# curs_overlay 3x 2024-04-20 ncurses 6.5 Library calls

    curs_overlay(3x)                 Library calls                curs_overlay(3x)

## NAME

           overlay,  overwrite,  copywin  -  overlay curses windows and manipulate
           them

## SYNOPSIS

           #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);

## DESCRIPTION

### 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
           destructive.

### copywin

           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.

## RETURN VALUE

           These  routines  return  the  integer  ERR upon failure and an OK (SVr4
           specifies only "an integer  value  other  than  ERR")  upon  successful
           completion.

           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.

## NOTES

           Note that overlay and overwrite may be macros.

## PORTABILITY

           These  functions  are  described  in X/Open Curses, Issue 4, which adds
           const qualifiers to the arguments.  It further specifies their behavior
           in  the  presence  of  characters  with  multibyte  renditions (not yet
           supported in this implementation).

## SEE ALSO

           curses(3x), curs_pad(3x), curs_refresh(3x)

    ncurses 6.5                       2024-04-20                  curs_overlay(3x)