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   5.6 (Berkeley) %G%";
#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.
 *
 */
overlay(win1, win2)
reg WINDOW      *win1, *win2; {

        reg char        *sp, *end;
        reg int         x, y, endy, endx, starty, startx;
        reg 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->_begx);
        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;
        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++;
                }
        }
}