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erase.c revision 1.16 
      1 /*	$NetBSD: erase.c,v 1.16 2003/02/17 11:07:19 dsl Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1981, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)erase.c	8.2 (Berkeley) 5/4/94";
     40 #else
     41 __RCSID("$NetBSD: erase.c,v 1.16 2003/02/17 11:07:19 dsl Exp $");
     42 #endif
     43 #endif				/* not lint */
     44 
     45 #include "curses.h"
     46 #include "curses_private.h"
     47 
     48 #ifndef _CURSES_USE_MACROS
     49 
     50 /*
     51  * erase --
     52  *	Erases everything on stdscr.
     53  */
     54 int
     55 erase(void)
     56 {
     57 	return werase(stdscr);
     58 }
     59 
     60 #endif
     61 
     62 /*
     63  * werase --
     64  *	Erases everything on the window.
     65  */
     66 int
     67 werase(WINDOW *win)
     68 {
     69 
     70 	int     minx, y;
     71 	__LDATA *sp, *end, *start, *maxx;
     72 
     73 #ifdef DEBUG
     74 	__CTRACE("werase: (%p)\n", win);
     75 #endif
     76 #ifdef __GNUC__
     77 	maxx = NULL;		/* XXX gcc -Wuninitialized */
     78 #endif
     79 	for (y = 0; y < win->maxy; y++) {
     80 		minx = -1;
     81 		start = win->lines[y]->line;
     82 		end = &start[win->maxx];
     83 		for (sp = start; sp < end; sp++)
     84 			if (sp->ch != ' ' || sp->attr != 0 ||
     85 			    sp->bch != win->bch || sp->battr != win->battr) {
     86 				maxx = sp;
     87 				if (minx == -1)
     88 					minx = sp - start;
     89 				sp->ch = ' ';
     90 				sp->bch = win->bch;
     91 				sp->attr = 0;
     92 				sp->battr = win->battr;
     93 			}
     94 		if (minx != -1)
     95 			__touchline(win, y, minx, maxx - win->lines[y]->line);
     96 	}
     97 	wmove(win, 0, 0);
     98 	return (OK);
     99 }
    100