#!/usr/bin/make -f
#
# This file:
#   http://angg.twu.net/bin/djvuize.html
#   http://angg.twu.net/bin/djvuize
#    (find-angg        "bin/djvuize")
#
# This is a makefile that I use to convert JPGs - usually photos of
# whiteboards - to black-and-white PNGs, and then to single-page
# DJVUs, then to a many-page DJVU, then to a many-page PDF. Each of
# the courses that I teach has a directory with photos of its
# whiteboards and with a makefile based on this one, and I use that
# makefile to produces a single-file printable PDF version of its
# whiteboards. For example:
#
#     http://angg.twu.net/2019.1-C2.html
#     http://angg.twu.net/2019.1-C2/
#     http://angg.twu.net/2019.1-C2/Makefile.html
#     http://angg.twu.net/2019.1-C2/Makefile
#     http://angg.twu.net/2019.1-C2/2019.1-C2.pdf
#      (find-angg        "2019.2-C2/Makefile")
#
# This was based on:
#      (find-angg        "SCANS/Makefile")
#
# See: (find-node "(make)Text Functions")

default:
	@echo Hello

THIS  = all
PNGS  = $(patsubst %.jpg,%.png,$(wildcard *.jpg))
DJVUS = $(patsubst %.png,%.djvu,$(wildcard *.png))

# (find-angg "bin/whiteboard")
# (find-es "gimp" "whiteboard")
pngs_:
	echo $(PNGS)
pngs: $(PNGS)
%.png: %.jpg
	whiteboard $(WHITEBOARDOPTS) $< $@

%.pgm: %.png
	convert $< $@
%.pbm: %.pgm
	mkbitmap -x -f 50 -t 0.4 $< -o $@
%.djvu: %.pbm
	cjb2 -lossy $< $@

djvus_:
	echo $(DJVUS)
djvus: $(DJVUS)

djvu: $(THIS).djvu
$(THIS).djvu: $(DJVUS)
	djvm -create $(THIS).djvu $(DJVUS)

pdf: $(THIS).pdf
%.pdf: %.djvu
	ddjvu -format=pdf $< $@