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Groups > comp.lang.postscript > #994
| From | "luser.droog" <luser.droog@gmail.com> |
|---|---|
| Newsgroups | comp.lang.postscript |
| Subject | Are trying to say that coconuts migrate? |
| Date | 2012-10-07 15:08 -0500 |
| Organization | unorganized |
| Message-ID | <k4snfo$cuj$1@dont-email.me> (permalink) |
| References | <k4on45$hj5$1@dont-email.me> |
luser.droog wrote:
> I snagged AK Dewdney's The Armchair Universe from the used book store,
> and spiffed-up by mandelbrot skillz.
>
> I put in the cardioid and bulb2 optimizations from wikipedia, but to
> get pretty spectra as you zoom, you have to increase the max-iterations,
> so each page gets slower and slower (whilst becoming more and more
> awesome).
>
> At some point it'll bottom-out the floats and turn into gibberish, but
> I haven't had the patience to get there yet...
I've evolved this into an "interactive" Mandelbrot-set Explorer.
After rendering, it prints a menu and offers a prompt.
At this prompt, you may type the single-letter commands presented.
Or redefine any parameters with normal postscript (> /maxit 20000 def).
If you enter a blank line, the menu exits, showpage is called and
the process repeats by first rendering the image using the current
parameters (hereafter called the Current Config).
Quit with Interrupt (Ctrl-C).
508(0)03:05 PM:ps 0> cat mandel2.ps
%!
/flushpage where{pop}{/flushpage{}def}ifelse
/rshow { dup stringwidth exch neg exch rmoveto show } def
/commands <<
/help {
(x:eXplore r:Render i:zoom-In o:zoom-Out hjkl:left-down-up-right)=
(az:increase-decrease resolution and iterations)=
}
/a { /M M 1.5 mul def /N N 1.5 mul def /maxit maxit 2 mul def }
/z { /M M .75 mul cvi def /N N .75 mul cvi def /maxit maxit 2 idiv def }
/x { /M 50 def /N 50 def /maxit 200 def }
/r { /M 400 def /N 400 def /maxit 2000 def }
/i { /side side mag div def /maxit maxit 1.2 mul def }
/o { /side side mag mul def /maxit maxit .8 mul cvi def }
/h { /xc xc side step div sub def }
/j { /yc yc side step div sub def }
/k { /yc yc side step div add def }
/l { /xc xc side step div add def }
>> def
commands begin
%calculation parameters
/xc
-.251
def %real center
/yc
.025
def %imaginary center
/side
3.5
%.01
def %length of each side
/M 50 def %rows
/N 50 def %cols
/maxit 200 def
%drawing parameters
currentlinewidth M 2 mul div setlinewidth
/fudge 1.09 def
/ht 500 def
/w 500 def
/resetx { /xloc 50 def } def resetx
/resety { /y 150 def } def resety
/preview true def
%interaction parameters
/mag 3 def %magnification factor
/step 3 def %fraction of view to move by
/menu {
%{
{ %loop until blank line
(Current Config)=
{/xc/yc/side/M/N/maxit} {
dup =string cvs (/) print print ( ) print
load =string cvs print ( def) =
} forall
help
flush
mark
{
%pstack
%count =string cvs print
(> )print flush
(%lineedit)(r)file dup bytesavailable
%dup = flush
dup 0 eq {pop stop}if %blank line: bust an exit
string readline pop
%0 1 index length 1 sub getinterval % chop
%commands 1 index known { commands exch get } if
cvx exec
} stopped {exit}if
cleartomark
} loop
%} stopped { quit } if
} def
/colorpixel {
q sub Q div
%dup .3 mul .7 add
.8
%dup 1 exch sub
%.5
1 index 1 exch sub
sethsbcolor
%dup 1 setrgbcolor
} def
/checkcardioid {
/q ac .25 sub dup mul
bc dup mul add def
ac .25 sub q add q mul
bc dup mul .25 mul
lt %{ /count maxit def exit } if
} def
/checkbulb {
ac 1 add dup mul
bc dup mul add
.0625 lt %{ /count maxit def exit } if
} def
/createtable {
/M M abs def % just in case the explorer flubbed it
/N N abs def %
/maxit maxit abs ceiling def %
M 0 eq { /M 50 def } if
N 0 eq { /N 50 def } if
maxit 0 eq { /maxit 200 def } if
/acorner xc side .5 mul sub def %least real % lower-left x value
/bcorner yc side .5 mul sub def %least imaginary % lower-left y value
/gap side N div def
/Q maxit def
/dh ht M div def
/dw w N div def
/fdh dh fudge mul def
/fdw dw fudge mul def
resetx
resety
/Courier 9 selectfont
% LL coords
xloc 5 sub y moveto bcorner =string cvs rshow
xloc y 12 sub moveto acorner =string cvs show
% LR
xloc w add 5 add y moveto bcorner =string cvs show
xloc w add y 12 sub moveto acorner side add =string cvs rshow
% UL
xloc 5 sub y ht add 12 sub moveto bcorner side add =string cvs rshow
xloc y ht add 3 add moveto acorner =string cvs show
% UR
xloc w add y ht add 3 add moveto acorner side add =string cvs rshow
xloc w add 5 add y ht add 12 sub moveto bcorner side add =string cvs show
/Courier-Bold [ dw maxit log ceiling div 2 mul 0 0 dh 1.2 mul 0 0]
selectfont
/tab [
0 1 M 1 sub { /m exch def
[
0 1 N 1 sub { /n exch def
/ac n gap mul acorner add def
/bc m gap mul bcorner add def
/az 0 def
/bz 0 def
/count 0 def
checkcardioid
checkbulb or {
/count maxit def
}{
{ % loop
az dup mul % z = z^2 + c
bz dup mul sub % = (az + bzi)^2 + ac + bci
ac add %= az^2-bz^2+ac + (2*az*bz+bc)i
2 az bz mul mul
bc add
/bz exch def
/az exch def
/size az dup mul bz dup mul add sqrt def
size 2 ge { exit } if
count maxit ge { exit } if
/count count 1 add def
} loop
} ifelse
count
%dup =
preview {
dup colorpixel
dup maxit ge {
xloc y fdw dh rectfill
}{
xloc y dw fdh rectstroke
xloc y moveto
dup =string cvs show
} ifelse
/xloc xloc dw add def
} if
} for
]
preview {
resetx
/y y dh add def
} if
} for
] def
} def
/findmaxmin {
/q 2 def /Q 0 def
tab {
{
dup maxit lt {
dup q lt { dup /q exch def } if
dup Q gt { dup /Q exch def } if
} if
pop
} forall
} forall
} def
/sketch {
resetx
resety
tab {
{
dup maxit ge { pop 0 setgray }{
colorpixel
} ifelse
xloc y fdw fdh rectfill
/xloc xloc dw add def
} forall
resetx
/y y dh add def
} forall
} def
% The Main Loop
% - draw the object according to current parameters
% - enter menu loop
% - showpage
{
createtable findmaxmin sketch flushpage
menu
showpage
} loop
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The cleft between the abdomen and the cephalothorax "luser.droog" <luser.droog@gmail.com> - 2012-10-06 02:37 -0500 Are trying to say that coconuts migrate? "luser.droog" <luser.droog@gmail.com> - 2012-10-07 15:08 -0500
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