Path: utzoo!attcan!uunet!cs.utexas.edu!romp!auschs!sergio!sergio
From: sergio@sergio.uucp (Sergio Perrone/30000)
Newsgroups: comp.graphics
Subject: Re: IRIS ANIMATION QUESTIONS
Message-ID: <2816@auschs.ibm.com>
Date: 31 Jul 90 14:10:37 GMT
References: <90Jul31.082130edt.7234@neat.cs.toronto.edu>
Sender: news@auschs.ibm.com
Reply-To: sergio@reed.UUCP (Sergio Perrone/30000)
Organization: IBM AWD, Austin, TX
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In article <90Jul31.082130edt.7234@neat.cs.toronto.edu> mgreen@cs.toronto.edu (Marc Green) writes:
>I just bought an IRIS but have been unable to perform animation the
>way I'd like. I'm hoping that someone may have had similar experience
>and offer some suggestions.
>
>I want to create animation by predrawing a series of frames and
>panning/scrolling to them. (The pictures have to be drawn pixel by
>pixel and cannot be redrawn in one or two sweeps so double buffering
>doesn't work. Even so I need at least 4 frames.) In my old system, I
>had hardware zoom and pan. I could do animation by:
>
>1) zooming up to create off screen memory. The lower resolution was
>OK. I can get by with 256 X 256.
>
>2) then draw 4-8 frames off screen
>
>3) and then make a movie by cycling them through the display buffer
>for viewing.
>
>Can I simulate this on the IRIS?
>
>I can work in color map mode and reduced resolution is OK. 
>
>Marc Green
>Trent University

How's this for an alternative...

1.  Open a graphics window, draw frames one at a time; as each one is drawn
    capture it into an array with rectread/lrectread.  Dump to a file or 
    keep in memory.  The array might be this -

    long int x[NUMFRAMES][256*256];

    for RGB data.

2.  Assuming your window is fullscreen, do ...

    rectzoom( 1280.0/256.0, 1024.0/256.0 );

3.  Now loop through your frames...

    for (i = 0; i < 8; i++){
      rectwrite/lrectwrite( 0, 0, 256-1, 256-1, x[i] );
    }

At the reduced resolution, this is tolerably fast on a PI and quite fast
on a GT/GTX/etc.

Marc

--- Marc Andreessen, IBM AWD Austin, sergio@sergio.austin.ibm.com   ---
--- Words and ideas contained herein are independent of IBM policy. ---