XSGIvcSetPlatformParameter(3)

     NAME
          XSGIvcSetPlatformParameter, XSGIvcQueryPlatformParameter -
          Set and query a video parameter unique to a graphics
          platform

     SYNOPSIS
          #include <X11/extensions/XSGIvc.h>

          void XSGIvcSetPlatformParameter(Display *display,
              int screen,
              int channel,
              int parameterID,
              void *parameterBlock,
              int sizeofParameterBlock)

          Status XSGIvcQueryPlatformParameter(Display *display,
              int screen,
              int channel,
              int parameterID,
              void *parameterBlock,
              int sizeofParameterBlock)

     PARAMETERS
          display                Specifies the connection to the X
                                 server.

          screen                 Specifies the screen of the X server.

          channel                Specifies the channel number.

          parameterID            Specifies which parameter is to be
                                 affected or queried.  The parameterID
                                 is unique only to a graphics hardware
                                 platform; the same parameterID may be
                                 used by different hardware platforms
                                 to define different operations.

          parameterBlock         A pointer to the parameter block to
                                 be used for the operation.

          sizeofParameterBlock   The size of the parameter block for
                                 this parameter.  The size must match
                                 the size expected for this
                                 parameterID.



     DESCRIPTION
          Some graphics hardware platforms may offer controls that are
          not supported across the entire range of Silicon GraphicsTM
          machines, but instead are unique to a certain graphics
          hardware platform.  In this circumstance, you may affect the
          control via XSGIvcSetPlatformParameter.

          Each hardware platform may optionally offer one or more
          platform-specific control parameters.  Because these are
          unique, these parameters are described in the documentation
          accompanying the hardware.  Each parameter has a different
          parameter block associated with it.  The constitution of the
          parameterBlock is defined by a structure provided by an
          included file that accompanies the hardware platform.

          You may retrieve the value of the parameter by calling
          XSGIvcQueryPlatformParameter which fills the parameter block
          with the current values of the control parameter.

          Note that if you use platform-specific control parameters,
          you are affecting a control used on only one platform.  The
          control is not guaranteed to operate on any other platform
          than the one on which the control parameter is designated.


     EVENTS
          When this control is altered, the server generates a
          PlatformParamNotify event.


     RETURNED VALUE
          XSGIvcQueryPlatformParameter returns TRUE if successful,
          FALSE upon failure.

          Parameter errors are reported via BadValue or BadMatch.



     EXAMPLE
          In the following contrived example, the graphics hardware
          platform called NewPlatform contains the following
          definitions to describe a parameter control named IOCUS
          whose type is integer.  The definitions might be contained
          in a file named XSGIvcNewPlatform.h and might include:

          #define IOCUS_PARAMETER 5
          #define IOCUS_MIN 0
          #define IOCUS_MAX 32

          typedef struct _iocus {
              int       value;
          }    iocus_t;

          To use the IOCUS control parameter, call the
          XSGIvcSetPlatformParameter function; the following example
          sets the value to its lowest value.

          #include <X11/extensions/XSGIvc.h>
          #include <XSGIvcNewPlatform.h>

          iocus_t     parameterBlock;
          int         channel = 2;

          parameterBlock.value = IOCUS_MIN;

          XSGIvcSetPlatformParameter(dpy,
              screen,
              channel,
              IOCUS_PARAMETER,
              &parameterBlock,
              sizeof(parameterBlock));



     SEE ALSO
          XSGIvc