "/BleedBox")}
in
process_pages (Pdfpage.ppstub remove_bleed_page) pdf range
(* Upright functionality *)
(* Return the pages from the pdf in the range, unordered. *)
let select_pages range pdf =
let pages = Pdfpage.pages_of_pagetree pdf in
option_map (function n -> try Some (select n pages) with _ -> None) range
(* If all pages are already upright, and the mediabox is (0,0)-based, do nothing
to save time. *)
let allupright range pdf =
let page_is_upright page =
page.Pdfpage.rotate = Pdfpage.Rotate0 &&
(let (minx, miny, _, _) = Pdf.parse_rectangle pdf page.Pdfpage.mediabox in
minx < 0.001 && miny < 0.001 && minx > ~-.0.001 && miny > ~-.0.001)
in
not (mem false (map page_is_upright (select_pages range pdf)))
let upright_transform pdf page =
let rotate =
Pdfpage.int_of_rotation page.Pdfpage.rotate
and cx, cy =
let minx, miny, maxx, maxy = Pdf.parse_rectangle pdf page.Pdfpage.mediabox in
(minx +. maxx) /. 2., (miny +. maxy) /. 2.
in
Pdftransform.mkrotate (cx, cy) (rad_of_deg (~-.(float rotate)))
let transform_boxes tr pdf page =
let f (minx, miny, maxx, maxy) =
let minx, miny = Pdftransform.transform_matrix tr (minx, miny)
and maxx, maxy = Pdftransform.transform_matrix tr (maxx, maxy) in
(minx, miny, maxx, maxy)
in
change_boxes f pdf page
let transform_contents ?(fast=false) tr pdf page =
let transform_op = Pdfops.Op_cm tr in
let page = change_pattern_matrices_page pdf (Pdftransform.matrix_invert tr) page in
Pdfannot.transform_annotations pdf tr page.Pdfpage.rest;
Pdfpage.prepend_operators pdf [transform_op] ~fast page
(* Change a page's media box so its minimum x and y are 0, making other
operations simpler to think about. Any shift that is done is reflected in
other boxes (clip etc.) *)
let rectify_boxes ?(fast=false) pdf page =
let minx, miny, _, _ =
Pdf.parse_rectangle pdf page.Pdfpage.mediabox
in
let f (iminx, iminy, imaxx, imaxy) =
iminx -. minx, iminy -. miny, imaxx -. minx, imaxy -. miny
in
let page = change_boxes f pdf page in
if minx <> 0. || miny <> 0.
then
begin let p, _, _ = shift_page ~fast [(-.minx),(-.miny)] pdf 1 page in p end
else page
let upright ?(fast=false) range pdf =
if allupright range pdf then pdf else
let upright_page _ pnum page =
let tr = upright_transform pdf page in
let page = transform_boxes tr pdf page in
let page = transform_contents ~fast tr pdf page in
(rectify_boxes ~fast pdf {page with Pdfpage.rotate = Pdfpage.Rotate0}, pnum, tr)
in
process_pages (upright_page pdf) pdf range
(* Rotating pages *)
let rotate_pdf r pdf range =
let rotate_page _ page =
{page with Pdfpage.rotate =
Pdfpage.rotation_of_int r}
in
process_pages (Pdfpage.ppstub rotate_page) pdf range
let rotate_pdf_by r pdf range =
let rotate_page_by _ page =
{page with Pdfpage.rotate =
Pdfpage.rotation_of_int ((Pdfpage.int_of_rotation page.Pdfpage.rotate + r) mod 360)}
in
process_pages (Pdfpage.ppstub rotate_page_by) pdf range
let rotate_page_contents ~fast rotpoint r pdf pnum page =
let rotation_point =
match rotpoint with
| None ->
let minx, miny, maxx, maxy = Pdf.parse_rectangle pdf page.Pdfpage.mediabox in
(minx +. maxx) /. 2., (miny +. maxy) /. 2.
| Some point -> point
in
let tr =
Pdftransform.matrix_of_op
(Pdftransform.Rotate (rotation_point, -.(rad_of_deg r)))
in let tr2 =
Pdftransform.matrix_of_op
(Pdftransform.Rotate (rotation_point, rad_of_deg r))
in
let transform_op = Pdfops.Op_cm tr in
let page = change_pattern_matrices_page pdf tr2 page in
Pdfannot.transform_annotations pdf tr page.Pdfpage.rest;
(Pdfpage.prepend_operators pdf [transform_op] ~fast page, pnum, tr)
let rotate_contents ?(fast=false) r pdf range =
process_pages (rotate_page_contents ~fast None r pdf) pdf range
(* Scale page data *)
let scale_pdf ?(fast=false) sxsylist pdf range =
let scale_page pnum page =
let sx, sy = List.nth sxsylist (pnum - 1) in
let f (xmin, ymin, xmax, ymax) =
xmin *. sx, ymin *. sy, xmax *. sx, ymax *. sy
in
let page = change_boxes f pdf page
and matrix = Pdftransform.matrix_of_op (Pdftransform.Scale ((0., 0.), sx, sy)) in
let transform_op =
Pdfops.Op_cm matrix
and page =
change_pattern_matrices_page pdf (Pdftransform.matrix_invert matrix) page
in
Pdfannot.transform_annotations pdf matrix page.Pdfpage.rest;
(Pdfpage.prepend_operators pdf ~fast [transform_op] page, pnum, matrix)
in
process_pages scale_page pdf range
(* Scale to fit page of size x * y *)
let scale_to_fit_pdf ?(fast=false) position input_scale xylist op pdf range =
let scale_page_to_fit pnum page =
let x, y = List.nth xylist (pnum - 1) in
let matrix =
let (minx, miny, maxx, maxy) =
(* Use cropbox if available *)
Pdf.parse_rectangle
pdf
(match Pdf.lookup_direct pdf "/CropBox" page.Pdfpage.rest with
| Some r -> r
| None -> page.Pdfpage.mediabox)
in
if maxx <= 0. || maxy <= 0. then failwith "Zero-sized pages are invalid" else
let fx = x /. maxx in let fy = y /. maxy in
let scale = fmin fx fy *. input_scale in
let trans_x =
match position with
Cpdfposition.Left _ -> 0.
| Cpdfposition.Right _ -> (x -. (maxx *. scale))
| _ -> (x -. (maxx *. scale)) /. 2.
and trans_y =
match position with
| Cpdfposition.Top _ -> (y -. (maxy *. scale))
| Cpdfposition.Bottom _ -> 0.
| _ -> (y -. (maxy *. scale)) /. 2.
in
(Pdftransform.matrix_of_transform
[Pdftransform.Translate (trans_x, trans_y);
Pdftransform.Scale ((0., 0.), scale, scale)])
in
let page =
change_boxes
(function (minx, miny, maxx, maxy) -> 0., 0., x, y)
pdf page
in
Pdfannot.transform_annotations pdf matrix page.Pdfpage.rest;
(Pdfpage.prepend_operators pdf [Pdfops.Op_cm matrix] ~fast
(change_pattern_matrices_page pdf (Pdftransform.matrix_invert matrix) page), pnum, matrix)
in
process_pages scale_page_to_fit pdf range
(* Add stack operators to a content stream to ensure it is composeable. On
-fast, we don't check for Q deficit, assuming PDF is ISO. *)
let protect fast pdf resources content =
let deficit =
if fast then 0 else
let ops = Pdfops.parse_operators pdf resources content in
let qs = length (keep (eq Pdfops.Op_q) ops) in
let bigqs = length (keep (eq Pdfops.Op_Q) ops) in
let deficit = if qs > bigqs then qs - bigqs else 0 in
if deficit <> 0 then Printf.eprintf "Q Deficit was nonzero. Fixing. %i\n%!" deficit;
deficit
in
let addstream ops = Pdf.addobj pdf (Pdfops.stream_of_ops ops) in
let q = addstream [Pdfops.Op_q] in
let qs = addstream (many Pdfops.Op_Q deficit @ [Pdfops.Op_Q]) in
[Pdf.Indirect q] @ content @ [Pdf.Indirect qs]
(* Does the page have a defined box e.g "/CropBox" *)
let hasbox pdf page boxname =
let pages = Pdfpage.pages_of_pagetree pdf in
if page > length pages || page < 1 then raise (Failure "hasbox: bad page") else
let p = select page pages in
match Pdf.lookup_direct pdf boxname p.Pdfpage.rest with
| Some _ -> true
| _ -> false
(* Flip pages *)
let flip_page ?(fast=false) transform_op pdf pnum page =
let minx, miny, maxx, maxy =
Pdf.parse_rectangle pdf page.Pdfpage.mediabox
in
let tr = transform_op minx miny maxx maxy in
let page = change_pattern_matrices_page pdf (Pdftransform.matrix_invert tr) page in
Pdfannot.transform_annotations pdf tr page.Pdfpage.rest;
(Pdfpage.prepend_operators pdf [Pdfops.Op_cm tr] ~fast page, pnum, tr)
let vflip_pdf ?(fast=false) pdf range =
let transform_op _ miny _ maxy =
Pdftransform.matrix_of_op
(Pdftransform.Scale ((0., ((miny +. maxy) /. 2.)), 1., -.1.))
in
process_pages (flip_page ~fast transform_op pdf) pdf range
let hflip_pdf ?(fast=false) pdf range =
let transform_op minx _ maxx _ =
Pdftransform.matrix_of_op
(Pdftransform.Scale (((minx +. maxx) /. 2., 0.), -.1., 1.))
in
process_pages (flip_page ~fast transform_op pdf) pdf range
let stamp_shift_of_position topline midline sw sh w h p =
let half x = x /. 2.
and dy =
if midline then sh /. 2.
else if topline then sh
else 0.
in
let open Cpdfposition in
match p with
| PosCentre (ox, oy) -> ox -. half sw, oy -. dy
| PosLeft (ox, oy) -> ox, oy -. dy
| PosRight (ox, oy) -> ox -. sw, oy -. dy
| Top o -> half w -. half sw, h -. o -. sh -. dy
| TopLeft o -> o, h -. sh -. o -. dy
| TopRight o -> w -. sw -. o, h -. sh -. o -. dy
| Left o -> o, half h -. half sh -. dy
| BottomLeft o -> o, o -. dy
| Bottom o -> half w -. half sw, o -. dy
| BottomRight o -> w -. sw -. o, o -. dy
| Right o -> w -. sw -. o, half h -. half sh -. dy
| Diagonal | ReverseDiagonal | Centre ->
half w -. half sw, half h -. half sh -. dy
(* Combine Pdfpage.rest items for two PDFs. For now, we combine /Annots, and
* copy everything else from adict. What else should we combine? *)
let combine_page_items pdf adict bdict =
let getannots dict =
begin match dict with
Pdf.Dictionary d ->
begin match lookup "/Annots" d with
Some (Pdf.Array items) -> items
| _ -> []
end
| _ -> []
end
in
let a_annots = getannots adict in
let b_annots = getannots bdict in
match a_annots @ b_annots with
[] -> adict
| annots -> Pdf.add_dict_entry adict "/Annots" (Pdf.Array annots)
let do_stamp relative_to_cropbox fast position topline midline scale_to_fit isover pdf o u opdf =
(* Scale page stamp o to fit page u *)
let sxmin, symin, sxmax, symax =
Pdf.parse_rectangle
pdf
(match Pdf.lookup_direct pdf "/CropBox" o.Pdfpage.rest with | Some r -> r | None -> o.Pdfpage.mediabox)
in let txmin, tymin, txmax, tymax =
Pdf.parse_rectangle
pdf
(match Pdf.lookup_direct pdf "/CropBox" u.Pdfpage.rest with | Some r -> r | None -> u.Pdfpage.mediabox)
in
let o =
if scale_to_fit then
let xmag = (txmax -. txmin) /. (sxmax -. sxmin) in
let ymag = (tymax -. tymin) /. (symax -. symin) in
let scale =
if xmag < 0.999 && ymag < 0.999 then
if xmag > ymag then xmag else ymag
else if xmag >= 1.001 && ymag >= 1.001 then
if xmag > ymag then ymag else xmag
else if xmag >= 1.001 then ymag
else xmag
in
let dx = txmin +. ((txmax -. txmin) -. (sxmax -. sxmin) *. scale) /. 2. in
let dy = tymin +. ((tymax -. tymin) -. (symax -. symin) *. scale) /. 2. in
let matrix =
(Pdftransform.matrix_of_transform
([Pdftransform.Translate (dx, dy)] @
(if relative_to_cropbox then [Pdftransform.Translate (txmin, tymin)] else []) @
[Pdftransform.Scale ((sxmin, symin), scale, scale)]))
in
Pdfannot.transform_annotations pdf matrix o.Pdfpage.rest;
let r = Pdfpage.prepend_operators pdf [Pdfops.Op_cm matrix] ~fast o in
change_pattern_matrices_page pdf (Pdftransform.matrix_invert matrix) r
else
let sw = sxmax -. sxmin and sh = symax -. symin
and w = txmax -. txmin and h = tymax -. tymin in
let dx, dy = stamp_shift_of_position topline midline sw sh w h position in
let matrix =
(Pdftransform.matrix_of_transform
((if relative_to_cropbox then [Pdftransform.Translate (txmin, tymin)] else []) @
[Pdftransform.Translate (dx, dy)]))
in
Pdfannot.transform_annotations pdf matrix o.Pdfpage.rest;
let r = Pdfpage.prepend_operators pdf [Pdfops.Op_cm matrix] ~fast o in
change_pattern_matrices_page pdf (Pdftransform.matrix_invert matrix) r
in
{u with
Pdfpage.content =
(if isover then ( @ ) else ( @@ ))
(protect fast pdf u.Pdfpage.resources u.Pdfpage.content)
(protect fast pdf o.Pdfpage.resources o.Pdfpage.content);
Pdfpage.rest =
combine_page_items pdf u.Pdfpage.rest o.Pdfpage.rest;
Pdfpage.resources =
Pdfpage.combine_pdf_resources pdf u.Pdfpage.resources o.Pdfpage.resources}
let stamp relative_to_cropbox position topline midline fast scale_to_fit isover range over pdf =
let prefix = Pdfpage.shortest_unused_prefix pdf in
Pdfpage.add_prefix over prefix;
let marks = Pdfmarks.read_bookmarks pdf in
let marks_refnumbers = Pdf.page_reference_numbers pdf in
let pdf = Pdfmarks.remove_bookmarks pdf in
let over = Pdfmarks.remove_bookmarks over in
let pageseqs = ilist 1 (Pdfpage.endpage pdf) in
let over_firstpage_pdf =
match Pdfpage.pages_of_pagetree over with
| [] -> error "empty PDF"
| h::_ -> Pdfpage.change_pages ~changes:[(1, 1)] true over [h]
in
let merged =
Pdfmerge.merge_pdfs
false false ["a"; "b"] [pdf; over_firstpage_pdf] [pageseqs; [1]]
in
let merged =
{merged with Pdf.saved_encryption = pdf.Pdf.saved_encryption}
in
let merged = Cpdfmetadata.copy_id true pdf merged in
let merged_pages = Pdfpage.pages_of_pagetree merged in
let under_pages, over_page =
all_but_last merged_pages, last merged_pages
in
let new_pages =
map2
(fun pageseq under_page ->
do_stamp relative_to_cropbox fast position topline midline scale_to_fit isover merged
(if mem pageseq range then over_page else
Pdfpage.blankpage Pdfpaper.a4)
under_page over)
pageseqs
under_pages
in
let changed =
let changes =
map (fun x -> (x, x)) (ilist 1 (length new_pages))
in
Pdfpage.change_pages ~changes true merged new_pages
in
let new_refnumbers = Pdf.page_reference_numbers changed in
let changetable = hashtable_of_dictionary (combine marks_refnumbers new_refnumbers) in
let new_marks = map (Cpdfbookmarks.change_bookmark changetable) marks in
Pdfmarks.add_bookmarks new_marks changed
(* Combine pages from two PDFs. For now, assume equal length. *)
(* If [over] has more pages than [under], chop the excess. If the converse, pad
[over] to the same length *)
let equalize_pages under over =
let length_under = Pdfpage.endpage under in
let length_over = Pdfpage.endpage over in
if length_over > length_under then
let changes =
map (fun x -> (x, x)) (ilist 1 length_under)
in
(under,
(Pdfpage.change_pages
~changes true over (take (Pdfpage.pages_of_pagetree over) length_under)))
else if length_under > length_over then
let changes =
map (fun x -> (x, x)) (ilist 1 length_over)
in
(under,
Pdfpage.change_pages
~changes true over
(Pdfpage.pages_of_pagetree over @
(many (Pdfpage.blankpage Pdfpaper.a4) (length_under - length_over))))
else
under, over
let combine_pages fast under over scaletofit swap equalize =
let debug_combine_pages = false in
let debug_pdf pdf n =
if debug_combine_pages then
begin Pdf.remove_unreferenced pdf; Pdfwrite.pdf_to_file pdf n end
in
Pdfpage.add_prefix over (Pdfpage.shortest_unused_prefix under);
let marks_under, marks_over = Pdfmarks.read_bookmarks under, Pdfmarks.read_bookmarks over in
let under, over = if equalize then equalize_pages under over else under, over in
let under_length, over_length = Pdfpage.endpage under, Pdfpage.endpage over in
if under_length <> over_length then
raise (Pdf.PDFError "combine_pages: not of equal length")
else
let pageseqs_under = ilist 1 (Pdfpage.endpage under) in
let pageseqs_over = ilist 1 (Pdfpage.endpage over) in
let merged =
Pdfmerge.merge_pdfs
false false ["a"; "b"] [under; over] [pageseqs_under; pageseqs_over]
in
debug_pdf merged "merged.pdf";
let under_pages, over_pages =
cleave (Pdfpage.pages_of_pagetree merged) under_length
in
let new_pages =
map2
(fun o u ->
do_stamp
false fast (BottomLeft 0.) false false scaletofit (not swap) merged o u over)
over_pages under_pages
in
(* Build the changes. 123456 -> 123123 *)
let changes =
let len = length new_pages in
combine (ilist 1 (len * 2)) (let x = ilist 1 len in x @ x)
in
let changed = Pdfpage.change_pages ~changes true merged new_pages in
let r = Pdfmarks.add_bookmarks (marks_under @ marks_over) changed in
debug_pdf r "final.pdf";
r
(* Just used by cpdflib for historical reasons *)
let setBox box minx maxx miny maxy pdf range =
let set_box_page _ page =
{page with
Pdfpage.rest =
Pdf.add_dict_entry
page.Pdfpage.rest box
(Pdf.Array [Pdf.Real minx; Pdf.Real miny; Pdf.Real maxx; Pdf.Real maxy])}
in
process_pages (Pdfpage.ppstub set_box_page) pdf range
(* Cropping *)
let crop_pdf ?(box="/CropBox") xywhlist pdf range =
let crop_page pagenum page =
{page with
Pdfpage.rest =
(Pdf.add_dict_entry
page.Pdfpage.rest
box
(let x, y, w, h = List.nth xywhlist (pagenum - 1) in
(Pdf.Array
[Pdf.Real x; Pdf.Real y;
Pdf.Real (x +. w); Pdf.Real (y +. h)])))}
in
process_pages (Pdfpage.ppstub crop_page) pdf range
(* Add rectangles on top of pages to show Media, Crop, Art, Trim, Bleed boxes.
*
* We use different dash lengths and colours to help distinguish coincident
* boxes The sequence of operators is postpended to the page content,
* appropriately protected to prevent pollution of matrices.
*
* /MediaBox: Solid red line
* /CropBox: Dashed 7 on 7 off green line
* /ArtBox: Dashed 5 on 5 off blue line
* /TrimBox: Dashed 3 on 3 off orange line
* /BleedBox: Dashed 2 on 2 off pink line *)
let get_rectangle pdf page box =
if box = "/MediaBox" then
match page.Pdfpage.mediabox with
Pdf.Array [a; b; c; d] as r -> Some (Pdf.parse_rectangle pdf r)
| _ -> None
else
match Pdf.lookup_direct pdf box page.Pdfpage.rest with
Some (Pdf.Array [a; b; c; d] as r) -> Some (Pdf.parse_rectangle pdf r)
| _ -> None
let show_boxes_page fast pdf _ page =
let make_ops (r, g, b) on off boxname =
match get_rectangle pdf page boxname with
Some (r1, r2, r3, r4) ->
[Pdfops.Op_q;
Pdfops.Op_RG (r /. 255., g /. 255., b /. 255.);
Pdfops.Op_w 1.;
Pdfops.Op_d ((if on = 0. && off = 0. then [] else [on; off]), 0.);
Pdfops.Op_re (r1, r2, r3 -. r1, r4 -. r2);
Pdfops.Op_S;
Pdfops.Op_Q]
| None -> []
in
let ops =
make_ops (255., 0., 0.) 0. 0. "/MediaBox"
@ make_ops (0., 255., 0.) 7. 7. "/CropBox"
@ make_ops (0., 0., 255.) 5. 5. "/ArtBox"
@ make_ops (255.,150.,0.) 3. 3. "/TrimBox"
@ make_ops (255.,9.,147.) 2. 2. "/BleedBox"
in
Pdfpage.postpend_operators pdf ops ~fast page
let show_boxes ?(fast=false) pdf range =
process_pages (Pdfpage.ppstub (show_boxes_page fast pdf)) pdf range
let allowance = 9.
let line (x0, y0, x1, y1) =
[Pdfops.Op_m (x0, y0);
Pdfops.Op_l (x1, y1);
Pdfops.Op_s]
let trim_marks_page fast pdf n page =
match get_rectangle pdf page "/TrimBox", get_rectangle pdf page "/MediaBox" with
| Some (tminx, tminy, tmaxx, tmaxy), Some (minx, miny, maxx, maxy) ->
let ops =
[Pdfops.Op_q;
Pdfops.Op_K (1., 1., 1., 1.);
Pdfops.Op_w 1.]
@ line (minx, tmaxy, tminy -. allowance, tmaxy) (* top left *)
@ line (tminx, tmaxy +. allowance, tminx, maxy)
@ line (tmaxx +. allowance, tmaxy, maxx, tmaxy) (* top right *)
@ line (tmaxx, tmaxy +. allowance, tmaxx, maxy)
@ line (tmaxx +. allowance, tminy, maxx, tminy) (* bottom right *)
@ line (tmaxx, tminy -. allowance, tmaxx, miny)
@ line (tminx -. allowance, tminy, minx, tminy) (* bottom left *)
@ line (tminx, tminy -. allowance, tminx, miny)
@ [Pdfops.Op_Q]
in
Pdfpage.postpend_operators pdf ops ~fast page
| _, _ ->
(*Printf.eprintf "warning: no /TrimBox found on page %i\n%!" n;*)
page
let trim_marks ?(fast=false) pdf range =
process_pages (Pdfpage.ppstub (trim_marks_page fast pdf)) pdf range
(* copy the contents of the box f to the box t. If mediabox_if_missing is set,
the contents of the mediabox will be used if the from fox is not available. If
mediabox_is_missing is false, the page is unaltered. *)
let copy_box f t mediabox_if_missing pdf range =
process_pages
(Pdfpage.ppstub (fun _ page ->
if f = "/MediaBox" then
{page with Pdfpage.rest =
(Pdf.add_dict_entry page.Pdfpage.rest t (page.Pdfpage.mediabox))}
else
match Pdf.lookup_direct pdf f page.Pdfpage.rest with
| Some pdfobject ->
if t = "/MediaBox"
then {page with
Pdfpage.mediabox = Pdf.direct pdf pdfobject}
else {page with Pdfpage.rest =
(Pdf.add_dict_entry page.Pdfpage.rest t (Pdf.direct pdf pdfobject))}
| None ->
if mediabox_if_missing
then {page with Pdfpage.rest = Pdf.add_dict_entry page.Pdfpage.rest t page.Pdfpage.mediabox}
else page))
pdf
range