Message-ID: <B0000039978@datasoft.datasoft.com.br>
From: "Cristovao Braga" <cbraga AT datasoft DOT com DOT br>
To: "Serge Golovin" <res AT marstu DOT mari DOT su>
Cc: <djgpp AT delorie DOT com>
Subject: Re: fli/flc files..
Date: Thu, 27 Feb 1997 22:53:35 -0300
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In order to play an animation backwards, you could create a simple file
format which stored each frame with RLE compression. Since each frame would
contain all data about itself, you could display them in any order.

To speed things up a bit, you could include a list of boxes bounding the
changed areas in the frame, in regard to next and previous ones. But I
don't think it would be worth for small animations.

Cristovao Braga

> From: Serge Golovin <res AT marstu DOT mari DOT su>
> 
> Nigel Taylor wrote:
> > The question is regarding moving within the animation, is it possible 
> > in any way to move BACKWARDS through an animation?? I cant see a 
> > function to do this but it doesnt seem a particularly difficult task 
> > to carry out unless there is something odd about the way that a FLI 
> > stores data and it is impossible to restore the "previous frame" ??
>
> You can NOT play flic backwards. Its stored in file with inter-frame
> compression, so that subsequent frame is just a difference from previous.
> Only (well, almost only) first frame is stored as whole picture.
> To move one frame back you need to cache screenshots of certain frames
> or begin with 1st frame and decomress all frames until you reach frame 
> with number current-1.
> Though there is "ring frame" its frame with differences between last and
> first frame. 
> -- 
> SerGo, aka RES