XSGIvcSetChannelInputRectangle(3XSGIvcSetChannelInputRectangle(3)
NAME
XSGIvcSetChannelInputRectangle,
XSGIvcQueryBestChannelRectangle - Video Pan and Zoom
SYNOPSIS
#include <X11/extensions/XSGIvc.h>
void XSGIvcSetChannelInputRectangle(Display *display,
int screen,
int channel,
XSGIvcRectangle rct)
Status XSGIvcQueryBestChannelRectangle(Display *display,
int screen,
int channel,
XSGIvcRectangle rct,
XSGIvcRectangle *rrct)
PARAMETERS
display Specifies the connection to the X server.
screen Specifies the screen of the X server.
channel Specifies the channel number.
rct Specifies the origin or/and the size to which
the rectangle should be set (specified in
pixels).
rrct Return the origin and the size of the rectangle
(specified in pixels).
DESCRIPTION
Each channel of an X server displays a rectangular region of
pixels of the root window. In operation, the channel
fetches the specified input rectangle from the frame buffer.
On configurations with one channel, the input rectangle is
usually the size of the root window; however, some X server
video hardware permits the input rectangle to change origin
and size.
To change the size or origin of the rectangle, use
XSGIvcSetInputRectangle. Both size and origin are required,
even if only one is changed. To determine the current size
and origin, use the XSGIvcQueryChannelInfo function.
If an X server does permit changes to the input rectangle,
the server may impose restrictions on the values of both
size and origin. The XSGIvcQueryBestChannelRectangle
function provides a means to determine the rectangle nearest
to the size and origin you specify. Determination of the
Page 1 (printed 7/20/06)
XSGIvcSetChannelInputRectangle(3XSGIvcSetChannelInputRectangle(3)
best rectangle is server-dependent, and different situations
may yield different results.
EVENTS
When this control is altered, the server generates a
ChannelInputRectangle event.
RETURNED VALUE
XSGIvcQueryBestChannelRectangle returns TRUE if a rectangle
is found of a valid supported size and origin (the valid
size of which is found in the returned variables); this
function returns FALSE when no valid rectangle was found
(among which is the case when the server does not support
change of size or origin).
Parameter errors are reported via BadValue or BadMatch.
SEE ALSO
XSGIvc, XSGIvcQueryChannelInfo
Page 2 (printed 7/20/06)
