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     XCreateGC(3X)                                  XCreateGC(3X)



     NAME
          XCreateGC, XCopyGC, XChangeGC, XFreeGC, XGContextFromGC
          - create or free graphics contexts

     SYNOPSIS
          GC XCreateGC(display, d, valuemask, values)
                Display *display;
                Drawable d;
                unsigned long valuemask;
                XGCValues *values;

          XCopyGC(display, src, valuemask, dest)
                Display *display;
                GC src, dest;
                unsigned long valuemask;

          XChangeGC(display, gc, valuemask, values)
                Display *display;
                GC gc;
                unsigned long valuemask;
                XGCValues *values;

          XFreeGC(display, gc)
                Display *display;
                GC gc;

          GContext XGContextFromGC(gc)
                GC gc;

     ARGUMENTS
          d         Specifies the drawable.

          dest      Specifies the destination GC.

          display   Specifies the connection to the X server.

          gc        Specifies the GC.

          src       Specifies the components of the source GC.

          valuemask Specifies which components in the GC are to
                    be set, copied, or changed . This argument is
                    the bitwise inclusive OR of one or more of
                    the valid GC component mask bits.

          values    Specifies any values as specified by the
                    valuemask.

     DESCRIPTION
          The XCreateGC function creates a graphics context and
          returns a GC.  The GC can be used with any destination
          drawable having the same root and depth as the



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     XCreateGC(3X)                                  XCreateGC(3X)



          specified drawable.  Use with other drawables results
          in a BadMatch error.

          XCreateGC can generate BadAlloc, BadDrawable, BadFont,
          BadMatch, BadPixmap, and BadValue errors.

          The XCopyGC function copies the specified components
          from the source GC to the destination GC.  The source
          and destination GCs must have the same root and depth,
          or a BadMatch error results.  The valuemask specifies
          which component to copy, as for XCreateGC.

          XCopyGC can generate BadAlloc, BadGC, and BadMatch
          errors.

          The XChangeGC function changes the components specified
          by valuemask for the specified GC.  The values argument
          contains the values to be set.  The values and
          restrictions are the same as for XCreateGC.  Changing
          the clip-mask overrides any previous XSetClipRectangles
          request on the context. Changing the dash-offset or
          dash-list overrides any previous XSetDashes request on
          the context.  The order in which components are
          verified and altered is server-dependent.  If an error
          is generated, a subset of the components may have been
          altered.

          XChangeGC can generate BadAlloc, BadFont, BadGC,
          BadMatch, BadPixmap, and BadValue errors.

          The XFreeGC function destroys the specified GC as well
          as all the associated storage.

          XFreeGC can generate a BadGC error.

     DIAGNOSTICS
          BadAlloc  The server failed to allocate the requested
                    resource or server memory.

          BadDrawable
                    A value for a Drawable argument does not name
                    a defined Window or Pixmap.

          BadFont   A value for a Font or GContext argument does
                    not name a defined Font.

          BadGC     A value for a GContext argument does not name
                    a defined GContext.

          BadMatch  An InputOnly window is used as a Drawable.

          BadMatch  Some argument or pair of arguments has the



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     XCreateGC(3X)                                  XCreateGC(3X)



                    correct type and range but fails to match in
                    some other way required by the request.

          BadPixmap A value for a Pixmap argument does not name a
                    defined Pixmap.

          BadValue  Some numeric value falls outside the range of
                    values accepted by the request.  Unless a
                    specific range is specified for an argument,
                    the full range defined by the argument's type
                    is accepted.  Any argument defined as a set
                    of alternatives can generate this error.

     SEE ALSO
          XQueryBestSize(3X11), XSetArcMode(3X11),
          XSetClipOrigin(3X11), XSetFillStyle(3X11),
          XSetFont(3X11), XSetLineAttributes(3X11),
          XSetState(3X11), XSetTile(3X11)
          Xlib Programming Manual




































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