/*
 * Copyright 2001 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

/*LINTLIBRARY*/

#ifndef lint
static char
sccsid[] = "@(#)overlay.c 1.9 89/07/13 SMI"; /* from UCB 5.2 86/02/12 */
#endif /* not lint */

#include        "curses.ext"
#include        <ctype.h>

#define min(a, b)       ((a) < (b) ? (a) : (b))
#define max(a, b)       ((a) > (b) ? (a) : (b))

/*
 *      This routine writes win1 on win2 non-destructively.
 */

int
overlay(WINDOW *win1, WINDOW *win2)
{
        char    *sp, *end;
        int     x, y, endy, endx, starty, startx;
        int     y1, y2;

#ifdef DEBUG
        fprintf(outf, "OVERLAY(%0.2o, %0.2o);\n", win1, win2);
#endif
        starty = max(win1->_begy, win2->_begy);
        startx = max(win1->_begx, win2->_begx);
        endy = min(win1->_maxy + win1->_begy, win2->_maxy + win2->_begy);
        endx = min(win1->_maxx + win1->_begx, win2->_maxx + win2->_begx);
#ifdef DEBUG
        fprintf(outf, "OVERLAY:from (%d,%d) to (%d,%d)\n",
            starty, startx, endy, endx);
#endif
        if (starty >= endy || startx >= endx)
                return (OK);
        y1 = starty - win1->_begy;
        y2 = starty - win2->_begy;
        for (y = starty; y < endy; y++, y1++, y2++) {
                end = &win1->_y[y1][endx - win1->_begx];
                x = startx - win2->_begx;
                for (sp = &win1->_y[y1][startx - win1->_begx]; sp < end; sp++) {
                        if (!isspace(*sp))
                                (void) mvwaddch(win2, y2, x, *sp);
                        x++;
                }
        }
        return (OK);
}