overlay, overwrite, copywin - overlay and manipulate overlapped curses


   #include <curses.h>

   int overlay(const WINDOW *srcwin, WINDOW *dstwin);
   int overwrite(const WINDOW *srcwin, WINDOW *dstwin);
   int copywin(const WINDOW *srcwin, WINDOW *dstwin, int sminrow,
         int smincol, int dminrow, int dmincol, int dmaxrow,
         int dmaxcol, int overlay);


   overlay, overwrite
   The overlay and overwrite routines overlay srcwin  on  top  of  dstwin.
   scrwin and dstwin are not required to be the same size; only text where
   the two windows overlap is copied.  The difference is that  overlay  is
   non-destructive   (blanks   are   not   copied)  whereas  overwrite  is

   The copywin routine provides a finer granularity of  control  over  the
   overlay  and  overwrite  routines.   As  in  the  prefresh  routine,  a
   rectangle is specified in the destination  window,  (dminrow,  dmincol)
   and  (dmaxrow,  dmaxcol),  and the upper-left-corner coordinates of the
   source window, (sminrow, smincol).  If the argument  overlay  is  true,
   then copying is non-destructive, as in overlay.


   Routines  that  return an integer return ERR upon failure, and OK (SVr4
   only specifies "an integer  value  other  than  ERR")  upon  successful

   X/Open  defines  no error conditions.  In this implementation, copywin,
   overlay and overwrite return an error if either of the window  pointers
   are null, or if some part of the window would be placed off-screen.


   Note that overlay and overwrite may be macros.


   The  XSI Curses standard, Issue 4 describes these functions (adding the
   const qualifiers).  It further specifies their behavior in the presence
   of  characters  with  multibyte  renditions  (not yet supported in this


   ncurses(3NCURSES), pad(3NCURSES), refresh(3NCURSES)



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