From: Daniel Colascione <dancol@dancol.org>
To: Juanma Barranquero <lekktu@gmail.com>
Cc: 10397@debbugs.gnu.org
Subject: bug#10397: [PATCH] Under Remote Desktop, NUMCOLORS is unreliable; workaround
Date: Thu, 29 Dec 2011 08:23:50 -0800 [thread overview]
Message-ID: <4EFC9416.6090005@dancol.org> (raw)
In-Reply-To: <CAAeL0STx_Ayi_GjRtheqbXBrdtBh9-Xa_5JZORxtE-c+KrxzgA@mail.gmail.com>
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On 12/29/11 8:13 AM, Juanma Barranquero wrote:
> On Thu, Dec 29, 2011 at 15:05, Daniel Colascione <dancol@dancol.org> wrote:
>
>> The workaround
>> seems harmless: on non-palettized displays, calculating the number of
>> display colors based on display bitness should produce good results.
>
> Even so, why fix what is not broken? Why can't you just do
>
> === modified file 'src/w32fns.c'
> --- src/w32fns.c 2011-12-04 08:02:42 +0000
> +++ src/w32fns.c 2011-12-29 16:10:33 +0000
> @@ -4511,5 +4511,12 @@
> cap = GetDeviceCaps (hdc, SIZEPALETTE);
> else
> - cap = GetDeviceCaps (hdc, NUMCOLORS);
> + {
> + cap = GetDeviceCaps (hdc, NUMCOLORS);
> + /* GetDeviceCaps (NUMCOLORS) is buggy under remote desktop and
> + sometimes returns the number of system reserved colors (20)
> + instead of the actual number of available colors. */
> + if (cap == 20)
> + cap = -1;
> + }
Why? What's the point of adding the extra complexity?
Setting cap to -1 leads to this line
1 << min (dpyinfo->n_planes * dpyinfo->n_cbits, 24);
which produces a reasonable result for direct color displays.
Why keep using NUMCOLORS, which we know to be broken?
> /* We force 24+ bit depths to 24-bit, both to prevent an overflow
>
>> + // GetDeviceCaps (NUMCOLORS) is buggy under remote desktop and sometimes
>> + // returns the number of system reserved colors (20) instead of
>> + // the actual number of available colors.
>
> Please, don't use "C++ / modern C" style comments; use /* */ instead.
>
That block slipped through.
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next prev parent reply other threads:[~2011-12-29 16:23 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-29 14:05 bug#10397: [PATCH] Under Remote Desktop, NUMCOLORS is unreliable; workaround Daniel Colascione
2011-12-29 16:13 ` Juanma Barranquero
2011-12-29 16:23 ` Daniel Colascione [this message]
2011-12-29 16:27 ` Juanma Barranquero
2011-12-29 16:42 ` Daniel Colascione
2011-12-29 16:45 ` Juanma Barranquero
2011-12-29 22:59 ` Daniel Colascione
2011-12-29 23:10 ` Juanma Barranquero
2011-12-29 23:13 ` Daniel Colascione
2011-12-29 23:18 ` Juanma Barranquero
2011-12-30 3:07 ` Juanma Barranquero
2011-12-30 3:18 ` Daniel Colascione
2011-12-30 8:51 ` Eli Zaretskii
2011-12-30 9:00 ` Eli Zaretskii
2011-12-30 12:24 ` Juanma Barranquero
2012-08-07 17:13 ` Eli Zaretskii
2012-08-07 17:33 ` Daniel Colascione
2012-08-07 18:07 ` Eli Zaretskii
2016-02-25 6:25 ` Lars Ingebrigtsen
2016-12-13 0:04 ` Glenn Morris
2011-12-30 1:04 ` Jason Rumney
2011-12-30 1:10 ` Daniel Colascione
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