In Bookmaker, allow multiple (optiopnally page-ranged) crop definitions.

diff --git a/bookmaker.py b/bookmaker.py
index ca3548bd702eb8425a001b420da2dc73b877a377..4a7ed31a6b572999e9d7d7dd6a5450d998541614 100755 (executable)
--- a/bookmaker.py
+++ b/bookmaker.py
@@ -9,30 +9,36 @@ parser = argparse.ArgumentParser(description="build print-ready book PDF")
 parser.add_argument("-i", "--input", dest="input_file", action="append", required=True, help="input PDF file")
 parser.add_argument("-o", "--output", dest="output_file", required=True, help="output PDF file")
 parser.add_argument("-p", "--pages", dest="page_range", action="append", help="page range, e.g., '3-end'")
-parser.add_argument("-c", "--crop", dest="crop_range", help="crops left, bottom, right, top – e.g., '10,10,10,10'")
+parser.add_argument("-c", "--crop", dest="crop_range", action="append", help="crops left, bottom, right, top – e.g., '10,10,10,10'; prefix with ':'-delimited page range to limit effect")
 parser.add_argument("-n", "--nup4", dest="nup4", action='store_true', help="puts 4 input pages onto 1 output page")
 parser.add_argument("-a", "--analyze", dest="analyze", action="store_true", help="print lines identifying spine, page borders")
 parser.add_argument("-t", "--symmetry", dest="symmetry", action="store_true", help="alternate horizontal crops between odd and even pages")
 parser.add_argument("-r", "--rotate", dest="rotate", type=int, action="append", help="rotate page of number by 90° (usable multiple times on same page!)")
-parser.add_argument("-m", "--margin", type=float, default=4.3, help="print margin (default 4.3)")
+parser.add_argument("-m", "--margin", type=float, default=4.3, help="print margin in mm (default 4.3)")
 args = parser.parse_args()
 
 
 # select pages from input files
+def parse_page_range(range_string, pages):
+    start_page = 0
+    end_page = len(pages)
+    if range_string:
+        start, end = range_string.split('-')
+        if not (len(start) == 0 or start == "start"):
+            start_page = int(start) - 1
+        if not (len(end) == 0 or end == "end"):
+            end_page = int(end)
+    return start_page, end_page
 pages_to_add = []
 opened_files = []
 for i, input_file in enumerate(args.input_file):
     file = open(input_file, 'rb')
     opened_files += [file]
     reader = pypdf.PdfReader(file)
-    start_page = 0
-    end_page = len(reader.pages)
+    range_string = None
     if args.page_range and len(args.page_range) > i:
-        start, end = args.page_range[i].split('-')
-        if not (len(start) == 0 or start == "start"):
-            start_page = int(start) - 1
-        if not (len(end) == 0 or end == "end"):
-            end_page = int(end)
+        range_string = args.page_range[i]
+    start_page, end_page = parse_page_range(range_string, reader.pages)
     for page_num in range(start_page, end_page):
         page = reader.pages[page_num]
         pages_to_add += [page]
@@ -56,49 +62,67 @@ for page in pages_to_add:
     page.mediabox.right = a4_width
     page.cropbox = page.mediabox
 
-# determine page crop
-crop_left, crop_bottom, crop_right, crop_top = 0, 0, 0, 0
+# determine page crops, zooms
+crops_at_page = [(0,0,0,0)]*len(pages_to_add)
+zoom_at_page = [1]*len(pages_to_add)
 if args.crop_range:
-    crop_left, crop_bottom, crop_right, crop_top = [float(x) for x in  args.crop_range.split(',')]
-cropped_width  = a4_width - crop_left - crop_right
-cropped_height = a4_height - crop_bottom - crop_top
-zoom = 1
-if args.crop_range:
-    zoom_horizontal = a4_width / (a4_width - crop_left - crop_right)
-    zoom_vertical = a4_height / (a4_height - crop_bottom - crop_top)
-    if (zoom_horizontal > 1 and zoom_vertical < 1) or (zoom_horizontal < 1 and zoom_vertical > 1):
-        print("Error: opposing zooms.")
-        exit(1)
-    elif zoom_horizontal + zoom_vertical > 2:
-        zoom = min(zoom_horizontal, zoom_vertical)
-    else:
-        zoom = max(zoom_horizontal, zoom_vertical)
+  for crop_range in args.crop_range:
+      initial_split = crop_range.split(':')
+      if len(initial_split) > 1:
+          page_range = initial_split[0]
+          crops = initial_split[1]
+      else:
+          page_range = None
+          crops = initial_split[0]
+      start_page, end_page = parse_page_range(page_range, pages_to_add)
+      crop_left, crop_bottom, crop_right, crop_top = [float(x) for x in  crops.split(',')]
+      cropped_width  = a4_width - crop_left - crop_right
+      cropped_height = a4_height - crop_bottom - crop_top
+      zoom = 1
+      zoom_horizontal = a4_width / (a4_width - crop_left - crop_right)
+      zoom_vertical = a4_height / (a4_height - crop_bottom - crop_top)
+      if (zoom_horizontal > 1 and zoom_vertical < 1) or (zoom_horizontal < 1 and zoom_vertical > 1):
+          print("Error: opposing zooms.")
+          exit(1)
+      elif zoom_horizontal + zoom_vertical > 2:
+          zoom = min(zoom_horizontal, zoom_vertical)
+      else:
+          zoom = max(zoom_horizontal, zoom_vertical)
+      for page_num in range(start_page, end_page):
+          crops_at_page[page_num] = (crop_left, crop_bottom, crop_right, crop_top)
+          zoom_at_page[page_num] = zoom
 
 writer = pypdf.PdfWriter()
 if not args.nup4:
     odd_page = True
-    for page in pages_to_add:
+    for i, page in enumerate(pages_to_add):
+        crop_left, crop_bottom, crop_right, crop_top = crops_at_page[i]
+        zoom = zoom_at_page[i]
         if args.symmetry and odd_page:
             page.add_transformation(pypdf.Transformation().translate(tx=-crop_right, ty=-crop_bottom))
         else:
             page.add_transformation(pypdf.Transformation().translate(tx=-crop_left, ty=-crop_bottom))
         page.add_transformation(pypdf.Transformation().scale(zoom, zoom))
+        cropped_width  = a4_width - crop_left - crop_right
+        cropped_height = a4_height - crop_bottom - crop_top
         page.mediabox.right = cropped_width * zoom
         page.mediabox.top = cropped_height * zoom
         writer.add_page(page)
         odd_page = not odd_page
+
 else:
-    n_pages_per_axis = 2
     points_per_mm = 2.83465
+    n_pages_per_axis = 2
+    spine_limit = 10
     printable_margin = args.margin * points_per_mm
     printable_scale = (a4_width - 2*printable_margin)/a4_width
-    spine_limit = 10 * points_per_mm
     half_width = a4_width / n_pages_per_axis
     half_height = a4_height / n_pages_per_axis
     section_scale_factor = 1 / n_pages_per_axis
     spine_part_of_page = (spine_limit / half_width) / printable_scale
     bonus_shrink_factor = 1 - spine_part_of_page
     new_page_order = []
+    new_i_order = []
     eight_pack = []
     mod_to_8 = len(pages_to_add) % 8
     if mod_to_8 > 0:
@@ -106,6 +130,7 @@ else:
             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
             pages_to_add += [new_page]
     i = 0
+    n_eights = 0
     for page in pages_to_add:
         if i == 0:
             eight_pack = []
@@ -113,6 +138,15 @@ else:
         i += 1
         if i == 8:
             i = 0
+            new_i_order += [8 * n_eights + 3,
+                            8 * n_eights + 0,
+                            8 * n_eights + 7,
+                            8 * n_eights + 4,
+                            8 * n_eights + 1,
+                            8 * n_eights + 2,
+                            8 * n_eights + 5,
+                            8 * n_eights + 6]
+            n_eights += 1
             new_page_order += [eight_pack[3]]  # page front, upper left
             new_page_order += [eight_pack[0]]  # page front, upper right
             new_page_order += [eight_pack[7]]  # page front, lower left
@@ -124,11 +158,14 @@ else:
     i = 0
     page_count = 0
     front_page = True
-    for page in new_page_order:
+    for j, page in enumerate(new_page_order):
         if i == 0:
             new_page = pypdf.PageObject.create_blank_page(width=a4_width, height=a4_height)
 
         # in-section transformations: align pages on top, left-hand pages to left, right-hand to right
+        new_i = new_i_order[j]
+        crop_left, crop_bottom, crop_right, crop_top = crops_at_page[new_i]
+        zoom = zoom_at_page[new_i]
         page.add_transformation(pypdf.Transformation().translate(ty=(a4_height / zoom - (a4_height - crop_top))))
         if i == 0 or i == 2:
             if args.symmetry: