[kaminkatze]

Originally Posted by geekmaster

The easiest is to ASSUME that the kindle has 300 byte-wide pixels per line, with values "dd if=$DZ of=$DF ..." or "echo -e '\xff'|dd of=$DF ...".

Something like this:

Spoiler:

#!/bin/sh

#===========================
# cleanup - delete tmp files
#---------------------------
trap 'cleanup ; exit' SIGINT SIGTERM
cleanup() {
  rm $DL $BF
}

#===========================
# initvar - init global vars
#---------------------------
initvar() {
  XF=140 XL=160 YF=190 YL=210
  DN=/dev/null DF=/dev/fb0 BF=$(mktemp "/tmp/tempXXXXXX") LL=300
  D='0' L='F' DD=/dev/zero DL=$(mktemp "/tmp/tempXXXXXX")
  echo -ne "\xFF" >$DL
  eips -c
  for x in $(seq $((XF-2)) $((XL+2))); do
    setpix $x $((YF-2)); setpix $x $((YL+2))
  done
  for y in $(seq $((YF-2)) $((YL+2))); do
    setpix $((XF-2)) $y; setpix $((XL+2)) $y
  done
}

#===========================
# usage: load x y name
#---------------------------
load() {
  local x=$((XF+$1)) y=$((YF+$2)) name=$3
  case "$name" in
  glider)
    setpix $((x+1)) $y
    setpix $((x+2)) $((y+1))
    setpix $x $((y+2))
    setpix $((x+1)) $((y+2))
    setpix $((x+2)) $((y+2)) ;;
  esac; eips ''
}

#===================================
# usage: setpix x y
#-----------------------------------
setpix() {
  local x=$1 y=$(($2*2))
  dd if=$DL of=$DF bs=1 count=1 seek=$((y*LL+x)) 2>$DN
  dd if=$DL of=$DF bs=1 count=1 seek=$(((y+1)*LL+x)) 2>$DN
}

#===================================
# update - update field
#-----------------------------------
update() {
  local b m t c v
  cat $DF > $BF
  for x in $(seq $XF $XL); do
  for y in $((YF-1)) $YF; do y=$((y*2))
    m=$b b=$(hexdump -v -s $((y*LL+x-1)) -n 3 -e '/1 "%X"' $BF)
  done
  for y in $(seq $YF $YL); do y=$((y*2))
    t=$m m=$b b=$(hexdump -v -s $(((y+2)*LL+x-1)) -n 3 -e '/1 "%X"' $BF)
    c=$(expr length "$b$m$t")
    v=$(hexdump -s $((y*LL+x)) -n 1 -e '"%X"' $BF)
    if [[ $v == $D ]]; then
      [[ $c -eq 12 ]] && v=$DL || v=$DD
    else
      [[ $c -lt 12 -o $c -gt 13 ]] && v=$DD || v=$DL
    fi
    dd if=$v of=$DF bs=1 count=1 seek=$((y*LL+x)) 2>$DN
    dd if=$v of=$DF bs=1 count=1 seek=$(((y+1)*LL+x)) 2>$DN
  done; done; eips ''
}

#===================================
# loop - update loop
# usage: loop steps
#-----------------------------------
loop() {
  local c=$1 p=0 t0=$(date +%s) t1
  eips "Generation: 0"
  while [[ $p -lt $c ]]; do
    update; p=$((p+1))
    t1=$(date +%s)
    eips "Generation: $p ($((t1-t0))s)"
    t0=$t1
  done
}

initvar
load 2 2 glider
loop 100
cleanup

Originally Posted by geekmaster

Another option I thought of was to use a 600-byte wide /tmp/buffer (to hold a scan line for both touch/k4 8-bit pixels or the k3/dx 4-bit pixels) and then for the k3/dx draw 4 different pixel pair bytes to the framebuffer based on the values (\x00 \xf0 \x0f \xff).

Any hints on how to condense the line? I tried some things with awk but had problems with \x00 in the input. (Never used awk before so this could be entirely my fault.)