DP=8
MOD=1
while [[ "${#MOD}" -le "${DP}" ]]
do
        MOD="${MOD}0"
done

ESCAPED=0

function ftofix {       # ftofix OUTPUTNAME "3.14"
        local _N="0"
        local D=0
        local X
        local Y

        # Convert "VAR" "-.3" into "VAR" "-" "0.3", etc
        case "$2" in
        [.]*)           set -- "$1" "" "0$2"            ;;
        [0-9]*)         set -- "$1" "" "$2"             ;;
        [+-][0-9.]*)    set -- "$1" "${2:0:1}" "${2:1}" ;;
        *)              return 1                        ;;
        esac

        for((X=0; X<${#3}; X++))
        do
                if [[ "${3:$X:1}" == "." ]]
                then
                        (( X++ )) ; break
                fi

                (( _N = (10*_N) + ${3:$X:1} ))
        done

        while [[ "$D" -lt "$DP" ]]
        do
                Y="${3:$((X+D)):1}"
                [ -z "$Y" ] && Y=0

                (( _N = (10*_N) + Y ))
                (( D++ ))
        done

        read "$1" <<EOF
${2}${_N}
EOF
}

function fixtof {
        _VAR="$1"
        _N="$2"
        _SIGN=""
        ((_N<0)) && _SIGN="-" && ((_N=-_N))
        _S=`printf "%s%d.%0${DP}d" "${_SIGN}" $((_N/MOD)) $((_N%MOD))`
        read $_VAR <<EOF
$_S
EOF
}

function escape { # R I
        # Z Z C C R
        set -- 0 0 $1 $2 $(( (($1*$1)+($2*$2))/MOD ))
        local N=0

        while [[ "$N" -lt "$EMAX" ]] && [[ "$5" -lt $((4*MOD)) ]]
        do
                set -- $(( $3 + (($1*$1) - ($2*$2))/MOD ))      \
                        $(( $4 + (2*$1*$2)/MOD )) $3 $4         \
                        $(( (($1*$1)+($2*$2))/MOD ))
                (( N++ ))
        done

        (( N >= EMAX )) && (( ESCAPED ++ ))

        return $N
}

Y=0

STUFF=" .oOo. -=%#%=-"

ftofix CY       ${1-0.0}
ftofix CX       ${2--0.5}
ftofix W        ${3-1.0}
EMAX=${4-100}

XMIN=$((CX-W))
XMAX=$((CX+W))
YMIN=$((CY-W))
YMAX=$((CY+W))

XSTEP=$(( (XMAX-XMIN) / 70 ))
YSTEP=$(( (YMAX-YMIN) / 20 ))

for ((Y=YMIN; Y < YMAX; Y += YSTEP ))
do
        S=""
        for ((X=XMIN; X < XMAX; X += XSTEP ))
        do
                escape "$X" "$Y"
                Z="$?"
                [ "$Z" -eq "$EMAX" ] && Z=0 || (( Z %= ${#STUFF} ))

                S="$S${STUFF:$Z:1}"
        done
        echo "|$S|"
done

echo "Escaped $ESCAPED times" >&2

exit 0

./mandel2.sh

|Ooooooooooooooooooooooooooooo...........    -=%%.#%=-- ........oooooooO|
|oooooooooooooooooooooooo.............     -=%#%o%%o%%=-    .......ooooo|
|oooooooooooooooooooo.............   ----==%%O      .# #=--      .....oo|
|oooooooooooooooo...........   -==%o%%%%%##%=.       O=%##%==----==- ...|
|oooooooooooo......        ---==% .  Ooo                   o-=-=oo%==  .|
|oooooo....             ----=%# =.                               = %--  |
|....  -=%%%==============%%#=.o                                  .%#== |
|     --=%% o-o-- %   =%##%%.%                                     o-%--|
|   -===%-=.=            -oO%                                      -.#- |
|==%%- O.o                 O                                       %=-  |
|                                                              --%%=--  |
|==%%- O.o                 O                                       %=-  |
|   -===%-=.=            -oO%                                      -.#- |
|     --=%% o-o-- %   =%##%%.%                                     o-%--|
|....  -=%%%==============%%#=.o                                  .%#== |
|oooooo....             ----=%# =.                               = %--  |
|oooooooooooo......        ---==% .  Ooo                   o-=-=oo%==  .|
|oooooooooooooooo...........   -==%o%%%%%##%=.       O=%##%==----==- ...|
|oooooooooooooooooooo.............   ----==%%O      .# #=--      .....oo|
|oooooooooooooooooooooooo.............     -=%#%o%%o%%=-    .......ooooo|

$