XSGIvcSetChannelInputRectangle(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
          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