NAME¶
X11::Protocol::Ext::TOG_CUP - colormap utilization policy extension
SYNOPSIS¶
use X11::Protocol;
my $X = X11::Protocol->new;
$X->init_extension('TOG-CUP')
or print "TOG-CUP extension not available";
DESCRIPTION¶
The TOG-CUP extension helps applications with private colormaps use the same
pixel for the same color in different colormaps.
Using common pixel values, were possible, means that when a private colormap is
in use ("$x->InstallColormap()", usually done by the window
manager) some of the colours in other windows will still appear correctly.
Note that this extension makes a subtle change to the core
"$X->AllocColor()" and "$X->AllocNamedColor()"
requests. Normally they allocate the first available pixel, but with TOG-CUP
if there's a matching colour in the default colormap and that same pixel in
the target colormap is free then that pixel is allocated, thus making that
colour the same in the two colormaps.
REQUESTS¶
The following are made available with an "init_extension()" per
"EXTENSIONS" in X11::Protocol.
my $bool = $X->init_extension('TOG-CUP');
- "($server_major, $server_minor) = $X->CupQueryVersion
($client_major, $client_minor)"
- Negotiate a protocol version with the server. $client_major and
$client_minor is what the client would like, the returned $server_major
and $server_minor is what the server will do, which might be different.
The current code supports up to 1.0. The intention would be to automatically
negotiate in "init_extension()" if necessary, which it's
currently not.
- "@colors = $X->CupGetReservedColormapEntries ($screen)"
- Return a list of reserved colormap entries in the default colormap of
screen number $screen (an integer 0 upwards). Each returned element is an
arrayref
[ $pixel, $red16, $blue16, $green16, $alloc_flags ]
$red16, $blue16 and $green16 are RGB colour components in the range 0 to
65535. $alloc_flags is currently unused.
Reserved colours are pre-allocated and unchanging. The core protocol
specifies "$X->{'black_pixel'}" and
"$X->{'white_pixel'}" and they're included in the result,
plus any further colours which might be reserved.
For example under the MS-DOS graphical overlay manager there's a certain set
of "desktop" colours which a server on that system might treat
as reserved.
- "@colors = $X->CupStoreColors ($colormap,
[$pixel,$red16,$green16,$blue16],...)"
- Allocate read-only colours in $colormap at particular pixels.
Each argument is an arrayref of desired pixel and RGB colour. (A $do_mask
parameter can be present at the end too but is unused and can be omitted.)
[ $pixel, $red16, $blue16, $green16 ]
The desired colour is allocated shareable read-only (like
"$X->AllocColor()") at the given $pixel if possible, or
another if necessary. The return is a similar list of arrayref elements,
one for each argument
[ $pixel, $red16, $blue16, $green16, $alloc_flags ]
The returned $pixel might differ from what was requested. If the requested
$pixel is already allocated, and it has a different colour, then another
pixel value is chosen.
The returned RGB components are the actual colour shade allocated. This
might differ if the visual has limited colour resolution (which is
likely).
The returned $alloc_flags has bit 0x08 set if the pixel was successfully
allocated, or clear if not. Other bits in $alloc_flags are currently
unused.
For example
my @ret = $X->CupStoreColors
($colormap,
[ 2, 65535,0,0], # red
[ 3, 0,65535,0], # green
[ 4, 16383,16383,16383]); # grey
foreach my $elem (@ret) {
my ($pixel, $red,$green,$blue, $alloc_ok) = @$elem;
my $ok = ($alloc_ok & 8 ? "allocated" : "oops, not allocated");
print "at $pixel actual $red,$green,$blue $ok\n";
}
SEE ALSO¶
X11::Protocol
Colormap Utilization Policy and Extension, Version 1.0
http://www.xfree86.org/current/tog-cup.html
/usr/share/doc/x11proto-xext-dev/tog-cup.txt.gz,
/usr/share/X11/doc/hardcopy/Xext/tog-cup.PS.gz
HOME PAGE¶
<
http://user42.tuxfamily.org/x11-protocol-other/index.html>
LICENSE¶
Copyright 2011, 2012, 2013 Kevin Ryde
X11-Protocol-Other is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later version.
X11-Protocol-Other is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details.
You should have received a copy of the GNU General Public License along with
X11-Protocol-Other. If not, see <
http://www.gnu.org/licenses/>.