Home | History | Annotate | Line # | Download | only in libcurses
refresh.c revision 1.40
      1 /*	$NetBSD: refresh.c,v 1.40 2000/08/02 10:50:49 itojun 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[] = "@(#)refresh.c	8.7 (Berkeley) 8/13/94";
     40 #else
     41 __RCSID("$NetBSD: refresh.c,v 1.40 2000/08/02 10:50:49 itojun Exp $");
     42 #endif
     43 #endif				/* not lint */
     44 
     45 #include <stdlib.h>
     46 #include <string.h>
     47 
     48 #include "curses.h"
     49 #include "curses_private.h"
     50 
     51 /* the following is defined and set up in setterm.c */
     52 extern struct tinfo *_cursesi_genbuf;
     53 
     54 static int curwin = 0;
     55 static short ly, lx;
     56 
     57 static void	domvcur __P((int, int, int, int));
     58 static int	makech __P((int));
     59 static void	quickch __P((void));
     60 static void	scrolln __P((int, int, int, int, int));
     61 
     62 #ifndef _CURSES_USE_MACROS
     63 
     64 /*
     65  * refresh --
     66  *	Make the current screen look like "stdscr" over the area covered by
     67  *	stdscr.
     68  */
     69 int
     70 refresh(void)
     71 {
     72 	return wrefresh(stdscr);
     73 }
     74 
     75 #endif
     76 
     77 /*
     78  * wnoutrefresh --
     79  *	Add the contents of "win" to the virtual window.
     80  */
     81 int
     82 wnoutrefresh(WINDOW *win)
     83 {
     84 	short	wy, wx, x_off;
     85 	__LINE	*wlp, *vlp;
     86 
     87 #ifdef DEBUG
     88 	__CTRACE("wnoutrefresh: win %0.2o, flags 0x%08x\n", win, win->flags);
     89 #endif
     90 
     91 	if (curwin)
     92 		return(OK);
     93 	__virtscr->cury = win->cury + win->begy;
     94 	__virtscr->curx = win->curx + win->begx;
     95 
     96 	/* Copy the window flags from "win" to "__virtscr" */
     97 	if (win->flags & __CLEAROK) {
     98 		if (win->flags & __FULLWIN)
     99 			__virtscr->flags |= __CLEAROK;
    100 		win->flags &= ~__CLEAROK;
    101 	}
    102 	__virtscr->flags &= ~__LEAVEOK;
    103 	__virtscr->flags |= win->flags;
    104 
    105 	for (wy = 0; wy < win->maxy && wy < __virtscr->maxy - win->begy; wy++) {
    106 		wlp = win->lines[wy];
    107 #ifdef DEBUG
    108 		__CTRACE("wnoutrefresh: wy %d\tf: %d\tl:%d\tflags %x\n", wy,
    109 		    *wlp->firstchp, *wlp->lastchp, wlp->flags);
    110 #endif
    111 		if ((wlp->flags & __ISDIRTY) == 0)
    112 			continue;
    113 		vlp = __virtscr->lines[wy + win->begy];
    114 
    115 		if (*wlp->firstchp < win->maxx + win->ch_off &&
    116 		    *wlp->lastchp >= win->ch_off) {
    117 			/* Copy line from "win" to "__virtscr". */
    118 			for (wx = 0, x_off = win->begx; wx < win->maxx &&
    119 			    x_off < __virtscr->maxx; wx++, x_off++) {
    120 				vlp->line[x_off].attr = wlp->line[wx].attr;
    121 				if (wlp->line[wx].attr & __COLOR)
    122 					vlp->line[x_off].attr |=
    123 					    wlp->line[wx].battr & ~__COLOR;
    124 				else
    125 					vlp->line[x_off].attr |=
    126 					    wlp->line[wx].battr;
    127 				if (wlp->line[wx].ch == ' ' &&
    128 				    wlp->line[wx].bch != ' ')
    129 					vlp->line[x_off].ch
    130 					    = wlp->line[wx].bch;
    131 				else
    132 					vlp->line[x_off].ch
    133 					    = wlp->line[wx].ch;
    134 			}
    135 
    136 			/* Set flags on "__virtscr" and unset on "win". */
    137 			if (wlp->flags & __ISPASTEOL)
    138 				vlp->flags |= __ISPASTEOL;
    139 			else
    140 				vlp->flags &= ~__ISPASTEOL;
    141 			if (wlp->flags & __ISDIRTY)
    142 				vlp->flags |= __ISDIRTY;
    143 
    144 #ifdef DEBUG
    145 			__CTRACE("win: firstch = %d, lastch = %d\n",
    146 			    *wlp->firstchp, *wlp->lastchp);
    147 #endif
    148 			/* Set change pointers on "__virtscr". */
    149 			if (*vlp->firstchp >
    150 			    *wlp->firstchp + win->begx - win->ch_off)
    151 				*vlp->firstchp =
    152 				    *wlp->firstchp + win->begx - win->ch_off;
    153 			if (*vlp->lastchp <
    154 			    *wlp->lastchp + win->begx - win->ch_off)
    155 				*vlp->lastchp =
    156 				    *wlp->lastchp + win->begx - win->ch_off;
    157 #ifdef DEBUG
    158 			__CTRACE("__virtscr: firstch = %d, lastch = %d\n",
    159 			    *vlp->firstchp, *vlp->lastchp);
    160 #endif
    161 
    162 			/* Set change pointers on "win". */
    163 			if (*wlp->firstchp >= win->ch_off)
    164 				*wlp->firstchp = win->maxx + win->ch_off;
    165 			if (*wlp->lastchp < win->maxx + win->ch_off)
    166 				*wlp->lastchp = win->ch_off;
    167 			if (*wlp->lastchp < *wlp->firstchp) {
    168 #ifdef DEBUG
    169 				__CTRACE("wnoutrefresh: line %d notdirty\n",
    170 				    wy);
    171 #endif
    172 				wlp->flags &= ~__ISDIRTY;
    173 			}
    174 		}
    175 	}
    176 
    177 	return (OK);
    178 }
    179 
    180 /*
    181  * wrefresh --
    182  *	Make the current screen look like "win" over the area coverd by
    183  *	win.
    184  */
    185 int
    186 wrefresh(WINDOW *win)
    187 {
    188 	int	retval;
    189 
    190 	curwin = (win == curscr);
    191 	if (!curwin)
    192 		retval = wnoutrefresh(win);
    193 	else
    194 		retval = OK;
    195 	if (retval == OK) {
    196 		retval = doupdate();
    197 		if (!win->flags & __LEAVEOK) {
    198 			win->cury = max(0, curscr->cury - win->begy);
    199 			win->curx = max(0, curscr->curx - win->begx);
    200 		}
    201 	}
    202 	curwin = 0;
    203 	return(retval);
    204 }
    205 
    206 /*
    207  * doupdate --
    208  *	Make the current screen look like the virtual window "__virtscr".
    209  */
    210 int
    211 doupdate(void)
    212 {
    213 	WINDOW	*win;
    214 	__LINE	*wlp;
    215 	short	 wy;
    216 	int	 dnum;
    217 
    218 	/* Check if we need to restart ... */
    219 	if (__endwin)
    220 		__restartwin();
    221 
    222 	if (curwin)
    223 		win = curscr;
    224 	else
    225 		win = __virtscr;
    226 
    227 	/* Initialize loop parameters. */
    228 	ly = curscr->cury;
    229 	lx = curscr->curx;
    230 	wy = 0;
    231 
    232 	if (!curwin)
    233 		for (wy = 0; wy < win->maxy; wy++) {
    234 			wlp = win->lines[wy];
    235 			if (wlp->flags & __ISDIRTY)
    236 				wlp->hash = __hash((char *)(void *)wlp->line,
    237 				    (int) (win->maxx * __LDATASIZE));
    238 		}
    239 
    240 	if ((win->flags & __CLEAROK) || (curscr->flags & __CLEAROK) || curwin) {
    241 		if (curscr->wattr & __COLOR)
    242 			__unsetattr(0);
    243 		tputs(CL, 0, __cputchar);
    244 		ly = 0;
    245 		lx = 0;
    246 		if (!curwin) {
    247 			curscr->flags &= ~__CLEAROK;
    248 			curscr->cury = 0;
    249 			curscr->curx = 0;
    250 			werase(curscr);
    251 		}
    252 		__touchwin(win);
    253 		win->flags &= ~__CLEAROK;
    254 	}
    255 	if (!CA) {
    256 		if (win->curx != 0)
    257 			__cputchar('\n');
    258 		if (!curwin)
    259 			werase(curscr);
    260 	}
    261 #ifdef DEBUG
    262 	__CTRACE("doupdate: (%0.2o): curwin = %d\n", win, curwin);
    263 	__CTRACE("doupdate: \tfirstch\tlastch\n");
    264 #endif
    265 
    266 	if (!curwin) {
    267 		/*
    268 		 * Invoke quickch() only if more than a quarter of the lines
    269 		 * in the window are dirty.
    270 		 */
    271 		for (wy = 0, dnum = 0; wy < win->maxy; wy++)
    272 			if (win->lines[wy]->flags & __ISDIRTY)
    273 				dnum++;
    274 		if (!__noqch && dnum > (int) win->maxy / 4)
    275 			quickch();
    276 	}
    277 
    278 #ifdef DEBUG
    279 	{
    280 		int	i, j;
    281 
    282 		__CTRACE("#####################################\n");
    283 		for (i = 0; i < curscr->maxy; i++) {
    284 			__CTRACE("C: %d:", i);
    285 			__CTRACE(" 0x%x \n", curscr->lines[i]->hash);
    286 			for (j = 0; j < curscr->maxx; j++)
    287 				__CTRACE("%c", curscr->lines[i]->line[j].ch);
    288 			__CTRACE("\n");
    289 			__CTRACE(" attr:");
    290 			for (j = 0; j < curscr->maxx; j++)
    291 				__CTRACE(" %x", curscr->lines[i]->line[j].attr);
    292 			__CTRACE("\n");
    293 			__CTRACE("W: %d:", i);
    294 			__CTRACE(" 0x%x \n", win->lines[i]->hash);
    295 			__CTRACE(" 0x%x ", win->lines[i]->flags);
    296 			for (j = 0; j < win->maxx; j++)
    297 				__CTRACE("%c", win->lines[i]->line[j].ch);
    298 			__CTRACE("\n");
    299 			__CTRACE(" attr:");
    300 			for (j = 0; j < win->maxx; j++)
    301 				__CTRACE(" %x",
    302 				    win->lines[i]->line[j].attr);
    303 			__CTRACE("\n");
    304 		}
    305 	}
    306 #endif				/* DEBUG */
    307 
    308 	for (wy = 0; wy < win->maxy; wy++) {
    309 		wlp = win->lines[wy];
    310 /* XXX: remove this debug */
    311 #ifdef DEBUG
    312 		__CTRACE("doupdate: wy %d\tf: %d\tl:%d\tflags %x\n", wy,
    313 		    *wlp->firstchp, *wlp->lastchp, wlp->flags);
    314 #endif
    315 		if (!curwin)
    316 			curscr->lines[wy]->hash = wlp->hash;
    317 		if (wlp->flags & __ISDIRTY) {
    318 			if (makech(wy) == ERR)
    319 				return (ERR);
    320 			else {
    321 				if (*wlp->firstchp >= 0)
    322 					*wlp->firstchp = win->maxx;
    323 				if (*wlp->lastchp < win->maxx)
    324 					*wlp->lastchp = 0;
    325 				if (*wlp->lastchp < *wlp->firstchp) {
    326 #ifdef DEBUG
    327 					__CTRACE("doupdate: line %d notdirty\n", wy);
    328 #endif
    329 					wlp->flags &= ~__ISDIRTY;
    330 				}
    331 			}
    332 
    333 		}
    334 #ifdef DEBUG
    335 		__CTRACE("\t%d\t%d\n", *wlp->firstchp, *wlp->lastchp);
    336 #endif
    337 	}
    338 
    339 #ifdef DEBUG
    340 	__CTRACE("doupdate: ly=%d, lx=%d\n", ly, lx);
    341 #endif
    342 
    343 	if (curwin)
    344 		domvcur(ly, lx, (int) win->cury, (int) win->curx);
    345 	else {
    346 		if (win->flags & __LEAVEOK) {
    347 			curscr->cury = ly;
    348 			curscr->curx = lx;
    349 		} else {
    350 			domvcur(ly, lx, win->cury, win->curx);
    351 			curscr->cury = win->cury;
    352 			curscr->curx = win->curx;
    353 		}
    354 	}
    355 
    356 	/* Don't leave the screen with attributes set. */
    357 	__unsetattr(0);
    358 	(void) fflush(stdout);
    359 	return (OK);
    360 }
    361 
    362 /*
    363  * makech --
    364  *	Make a change on the screen.
    365  */
    366 static int
    367 makech(wy)
    368 	int	wy;
    369 {
    370 	WINDOW	*win;
    371 	static __LDATA blank = {' ', 0, ' ', 0};
    372 	__LDATA *nsp, *csp, *cp, *cep;
    373 	int	clsp, nlsp;	/* Last space in lines. */
    374 	int	lch, wx;
    375 	char	*ce;
    376 	attr_t	lspc;		/* Last space colour */
    377 	attr_t	off, on;
    378 
    379 #ifdef __GNUC__
    380 	nlsp = lspc = 0;	/* XXX gcc -Wuninitialized */
    381 #endif
    382 	if (curwin)
    383 		win = curscr;
    384 	else
    385 		win = __virtscr;
    386 	/* Is the cursor still on the end of the last line? */
    387 	if (wy > 0 && curscr->lines[wy - 1]->flags & __ISPASTEOL) {
    388 		domvcur(ly, lx, ly + 1, 0);
    389 		ly++;
    390 		lx = 0;
    391 	}
    392 	wx = *win->lines[wy]->firstchp;
    393 	if (wx < 0)
    394 		wx = 0;
    395 	else
    396 		if (wx >= win->maxx)
    397 			return (OK);
    398 	lch = *win->lines[wy]->lastchp;
    399 	if (lch < 0)
    400 		return (OK);
    401 	else
    402 		if (lch >= (int) win->maxx)
    403 			lch = win->maxx - 1;
    404 
    405 	if (curwin)
    406 		csp = &blank;
    407 	else
    408 		csp = &curscr->lines[wy]->line[wx];
    409 
    410 	nsp = &win->lines[wy]->line[wx];
    411 	if (CE && !curwin) {
    412 		cp = &win->lines[wy]->line[win->maxx - 1];
    413 		lspc = cp->attr & __COLOR;
    414 		while (cp->ch == ' ' && cp->attr == lspc)
    415 			if (cp-- <= win->lines[wy]->line)
    416 				break;
    417 		nlsp = cp - win->lines[wy]->line;
    418 	}
    419 	if (!curwin)
    420 		ce = CE;
    421 	else
    422 		ce = NULL;
    423 
    424 	while (wx <= lch) {
    425 		if (memcmp(nsp, csp, sizeof(__LDATA)) == 0) {
    426 			if (wx <= lch) {
    427 				while (wx <= lch &&
    428 				    memcmp(nsp, csp, sizeof(__LDATA)) == 0) {
    429 					nsp++;
    430 					if (!curwin)
    431 						++csp;
    432 					++wx;
    433 				}
    434 				continue;
    435 			}
    436 			break;
    437 		}
    438 		domvcur(ly, lx, wy, wx);
    439 
    440 #ifdef DEBUG
    441 		__CTRACE("makech: 1: wx = %d, ly= %d, lx = %d, newy = %d, newx = %d\n",
    442 		    wx, ly, lx, wy, wx);
    443 #endif
    444 		ly = wy;
    445 		lx = wx;
    446 		while (memcmp(nsp, csp, sizeof(__LDATA)) != 0 && wx <= lch) {
    447 			if (ce != NULL &&
    448 			    wx >= nlsp && nsp->ch == ' ' && nsp->attr == lspc) {
    449 				/* Check for clear to end-of-line. */
    450 				cep = &curscr->lines[wy]->line[win->maxx - 1];
    451 				while (cep->ch == ' ' && cep->attr == lspc)
    452 					if (cep-- <= csp)
    453 						break;
    454 				clsp = cep - curscr->lines[wy]->line -
    455 				    win->begx * __LDATASIZE;
    456 #ifdef DEBUG
    457 				__CTRACE("makech: clsp = %d, nlsp = %d\n",
    458 				    clsp, nlsp);
    459 #endif
    460 				if (((clsp - nlsp >= strlen(CE) &&
    461 				    clsp < win->maxx * __LDATASIZE) ||
    462 				    wy == win->maxy - 1) &&
    463 				    (!(lspc & __COLOR) ||
    464 				    ((lspc & __COLOR) && UT))) {
    465 					__unsetattr(0);
    466 					if ((lspc & __COLOR) !=
    467 					    (curscr->wattr & __COLOR)) {
    468 						__set_color(lspc);
    469 						curscr->wattr &= ~__COLOR;
    470 						curscr->wattr |= lspc & __COLOR;
    471 					}
    472 					tputs(CE, 0, __cputchar);
    473 					lx = wx + win->begx;
    474 					while (wx++ <= clsp) {
    475 						csp->ch = ' ';
    476 						csp->attr = lspc;
    477 						csp++;
    478 					}
    479 					return (OK);
    480 				}
    481 				ce = NULL;
    482 			}
    483 
    484 			/*
    485 			 * Unset colour if appropriate.  Check to see
    486 			 * if we also turn off standout, underscore and
    487 			 * attributes.
    488 			 */
    489 			if (!(nsp->attr & __COLOR) &&
    490 			    (curscr->wattr & __COLOR)) {
    491 				if (OC != NULL && CC == NULL)
    492 					tputs(OC, 0, __cputchar);
    493 				if (OP != NULL) {
    494 					tputs(OP, 0, __cputchar);
    495 					curscr->wattr &= __mask_OP;
    496 				}
    497 			}
    498 
    499 			off = ~nsp->attr & curscr->wattr;
    500 
    501 			/*
    502 			 * Unset attributes as appropriate.  Unset first
    503 			 * so that the relevant attributes can be reset
    504 			 * (because 'me' unsets 'mb', 'md', 'mh', 'mk',
    505 			 * 'mp' and 'mr').  Check to see if we also turn off
    506 			 * standout, attributes and colour.
    507 			 */
    508 			if (off & __TERMATTR && ME != NULL) {
    509 				tputs(ME, 0, __cputchar);
    510 				curscr->wattr &= __mask_ME;
    511 				off &= __mask_ME;
    512 			}
    513 
    514 			/*
    515 			 * Exit underscore mode if appropriate.
    516 			 * Check to see if we also turn off standout,
    517 			 * attributes and colour.
    518 			 */
    519 			if (off & __UNDERSCORE && UE != NULL) {
    520 				tputs(UE, 0, __cputchar);
    521 				curscr->wattr &= __mask_UE;
    522 				off &= __mask_UE;
    523 			}
    524 
    525 			/*
    526 			 * Exit standout mode as appropriate.
    527 			 * Check to see if we also turn off underscore,
    528 			 * attributes and colour.
    529 			 * XXX
    530 			 * Should use UC if SO/SE not available.
    531 			 */
    532 			if (off & __STANDOUT && SE != NULL) {
    533 				tputs(SE, 0, __cputchar);
    534 				curscr->wattr &= __mask_SE;
    535 				off &= __mask_SE;
    536 			}
    537 
    538 			if (off & __ALTCHARSET && AE != NULL) {
    539 				tputs(AE, 0, __cputchar);
    540 				curscr->wattr &= ~__ALTCHARSET;
    541 			}
    542 
    543 			on = nsp->attr & ~curscr->wattr;
    544 
    545 			/*
    546 			 * Enter standout mode if appropriate.
    547 			 */
    548 			if (on & __STANDOUT && SO != NULL && SE != NULL) {
    549 				tputs(SO, 0, __cputchar);
    550 				curscr->wattr |= __STANDOUT;
    551 			}
    552 
    553 			/*
    554 			 * Enter underscore mode if appropriate.
    555 			 * XXX
    556 			 * Should use UC if US/UE not available.
    557 			 */
    558 			if (on & __UNDERSCORE && US != NULL && UE != NULL) {
    559 				tputs(US, 0, __cputchar);
    560 				curscr->wattr |= __UNDERSCORE;
    561 			}
    562 
    563 			/*
    564 			 * Set other attributes as appropriate.
    565 			 */
    566 			if (ME != NULL) {
    567 				if (on & __BLINK && MB != NULL) {
    568 					tputs(MB, 0, __cputchar);
    569 					curscr->wattr |= __BLINK;
    570 				}
    571 				if (on & __BOLD && MD != NULL) {
    572 					tputs(MD, 0, __cputchar);
    573 					curscr->wattr |= __BOLD;
    574 				}
    575 				if (on & __DIM && MH != NULL) {
    576 					tputs(MH, 0, __cputchar);
    577 					curscr->wattr |= __DIM;
    578 				}
    579 				if (on & __BLANK && MK != NULL) {
    580 					tputs(MK, 0, __cputchar);
    581 					curscr->wattr |= __BLANK;
    582 				}
    583 				if (on & __PROTECT && MP != NULL) {
    584 					tputs(MP, 0, __cputchar);
    585 					curscr->wattr |= __PROTECT;
    586 				}
    587 				if (on & __REVERSE && MR != NULL) {
    588 					tputs(MR, 0, __cputchar);
    589 					curscr->wattr |= __REVERSE;
    590 				}
    591 			}
    592 
    593 			/* Set/change colour as appropriate. */
    594 			if ((nsp->attr & __COLOR) &&
    595 			    cO != NULL && (OC != NULL || OP != NULL)) {
    596 				if ((nsp->attr & __COLOR) !=
    597 				    (curscr->wattr & __COLOR)) {
    598 					__set_color(nsp->attr);
    599 					curscr->wattr &= ~__COLOR;
    600 					curscr->wattr |= nsp->attr &
    601 					    __COLOR;
    602 				}
    603 			}
    604 
    605 			/* Enter/exit altcharset mode as appropriate. */
    606 			if (on & __ALTCHARSET && AS != NULL && AE != NULL) {
    607 				tputs(AS, 0, __cputchar);
    608 				curscr->wattr |= __ALTCHARSET;
    609 			}
    610 
    611 			wx++;
    612 			if (wx >= win->maxx &&
    613 			    wy == win->maxy - 1 && !curwin)
    614 				if (win->flags & __SCROLLOK) {
    615 					if (win->flags & __ENDLINE)
    616 						__unsetattr(1);
    617 					if (!(win->flags & __SCROLLWIN)) {
    618 						if (!curwin) {
    619 							csp->attr = nsp->attr;
    620 							__cputchar((int)
    621 							    (csp->ch =
    622 							    nsp->ch));
    623 						} else
    624 							__cputchar((int) nsp->ch);
    625 					}
    626 					if (wx < curscr->maxx) {
    627 						domvcur(ly, wx,
    628 						    (int) (win->maxy - 1),
    629 						    (int) (win->maxx - 1));
    630 					}
    631 					ly = win->maxy - 1;
    632 					lx = win->maxx - 1;
    633 					return (OK);
    634 				}
    635 			if (wx < win->maxx || wy < win->maxy - 1 ||
    636 			    !(win->flags & __SCROLLWIN)) {
    637 				if (!curwin) {
    638 					csp->attr = nsp->attr;
    639 					__cputchar((int) (csp->ch = nsp->ch));
    640 					csp++;
    641 				} else
    642 					__cputchar((int) nsp->ch);
    643 			}
    644 #ifdef DEBUG
    645 			__CTRACE("makech: putchar(%c)\n", nsp->ch & 0177);
    646 #endif
    647 			if (UC && ((nsp->attr & __STANDOUT) ||
    648 			    (nsp->attr & __UNDERSCORE))) {
    649 				__cputchar('\b');
    650 				tputs(UC, 0, __cputchar);
    651 			}
    652 			nsp++;
    653 #ifdef DEBUG
    654 			__CTRACE("makech: 2: wx = %d, lx = %d\n", wx, lx);
    655 #endif
    656 		}
    657 		if (lx == wx)	/* If no change. */
    658 			break;
    659 		lx = wx;
    660 		if (lx >= COLS && AM)
    661 			lx = COLS - 1;
    662 		else
    663 			if (wx >= win->maxx) {
    664 				domvcur(ly, lx, ly,
    665 				    (int) (win->maxx - 1));
    666 				lx = win->maxx - 1;
    667 			}
    668 #ifdef DEBUG
    669 		__CTRACE("makech: 3: wx = %d, lx = %d\n", wx, lx);
    670 #endif
    671 	}
    672 
    673 	return (OK);
    674 }
    675 
    676 /*
    677  * domvcur --
    678  *	Do a mvcur, leaving attributes if necessary.
    679  */
    680 static void
    681 domvcur(oy, ox, ny, nx)
    682 	int	oy, ox, ny, nx;
    683 {
    684 	__unsetattr(1);
    685 	__mvcur(oy, ox, ny, nx, 1);
    686 }
    687 
    688 /*
    689  * Quickch() attempts to detect a pattern in the change of the window
    690  * in order to optimize the change, e.g., scroll n lines as opposed to
    691  * repainting the screen line by line.
    692  */
    693 
    694 static void
    695 quickch(void)
    696 {
    697 #define THRESH		(int) __virtscr->maxy / 4
    698 
    699 	__LINE *clp, *tmp1, *tmp2;
    700 	int	bsize, curs, curw, starts, startw, i, j;
    701 	int	n, target, cur_period, bot, top, sc_region;
    702 	__LDATA buf[1024];
    703 	u_int	blank_hash;
    704 	attr_t	bcolor;
    705 
    706 #ifdef __GNUC__
    707 	curs = curw = starts = startw = 0;	/* XXX gcc -Wuninitialized */
    708 #endif
    709 	/*
    710 	 * Find how many lines from the top of the screen are unchanged.
    711 	 */
    712 	for (top = 0; top < __virtscr->maxy; top++)
    713 		if (__virtscr->lines[top]->flags & __ISDIRTY &&
    714 		    (__virtscr->lines[top]->hash != curscr->lines[top]->hash ||
    715 		     memcmp(__virtscr->lines[top]->line,
    716 			  curscr->lines[top]->line,
    717 			  (size_t) __virtscr->maxx * __LDATASIZE) != 0))
    718 			break;
    719 		else
    720 			__virtscr->lines[top]->flags &= ~__ISDIRTY;
    721 	/*
    722 	 * Find how many lines from bottom of screen are unchanged.
    723 	 */
    724 	for (bot = __virtscr->maxy - 1; bot >= 0; bot--)
    725 		if (__virtscr->lines[bot]->flags & __ISDIRTY &&
    726 		    (__virtscr->lines[bot]->hash != curscr->lines[bot]->hash ||
    727 		     memcmp(__virtscr->lines[bot]->line,
    728 			  curscr->lines[bot]->line,
    729 			  (size_t) __virtscr->maxx * __LDATASIZE) != 0))
    730 			break;
    731 		else
    732 			__virtscr->lines[bot]->flags &= ~__ISDIRTY;
    733 
    734 	/*
    735 	 * Work round an xterm bug where inserting lines causes all the
    736 	 * inserted lines to be covered with the background colour we
    737 	 * set on the first line (even if we unset it for subsequent
    738 	 * lines).
    739 	 */
    740 	bcolor = __virtscr->lines[min(top,
    741 	    __virtscr->maxy - 1)]->line[0].attr & __COLOR;
    742 	for (i = top + 1, j = 0; i < bot; i++) {
    743 		if ((__virtscr->lines[i]->line[0].attr & __COLOR) != bcolor) {
    744 			bcolor = __virtscr->lines[i]->line[__virtscr->maxx].
    745 			    attr & __COLOR;
    746 			j = i - top;
    747 		} else
    748 			break;
    749 	}
    750 	top += j;
    751 
    752 #ifdef NO_JERKINESS
    753 	/*
    754 	 * If we have a bottom unchanged region return.  Scrolling the
    755 	 * bottom region up and then back down causes a screen jitter.
    756 	 * This will increase the number of characters sent to the screen
    757 	 * but it looks better.
    758 	 */
    759 	if (bot < __virtscr->maxy - 1)
    760 		return;
    761 #endif				/* NO_JERKINESS */
    762 
    763 	/*
    764 	 * Search for the largest block of text not changed.
    765 	 * Invariants of the loop:
    766 	 * - Startw is the index of the beginning of the examined block in
    767 	 *   __virtscr.
    768 	 * - Starts is the index of the beginning of the examined block in
    769 	 *   curscr.
    770 	 * - Curw is the index of one past the end of the exmined block in
    771 	 *   __virtscr.
    772 	 * - Curs is the index of one past the end of the exmined block in
    773 	 *   curscr.
    774 	 * - bsize is the current size of the examined block.
    775 	*/
    776 
    777 	for (bsize = bot - top; bsize >= THRESH; bsize--) {
    778 		for (startw = top; startw <= bot - bsize; startw++)
    779 			for (starts = top; starts <= bot - bsize;
    780 			    starts++) {
    781 				for (curw = startw, curs = starts;
    782 				    curs < starts + bsize; curw++, curs++)
    783 					if (__virtscr->lines[curw]->hash !=
    784 					    curscr->lines[curs]->hash)
    785 						break;
    786 				if (curs != starts + bsize)
    787 					continue;
    788 				for (curw = startw, curs = starts;
    789 				    curs < starts + bsize; curw++, curs++)
    790 					if (memcmp(__virtscr->lines[curw]->line,
    791 					    curscr->lines[curs]->line,
    792 					    (size_t) __virtscr->maxx *
    793 					    __LDATASIZE) != 0)
    794 						break;
    795 				if (curs == starts + bsize)
    796 					goto done;
    797 			}
    798 	}
    799 done:
    800 
    801 	/* Did not find anything */
    802 	if (bsize < THRESH)
    803 		return;
    804 
    805 #ifdef DEBUG
    806 	__CTRACE("quickch:bsize=%d,starts=%d,startw=%d,curw=%d,curs=%d,top=%d,bot=%d\n",
    807 	    bsize, starts, startw, curw, curs, top, bot);
    808 #endif
    809 
    810 	/*
    811 	 * Make sure that there is no overlap between the bottom and top
    812 	 * regions and the middle scrolled block.
    813 	 */
    814 	if (bot < curs)
    815 		bot = curs - 1;
    816 	if (top > starts)
    817 		top = starts;
    818 
    819 	n = startw - starts;
    820 
    821 #ifdef DEBUG
    822 	__CTRACE("#####################################\n");
    823 	for (i = 0; i < curscr->maxy; i++) {
    824 		__CTRACE("C: %d:", i);
    825 		__CTRACE(" 0x%x \n", curscr->lines[i]->hash);
    826 		for (j = 0; j < curscr->maxx; j++)
    827 			__CTRACE("%c", curscr->lines[i]->line[j].ch);
    828 		__CTRACE("\n");
    829 		__CTRACE(" attr:");
    830 		for (j = 0; j < curscr->maxx; j++)
    831 			__CTRACE(" %x", curscr->lines[i]->line[j].attr);
    832 		__CTRACE("\n");
    833 		__CTRACE("W: %d:", i);
    834 		__CTRACE(" 0x%x \n", __virtscr->lines[i]->hash);
    835 		__CTRACE(" 0x%x ", __virtscr->lines[i]->flags);
    836 		for (j = 0; j < __virtscr->maxx; j++)
    837 			__CTRACE("%c", __virtscr->lines[i]->line[j].ch);
    838 		__CTRACE("\n");
    839 		__CTRACE(" attr:");
    840 		for (j = 0; j < __virtscr->maxx; j++)
    841 			__CTRACE(" %x", __virtscr->lines[i]->line[j].attr);
    842 		__CTRACE("\n");
    843 	}
    844 #endif
    845 
    846 	/* So we don't have to call __hash() each time */
    847 	for (i = 0; i < __virtscr->maxx; i++) {
    848 		buf[i].ch = ' ';
    849 		buf[i].bch = ' ';
    850 		buf[i].attr = 0;
    851 		buf[i].battr = 0;
    852 	}
    853 	blank_hash = __hash((char *)(void *)buf,
    854 	    (int) (__virtscr->maxx * __LDATASIZE));
    855 
    856 	/*
    857 	 * Perform the rotation to maintain the consistency of curscr.
    858 	 * This is hairy since we are doing an *in place* rotation.
    859 	 * Invariants of the loop:
    860 	 * - I is the index of the current line.
    861 	 * - Target is the index of the target of line i.
    862 	 * - Tmp1 points to current line (i).
    863 	 * - Tmp2 and points to target line (target);
    864 	 * - Cur_period is the index of the end of the current period.
    865 	 *   (see below).
    866 	 *
    867 	 * There are 2 major issues here that make this rotation non-trivial:
    868 	 * 1.  Scrolling in a scrolling region bounded by the top
    869 	 *     and bottom regions determined (whose size is sc_region).
    870 	 * 2.  As a result of the use of the mod function, there may be a
    871 	 *     period introduced, i.e., 2 maps to 4, 4 to 6, n-2 to 0, and
    872 	 *     0 to 2, which then causes all odd lines not to be rotated.
    873 	 *     To remedy this, an index of the end ( = beginning) of the
    874 	 *     current 'period' is kept, cur_period, and when it is reached,
    875 	 *     the next period is started from cur_period + 1 which is
    876 	 *     guaranteed not to have been reached since that would mean that
    877 	 *     all records would have been reached. (think about it...).
    878 	 *
    879 	 * Lines in the rotation can have 3 attributes which are marked on the
    880 	 * line so that curscr is consistent with the visual screen.
    881 	 * 1.  Not dirty -- lines inside the scrolled block, top region or
    882 	 *                  bottom region.
    883 	 * 2.  Blank lines -- lines in the differential of the scrolling
    884 	 *		      region adjacent to top and bot regions
    885 	 *                    depending on scrolling direction.
    886 	 * 3.  Dirty line -- all other lines are marked dirty.
    887 	 */
    888 	sc_region = bot - top + 1;
    889 	i = top;
    890 	tmp1 = curscr->lines[top];
    891 	cur_period = top;
    892 	for (j = top; j <= bot; j++) {
    893 		target = (i - top + n + sc_region) % sc_region + top;
    894 		tmp2 = curscr->lines[target];
    895 		curscr->lines[target] = tmp1;
    896 		/* Mark block as clean and blank out scrolled lines. */
    897 		clp = curscr->lines[target];
    898 #ifdef DEBUG
    899 		__CTRACE("quickch: n=%d startw=%d curw=%d i = %d target=%d ",
    900 		    n, startw, curw, i, target);
    901 #endif
    902 		if ((target >= startw && target < curw) || target < top
    903 		    || target > bot) {
    904 #ifdef DEBUG
    905 			__CTRACE("-- notdirty\n");
    906 #endif
    907 			__virtscr->lines[target]->flags &= ~__ISDIRTY;
    908 		} else
    909 			if ((n > 0 && target >= top && target < top + n) ||
    910 			    (n < 0 && target <= bot && target > bot + n)) {
    911 				if (clp->hash != blank_hash || memcmp(clp->line,
    912 				    buf, (size_t) __virtscr->maxx * __LDATASIZE) !=0) {
    913 					(void)memcpy(clp->line,  buf,
    914 					    (size_t) __virtscr->maxx * __LDATASIZE);
    915 #ifdef DEBUG
    916 					__CTRACE("-- blanked out: dirty\n");
    917 #endif
    918 					clp->hash = blank_hash;
    919 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
    920 				} else {
    921 #ifdef DEBUG
    922 					__CTRACE(" -- blank line already: dirty\n");
    923 #endif
    924 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
    925 				}
    926 			} else {
    927 #ifdef DEBUG
    928 				__CTRACE(" -- dirty\n");
    929 #endif
    930 				__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
    931 			}
    932 		if (target == cur_period) {
    933 			i = target + 1;
    934 			tmp1 = curscr->lines[i];
    935 			cur_period = i;
    936 		} else {
    937 			tmp1 = tmp2;
    938 			i = target;
    939 		}
    940 	}
    941 #ifdef DEBUG
    942 	__CTRACE("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$\n");
    943 	for (i = 0; i < curscr->maxy; i++) {
    944 		__CTRACE("C: %d:", i);
    945 		for (j = 0; j < curscr->maxx; j++)
    946 			__CTRACE("%c", curscr->lines[i]->line[j].ch);
    947 		__CTRACE("\n");
    948 		__CTRACE("W: %d:", i);
    949 		for (j = 0; j < __virtscr->maxx; j++)
    950 			__CTRACE("%c", __virtscr->lines[i]->line[j].ch);
    951 		__CTRACE("\n");
    952 	}
    953 #endif
    954 	if (n != 0)
    955 		scrolln(starts, startw, curs, bot, top);
    956 }
    957 
    958 /*
    959  * scrolln --
    960  *	Scroll n lines, where n is starts - startw.
    961  */
    962 static void /* ARGSUSED */
    963 scrolln(starts, startw, curs, bot, top)
    964 	int	starts, startw, curs, bot, top;
    965 {
    966 	int	i, oy, ox, n;
    967 
    968 	oy = curscr->cury;
    969 	ox = curscr->curx;
    970 	n = starts - startw;
    971 
    972 	/*
    973 	 * XXX
    974 	 * The initial tests that set __noqch don't let us reach here unless
    975 	 * we have either CS + HO + SF/sf/SR/sr, or AL + DL.  SF/sf and SR/sr
    976 	 * scrolling can only shift the entire scrolling region, not just a
    977 	 * part of it, which means that the quickch() routine is going to be
    978 	 * sadly disappointed in us if we don't have CS as well.
    979 	 *
    980 	 * If CS, HO and SF/sf are set, can use the scrolling region.  Because
    981 	 * the cursor position after CS is undefined, we need HO which gives us
    982 	 * the ability to move to somewhere without knowledge of the current
    983 	 * location of the cursor.  Still call __mvcur() anyway, to update its
    984 	 * idea of where the cursor is.
    985 	 *
    986 	 * When the scrolling region has been set, the cursor has to be at the
    987 	 * last line of the region to make the scroll happen.
    988 	 *
    989 	 * Doing SF/SR or AL/DL appears faster on the screen than either sf/sr
    990 	 * or al/dl, and, some terminals have AL/DL, sf/sr, and CS, but not
    991 	 * SF/SR.  So, if we're scrolling almost all of the screen, try and use
    992 	 * AL/DL, otherwise use the scrolling region.  The "almost all" is a
    993 	 * shameless hack for vi.
    994 	 */
    995 	if (n > 0) {
    996 		if (CS != NULL && HO != NULL && (SF != NULL ||
    997 		    ((AL == NULL || DL == NULL ||
    998 		    top > 3 || bot + 3 < __virtscr->maxy) && sf != NULL))) {
    999 			tputs(__tscroll(CS, top, bot + 1), 0, __cputchar);
   1000 			__mvcur(oy, ox, 0, 0, 1);
   1001 			tputs(HO, 0, __cputchar);
   1002 			__mvcur(0, 0, bot, 0, 1);
   1003 			if (SF != NULL)
   1004 				tputs(__tscroll(SF, n, 0), 0, __cputchar);
   1005 			else
   1006 				for (i = 0; i < n; i++)
   1007 					tputs(sf, 0, __cputchar);
   1008 			tputs(__tscroll(CS, 0, (int) __virtscr->maxy), 0, __cputchar);
   1009 			__mvcur(bot, 0, 0, 0, 1);
   1010 			tputs(HO, 0, __cputchar);
   1011 			__mvcur(0, 0, oy, ox, 1);
   1012 			return;
   1013 		}
   1014 
   1015 		/* Scroll up the block. */
   1016 		if (SF != NULL && top == 0) {
   1017 			__mvcur(oy, ox, bot, 0, 1);
   1018 			tputs(__tscroll(SF, n, 0), 0, __cputchar);
   1019 		} else
   1020 			if (DL != NULL) {
   1021 				__mvcur(oy, ox, top, 0, 1);
   1022 				tputs(__tscroll(DL, n, 0), 0, __cputchar);
   1023 			} else
   1024 				if (dl != NULL) {
   1025 					__mvcur(oy, ox, top, 0, 1);
   1026 					for (i = 0; i < n; i++)
   1027 						tputs(dl, 0, __cputchar);
   1028 				} else
   1029 					if (sf != NULL && top == 0) {
   1030 						__mvcur(oy, ox, bot, 0, 1);
   1031 						for (i = 0; i < n; i++)
   1032 							tputs(sf, 0, __cputchar);
   1033 					} else
   1034 						abort();
   1035 
   1036 		/* Push down the bottom region. */
   1037 		__mvcur(top, 0, bot - n + 1, 0, 1);
   1038 		if (AL != NULL)
   1039 			tputs(__tscroll(AL, n, 0), 0, __cputchar);
   1040 		else
   1041 			if (al != NULL)
   1042 				for (i = 0; i < n; i++)
   1043 					tputs(al, 0, __cputchar);
   1044 			else
   1045 				abort();
   1046 		__mvcur(bot - n + 1, 0, oy, ox, 1);
   1047 	} else {
   1048 		/*
   1049 		 * !!!
   1050 		 * n < 0
   1051 		 *
   1052 		 * If CS, HO and SR/sr are set, can use the scrolling region.
   1053 		 * See the above comments for details.
   1054 		 */
   1055 		if (CS != NULL && HO != NULL && (SR != NULL ||
   1056 		    ((AL == NULL || DL == NULL ||
   1057 		    top > 3 || bot + 3 < __virtscr->maxy) && sr != NULL))) {
   1058 			tputs(__tscroll(CS, top, bot + 1), 0, __cputchar);
   1059 			__mvcur(oy, ox, 0, 0, 1);
   1060 			tputs(HO, 0, __cputchar);
   1061 			__mvcur(0, 0, top, 0, 1);
   1062 
   1063 			if (SR != NULL)
   1064 				tputs(__tscroll(SR, -n, 0), 0, __cputchar);
   1065 			else
   1066 				for (i = n; i < 0; i++)
   1067 					tputs(sr, 0, __cputchar);
   1068 			tputs(__tscroll(CS, 0, (int) __virtscr->maxy), 0, __cputchar);
   1069 			__mvcur(top, 0, 0, 0, 1);
   1070 			tputs(HO, 0, __cputchar);
   1071 			__mvcur(0, 0, oy, ox, 1);
   1072 			return;
   1073 		}
   1074 
   1075 		/* Preserve the bottom lines. */
   1076 		__mvcur(oy, ox, bot + n + 1, 0, 1);
   1077 		if (SR != NULL && bot == __virtscr->maxy)
   1078 			tputs(__tscroll(SR, -n, 0), 0, __cputchar);
   1079 		else
   1080 			if (DL != NULL)
   1081 				tputs(__tscroll(DL, -n, 0), 0, __cputchar);
   1082 			else
   1083 				if (dl != NULL)
   1084 					for (i = n; i < 0; i++)
   1085 						tputs(dl, 0, __cputchar);
   1086 				else
   1087 					if (sr != NULL && bot == __virtscr->maxy)
   1088 						for (i = n; i < 0; i++)
   1089 							tputs(sr, 0, __cputchar);
   1090 					else
   1091 						abort();
   1092 
   1093 		/* Scroll the block down. */
   1094 		__mvcur(bot + n + 1, 0, top, 0, 1);
   1095 		if (AL != NULL)
   1096 			tputs(__tscroll(AL, -n, 0), 0, __cputchar);
   1097 		else
   1098 			if (al != NULL)
   1099 				for (i = n; i < 0; i++)
   1100 					tputs(al, 0, __cputchar);
   1101 			else
   1102 				abort();
   1103 		__mvcur(top, 0, oy, ox, 1);
   1104 	}
   1105 }
   1106 
   1107 /*
   1108  * __unsetattr --
   1109  *	Unset attributes on curscr.  Leave standout, attribute and colour
   1110  *	modes if necessary (!MS).  Always leave altcharset (xterm at least
   1111  *	ignores a cursor move if we don't).
   1112  */
   1113 void /* ARGSUSED */
   1114 __unsetattr(int checkms)
   1115 {
   1116 	int	isms;
   1117 
   1118 	if (checkms)
   1119 		if (!MS) {
   1120 			isms = 1;
   1121 		} else {
   1122 			isms = 0;
   1123 		}
   1124 	else
   1125 		isms = 1;
   1126 #ifdef DEBUG
   1127 	__CTRACE("__unsetattr: checkms = %d, MS = %s, wattr = %08x\n",
   1128 	    checkms, MS ? "TRUE" : "FALSE", curscr->wattr);
   1129 #endif
   1130 
   1131 	/*
   1132          * Don't leave the screen in standout mode (check against MS).  Check
   1133 	 * to see if we also turn off underscore, attributes and colour.
   1134 	 */
   1135 	if (curscr->wattr & __STANDOUT && isms) {
   1136 		tputs(SE, 0, __cputchar);
   1137 		curscr->wattr &= __mask_SE;
   1138 	}
   1139 	/*
   1140 	 * Don't leave the screen in underscore mode (check against MS).
   1141 	 * Check to see if we also turn off attributes.  Assume that we
   1142 	 * also turn off colour.
   1143 	 */
   1144 	if (curscr->wattr & __UNDERSCORE && isms) {
   1145 		tputs(UE, 0, __cputchar);
   1146 		curscr->wattr &= __mask_UE;
   1147 	}
   1148 	/*
   1149 	 * Don't leave the screen with attributes set (check against MS).
   1150 	 * Assume that also turn off colour.
   1151 	 */
   1152 	if (curscr->wattr & __TERMATTR && isms) {
   1153 		tputs(ME, 0, __cputchar);
   1154 		curscr->wattr &= __mask_ME;
   1155 	}
   1156 	/* Don't leave the screen with altcharset set (don't check MS). */
   1157 	if (curscr->wattr & __ALTCHARSET) {
   1158 		tputs(AE, 0, __cputchar);
   1159 		curscr->wattr &= ~__ALTCHARSET;
   1160 	}
   1161 	/* Don't leave the screen with colour set (check against MS). */
   1162 	if (curscr->wattr & __COLOR && isms) {
   1163 		if (OC != NULL && CC == NULL)
   1164 			tputs(OC, 0, __cputchar);
   1165 		if (OP != NULL) {
   1166 			tputs(OP, 0, __cputchar);
   1167 			curscr->wattr &= __mask_OP;
   1168 		}
   1169 	}
   1170 }
   1171