usr/src/lib/libcurses/toucholap.c

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

#ifndef lint
static char sccsid[] = "@(#)toucholap.c 5.8 (Berkeley) %G%";
#endif /* not lint */

#include <curses.h>

/*
 * touchoverlap --
 *      Touch, on win2, the part that overlaps with win1.
 */
int
touchoverlap(win1, win2)
        register WINDOW *win1, *win2;
{
        register int y, endy, endx, starty, startx;

#ifdef DEBUG
        __TRACE("touchoverlap: (%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("touchoverlap: from (%d,%d) to (%d,%d)\n",
            starty, startx, endy, endx);
        __TRACE("touchoverlap: win1 (%d,%d) to (%d,%d)\n",
            win1->begy, win1->begx, win1->begy + win1->maxy,
            win1->begx + win1->maxx);
        __TRACE("touchoverlap: win2 (%d,%d) to (%d,%d)\n",
            win2->begy, win2->begx, win2->begy + win2->maxy,
            win2->begx + win2->maxx);
#endif
        if (starty >= endy || startx >= endx)
                return (OK);
        starty -= win2->begy;
        startx -= win2->begx;
        endy -= win2->begy;
        endx -= win2->begx;
        for (--endx, y = starty; y < endy; y++)
                __touchline(win2, y, startx, endx, 0);
        return (OK);
}