imposeBooklet.py

#!/usr/bin/env python3
# coding: utf-8

# -------------- #
# impose booklet #
# -------------- #

### Modules
from os import mkdir
from os.path import basename, join, exists
import drawBot as dB

### Constants
FROM_MM_TO_PT = 2.834627813
CROP_LEN = 5*FROM_MM_TO_PT
CROP_DIS = 2*FROM_MM_TO_PT

### Variables - EDIT HERE!!!
fileName = 'booklet/drafts/20190412_booklet_v02.pdf'
sheetCanvas = 297*FROM_MM_TO_PT, 210*FROM_MM_TO_PT
pagesPerSignature = 16
outputFolder = 'imposed'
marks = False

bleed = {
    'ver': 5*FROM_MM_TO_PT,
    'hor': 5*FROM_MM_TO_PT,
}

### Instructions
inputPages = dB.numberOfPages(fileName)
assert inputPages % 4 == 0, 'check the amount of input pages'
assert inputPages % pagesPerSignature == 0, 'check the amount of input pages'

if exists(outputFolder) is False:
    mkdir(outputFolder)

for signature in range(inputPages//pagesPerSignature):
    startingPage = signature*pagesPerSignature
    pages = list(range(startingPage+1, startingPage+pagesPerSignature+1))

    dB.newDrawing()
    for eachPage in range(pagesPerSignature//2):
        dB.newPage(*sheetCanvas)

        if eachPage % 2 == 1:
            lftPageIndex = eachPage
            rgtPageIndex = -(eachPage+1)
        else:
            rgtPageIndex = eachPage
            lftPageIndex = -(eachPage+1)
        lftPageNumber = pages[lftPageIndex]
        rgtPageNumber = pages[rgtPageIndex]

        imgWdt, imgHgt = dB.imageSize(fileName)

        with dB.savedState():
            dB.translate(dB.width()/2, dB.height()/2-imgHgt/2)
            dB.image(fileName, (-imgWdt, 0), pageNumber=lftPageNumber)
            dB.image(fileName, (0, 0), pageNumber=rgtPageNumber)

        if marks is True:
            with dB.savedState():
                dB.cmykStroke(1, 1, 1, 1)
                dB.translate(dB.width()/2, dB.height()/2)

                # crop marks
                for scaling in [(-1, -1), (1, -1), (-1, 1), (1, 1)]:
                    with dB.savedState():
                        dB.scale(*scaling)
                        dB.translate(imgWdt-bleed['hor'], imgHgt/2-bleed['ver'])
                        # btm lft
                        pt1 = CROP_DIS,          0
                        pt2 = CROP_DIS+CROP_LEN, 0

                        dB.line(pt1, pt2)   # hor
                        pt3 = 0, CROP_DIS
                        pt4 = 0, CROP_LEN+CROP_DIS
                        dB.line(pt3, pt4)   # ver

                # fold marks
                for scaling in [(1, 1), (1, -1)]:
                    with dB.savedState():
                        dB.scale(*scaling)
                        pt5 = 0, imgHgt/2 - bleed['ver'] + CROP_DIS
                        pt6 = 0, imgHgt/2 - bleed['ver'] + CROP_DIS + CROP_LEN
                        dB.line(pt5, pt6)

    cleanFileName = basename(fileName).replace('.pdf', '')
    dB.saveImage(join(outputFolder, f"{cleanFileName}_sign{signature+1:0>2d}.pdf"))
    dB.endDrawing()