| Re: Object Rubberband Selection Box [message #19797 is a reply to message #19796] |
Tue, 25 April 2000 00:00   |
promashkin
Messages: 169
Registered: December 1999
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Senior Member |
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Hi David,
Not questioning your judgement, I tried the rubberband code I have not
used since I got new computer that has OpenGL supporting ATI-128 card,
w/16 Mb of video ram. I must admit that either rendering method is very
fast, so much so that I can barely make my rubberband "lag" behind the
cursor if I move it across the screen as fast as I can. Also, hardware
rendering appears to be a tad faster in my case. I, no doubt, have a
plainer code than David, so bells and whistles that he has might change
the picture.
Let's just say this Mac (G4-400) is the first Mac I ever had that
performs very nicely and faster than any PC I used (well, I don't have a
real fast one :). Mmaybe the s-l-o-w rubberband is caused by a slow computer?
Cheers,
Pavel
David Fanning wrote:
>
> Hi Folks,
>
> The other day someone complained to me in an e-mail that
> their rubberband selection box in an object graphics program was
> v-e-r-y slow to render. Did I have any ideas?
>
> Since I vaguely remembered doing this before, a long time
> ago, and since I didn't recall any particular problems with
> it, I decided to look into it. I modified my direct graphics
> ZIMAGE program to use object graphics rather than direct
> graphics. Guess what? It was p-a-i-n-f-u-l-l-y slow to
> render!
>
> Humm. What is going on here!? I was instancing my scene.
> I was using a Polyline object for the box. Surely all of
> that was right...
>
> After futzing around for an hour or so I decided to
> check my rendering setting. Hardware acceleration.
> Oh, oh. That should work. Let's try software rendering
> just for laughs. Yikes! Rendering was well over 2 orders
> of magnitude FASTER! In fact, the damn thing worked now.
>
> I checked with the folks at RSI (luckily) before I chucked
> my graphics accelerator card out the window, and they tell
> me that IDL's software renderer has been optimized for
> object instancing. I'm still dubious, but the results
> are irrefutable in this instance. :-)
>
> Anyhow, I thought that was worth knowing and it made me
> feel like I had gotten *something* done today, anyway.
>
> You can find the program I wrote here, if you are interested:
>
> http://www.dfanning.com/programs/zoombox.pro
>
> Cheers,
>
> David
>
> --
> David Fanning, Ph.D.
> Fanning Software Consulting
> Phone: 970-221-0438 E-Mail: davidf@dfanning.com
> Coyote's Guide to IDL Programming: http://www.dfanning.com/
> Toll-Free IDL Book Orders: 1-888-461-0155
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