Terribly hacky script for generating GIFs of font changes over time

chardiff.sh

#!/bin/bash -e
#
# Generate GIFs of font changes over time
#
# HERE BE DRAGONS!
# This is a hack of a script. It won't just run for you. Edit it to suit your system and needs.
#
pushd "$(dirname "$0")" >/dev/null
chardiffdir=$PWD
pushd "../.." >/dev/null
srcdir=$PWD
fontsample=$srcdir/misc/tools/fontsample/fontsample
popd >/dev/null
popd >/dev/null

outfile=$1
text=$2
xscale=$3
yscale=$4
fontscale=$5
tracking=$6
tile=$7
if [[ "$outfile" == "" ]] || [[ "$text" == "" ]] || [[ "$outfile" == "-h" ]]; then
  echo "usage: $0 <outfile.gif> <text> [<scale> | <xscale> <yscale> [<fontscale> [<tracking> [<tile>]]]]" >&2
  echo "<tile>   The number of rows to tile over. Defaults to 1." >&2
  exit 1
fi
if [[ "$xscale" == "" ]]; then xscale=1; fi
if [[ "$yscale" == "" ]]; then yscale=$xscale; fi
if [[ "$fontscale" == "" ]]; then fontscale=$yscale; fi
if [[ "$tracking" == "" ]]; then tracking=0; fi
if [[ "$tile" == "" ]]; then tile=1; fi

fontsize=$(echo 200 '*' $fontscale | bc -l)
width=$(echo 196 '*' $xscale | bc -l)
height=$(echo 256 '*' $yscale | bc -l)
tracking=$(echo "$tracking * $fontscale" | bc -l)
if [[ "${tracking:0:1}" != "-" ]]; then
  # imagemagick requires positive numbers to be prefixed with + (I think?)
  tracking="+${tracking}"
fi

# space in unscaled pixels to add at bottom for label
labelpadding=40

workdir="$chardiffdir/work"
rm -rf "$workdir"
# workdir=$(mktemp -d "$chardiffdir/work.XXXXXX")
# echo "using workdir $workdir"
# function cleanup_workdir {
#   echo "removing workdir $workdir"
#   rm -r "$workdir"
# }
# trap cleanup_workdir EXIT

# ABCDEFGHIJKLMNOPQRSTUVWXYZ
# abcdefghijklmnopqrstuvwxyz

mkdir -p "$workdir/subframe"
mkdir -p "$workdir/frame"

pushd "${chardiffdir}/fonts" >/dev/null
# generate images
echo "render ${#text} glyphs"
for (( i=0; i<${#text}; i++ )); do
  letter=${text:$i:1}
  # echo "render \"$letter\""
  for v in *.*; do
    framenum=$i
    if [[ ${#framenum} -eq 1 ]]; then
      framenum=00${framenum}
    elif [[ ${#framenum} -eq 2 ]]; then
      framenum=0${framenum}
    fi
    $fontsample -t "$letter" \
      -z $fontsize \
      -width $width \
      -height $height \
      -o "$workdir/subframe/$v-$framenum.png" "$PWD/$v/"*"Regular.otf" >/dev/null &
  done
done
# count versions while we wait for fontsample to finish
numversions=0
for v in *.*; do
  ((numversions++))
done
# wait for fontsample to finish
wait
# compose frames
i=0
framewidth=
frameheight=
echo "compositing ${numversions} frames"
for v in *.*; do
  ver_major=${v/.*/}
  ver_minor=${v#*.}
  # echo "compose frame $(expr $i '+' 1)/${numversions}  (v${ver_major}.$(expr ${ver_minor}))"

  if [[ $i -eq 0 ]]; then
    # first frame montage in main process so we can set framewidth and frameheight in main env
    montage "$workdir/subframe/$v-"*".png" -mode Concatenate -background "#fff" -geometry $tracking+0 -tile "x${tile}" "$workdir/frame/$v.png"
    framewidth=$(identify -format '%W' "$workdir/frame/$v.png")
    frameheight=$(identify -format '%H' "$workdir/frame/$v.png")
    echo "final size: ${framewidth}×$(expr $frameheight '+' $labelpadding)px"
  fi

  (
    if [[ $i -gt 0 ]]; then
      montage "$workdir/subframe/$v-"*".png" -mode Concatenate -background "#fff" -geometry $tracking+0 -tile "x${tile}" "$workdir/frame/$v.png"
    fi
    # extent here adds space at bottom for the label
    convert \
      -gravity North \
      -extent "${framewidth}x$(echo "$labelpadding + $frameheight" | bc -l)" \
      -gravity SouthWest \
      -fill "#0008" -annotate +20+10 "Inter v${ver_major}.$(expr ${ver_minor})" \
      -font /Users/rsms/src/inter/build/fonts/const/Inter-Regular.otf -pointsize 22 \
      "$workdir/frame/$v.png" "$workdir/frame/$v.png"
  ) &

  # montage "$workdir/subframe/$v-"*".png" -mode Concatenate -background "#fff" -geometry $tracking+0 -tile "x${tile}" "-" | \
  #   convert \
  #     -fill "#0008" -annotate +20+10 "Inter v${ver_major}.$(expr ${ver_minor})" \
  #     -gravity SouthWest \
  #     -font /Users/rsms/src/inter/build/fonts/const/Inter-Regular.otf -pointsize 22 \
  #     "-" "$workdir/frame/$v.png" &

  ((i++))
done
wait
popd >/dev/null

echo "build GIF animation"
# https://imagemagick.org/Usage/anim_opt/
convert -delay 5 -loop 0 -coalesce -layers OptimizeFrame -layers OptimizeTransparency "$workdir/frame/"*".png" "$outfile"

gifsicle -O2 "$outfile" -o "$outfile"

eval $(stat -s "$outfile")
echo "wrote $outfile ($(expr ${st_size} '/' 1024)kB)"

# need gifsicle? Try `brew install gifsicle`


# # rename font/version folders
# # cd fonts
# # for v in *.*; do
# #   major=${v/.*/}
# #   minor=${v#*.}
# #   if [ ${#minor} -eq 1 ]; then
# #     minor=0${minor}
# #   fi
# #   name2="${major}.${minor}"
# #   echo mv "$v" "${name2}"
# # done
# # cd ..


# # montage tiles_*.jpg -geometry 0 -tile 10x  result.jpg