+def collect_per_page_crops_and_zooms(args_crops, args_symmetry, pages_to_add):
+ crop_at_page = [PageCrop()] * len(pages_to_add)
+ zoom_at_page = [1]*len(pages_to_add)
+ if args_crops:
+ for c_string in args_crops:
+ page_range, crops = split_crops_string(c_string)
+ start_page, end_page = parse_page_range(page_range, pages_to_add)
+ prefix = "-c, -t" if args_symmetry else "-c"
+ suffix = " (but alternating left and right crop between even and odd pages)" if args_symmetry else ""
+ page_crop_cm = PageCrop(*[x for x in crops.split(',')])
+ page_crop = PageCrop(*[float(x) * POINTS_PER_CM for x in page_crop_cm])
+ crop_listing = ", ".join([f"{key} {val}cm" for key, val in page_crop_cm._asdict().items()])
+ print(f"{prefix}: to pages {start_page + 1} to {end_page} applying crop: {crop_listing}{suffix}")
+ cropped_width = A4_WIDTH - page_crop.left - page_crop.right
+ cropped_height = A4_HEIGHT - page_crop.bottom - page_crop.top
+ zoom = 1
+ zoom_horizontal = A4_WIDTH / (A4_WIDTH - page_crop.left - page_crop.right)
+ zoom_vertical = A4_HEIGHT / (A4_HEIGHT - page_crop.bottom - page_crop.top)
+ if (zoom_horizontal > 1 and zoom_vertical < 1) or (zoom_horizontal < 1 and zoom_vertical > 1):
+ raise HandledException("-c: crops would create opposing zoom directions")
+ 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):
+ if args_symmetry and page_num % 2:
+ crop_at_page[page_num] = PageCrop(left=page_crop.right, right=page_crop.left, bottom=page_crop.bottom, top=page_crop.top)
+ else:
+ crop_at_page[page_num] = page_crop
+ zoom_at_page[page_num] = zoom
+ return crop_at_page, zoom_at_page
+
+def build_single_pages_output(writer, pages_to_add, crop_at_page, zoom_at_page):
+ print("building 1-input-page-per-output-page book")
+ odd_page = True
+ for i, page in enumerate(pages_to_add):
+ zoom = zoom_at_page[i]
+ page.add_transformation(pypdf.Transformation().translate(tx=-crop_at_page[i].left, ty=-crop_at_page[i].bottom))
+ page.add_transformation(pypdf.Transformation().scale(zoom, zoom))
+ cropped_width = A4_WIDTH - crop_at_page[i].left - crop_at_page[i].right
+ cropped_height = A4_HEIGHT - crop_at_page[i].bottom - crop_at_page[i].top
+ page.mediabox.right = cropped_width * zoom
+ page.mediabox.top = cropped_height * zoom
+ writer.add_page(page)
+ odd_page = not odd_page
+ print(f"built page number {i+1} (of {len(pages_to_add)})")
+
+def build_nup4_output(writer, pages_to_add, crop_at_page, zoom_at_page, args_print_margin, args_analyze, canvas_class):
+ print("-n: building 4-input-pages-per-output-page book")
+ print(f"-m: applying printable-area margin of {args_print_margin}cm")
+ if args_analyze:
+ print("-a: drawing page borders, spine limits")
+ printable_margin = args_print_margin * POINTS_PER_CM
+ printable_scale = (A4_WIDTH - 2 * printable_margin)/A4_WIDTH
+ spine_part_of_page = (SPINE_LIMIT / A4_HALF_WIDTH) / printable_scale
+ bonus_shrink_factor = 1 - spine_part_of_page
+ pages_to_add, new_i_order = resort_pages_for_nup4(pages_to_add)
+ nup4_position = 0
+ page_count = 0
+ is_front_page = True
+ for i, page in enumerate(pages_to_add):
+ if nup4_position == 0:
+ new_page = pypdf.PageObject.create_blank_page(width=A4_WIDTH, height=A4_HEIGHT)
+ corrected_i = new_i_order[i]
+ nup4_inner_page_transform(page, crop_at_page[corrected_i], zoom_at_page[corrected_i], bonus_shrink_factor, printable_margin, printable_scale, nup4_position)
+ nup4_outer_page_transform(page, bonus_shrink_factor, nup4_position)
+ new_page.merge_page(page)
+ page_count += 1
+ print(f"merged page number {page_count} (of {len(pages_to_add)})")
+ nup4_position += 1
+ if nup4_position > 3:
+ ornate_nup4(writer, args_analyze, is_front_page, new_page, printable_margin, printable_scale, bonus_shrink_factor, canvas_class)
+ writer.add_page(new_page)
+ nup4_position = 0
+ is_front_page = not is_front_page
+
+def resort_pages_for_nup4(pages_to_add):
+ new_page_order = []
+ new_i_order = []
+ eight_pack = []
+ i = 0
+ n_eights = 0
+ for page in pages_to_add:
+ if i == 0:
+ eight_pack = []
+ eight_pack += [page]
+ i += 1
+ if i == 8:
+ i = 0
+ for n in PAGE_ORDER_FOR_NUP4:
+ new_i_order += [8 * n_eights + n]
+ new_page_order += [eight_pack[n]]
+ n_eights += 1
+ return new_page_order, new_i_order
+
+def nup4_inner_page_transform(page, crop, zoom, bonus_shrink_factor, printable_margin, printable_scale, nup4_position):
+ page.add_transformation(pypdf.Transformation().translate(ty=(A4_HEIGHT / zoom - (A4_HEIGHT - crop.top))))
+ if nup4_position == 0 or nup4_position == 2:
+ page.add_transformation(pypdf.Transformation().translate(tx=-crop.left))
+ elif nup4_position == 1 or nup4_position == 3:
+ page.add_transformation(pypdf.Transformation().translate(tx=(A4_WIDTH / zoom - (A4_WIDTH - crop.right))))
+ page.add_transformation(pypdf.Transformation().scale(zoom * bonus_shrink_factor, zoom * bonus_shrink_factor))
+ if nup4_position == 2 or nup4_position == 3:
+ page.add_transformation(pypdf.Transformation().translate(ty=-2*printable_margin/printable_scale))
+
+def nup4_outer_page_transform(page, bonus_shrink_factor, nup4_position):
+ page.add_transformation(pypdf.Transformation().translate(ty=(1-bonus_shrink_factor)*A4_HEIGHT))
+ if nup4_position == 0 or nup4_position == 1:
+ y_section = A4_HEIGHT
+ page.mediabox.bottom = A4_HALF_HEIGHT
+ page.mediabox.top = A4_HEIGHT
+ if nup4_position == 2 or nup4_position == 3:
+ y_section = 0
+ page.mediabox.bottom = 0
+ page.mediabox.top = A4_HALF_HEIGHT
+ if nup4_position == 0 or nup4_position == 2:
+ x_section = 0
+ page.mediabox.left = 0
+ page.mediabox.right = A4_HALF_WIDTH
+ if nup4_position == 1 or nup4_position == 3:
+ page.add_transformation(pypdf.Transformation().translate(tx=(1-bonus_shrink_factor)*A4_WIDTH))
+ x_section = A4_WIDTH
+ page.mediabox.left = A4_HALF_WIDTH
+ page.mediabox.right = A4_WIDTH
+ page.add_transformation(pypdf.Transformation().translate(tx=x_section, ty=y_section))
+ page.add_transformation(pypdf.Transformation().scale(QUARTER_SCALE_FACTOR, QUARTER_SCALE_FACTOR))
+
+def ornate_nup4(writer, args_analyze, is_front_page, new_page, printable_margin, printable_scale, bonus_shrink_factor, canvas_class):
+ if args_analyze:
+ # borders
+ packet = io.BytesIO()
+ c = canvas_class(packet, pagesize=A4)
+ c.setLineWidth(0.1)
+ c.line(0, A4_HEIGHT, A4_WIDTH, A4_HEIGHT)
+ c.line(0, A4_HALF_HEIGHT, A4_WIDTH, A4_HALF_HEIGHT)
+ c.line(0, 0, A4_WIDTH, 0)
+ c.line(0, A4_HEIGHT, 0, 0)
+ c.line(A4_HALF_WIDTH, A4_HEIGHT, A4_HALF_WIDTH, 0)
+ c.line(A4_WIDTH, A4_HEIGHT, A4_WIDTH, 0)
+ c.save()
+ new_pdf = pypdf.PdfReader(packet)
+ new_page.merge_page(new_pdf.pages[0])
+ printable_offset_x = printable_margin
+ printable_offset_y = printable_margin * A4_HEIGHT / A4_WIDTH
+ new_page.add_transformation(pypdf.Transformation().scale(printable_scale, printable_scale))
+ new_page.add_transformation(pypdf.Transformation().translate(tx=printable_offset_x, ty=printable_offset_y))
+ x_left_spine_limit = A4_HALF_WIDTH * bonus_shrink_factor
+ x_right_spine_limit = A4_WIDTH - x_left_spine_limit
+ if args_analyze or is_front_page:
+ packet = io.BytesIO()
+ c = canvas_class(packet, pagesize=A4)
+ if args_analyze:
+ # spine lines
+ c.setLineWidth(0.1)
+ c.line(x_left_spine_limit, A4_HEIGHT, x_left_spine_limit, 0)
+ c.line(x_right_spine_limit, A4_HEIGHT, x_right_spine_limit, 0)
+ if is_front_page:
+ c.setLineWidth(0.2)
+ draw_cut(c, x_left_spine_limit, (1))
+ draw_cut(c, x_right_spine_limit, (-1))
+ if args_analyze or is_front_page:
+ c.save()
+ new_pdf = pypdf.PdfReader(packet)
+ new_page.merge_page(new_pdf.pages[0])
+
+def draw_cut(canvas, x_spine_limit, direction):
+ outer_start_x = x_spine_limit - 0.5 * CUT_WIDTH * direction
+ inner_start_x = x_spine_limit + 0.5 * CUT_WIDTH * direction
+ middle_point_y = A4_HALF_HEIGHT + MIDDLE_POINT_DEPTH * direction
+ end_point_y = A4_HALF_HEIGHT + CUT_DEPTH * direction
+ canvas.line(inner_start_x, A4_HALF_HEIGHT, x_spine_limit, end_point_y)
+ canvas.line(x_spine_limit, end_point_y, x_spine_limit, middle_point_y)
+ canvas.line(x_spine_limit, middle_point_y, outer_start_x, A4_HALF_HEIGHT)