In Bookmaker, document code and its execution better.

[misc] / bookmaker.py

diff --git a/bookmaker.py b/bookmaker.py
index 72ffbfa05862424972a3d3f5b291ed4b2d215359..64acf6fbbd440b84a3ed7026123352e927935ff4 100755 (executable)
--- a/bookmaker.py
+++ b/bookmaker.py
@@ -4,18 +4,22 @@ import argparse
 import io
 from reportlab.lib.pagesizes import A4
 a4_width, a4_height = A4
+points_per_cm = 10 * 72 / 25.4
+cut_depth = 1.95 * points_per_cm
+cut_width = 1.05 * points_per_cm
+middle_point_depth = 0.4 * points_per_cm
 
 parser = argparse.ArgumentParser(description="build print-ready book PDF")
 parser.add_argument("-i", "--input_file", action="append", required=True, help="input PDF file")
 parser.add_argument("-o", "--output_file", required=True, help="output PDF file")
 parser.add_argument("-p", "--page_range", action="append", help="page range, e.g., '3-end'")
-parser.add_argument("-c", "--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", action='store_true', help="puts 4 input pages onto 1 output page")
-parser.add_argument("-a", "--analyze", action="store_true", help="print lines identifying spine, page borders")
+parser.add_argument("-c", "--crop_range", action="append", help="cm crops left, bottom, right, top – e.g., '10,10,10,10'; prefix with ':'-delimited page range to limit effect")
 parser.add_argument("-t", "--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 in mm (default 4.3)")
-parser.add_argument("-s", "--spine", type=float, default=10, help="on --nup4, mm width of margin hidden in spine (default 10)")
+parser.add_argument("-n", "--nup4", action='store_true', help="puts 4 input pages onto 1 output page")
+parser.add_argument("-a", "--analyze", action="store_true", help="in --nup4, print lines identifying spine, page borders")
+parser.add_argument("-m", "--margin", type=float, default=0.43, help="print margin for --nup4 in cm (default 0.43)")
+parser.add_argument("-s", "--spine", type=float, default=1, help="on --nup4, cm width of margin hidden in spine (default 1)")
 args = parser.parse_args()
 
 
@@ -40,10 +44,12 @@ for i, input_file in enumerate(args.input_file):
     if args.page_range and len(args.page_range) > i:
         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]
+    new_page_num = 0
+    for old_page_num in range(start_page, end_page):
+        new_page_num += 1
+        page = reader.pages[new_page_num]
         pages_to_add += [page]
-        print("read in %s page number %d" % (input_file, page_num+1))
+        print("-i, -p: read in %s page number %d as new page %d" % (input_file, new_page_num+1, new_page_num))
 
 # rotate page canvas
 if args.rotate:
@@ -52,6 +58,7 @@ if args.rotate:
         page.add_transformation(pypdf.Transformation().translate(tx=-a4_width/2, ty=-a4_height/2))
         page.add_transformation(pypdf.Transformation().rotate(-90))
         page.add_transformation(pypdf.Transformation().translate(tx=a4_width/2, ty=a4_height/2))
+        print("-r: rotating (by 90°) page", rotate)
 
 # normalize all pages to portrait A4
 for page in pages_to_add:
@@ -76,7 +83,8 @@ if args.crop_range:
           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(',')]
+      crop_left, crop_bottom, crop_right, crop_top = [float(x) * points_per_cm for x in  crops.split(',')]
+      print("-c: to pages %d to %d applying crops: left %dcm, bottom %dcm, right %dcm, top %dcm" % (start_page + 1, end_page, crop_left, crop_bottom, crop_right, crop_top))
       cropped_width  = a4_width - crop_left - crop_right
       cropped_height = a4_height - crop_bottom - crop_top
       zoom = 1
@@ -112,10 +120,9 @@ if not args.nup4:
         odd_page = not odd_page
 
 else:
-    points_per_mm = 2.83465
     n_pages_per_axis = 2
-    spine_limit = args.spine * points_per_mm
-    printable_margin = args.margin * points_per_mm
+    spine_limit = args.spine * points_per_cm
+    printable_margin = args.margin * points_per_cm
     printable_scale = (a4_width - 2*printable_margin)/a4_width
     half_width = a4_width / n_pages_per_axis
     half_height = a4_height / n_pages_per_axis
@@ -239,9 +246,6 @@ else:
                 c.line(x_right_spine_limit, a4_height, x_right_spine_limit, 0)
             if front_page:
                 c.setLineWidth(0.2)
-                cut_depth = 19.5 * points_per_mm
-                cut_width = 10.5 * points_per_mm
-                middle_point_depth = 4 * points_per_mm
 
                 start_up_left_left_x = x_left_spine_limit - 0.5 * cut_width
                 start_up_left_right_x = x_left_spine_limit + 0.5 * cut_width
@@ -266,8 +270,9 @@ else:
             writer.add_page(new_page)
             i = 0
             front_page = not front_page
+
+# write and close
 for file in opened_files:
     file.close()
-
 with open(args.output_file, 'wb') as output_file:
     writer.write(output_file)