XdbeGetVisualInfo(3X11) X FUNCTIONS XdbeGetVisualInfo(3X11)
XdbeGetVisualInfo - Get dbe Visual Informations
#include <X11/extensions/Xdbe.h>
XdbeScreenVisualInfo *XdbeGetVisualInfo(
Display *dpy,
Drawable *screen_specifiers,
int *num_screens)
This function returns information about which visuals sup-
port double buffering. The argument num_screens specifies
how many elements there are in the screen_specifiers list.
Each drawable in screen_specifiers designates a screen for
which the supported visuals are being requested. If
num_screens is zero, information for all screens is
requested. In this case, upon return from this function,
num_screens will be set to the number of screens that were
found. If an error occurs, this function returns NULL, else
it returns a pointer to a list of XdbeScreenVisualInfo
structures of length num_screens. The nth element in the
returned list corresponds to the nth drawable in the
screen_specifiers list, unless num_screens was passed in
with the value zero, in which case the nth element in the
returned list corresponds to the nth screen of the server,
starting with screen zero. The XdbeScreenVisualInfo struc-
ture has the following fields:
int count
XdbeVisualInfo *visinfo
count specifies the number of items in visinfo. visinfo
specifies a list of visuals, depths, and performance hints
for this screen.
The XdbeVisualInfo structure has the following fields:
VisualID visual
int depth
int perflevel
visual specifies one visual ID that supports double-
buffering. depth specifies the depth of the visual. per-
flevel is a performance hint.
The only operation defined on a perflevel is comparison to a
perflevel of another visual on the same screen. The visual
having the higher perflevel is likely to have better
double-buffering graphics performance than the visual having
the lower perflevel. Nothing can be deduced from the
XFree86 Version 4.5.0 1
XdbeGetVisualInfo(3X11) X FUNCTIONS XdbeGetVisualInfo(3X11)
following: the magnitude of the difference of two perflev-
els, a perflevel value in isolation, or comparing perflevels
from different servers.
BadDrawable
One or more values passed in screen_specifiers is not a
valid drawable.
DBE, XdbeAllocateBackBufferName(), XdbeBeginIdiom(),
XdbeDeallocateBackBufferName(), XdbeEndIdiom(), XdbeFreeV-
isualInfo(), XdbeGetBackBufferAttributes(), XdbeQueryExten-
sion(), XdbeSwapBuffers().
XFree86 Version 4.5.0 2
Generated on 2012-02-20 02:47:02 by $MirOS: src/scripts/roff2htm,v 1.70 2011/12/03 18:21:12 tg Exp $
These manual pages and other documentation are copyrighted by their respective writers;
their source is available at our CVSweb,
AnonCVS, and other mirrors. The rest is Copyright © 2002‒2011 The MirOS Project, Germany.
This product includes material
provided by Thorsten Glaser.
This manual page’s HTML representation is supposed to be valid XHTML/1.1; if not, please send a bug report – diffs preferred.