[unix-history] / usr / src / lib / libcurses / overlay.c

/*
* Copyright (c) 1981 Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char sccsid[] = "@(#)overlay.c   5.7 (Berkeley) %G%";
#endif  /* not lint */

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

/*
* overlay --
*      Writes win1 on win2 non-destructively.
*/
int
overlay(win1, win2)
       register WINDOW *win1, *win2;
{

       register int x, y, y1, y2, endy, endx, starty, startx;
       register char *sp, *end;

#ifdef DEBUG
       __TRACE("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->_begx);
       endx = min(win1->_maxx + win1->_begx, win2->_maxx + win2->_begx);
#ifdef DEBUG
       __TRACE("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))
                               mvwaddch(win2, y2, x, *sp);
                       x++;
               }
       }
       return (OK);
}