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List:       kde-devel
Subject:    Re: kimgio and qimgio : nonsense.
From:       Sirtaj Singh Kang <ssk () physics ! unimelb ! edu ! au>
Date:       1999-05-23 14:46:36
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On Sun, 23 May 1999, Jo Dillon wrote:
[snip]
>   Whereas Qt uses RGB in one table and A in another, if I recall correctly.

I don't know what happens inside a QPixmap, but QImage also stores the
alpha channel for each pixel in the MSB of the 32-bit data.

> and XCopyArea from the X pixmap to QPixmap.handle(). That's still wasteful
> of server-side memory though. Grr.

That would be absolutely disastrous considering how X servers grow in
memory footprint over time. I looked at some of the Imlib image loading
routines after writing the PNG reader. It looked almost exactly the same
as my code (except that imlib saves the gamma info etc in a separate
struct, whereas I got libpng to use it while decoding) so I don't think
that's where the speed improvement comes from. I guess it has to be
somewhere in the conversion to an X Pixmap. 

Anyone feel like checking this? 

-Taj.

Sirtaj S. Kang       taj@kde.org         ssk@physics.unimelb.edu.au
Univ of Melbourne	
			"I'm a commercial operating system."
				-Doug Michels (CEO SCO)

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