# curs_overlay 3x 2025-01-18 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 functions return OK on success and ERR on failure.

           In ncurses, they return ERR if

           o   either of the window pointers are null, or

           o   any part of the window would be placed off-screen.

## NOTES

           overlay and overwrite may be implemented as macros.

## PORTABILITY

           X/Open Curses Issue 4 describes these functions.  It specifies no error
           conditions for them.  It 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).

           SVr4 describes a successful return value  only  as  "an  integer  value
           other than ERR".

## SEE ALSO

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

    ncurses 6.5                       2025-01-18                  curs_overlay(3x)