#!/usr/bin/env bash

#
# papersize.bash - Single source of truth for GNU troff papersizes
#
# Generates a list of paper formats which can then be transformed
# into generated code for gropdf, papersize.tmac, and libgroff.
# See accompanying gropdf.pl.awk, papersize.tmac.awk, paper.cpp.awk.
#

# Generate paper format for given series and start dimensions
# Returns lines that specify the paper format name and dimensions (width x height)
# and dimension unit indicator metric implying millimeters, e.g.:
# a4 210 297 metric
function iso() {
  series=$1 # The name of the series
  width=$2  # The starting width
  height=$3 # The starting height
  count=$4  # The number of formats to generate, e.g. 10 = A0-A10
  for format in $(seq 0 $count); do
    metric $series$format $width $height
    tmp=$height
    height=$width
    width=$(( tmp / 2 ))
  done
}

# Prints the given first 3 arguments and
# appends the metric dimension unit indicator implying millimeters, e.g.:
# $1 $2 $3 metric
function metric() {
  echo ${1:-unknown} ${2:-0} ${3:-0} metric
}

# Prints the given first 3 arguments and
# appends the imperial dimension unit indicator implying inches, e.g.:
# $1 $2 $3 imperial
function imperial() {
  echo ${1:-unknown} ${2:-0} ${3:-0} imperial
}

#
# Single source of truth for papersizes
#

# ISO Papersizes specified in millimeters
iso a  841 1189 10 
iso b 1000 1414 10 
iso c  917 1297 10 
iso d  771 1090  8 

# ISO Envelopes
metric dl 220 110

# US Papersizes specified in inches
imperial letter     8.5  11
imperial legal      8.5  14
imperial jrlegal    5     8
imperial tabloid   11    17
imperial ledger    17    11
imperial statement  5.5   8.5
# These dimensions for executive paper format are what all printer manufacturers use.
imperial executive  7.25 10.5

# US Envelopes
imperial monarch 7.5  3.875
imperial com10   9.5  4.125