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List:       kde-core-devel
Subject:    Re: Review Request: KColorSpace::KHCY::KHCY(const & QColor)
From:       "Matthew Woehlke" <mw_triad () users ! sourceforge ! net>
Date:       2009-06-22 19:55:51
Message-ID: 20090622195551.13681.51737 () localhost
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This seems overly complicated (and also wrong if >8-bit color precision is in play). \
Can the 'r', 'g', 'b' qreals be trusted, or do they have similar problems? If yes, I \
think it works (better) to simply replace the entire 'if (0.0 == y || 1.0 == y)' test \
with 'if (r == g && g == b)'?

- Matthew


On 2009-06-21 22:44:32, Michael Kreitzer wrote:
> 
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> This is an automatically generated e-mail. To reply, visit:
> http://reviewboard.kde.org/r/868/
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> 
> (Updated 2009-06-21 22:44:32)
> 
> 
> Review request for kdelibs.
> 
> 
> Summary
> -------
> 
> The constructor KColorSpace::KHCY::KHCY(const & QColor) has a floating point \
> precision error exposed by the -ftree-pre flag in gcc 4.4 which is enabled with -O2 \
> optimizations. The result is an invalid chroma calculation in the corner case of \
> full white (1.0, 1.0, 1.0 in rgb). The patch works around this by performing an \
> integer comparison of r, g, and b and setting chroma to 0.0 if all 3 are equal. 
> 
> This addresses bugs 194703 and 195522.
> https://bugs.kde.org/show_bug.cgi?id=194703
> https://bugs.kde.org/show_bug.cgi?id=195522
> 
> 
> Diffs
> -----
> 
> trunk/KDE/kdelibs/kdeui/colors/kcolorspaces.cpp 985087 
> 
> Diff: http://reviewboard.kde.org/r/868/diff
> 
> 
> Testing
> -------
> 
> This patch corrects the test case code in bug 195522. It also removes all color \
> errors when applied to my system wide kdelibs library. 
> 
> Thanks,
> 
> Michael
> 
> 


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