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From: marbru@attc.UUCP (Martin Brunecky)
Newsgroups: comp.windows.x
Subject: Re: X{Put,Get}Scanline (was Re: XImages)
Message-ID: <953@attc.UUCP>
Date: 4 Jan 91 15:53:14 GMT
References: <935@attc.UUCP> <9012172158.AA07950@expire.lcs.mit.edu> <938@attc.UUCP> <1990Dec19.225710.4008@dsd.es.com> <3391@gazette.bcm.tmc.edu> <949@attc.UUCP> <12607@life.ai.mit.edu>
Reply-To: marbru@auto-trol.UUCP (Martin Brunecky)
Organization: Auto-trol Technology, Denver
Lines: 36

In article <12607@life.ai.mit.edu> sundar@ai.mit.edu writes:
>In article <949@attc.UUCP>, marbru@attc.UUCP (Martin Brunecky) writes:
>|> In article <3391@gazette.bcm.tmc.edu> etaylor@wilkins.iaims.bcm.tmc.edu (Eric Taylor) writes:
>|> >X{PutGet}ScanLine sounds like one of the best ideas I have heard
>|> >in a while concerning images.  This would be a VERY good way to
>|> >speed up imaging applications without having to sacrifice 
>|> >generality for different depths.
>|> 
>Is there any reason not to make this independent of the routines 
>needed to deal with XImages? I can see other programs which have
>nothing to do with Images benefitting from X{PutGet}ScanLine.

 If by "independent of the routines needed to deal with XImages" you
 mean X{Put|Get}ScanLine that would operate on a *drawable* as oposed
 to XImage, there is a reason:
 Such functions would require a protocol extension, UNLESS implemented
 as a convenience functions internally calling X{Put|Get}ScanLine operating
 on XImage and X{Put|Get}Image. 
 Implementations using XDrawPoints etc. are also possible - but in most
 cases much less efficient than the one using the XImage interface.
 If we had the X{Put|Get}Image, writing such a convenience function
 would be trivial.

 
 In my opinion, going directly to a drawable for each scanline would not
 be very efficient. In my applications, I would always try to get/put
 an image strip using X{Get|Put}Image, process individual lines using
 X{Get|Put}ScanLine ( there are definitely tradeoffs - how many scanlines
 pers strip, neither 1 nor "ALL" being optimum - dependent on the client
 and server combination, transfer direction etc.).

-- 
=*= Opinions presented here are solely of my own and not those of Auto-trol =*=
Martin Brunecky                           {...}sunpeaks!auto-trol!marbru
(303) 252-2499                        (sometimes also:  marbru@auto-trol.COM )
Auto-trol Technology Corp. 12500 North Washington St., Denver, CO 80241-2404