#!/bin/bash

#############################################################

# #

# Program: mzoom #

# Author: dw #

# Date: 2007-07-07 #

# Purpose: Explore the Mandelbrot set in bash! #

# Usage: See below #

# Version: 1.01.6930 #

# #

#############################################################

#### Usage: Run with no arguments, program will draw full mandelbrot set. After set is complete,

#### use the arrow keys to navigate to the upper left corner of an area you want to zoom into,

#### then press the "z" key once, use the right arrow key again to move to the right, you are now

#### deciding how big of a "box" to draw around the area, when you are far enough to the right,

#### press the "z" key one more time, this will draw a box roughly around the area to be zoomed

#### into, after a brief pause, the program will zoom into the area you selected. Repeat process

#### to continue zooming, use control c to exit.

#### As your level of zoom increases, you'll want to increase the number of iterations, you can

#### do this by pressing the "i" key while in zoom mode, anytime before pressing the second "z",

#### this will increase the max iterations by 50 each time.

#### This program uses integer math to explore the Mandelbrot set, it will not zoom in as far as

#### a "real" Mandelbrot explorer, but floating point was just too slow in bash, you'll know when

#### you hit the limit, I have tested it to about 2,000,000 magnification. My bash/python hybred

#### version zooms much further and is over 40 times faster. :-)

#### GET CURRENT SCREEN SIZE - METHOD 1

w=`tput cols`

e=`tput lines`

#### DO WE HAVE A SCREEN SIZE? IF NOT, TRY METHOD 2

if [ ! "$w" ]

then

#### GET CURRENT SCREEN SIZE - METHOD 2

w=`stty -a | grep rows | awk -F ";" '{print$3}' | awk '{print$2}'`

e=`stty -a | grep rows | awk -F ";" '{print$2}' | awk '{print$2}'`

#### HOW ABOUT NOW?

if [ ! "$w" ]

then

clear;echo;echo "COULD NOT OBTAIN SCREEN SIZE";echo;exit

fi

fi

#### SET MAX X & Y

((w = w - 1));((e = e - 1));maxy="$e";maxx="$w"

#### SETUP THE COLOR VARIABLES

off="\033[0m";gry="\033[1;0m";red="\033[1;31m";grn="\033[1;32m";yel="\033[1;33m"

blu="\033[1;34m";pur="\033[1;35m";aqu="\033[1;36m";wht="\033[1;37m"

#### SET THE BC PRECESION

pre=20

#### SETUP THE MANDELBROT VARIABLES

si=$(echo "scale=$pre;(2.5)" | bc) ### length of side = 2.5

c=$(echo "scale=$pre;(-2.00)" | bc) ### acorner = -2

k=$(echo "scale=$pre;(-1.25)" | bc) ### bcorner = -1.25

it=100 ### iterations = 100

#### SETUP THE COLOR ARRAYS

p[1]="$gry";p[2]="$wht";p[3]="$red";p[4]="$grn";p[5]="$yel"

p[6]="$blu";p[7]="$pur";p[8]="$aqu";p[9]="$wht"

nsi=$(echo "scale=$pre;(2.5)" | bc)

#### THE MAIN ROUTINE

mandelbrot()

{

#### FILL THE COLOR ARRAY

x=1;z=0;xx=1

while ((x < it))

do

((z++))

if ((z > 9))

then

z=1

fi

pix["$x"]="${p[$z]}""$xx"

((x++));((xx++))

if ((xx > 9))

then

xx=1

fi

done

#### AUTO CALCULATE ASPECT RATIO

ar=$(echo "scale=$pre;($w/$e)/2" | bc)

gr=$(echo "scale=$pre;($si/($w/$ar))" | bc)

#### MULTIPLIER FOR INTEGER MATH IS 2^27 SO WE USE A 27 BIT SHIFT IN THE MAIN LOOP

mul=134217728;clear;m=0;n=0;pxl="M";g=`echo "$gr" | awk '{print(int($1*'"$mul"'))}'`

hr=$(echo "scale=$pre;($si/$e)" | bc);h=`echo "$hr" | awk '{print(int($1*'"$mul"'))}'`

gcr=$(echo "scale=$pre;(($gr+$c)*$mul)" | bc);gc=`echo "$gcr" | awk '{print(int($1))}'`

mhkr=$(echo "scale=$pre;(($hr+$k)*$mul)" | bc);mhk=`echo "$mhkr" | awk '{print(int($1))}'`

ngc="$gc";writexy="tput cup";((mul4 = mul << 2))

#### PRINT ZOOM RATIO, ITERATIONS AND COORDINATES AT LOWER LEFT CORNER OF SCREEN

mag1=$(echo "scale=$pre;(2.5/$nsi)" | bc);echo -e "$wht"

mag2=`echo "$mag1" | awk '{print int($0)}'`

$writexy $((maxy - 3)) 0;echo -n " ZOOM = $mag2"

$writexy $((maxy - 2)) 0;echo -n " ACORNER = $c "

$writexy $((maxy - 1)) 0;echo -n " BCORNER = $k "

$writexy $((maxy - 0)) 0;echo -n " ITERATIONS = $it "

#### THE MAIN LOOP WITH 27 BIT SHIFT

while ((m < e))

do

x=1;tput cup $m $n

while ((x < it))

do

((v = (a * b) >> 27));((a = (aq - bq) + ngc));((b = (v << 1) + mhk))

((aq = (a * a) >> 27));((bq = (b * b) >> 27))

if ((aq + bq > mul4))

then

echo -en ${pix[$x]};((x = it))

fi

((x++))

done

a=0;b=0;aq=0;bq=0;((n++));((ngc = ngc + g))

if ((n > w))

then

n=0;((m++));ngc=gc;((mhk = mhk + h))

fi

done

echo -en "$off"

}

#### THE ZOOM ROUTINE

zoomin()

{

zoom=0;x=0;y=0;maxy="$e";maxx="$w";beenhere=0

read_keys()

{

key="";read -sn1 key

case "$key" in

A) ((y--));if ((y < 0));then y=0;fi

;;

B) ((y++));if ((y > maxy));then ((y--));fi

;;

D) ((x--));if ((x < 0));then x=0;fi

;;

C) ((x++));if ((x > maxx));then ((x--));fi

;;

i) ((it = it + 50));tput cup $maxy 0;echo -en "$red ITERATIONS = $it $off"

;;

z) ((zoom++));beenhere=1

;;

esac

}

while ((zoom != 2))

do

if ((zoom == 1)) && ((beenhere == 1));then x1="$x";y1="$y";beenhere=0;fi

if ((zoom == 2)) && ((beenhere == 1));then x2="$x";y2="$y";beenhere=0;zoom=3;fi

if ((zoom != 2));then read_keys;fi

if ((beenhere == 0));then tput cup $y $x;echo -en "$wht#$off";fi

done

X1="$x1";Y1="$y1";X2="$x";Y2="$y";Y1org="$Y1";X1org="$X1";X2org="$X2"

if ((X1 >= X2));then clear;echo;echo "X2 MUST BE GREATER THAN X1";echo;exit;fi

#### DRAW CRAPPY BOX

((dif = X2 - X1));xx="$X1";((xxx = xx + dif));tput cup $Y1 $X1

while ((xx < xxx))

do

((xx++));tput cup $Y1 $xx;echo -en "$wht#$off"

done

xx="$Y1";((xxx = xx + (dif >> 1)));tput cup $Y1 $X1

while ((xx < xxx))

do

((xx++));if ((xx > maxy)); then xxx="$maxy";fi

tput cup $xx $X1;echo -en "$wht#$off"

done

Y2="$xx";((xx = X1));tput cup $Y2 $X1;((xxx = X1 + dif))

while ((xx < xxx))

do

((xx++));tput cup $Y2 $xx;echo -en "$wht#$off"

done

xx="$Y1";((xxx = xx + (dif >> 1)));((X1 = X1 + dif));tput cup $Y1 $X1

while ((xx < xxx))

do

((xx++));if ((xx > maxy)); then xxx="$maxy";fi

tput cup $xx $X1;echo -en "$wht#$off"

done

#### SET COORDINATES FOR ZOOMED IN AREA

nc=$(echo "scale=$pre;(($X1org*$gr)+$c)" | bc)

nk=$(echo "scale=$pre;(($Y1org*$hr)+$k)" | bc)

nsi=$(echo "scale=$pre;(($X2org-$X1org)*$gr)" | bc)

c="$nc";k="$nk";si="$nsi";ngc=0;mhk=0;gc=0;hk=0

sleep 1

}

#### THE INFINITE LOOP

while [ 1 ]

do

mandelbrot

tput cup $maxy 0;echo -en "$grn READY TO ZOOM IN $off"

zoomin

done