/useful/trunk-1

#!/usr/bin/env bash

####

# FILE NAME process_text_to_image.sh

#

# Changes

#

# 2018-09-03:

#   * added --no-header for when you want to use your own pandoc header

#

# 2018-09-22

#   * Fixed --no-header...

#     Seemed to have forgotten the "$" infront of the variable.

#

# 2021-01-13

#   * fixed up the if statments.

#

####

__DPI=300

__IN_FILE=

__OUT_FILE=big_image

__PERSERVE_TMP=false

__INVERT_COLOURS=false

__NO__PANDOC_HEADER=false

__CWD=$PWD

__PANDOC_HEADER="

geometry: margin=0.5cm

papersize: a5

mainfont: DejaVu Serif

fontsize: 12pt

"

__TITLE=""

echo "-----"

echo "---"

echo "--"

echo "-"

function __usage () {

  echo "process_text_to_image.sh - Takes one text file and convernts it to a single"

  echo "image using pandoc, xelatex, imagemagick, pdftoppm, pdfcrop"

  echo ""

  echo "!IMPORTANT! The folder \"./tmp/\" in the current working directory will be"

  echo "            used as a temporary storage, and may be deleted, along with it's"

  echo "            contents!"

  echo ""

  echo "---------------------"

  echo ""

  echo "-h	--help"

  echo "	Print this help message"

  echo ""

  echo "-i <file>	--input <file>"

  echo "	The file to use to convert to an image. "

  echo ""

  echo "-o <file>	--output <file>"

  echo "	The image to output to. (Default=big_image.png)"

  echo ""

  echo "-d <integer>	-- dpi <integer>"

  echo "	Set the dpi of the intermediate image relative to an a5 paper."

  echo "	(Default=300)"

  echo ""

  echo "-p		--perserve"

  echo "	Do not delete the TMP folder."

  echo ""

  echo "-invert"

  echo "	Invert the colours of the final image."

  echo ""

  echo "-t \"name\"	--title \"name\""

  echo "	Set the title on the the title page."

  echo ""

  echo "--no-header"

  echo "	Do not insert the pandoc header. (Default:"

  echo "$__PANDOC_HEADER"

  echo ")"

  echo ""

  echo "---------------------"

  echo ""

  echo "If you are getting an error from convert that the height or width exeeds"

  echo "some value, you may want to check the ImageMagick policy.xml file."

  echo ""

  echo "The path to ImageMagick policy file is:"

  convert -list policy | grep .xml 

  echo ""

  echo "---------------------"

}

function __main () {

  #ESCAPED_CWD=$(echo ${CWD} | sed 's/ /\\ /g' | sed "s/'/\\\'/g" )

  echo "__IN_FILE\: $__IN_FILE"

  echo "__OUT_FILE\: $__OUT_FILE"

  echo "CWD\: $__CWD"

  echo "__DPI: $__DPI"

  #echo "ESCAPED_CWD\: $ESCAPED_CWD"

  if [[ ! -e "$__CWD/$__IN_FILE" ]]

  then

    echo "!!!in file does not exist!!!"

    echo ""

    #print_help

    exit 1

  fi

  # first we create a temp folder.

  mkdir -p "$__CWD/tmp"

  #next we want to copy our file into it.

  cp "$__CWD/$__IN_FILE" "$__CWD/tmp/text.txt"

  cd "$__CWD/tmp"

  # Now we can start the work for this.

  if [[ $__NO__PANDOC_HEADER == false ]]

  then

    # We add a special header to the file to make it pandoc know what to do.

    printf '%s\n' "---" "$(cat "$__CWD/tmp/text.txt")" > "$__CWD/tmp/text.txt"

    if [ -n __TITLE="" ]

    then

      printf '%s\n' "title: ${__TITLE}" "$(cat "$__CWD/tmp/text.txt")" > "$__CWD/tmp/text.txt"

    fi

    printf '%s' "$__PANDOC_HEADER" "$(cat "$__CWD/tmp/text.txt")" > "$__CWD/tmp/text.txt"

    printf '%s' "---" "$(cat "$__CWD/tmp/text.txt")" > "$__CWD/tmp/text.txt"

  fi

  # Now we use pandoc to do to convert it to a PDF.

  pandoc --pdf-engine=xelatex "$__CWD/tmp/text.txt" -o "$__CWD/tmp/text.pdf"

  pdfcrop --margins '10 5 10 5' "$__CWD/tmp/text.pdf" "$__CWD/tmp/text-croped.pdf"

  # Convert it to images

  pdftoppm "$__CWD/tmp/text-croped.pdf" "$__CWD/tmp/page" -png -rx $__DPI -ry $__DPI -gray

  # convert make the colour space greyscale and the append to each other

  convert -append -colorspace gray +matte -depth 8 "$__CWD/tmp/page-*.png" "$__CWD/tmp/big-page.png"

  FINAL_IMAGE=""

  # If we invert the final image this is where we do it.

  if [[ $__INVERT_COLOURS == true ]]

  then

    convert "$__CWD/tmp/big-page.png" -channel RGB -negate "$__CWD/tmp/big-page-inverted.png"

    FINAL_IMAGE="$__CWD/tmp/big-page-inverted.png"

  else

    FINAL_IMAGE="$__CWD/tmp/big-page.png"

  fi

  cp "$FINAL_IMAGE" "$__CWD/$__OUT_FILE.png"

  ####

  # Cleanup of eveything.

  ####

  if [[ $__PERSERVE_TMP == true ]]

  then

    echo "Not cleaning up!"

  else

    rm -r "$__CWD/tmp"

  fi

}

function __parse_args () {

  if [[ -z "$1" ]]

  then

    echo "Try --help or -h."

    exit 1

  fi

  while [[ $# -gt 0 ]]

  do

    case "${1}" in

      -i|--input)

      __IN_FILE="$2"

      shift

      shift

      ;;

      -o|--output)

      __OUT_FILE="$2"

      shift

      shift

      ;;

      -t|--title)

      __TITLE="$2"

      shift

      shift

      ;;

      -d|--dpi)

      __DPI="$2"

      shift

      shift

      ;;

      -p|--perserve)

      __PERSERVE_TMP=true

      shift

      ;;

      --invert)

      __INVERT_COLOURS=true

      shift

      ;;

      --no-header)

      __NO__PANDOC_HEADER=true

      shift

      ;;

      -h|--help)

      __usage

      exit

      shift

      ;;

      *)

      #print_help

      #exit 1

      shift

      ;;

      --)

      shift

      break

      ;;

    esac

  done

}

__parse_args "${@}"

__main

echo "-"

echo "--"

echo "---"

echo "----"