overlay.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)overlay.c	4.1	(ULTRIX)	7/2/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1984 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
# 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.
 *
 * 11/5/82 (Berkeley) @(#)overlay.c	1.4
 */
overlay(win1, win2)
reg WINDOW	*win1, *win2; {

	reg char	*sp, *end;
	reg int		x, y, endy, endx, starty, startx;

# ifdef DEBUG
	fprintf(outf, "OVERLAY(%0.2o, %0.2o);\n", win1, win2);
# endif
	starty = max(win1->_begy, win2->_begy) - win1->_begy;
	startx = max(win1->_begx, win2->_begx) - win1->_begx;
	endy = min(win1->_maxy, win2->_maxy) - win1->_begy - 1;
	endx = min(win1->_maxx, win2->_maxx) - win1->_begx - 1;
/*
The bug found in overlay() is where the last line of the window
being overlayed is not overlayed.   It seems that the
extraction of this library from "vi" has bitten us again.
The problem is that the computation of "endy" takes into account
the fact that "_maxy" is "1 relative".  The subtraction of 1 now makes
it "0 relative", but the for-loop is treating it as "1 relative".
*/
	for (y = starty; y <= endy; y++) {
		end = &win1->_y[y][endx];
		x = startx + win1->_begx;
		for (sp = &win1->_y[y][startx]; sp <= end; sp++) {
			if (!isspace(*sp))
				mvwaddch(win2, y + win1->_begy, x, *sp);
			x++;
		}
	}
}