More progress on -chop

Changes

@@ -11,6 +11,7 @@ o Identify PDF/A, PDF/X, PDF/E, PDF/VT, PDF/UA in -info
 o Identify AcroForm in -info
 o Extract font files from a document
 o List images on a page with -list-images[-json]
+o Chop pages up into sections with -chop
 
 Extended features:
 

cpdfchop.ml

@@ -2,11 +2,24 @@ open Pdfutil
 open Cpdferror
 
 (* Resources - what to do with each. Bookmarks? Annotations - must be duplicated... *)
-(* Test how the sharing affects other cpdf operations. *)
+(* Test how the sharing affects other cpdf operations - especially with -fast! *)
+(* Allow different orders - btt / ltr etc. *)
 
 (* Chop a single page into pieces. We prefer the cropbox when available. We set
    mediabox only, and delete any other boxes. *)
-let chop_boxes x y p = [p; p]
+(* FIXME check non-zero based boxes *)
+let chop_boxes x y p =
+  if x < 1 || y < 1 then Cpdferror.error "chop_boxes bad specification" else
+    let move_page p dx dy = Printf.printf "move_page %f %f\n" dx dy; p in
+    let minx, miny, maxx, maxy = 0., 0., 540., 666. in
+    let w, h = (maxx -. minx) /. float_of_int x, (maxy -. miny) /. float_of_int y in
+    let ps = ref [] in
+      for ty = 0 to x do
+        for tx = 0 to y do
+          ps =| move_page p (w *. float_of_int tx) (h *. float_of_int ty *. ~-.1.)
+        done
+      done;
+      rev !ps
 
 (* Chop pages in the range into pieces *)
 let chop ~x ~y pdf range =