From 15842dbd36f94f2ab125be3a4ceefded7a0cab95 Mon Sep 17 00:00:00 2001
From: John Whitington <john@coherentgraphics.co.uk>
Date: Mon, 22 Jan 2024 16:36:37 +0000
Subject: [PATCH] Adds -shift-boxes

---
 Changes        |  1 +
 cpdfcommand.ml | 20 +++++++++++++++++++-
 cpdfmanual.tex |  1 +
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/Changes b/Changes
index 4ceabea..5d82c56 100644
--- a/Changes
+++ b/Changes
@@ -20,6 +20,7 @@ o Build PDF files from JBIG2 streams, including globals
 o Reprocess images within PDFs to further compress them
 o Extract streams to disk
 o Explore PDFs by printing objects
+o Shift page boxes with -shift-boxes
 
 Extended features:
 
diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index 77e11ce..a5468e9 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -118,6 +118,7 @@ type op =
   | PadMultiple of int
   | PadMultipleBefore of int
   | Shift
+  | ShiftBoxes
   | Scale
   | ScaleToFit
   | ScaleContents of float
@@ -260,6 +261,7 @@ let string_of_op = function
   | PadMultiple _ -> "PadMultiple"
   | PadMultipleBefore _ -> "PadMultipleBefore"
   | Shift -> "Shift"
+  | ShiftBoxes -> "ShiftBoxes"
   | Scale -> "Scale"
   | ScaleToFit -> "ScaleToFit"
   | ScaleContents _ -> "ScaleContents"
@@ -907,7 +909,7 @@ let banned banlist = function
   | Rotateby _ | Upright | VFlip | HFlip | Impose _ | Chop _ ->
       mem Pdfcrypt.NoAssemble banlist
   | TwoUp|TwoUpStack|RemoveBookmarks|AddRectangle|RemoveText|
-    Draft|Shift|Scale|ScaleToFit|RemoveAttachedFiles|
+    Draft|Shift|ShiftBoxes | Scale|ScaleToFit|RemoveAttachedFiles|
     RemoveAnnotations|RemoveFonts|Crop|RemoveCrop|Trim|RemoveTrim|Bleed|RemoveBleed|Art|RemoveArt|
     CopyBox|MediaBox|HardBox _|SetTrapped|SetUntrapped|Presentation|
     BlackText|BlackLines|BlackFills|CopyFont _|StampOn _|StampUnder _|StampAsXObject _|
@@ -1201,6 +1203,10 @@ let setshift s =
   setop Shift ();
   args.coord <- s
 
+let setshiftboxes s =
+  setop ShiftBoxes ();
+  args.coord <- s
+
 let setscale s =
   setop Scale ();
   args.coord <- s
@@ -2171,6 +2177,9 @@ and specs =
    ("-shift",
       Arg.String setshift,
       " -shift \"dx dy\" shifts the chosen pages");
+   ("-shift-boxes",
+      Arg.String setshiftboxes,
+      " -shift \"dx dy\" shifts the chosen pages");
    ("-rotate",
        Arg.Int setrotate,
        " Set rotation of pages to 0, 90, 180, 270");
@@ -4183,6 +4192,15 @@ let go () =
         let range = parse_pagespec_allow_empty pdf (get_pagespec ()) in
           let dxdylist = Cpdfcoord.parse_coordinates pdf args.coord in
             write_pdf false (Cpdfpage.shift_pdf ~fast:args.fast dxdylist pdf range)
+  | Some ShiftBoxes ->
+      let pdf = get_single_pdf args.op false in
+      let range = parse_pagespec_allow_empty pdf (get_pagespec ()) in
+      let dxdylist = Cpdfcoord.parse_coordinates pdf args.coord in
+      let dx, dy = match dxdylist with (a, b)::_ -> a, b | _ -> 0.0, 0.0 in
+      Printf.printf "dx = %f, dy = %f\n" dx dy;
+      let f (xmin, xmax, ymin, ymax) = (xmin +. dx, xmax +. dx, ymin +. dy, ymax +. dy) in
+      let fpage _ p = Cpdfpage.change_boxes f pdf p in
+        write_pdf false (Cpdfpage.process_pages (Pdfpage.ppstub fpage) pdf range)
   | Some Scale ->
       let pdf = get_single_pdf args.op false in
         let range = parse_pagespec_allow_empty pdf (get_pagespec ()) in
diff --git a/cpdfmanual.tex b/cpdfmanual.tex
index 4a32394..1e0dc85 100644
--- a/cpdfmanual.tex
+++ b/cpdfmanual.tex
@@ -16,6 +16,7 @@
 %Document -extract-stream - check enc
 %Document -obj - check enc
 %Document -merge-no-struct-trees in merge and collate
+%Document -shift-boxes
 \documentclass{book}
 % Edit here to produce cpdfmanual.pdf, cpdflibmanual.pdf, pycpdfmanual.pdf,
 % dotnetcpdflibmanual.pdf, jcpdflibmanual.pdf jscpdflibmanual.pdf etc.