Hi

This has probably been done at least 83 times before but I thought I'd share
anyway.

jim
p.s. blink and you'll miss it...

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Attachments:
Download 'movie1000.mpg' (562 KB)

> This has probably been done at least 83 times before but I thought I'd share
> anyway.

Yeah, I did this too once - but not as good.

I really wanna try this with *lots* of different IFS's... I don't know 
if you've seen it, but on my copy of RedHat there was an IFS 
screensaver. Seems to be able to draw random IFS's in realtime => very 
impressive! (That's gotta take some SERIOUS CPU time...)

Andrew @ home on Mozilla.

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Andrew C on Mozilla wrote:
> I really wanna try this with *lots* of different IFS's... I don't know 
> if you've seen it, but on my copy of RedHat there was an IFS 
> screensaver. Seems to be able to draw random IFS's in realtime => very 
> impressive! (That's gotta take some SERIOUS CPU time...)

Actually no. I'm sorry if I destroy an illusion, but apparently this 
screensaver precalculates the IFS once, then draws it in various sizes 
and rotations, and with varying angles for the branches. This can be 
done very efficiently with matrices, and the drawing itself is just a a 
matter of setting a few pixels to a color.

On the box where I'm sitting now (Fedora Core 1.0 on an Athlon 800) the 
system load doesn't go up by more than perhaps 1% when this screensaver 
is started.

-- 
(defun f(p x)(If(Eq x nil)nil(If(p(Car x))(Cons(Car x)(f p(Cdr x)))(f p
(Cdr x)))))(defun q(x)(Q nil x))(defun Q(a x)(If(Eq x nil)a(Q(Cons(Car
x)(Q a(f(Lt(Car x))(Cdr x))))(f(Gt(Car x))(Cdr x)))))

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Hi. May I see the code for this effect? I suppose the process could be used
with a variety of "target shapes..."

Thanks much,
Dennis

"James Taylor" <jim### [at] blueyondercouk> wrote in message
news:40368248@news.povray.org...
> Hi
>
> This has probably been done at least 83 times before but I thought I'd
share
> anyway.
>
> jim
> p.s. blink and you'll miss it...
>
>
>

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Dennis Miller wrote:
> Hi. May I see the code for this effect? I suppose the process could be used
> with a variety of "target shapes..."

I just got myself the source of xscreensaver 
(http://www.jwz.org/xscreensaver/) and looked into 
xscreensaver-4.14/hacks/ifs.c. I don't claim I understand that code in 
its entirety after the few minutes I spent reading it, but it appears to 
me that this mess of a code does pretty much what I suspected: 
precalculate once, then just repeatedly transform and draw. But I could 
err, of course. Anyway, with this code being such a mess I doubt you 
could easily adapt it to other shapes. IMHO it would be better to write 
a new program from scratch...

-- 
(defun f(p x)(If(Eq x nil)nil(If(p(Car x))(Cons(Car x)(f p(Cdr x)))(f p
(Cdr x)))))(defun q(x)(Q nil x))(defun Q(a x)(If(Eq x nil)a(Q(Cons(Car
x)(Q a(f(Lt(Car x))(Cdr x))))(f(Gt(Car x))(Cdr x)))))

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"Dennis Miller" <dhm### [at] comcastnet> wrote in message
news:403a9622$1@news.povray.org...
> Hi. May I see the code for this effect? I suppose the process could be
used
> with a variety of "target shapes..."

Hi Dennis,

I've posted the scene files to p.b.scene-files for you to take a gander at
:)
The way the code is setup should make it extremely easy to use other target
shapes. The target shape is simply held in the "seirp_array" array in the
code so just replace that part of the code which calculates the shape.

jim

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Thanks much. Will take a look.
Best,
Dennis
"James Taylor" <jim### [at] blueyondercouk> wrote in message
news:403bdcb2@news.povray.org...
> "Dennis Miller" <dhm### [at] comcastnet> wrote in message
> news:403a9622$1@news.povray.org...
> > Hi. May I see the code for this effect? I suppose the process could be
> used
> > with a variety of "target shapes..."
>
> Hi Dennis,
>
> I've posted the scene files to p.b.scene-files for you to take a gander at
> :)
> The way the code is setup should make it extremely easy to use other
target
> shapes. The target shape is simply held in the "seirp_array" array in the
> code so just replace that part of the code which calculates the shape.
>
> jim
>
>

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