Double Buffering?
Jason Weber
I am writing GL for the Amiga so that I can do some work at home.
(GL is the graphics language used on Silicon Graphics machines).
I got most of it working pretty well, but I've got some questions.
Can I double buffer a single window and, if so, how?
For now, I cloned the RastPort and gave it a new PixMap. I draw in the
backbuffer and do a raster copy to the front. It is not very fast, but
it's better than having the flashing of single buffer draws.
There is something in my device manual about double-buffering but it talks
second-hand (ie. do something like this, something like that, etc) and
gives no examples. I do get the impression that I may have to double buffer
the whole screen. This would make it different than GL which I don't like.
If someone could give me an example, I would really appreciate it.
If you ask why I want to write in GL, let me give you some examples of the
length of the source:
Open new window: 2-4 lines
Animate 3D cube in orthogonal or perspective view: about 10 lines
read keyboard/event from que: 2 lines
poll keyboard/mouse directly: 1 line
Of course, all programmers will build their own library to do these things.
But, using GL, I can take source to the SG with no changes.
Please respond to my question. I would also appreciate an email response
in case I miss the news response somehow.
_ Jason Weber Phone:(703)704-1796
( \ _ \ /_ / _ _ Teletronics Inc 704-3901
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// Modeling Simulation Branch
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Tobias Ruland
>I am writing GL for the Amiga so that I can do some work at home.
>(GL is the graphics language used on Silicon Graphics machines).
>I got most of it working pretty well, but I've got some questions.
>Can I double buffer a single window and, if so, how?
double-buffering is integrated in the operating system since v39!
i can post an example code if you want me to.
tobias
Richard Johnson
then flip it to the front. Does anybody know of a better way?
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Jason Weber
>double-buffering is integrated in the operating system since v39!
>i can post an example code if you want me to.
>
> tobias
>
Please do!
Most responses implied I could only double buffer a screen
or bob. I would like to see how you double buffer a window.
Nick C. Fotis
>I am writing GL for the Amiga so that I can do some work at home.
>(GL is the graphics language used on Silicon Graphics machines).
>If you ask why I want to write in GL, let me give you some examples of the
>length of the source:
>Open new window: 2-4 lines
>Animate 3D cube in orthogonal or perspective view: about 10 lines
>read keyboard/event from que: 2 lines
>poll keyboard/mouse directly: 1 line
>Of course, all programmers will build their own library to do these things.
>But, using GL, I can take source to the SG with no changes.
[ I'm pretty sorry I can't help with the double buffering issue ]
But I would like to ask publically: has anyone plans to port
OpenGL to the Amiga?? The people at SGI told me that there was no
interest in porting from CBM or a third party vendor.
[ Or at least: will someone (like the poster) put out a GL library for
the Amiga?? ]
I declare here that I would *love* to get a Zorro III board with hardware
and libraries for running OpenGL (like the EGS boards for 2D work).
Anyone interested? The Amiga could use either the Du Pont Pixel chips
or something like the IrisVision board. I would like to develop 3D
software for such a machine...
Sorry for this blabber, but I wanted to steam off... [or so.. ;-) ]
Greetings,
Nick.
--
Nick (Nikolaos) Fotis National Technical Univ. of Athens, Greece
HOME: 16 Esperidon St., InterNet : nfo...@theseas.ntua.gr
Halandri, GR - 152 32 UUCP: mcsun!pythia!theseas!nfotis
Athens, GREECE FAX: (+30 1) 77 84 578
Mike Austin
: double-buffering is integrated in the operating system since v39!
: i can post an example code if you want me to.
: tobias
You mean that drawing lines, boexes, etc in V.39 is automatically double
buffered? That would be awsome!
Michael van Elst
>: double-buffering is integrated in the operating system since v39!
>: i can post an example code if you want me to.
>You mean that drawing lines, boexes, etc in V.39 is automatically double
>buffered? That would be awsome!
Obviously not. :)
V39 just added support for double buffering of Intuition screens.
Regards,
--
Michael van Elst
UUCP: universe!local-cluster!milky-way!sol!earth!uunet!unido!mpirbn!p554mve
Internet: p55...@mpirbn.mpifr-bonn.mpg.de
"A potential Snark may lurk in every tree."
Richard Johnson
TE> i can post an example code if you want me to.
I only have workbench 1.3. How does v39 implement double buffering?
Is it fast? I'd like to see the example code.
Eric Schug
> I am writing GL for the Amiga so that I can do some work at home.
> (GL is the graphics language used on Silicon Graphics machines).
> I got most of it working pretty well, but I've got some questions.
> Can I double buffer a single window and, if so, how?
For some help, here are two programs:
For double buffering look at NBuff on aminet.
And for writing GL like routines look at a package called vogl (use archie).
Vogl is a package of machine independant routines that work similar to SGI's GL.
Because they are machine independant it is slow, and the package doesn't include
an amiga driver. I also use GL, but I never found vogl useful enough to use
at home because, it is slow and doesn't have any of the lighting routines that
I use the most. If your really interested in vogl I could send you a copy of
my half finished amiga driver code (devices dont work properly). Not being
satisfied with vogl I am (slowly) writing my own vector/lighting graphics
routines my hope it to get nice INTERACTIVE rendering routines.
If you find any more useful programs please tell me as I am always looking
for ways to save myself some work.
Eric Schug.
email => sc...@u.washingtion.edu