xref: /netbsd-src/lib/libcurses/refresh.c (revision 28c37e673e4d9b6cbdc7483062b915cc61d1ccf5)
1 /*	$NetBSD: refresh.c,v 1.47 2002/08/04 16:43:08 jdc 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 1.47 2002/08/04 16:43:08 jdc 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 static void	domvcur __P((int, int, int, int));
52 static int	makech __P((int));
53 static void	quickch __P((void));
54 static void	scrolln __P((int, int, int, int, int));
55 
56 #ifndef _CURSES_USE_MACROS
57 
58 /*
59  * refresh --
60  *	Make the current screen look like "stdscr" over the area covered by
61  *	stdscr.
62  */
63 int
64 refresh(void)
65 {
66 	return wrefresh(stdscr);
67 }
68 
69 #endif
70 
71 /*
72  * wnoutrefresh --
73  *	Add the contents of "win" to the virtual window.
74  */
75 int
76 wnoutrefresh(WINDOW *win)
77 {
78 	return _cursesi_wnoutrefresh(_cursesi_screen, win);
79 }
80 
81 
82 /*
83  * _cursesi_wnoutrefresh --
84  *      Does the grunt work for wnoutrefresh to the given screen.
85  *
86  */
87 int
88 _cursesi_wnoutrefresh(SCREEN *screen, WINDOW *win)
89 {
90 
91 	short	wy, wx, x_off;
92 	__LINE	*wlp, *vlp;
93 
94 #ifdef DEBUG
95 	__CTRACE("wnoutrefresh: win %0.2o, flags 0x%08x\n", win, win->flags);
96 #endif
97 
98 	if (screen->curwin)
99 		return(OK);
100 	screen->__virtscr->cury = win->cury + win->begy;
101 	screen->__virtscr->curx = win->curx + win->begx;
102 
103 	/* Copy the window flags from "win" to "__virtscr" */
104 	if (win->flags & __CLEAROK) {
105 		if (win->flags & __FULLWIN)
106 			screen->__virtscr->flags |= __CLEAROK;
107 		win->flags &= ~__CLEAROK;
108 	}
109 	screen->__virtscr->flags &= ~__LEAVEOK;
110 	screen->__virtscr->flags |= win->flags;
111 
112 	for (wy = 0; wy < win->maxy && wy < screen->__virtscr->maxy - win->begy; wy++) {
113 		wlp = win->lines[wy];
114 #ifdef DEBUG
115 		__CTRACE("wnoutrefresh: wy %d\tf: %d\tl:%d\tflags %x\n", wy,
116 		    *wlp->firstchp, *wlp->lastchp, wlp->flags);
117 #endif
118 		if ((wlp->flags & __ISDIRTY) == 0)
119 			continue;
120 		vlp = screen->__virtscr->lines[wy + win->begy];
121 
122 		if (*wlp->firstchp < win->maxx + win->ch_off &&
123 		    *wlp->lastchp >= win->ch_off) {
124 			/* Copy line from "win" to "__virtscr". */
125 			for (wx = 0, x_off = win->begx; wx < win->maxx &&
126 			    x_off < screen->__virtscr->maxx; wx++, x_off++) {
127 				vlp->line[x_off].attr = wlp->line[wx].attr;
128 				if (wlp->line[wx].attr & __COLOR)
129 					vlp->line[x_off].attr |=
130 					    wlp->line[wx].battr & ~__COLOR;
131 				else
132 					vlp->line[x_off].attr |=
133 					    wlp->line[wx].battr;
134 				if (wlp->line[wx].ch == ' ' &&
135 				    wlp->line[wx].bch != ' ')
136 					vlp->line[x_off].ch
137 					    = wlp->line[wx].bch;
138 				else
139 					vlp->line[x_off].ch
140 					    = wlp->line[wx].ch;
141 			}
142 
143 			/* Set flags on "__virtscr" and unset on "win". */
144 			if (wlp->flags & __ISPASTEOL)
145 				vlp->flags |= __ISPASTEOL;
146 			else
147 				vlp->flags &= ~__ISPASTEOL;
148 			if (wlp->flags & __ISDIRTY)
149 				vlp->flags |= __ISDIRTY;
150 
151 #ifdef DEBUG
152 			__CTRACE("win: firstch = %d, lastch = %d\n",
153 			    *wlp->firstchp, *wlp->lastchp);
154 #endif
155 			/* Set change pointers on "__virtscr". */
156 			if (*vlp->firstchp >
157 			    *wlp->firstchp + win->begx - win->ch_off)
158 				*vlp->firstchp =
159 				    *wlp->firstchp + win->begx - win->ch_off;
160 			if (*vlp->lastchp <
161 			    *wlp->lastchp + win->begx - win->ch_off)
162 				*vlp->lastchp =
163 				    *wlp->lastchp + win->begx - win->ch_off;
164 #ifdef DEBUG
165 			__CTRACE("__virtscr: firstch = %d, lastch = %d\n",
166 			    *vlp->firstchp, *vlp->lastchp);
167 #endif
168 
169 			/* Set change pointers on "win". */
170 			if (*wlp->firstchp >= win->ch_off)
171 				*wlp->firstchp = win->maxx + win->ch_off;
172 			if (*wlp->lastchp < win->maxx + win->ch_off)
173 				*wlp->lastchp = win->ch_off;
174 			if (*wlp->lastchp < *wlp->firstchp) {
175 #ifdef DEBUG
176 				__CTRACE("wnoutrefresh: line %d notdirty\n",
177 				    wy);
178 #endif
179 				wlp->flags &= ~__ISDIRTY;
180 			}
181 		}
182 	}
183 
184 	return (OK);
185 }
186 
187 /*
188  * wrefresh --
189  *	Make the current screen look like "win" over the area coverd by
190  *	win.
191  */
192 int
193 wrefresh(WINDOW *win)
194 {
195 	int retval;
196 
197 	_cursesi_screen->curwin = (win == _cursesi_screen->curscr);
198 	if (!_cursesi_screen->curwin)
199 		retval = _cursesi_wnoutrefresh(_cursesi_screen, win);
200 	else
201 		retval = OK;
202 	if (retval == OK) {
203 		retval = doupdate();
204 		if (!win->flags & __LEAVEOK) {
205 			win->cury = max(0, curscr->cury - win->begy);
206 			win->curx = max(0, curscr->curx - win->begx);
207 		}
208 	}
209 	_cursesi_screen->curwin = 0;
210 	return(retval);
211 }
212 
213 /*
214  * doupdate --
215  *	Make the current screen look like the virtual window "__virtscr".
216  */
217 int
218 doupdate(void)
219 {
220 	WINDOW	*win;
221 	__LINE	*wlp;
222 	short	 wy;
223 	int	 dnum;
224 
225 	/* Check if we need to restart ... */
226 	if (_cursesi_screen->endwin)
227 		__restartwin();
228 
229 	if (_cursesi_screen->curwin)
230 		win = curscr;
231 	else
232 		win = _cursesi_screen->__virtscr;
233 
234 	/* Initialize loop parameters. */
235 	_cursesi_screen->ly = curscr->cury;
236 	_cursesi_screen->lx = curscr->curx;
237 	wy = 0;
238 
239 	if (!_cursesi_screen->curwin)
240 		for (wy = 0; wy < win->maxy; wy++) {
241 			wlp = win->lines[wy];
242 			if (wlp->flags & __ISDIRTY)
243 				wlp->hash = __hash((char *)(void *)wlp->line,
244 				    (int) (win->maxx * __LDATASIZE));
245 		}
246 
247 	if ((win->flags & __CLEAROK) || (curscr->flags & __CLEAROK) ||
248 	    _cursesi_screen->curwin) {
249 		if (curscr->wattr & __COLOR)
250 			__unsetattr(0);
251 		tputs(__tc_cl, 0, __cputchar);
252 		_cursesi_screen->ly = 0;
253 		_cursesi_screen->lx = 0;
254 		if (!_cursesi_screen->curwin) {
255 			curscr->flags &= ~__CLEAROK;
256 			curscr->cury = 0;
257 			curscr->curx = 0;
258 			werase(curscr);
259 		}
260 		__touchwin(win);
261 		win->flags &= ~__CLEAROK;
262 	}
263 	if (!__CA) {
264 		if (win->curx != 0)
265 			__cputchar('\n');
266 		if (!_cursesi_screen->curwin)
267 			werase(curscr);
268 	}
269 #ifdef DEBUG
270 	__CTRACE("doupdate: (%0.2o): curwin = %d\n", win,
271 		 _cursesi_screen->curwin);
272 	__CTRACE("doupdate: \tfirstch\tlastch\n");
273 #endif
274 
275 	if (!_cursesi_screen->curwin) {
276 		/*
277 		 * Invoke quickch() only if more than a quarter of the lines
278 		 * in the window are dirty.
279 		 */
280 		for (wy = 0, dnum = 0; wy < win->maxy; wy++)
281 			if (win->lines[wy]->flags & __ISDIRTY)
282 				dnum++;
283 		if (!__noqch && dnum > (int) win->maxy / 4)
284 			quickch();
285 	}
286 
287 #ifdef DEBUG
288 	{
289 		int	i, j;
290 
291 		__CTRACE("#####################################\n");
292 		for (i = 0; i < curscr->maxy; i++) {
293 			__CTRACE("C: %d:", i);
294 			__CTRACE(" 0x%x \n", curscr->lines[i]->hash);
295 			for (j = 0; j < curscr->maxx; j++)
296 				__CTRACE("%c", curscr->lines[i]->line[j].ch);
297 			__CTRACE("\n");
298 			__CTRACE(" attr:");
299 			for (j = 0; j < curscr->maxx; j++)
300 				__CTRACE(" %x",
301 					 curscr->lines[i]->line[j].attr);
302 			__CTRACE("\n");
303 			__CTRACE("W: %d:", i);
304 			__CTRACE(" 0x%x \n", win->lines[i]->hash);
305 			__CTRACE(" 0x%x ", win->lines[i]->flags);
306 			for (j = 0; j < win->maxx; j++)
307 				__CTRACE("%c", win->lines[i]->line[j].ch);
308 			__CTRACE("\n");
309 			__CTRACE(" attr:");
310 			for (j = 0; j < win->maxx; j++)
311 				__CTRACE(" %x",
312 				    win->lines[i]->line[j].attr);
313 			__CTRACE("\n");
314 		}
315 	}
316 #endif				/* DEBUG */
317 
318 	for (wy = 0; wy < win->maxy; wy++) {
319 		wlp = win->lines[wy];
320 /* XXX: remove this debug */
321 #ifdef DEBUG
322 		__CTRACE("doupdate: wy %d\tf: %d\tl:%d\tflags %x\n", wy,
323 		    *wlp->firstchp, *wlp->lastchp, wlp->flags);
324 #endif
325 		if (!_cursesi_screen->curwin)
326 			curscr->lines[wy]->hash = wlp->hash;
327 		if (wlp->flags & __ISDIRTY) {
328 			if (makech(wy) == ERR)
329 				return (ERR);
330 			else {
331 				if (*wlp->firstchp >= 0)
332 					*wlp->firstchp = win->maxx;
333 				if (*wlp->lastchp < win->maxx)
334 					*wlp->lastchp = 0;
335 				if (*wlp->lastchp < *wlp->firstchp) {
336 #ifdef DEBUG
337 					__CTRACE("doupdate: line %d notdirty\n", wy);
338 #endif
339 					wlp->flags &= ~__ISDIRTY;
340 				}
341 			}
342 
343 		}
344 #ifdef DEBUG
345 		__CTRACE("\t%d\t%d\n", *wlp->firstchp, *wlp->lastchp);
346 #endif
347 	}
348 
349 #ifdef DEBUG
350 	__CTRACE("doupdate: ly=%d, lx=%d\n", _cursesi_screen->ly,
351 		 _cursesi_screen->lx);
352 #endif
353 
354 	if (_cursesi_screen->curwin)
355 		domvcur(_cursesi_screen->ly, _cursesi_screen->lx,
356 			(int) win->cury, (int) win->curx);
357 	else {
358 		if (win->flags & __LEAVEOK) {
359 			curscr->cury = _cursesi_screen->ly;
360 			curscr->curx = _cursesi_screen->lx;
361 		} else {
362 			domvcur(_cursesi_screen->ly, _cursesi_screen->lx,
363 				win->cury, win->curx);
364 			curscr->cury = win->cury;
365 			curscr->curx = win->curx;
366 		}
367 	}
368 
369 	/* Don't leave the screen with attributes set. */
370 	__unsetattr(0);
371 	(void) fflush(_cursesi_screen->outfd);
372 	return (OK);
373 }
374 
375 /*
376  * makech --
377  *	Make a change on the screen.
378  */
379 static int
380 makech(wy)
381 	int	wy;
382 {
383 	WINDOW	*win;
384 	static __LDATA blank = {' ', 0, ' ', 0};
385 	__LDATA *nsp, *csp, *cp, *cep;
386 	int	clsp, nlsp;	/* Last space in lines. */
387 	int	lch, wx;
388 	char	*ce;
389 	attr_t	lspc;		/* Last space colour */
390 	attr_t	off, on;
391 
392 #ifdef __GNUC__
393 	nlsp = lspc = 0;	/* XXX gcc -Wuninitialized */
394 #endif
395 	if (_cursesi_screen->curwin)
396 		win = curscr;
397 	else
398 		win = __virtscr;
399 	/* Is the cursor still on the end of the last line? */
400 	if (wy > 0 && curscr->lines[wy - 1]->flags & __ISPASTEOL) {
401 		domvcur(_cursesi_screen->ly, _cursesi_screen->lx,
402 			_cursesi_screen->ly + 1, 0);
403 		_cursesi_screen->ly++;
404 		_cursesi_screen->lx = 0;
405 	}
406 	wx = *win->lines[wy]->firstchp;
407 	if (wx < 0)
408 		wx = 0;
409 	else
410 		if (wx >= win->maxx)
411 			return (OK);
412 	lch = *win->lines[wy]->lastchp;
413 	if (lch < 0)
414 		return (OK);
415 	else
416 		if (lch >= (int) win->maxx)
417 			lch = win->maxx - 1;
418 
419 	if (_cursesi_screen->curwin)
420 		csp = &blank;
421 	else
422 		csp = &curscr->lines[wy]->line[wx];
423 
424 	nsp = &win->lines[wy]->line[wx];
425 	if (__tc_ce && !_cursesi_screen->curwin) {
426 		cp = &win->lines[wy]->line[win->maxx - 1];
427 		lspc = cp->attr & __COLOR;
428 		while (cp->ch == ' ' && cp->attr == lspc)
429 			if (cp-- <= win->lines[wy]->line)
430 				break;
431 		nlsp = cp - win->lines[wy]->line;
432 		if (nlsp < 0)
433 			nlsp = 0;
434 	}
435 	if (!_cursesi_screen->curwin)
436 		ce = __tc_ce;
437 	else
438 		ce = NULL;
439 
440 	while (wx <= lch) {
441 		if (memcmp(nsp, csp, sizeof(__LDATA)) == 0) {
442 			if (wx <= lch) {
443 				while (wx <= lch &&
444 				    memcmp(nsp, csp, sizeof(__LDATA)) == 0) {
445 					nsp++;
446 					if (!_cursesi_screen->curwin)
447 						++csp;
448 					++wx;
449 				}
450 				continue;
451 			}
452 			break;
453 		}
454 		domvcur(_cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
455 
456 #ifdef DEBUG
457 		__CTRACE("makech: 1: wx = %d, ly= %d, lx = %d, newy = %d, newx = %d\n",
458 		    wx, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
459 #endif
460 		_cursesi_screen->ly = wy;
461 		_cursesi_screen->lx = wx;
462 		while (memcmp(nsp, csp, sizeof(__LDATA)) != 0 && wx <= lch) {
463 			if (ce != NULL &&
464 			    wx >= nlsp && nsp->ch == ' ' && nsp->attr == lspc) {
465 				/* Check for clear to end-of-line. */
466 				cep = &curscr->lines[wy]->line[win->maxx - 1];
467 				while (cep->ch == ' ' && cep->attr == lspc)
468 					if (cep-- <= csp)
469 						break;
470 				clsp = cep - curscr->lines[wy]->line -
471 				    win->begx * __LDATASIZE;
472 #ifdef DEBUG
473 				__CTRACE("makech: clsp = %d, nlsp = %d\n",
474 				    clsp, nlsp);
475 #endif
476 				if (((clsp - nlsp >= strlen(__tc_ce) &&
477 				    clsp < win->maxx * __LDATASIZE) ||
478 				    wy == win->maxy - 1) &&
479 				    (!(lspc & __COLOR) ||
480 				    ((lspc & __COLOR) && __tc_ut))) {
481 					__unsetattr(0);
482 					if (__using_color &&
483 					    ((lspc & __COLOR) !=
484 					    (curscr->wattr & __COLOR)))
485 						__set_color(curscr, lspc &
486 						    __COLOR);
487 					tputs(__tc_ce, 0, __cputchar);
488 					_cursesi_screen->lx = wx + win->begx;
489 					while (wx++ <= clsp) {
490 						csp->ch = ' ';
491 						csp->attr = lspc;
492 						csp++;
493 					}
494 					return (OK);
495 				}
496 				ce = NULL;
497 			}
498 
499 #ifdef DEBUG
500 				__CTRACE("makech: have attributes %08x, need attributes %08x\n", curscr->wattr, nsp->attr);
501 #endif
502 
503 			off = ~nsp->attr & curscr->wattr;
504 
505 			/*
506 			 * Unset attributes as appropriate.  Unset first
507 			 * so that the relevant attributes can be reset
508 			 * (because 'me' unsets 'mb', 'md', 'mh', 'mk',
509 			 * 'mp' and 'mr').  Check to see if we also turn off
510 			 * standout, attributes and colour.
511 			 */
512 			if (off & __TERMATTR && __tc_me != NULL) {
513 				tputs(__tc_me, 0, __cputchar);
514 				curscr->wattr &= __mask_me;
515 				off &= __mask_me;
516 			}
517 
518 			/*
519 			 * Exit underscore mode if appropriate.
520 			 * Check to see if we also turn off standout,
521 			 * attributes and colour.
522 			 */
523 			if (off & __UNDERSCORE && __tc_ue != NULL) {
524 				tputs(__tc_ue, 0, __cputchar);
525 				curscr->wattr &= __mask_ue;
526 				off &= __mask_ue;
527 			}
528 
529 			/*
530 			 * Exit standout mode as appropriate.
531 			 * Check to see if we also turn off underscore,
532 			 * attributes and colour.
533 			 * XXX
534 			 * Should use uc if so/se not available.
535 			 */
536 			if (off & __STANDOUT && __tc_se != NULL) {
537 				tputs(__tc_se, 0, __cputchar);
538 				curscr->wattr &= __mask_se;
539 				off &= __mask_se;
540 			}
541 
542 			if (off & __ALTCHARSET && __tc_ae != NULL) {
543 				tputs(__tc_ae, 0, __cputchar);
544 				curscr->wattr &= ~__ALTCHARSET;
545 			}
546 
547 			/* Set/change colour as appropriate. */
548 			if (__using_color)
549 				__set_color(curscr, nsp->attr & __COLOR);
550 
551 			on = nsp->attr & ~curscr->wattr;
552 
553 			/*
554 			 * Enter standout mode if appropriate.
555 			 */
556 			if (on & __STANDOUT && __tc_so != NULL && __tc_se
557 			    != NULL) {
558 				tputs(__tc_so, 0, __cputchar);
559 				curscr->wattr |= __STANDOUT;
560 			}
561 
562 			/*
563 			 * Enter underscore mode if appropriate.
564 			 * XXX
565 			 * Should use uc if us/ue not available.
566 			 */
567 			if (on & __UNDERSCORE && __tc_us != NULL &&
568 			    __tc_ue != NULL) {
569 				tputs(__tc_us, 0, __cputchar);
570 				curscr->wattr |= __UNDERSCORE;
571 			}
572 
573 			/*
574 			 * Set other attributes as appropriate.
575 			 */
576 			if (__tc_me != NULL) {
577 				if (on & __BLINK && __tc_mb != NULL) {
578 					tputs(__tc_mb, 0, __cputchar);
579 					curscr->wattr |= __BLINK;
580 				}
581 				if (on & __BOLD && __tc_md != NULL) {
582 					tputs(__tc_md, 0, __cputchar);
583 					curscr->wattr |= __BOLD;
584 				}
585 				if (on & __DIM && __tc_mh != NULL) {
586 					tputs(__tc_mh, 0, __cputchar);
587 					curscr->wattr |= __DIM;
588 				}
589 				if (on & __BLANK && __tc_mk != NULL) {
590 					tputs(__tc_mk, 0, __cputchar);
591 					curscr->wattr |= __BLANK;
592 				}
593 				if (on & __PROTECT && __tc_mp != NULL) {
594 					tputs(__tc_mp, 0, __cputchar);
595 					curscr->wattr |= __PROTECT;
596 				}
597 				if (on & __REVERSE && __tc_mr != NULL) {
598 					tputs(__tc_mr, 0, __cputchar);
599 					curscr->wattr |= __REVERSE;
600 				}
601 			}
602 
603 			/* Enter/exit altcharset mode as appropriate. */
604 			if (on & __ALTCHARSET && __tc_as != NULL &&
605 			    __tc_ae != NULL) {
606 				tputs(__tc_as, 0, __cputchar);
607 				curscr->wattr |= __ALTCHARSET;
608 			}
609 
610 			wx++;
611 			if (wx >= win->maxx &&
612 			    wy == win->maxy - 1 && !_cursesi_screen->curwin)
613 				if (win->flags & __SCROLLOK) {
614 					if (win->flags & __ENDLINE)
615 						__unsetattr(1);
616 					if (!(win->flags & __SCROLLWIN)) {
617 						if (!_cursesi_screen->curwin) {
618 							csp->attr = nsp->attr;
619 							__cputchar((int)
620 							    (csp->ch =
621 							    nsp->ch));
622 						} else
623 							__cputchar((int) nsp->ch);
624 					}
625 					if (wx < curscr->maxx) {
626 						domvcur(_cursesi_screen->ly, wx,
627 						    (int) (win->maxy - 1),
628 						    (int) (win->maxx - 1));
629 					}
630 					_cursesi_screen->ly = win->maxy - 1;
631 					_cursesi_screen->lx = win->maxx - 1;
632 					return (OK);
633 				}
634 			if (wx < win->maxx || wy < win->maxy - 1 ||
635 			    !(win->flags & __SCROLLWIN)) {
636 				if (!_cursesi_screen->curwin) {
637 					csp->attr = nsp->attr;
638 					__cputchar((int) (csp->ch = nsp->ch));
639 					csp++;
640 				} else
641 					__cputchar((int) nsp->ch);
642 			}
643 #ifdef DEBUG
644 			__CTRACE("makech: putchar(%c)\n", nsp->ch & 0177);
645 #endif
646 			if (__tc_uc && ((nsp->attr & __STANDOUT) ||
647 			    (nsp->attr & __UNDERSCORE))) {
648 				__cputchar('\b');
649 				tputs(__tc_uc, 0, __cputchar);
650 			}
651 			nsp++;
652 #ifdef DEBUG
653 			__CTRACE("makech: 2: wx = %d, lx = %d\n", wx, _cursesi_screen->lx);
654 #endif
655 		}
656 		if (_cursesi_screen->lx == wx)	/* If no change. */
657 			break;
658 		_cursesi_screen->lx = wx;
659 		if (_cursesi_screen->lx >= COLS && __tc_am)
660 			_cursesi_screen->lx = COLS - 1;
661 		else
662 			if (wx >= win->maxx) {
663 				domvcur(_cursesi_screen->ly,
664 					_cursesi_screen->lx,
665 					_cursesi_screen->ly,
666 					(int) (win->maxx - 1));
667 				_cursesi_screen->lx = win->maxx - 1;
668 			}
669 #ifdef DEBUG
670 		__CTRACE("makech: 3: wx = %d, lx = %d\n", wx,
671 			 _cursesi_screen->lx);
672 #endif
673 	}
674 
675 	return (OK);
676 }
677 
678 /*
679  * domvcur --
680  *	Do a mvcur, leaving attributes if necessary.
681  */
682 static void
683 domvcur(oy, ox, ny, nx)
684 	int	oy, ox, ny, nx;
685 {
686 	__unsetattr(1);
687 	__mvcur(oy, ox, ny, nx, 1);
688 }
689 
690 /*
691  * Quickch() attempts to detect a pattern in the change of the window
692  * in order to optimize the change, e.g., scroll n lines as opposed to
693  * repainting the screen line by line.
694  */
695 
696 static __LDATA buf[128];
697 static  u_int last_hash;
698 static  size_t last_hash_len;
699 #define BLANKSIZE (sizeof(buf) / sizeof(buf[0]))
700 
701 static void
702 quickch(void)
703 {
704 #define THRESH		(int) __virtscr->maxy / 4
705 
706 	__LINE *clp, *tmp1, *tmp2;
707 	int	bsize, curs, curw, starts, startw, i, j;
708 	int	n, target, cur_period, bot, top, sc_region;
709 	u_int	blank_hash;
710 	attr_t	bcolor;
711 
712 #ifdef __GNUC__
713 	curs = curw = starts = startw = 0;	/* XXX gcc -Wuninitialized */
714 #endif
715 	/*
716 	 * Find how many lines from the top of the screen are unchanged.
717 	 */
718 	for (top = 0; top < __virtscr->maxy; top++)
719 		if (__virtscr->lines[top]->flags & __ISDIRTY &&
720 		    (__virtscr->lines[top]->hash != curscr->lines[top]->hash ||
721 		     memcmp(__virtscr->lines[top]->line,
722 			  curscr->lines[top]->line,
723 			  (size_t) __virtscr->maxx * __LDATASIZE) != 0))
724 			break;
725 		else
726 			__virtscr->lines[top]->flags &= ~__ISDIRTY;
727 	/*
728 	 * Find how many lines from bottom of screen are unchanged.
729 	 */
730 	for (bot = __virtscr->maxy - 1; bot >= 0; bot--)
731 		if (__virtscr->lines[bot]->flags & __ISDIRTY &&
732 		    (__virtscr->lines[bot]->hash != curscr->lines[bot]->hash ||
733 		     memcmp(__virtscr->lines[bot]->line,
734 			  curscr->lines[bot]->line,
735 			  (size_t) __virtscr->maxx * __LDATASIZE) != 0))
736 			break;
737 		else
738 			__virtscr->lines[bot]->flags &= ~__ISDIRTY;
739 
740 	/*
741 	 * Work round an xterm bug where inserting lines causes all the
742 	 * inserted lines to be covered with the background colour we
743 	 * set on the first line (even if we unset it for subsequent
744 	 * lines).
745 	 */
746 	bcolor = __virtscr->lines[min(top,
747 	    __virtscr->maxy - 1)]->line[0].attr & __COLOR;
748 	for (i = top + 1, j = 0; i < bot; i++) {
749 		if ((__virtscr->lines[i]->line[0].attr & __COLOR) != bcolor) {
750 			bcolor = __virtscr->lines[i]->line[__virtscr->maxx].
751 			    attr & __COLOR;
752 			j = i - top;
753 		} else
754 			break;
755 	}
756 	top += j;
757 
758 #ifdef NO_JERKINESS
759 	/*
760 	 * If we have a bottom unchanged region return.  Scrolling the
761 	 * bottom region up and then back down causes a screen jitter.
762 	 * This will increase the number of characters sent to the screen
763 	 * but it looks better.
764 	 */
765 	if (bot < __virtscr->maxy - 1)
766 		return;
767 #endif				/* NO_JERKINESS */
768 
769 	/*
770 	 * Search for the largest block of text not changed.
771 	 * Invariants of the loop:
772 	 * - Startw is the index of the beginning of the examined block in
773 	 *   __virtscr.
774 	 * - Starts is the index of the beginning of the examined block in
775 	 *   curscr.
776 	 * - Curw is the index of one past the end of the exmined block in
777 	 *   __virtscr.
778 	 * - Curs is the index of one past the end of the exmined block in
779 	 *   curscr.
780 	 * - bsize is the current size of the examined block.
781 	*/
782 
783 	for (bsize = bot - top; bsize >= THRESH; bsize--) {
784 		for (startw = top; startw <= bot - bsize; startw++)
785 			for (starts = top; starts <= bot - bsize;
786 			    starts++) {
787 				for (curw = startw, curs = starts;
788 				    curs < starts + bsize; curw++, curs++)
789 					if (__virtscr->lines[curw]->hash !=
790 					    curscr->lines[curs]->hash)
791 						break;
792 				if (curs != starts + bsize)
793 					continue;
794 				for (curw = startw, curs = starts;
795 				    curs < starts + bsize; curw++, curs++)
796 					if (memcmp(__virtscr->lines[curw]->line,
797 					    curscr->lines[curs]->line,
798 					    (size_t) __virtscr->maxx *
799 					    __LDATASIZE) != 0)
800 						break;
801 				if (curs == starts + bsize)
802 					goto done;
803 			}
804 	}
805 done:
806 
807 	/* Did not find anything */
808 	if (bsize < THRESH)
809 		return;
810 
811 #ifdef DEBUG
812 	__CTRACE("quickch:bsize=%d,starts=%d,startw=%d,curw=%d,curs=%d,top=%d,bot=%d\n",
813 	    bsize, starts, startw, curw, curs, top, bot);
814 #endif
815 
816 	/*
817 	 * Make sure that there is no overlap between the bottom and top
818 	 * regions and the middle scrolled block.
819 	 */
820 	if (bot < curs)
821 		bot = curs - 1;
822 	if (top > starts)
823 		top = starts;
824 
825 	n = startw - starts;
826 
827 #ifdef DEBUG
828 	__CTRACE("#####################################\n");
829 	for (i = 0; i < curscr->maxy; i++) {
830 		__CTRACE("C: %d:", i);
831 		__CTRACE(" 0x%x \n", curscr->lines[i]->hash);
832 		for (j = 0; j < curscr->maxx; j++)
833 			__CTRACE("%c", curscr->lines[i]->line[j].ch);
834 		__CTRACE("\n");
835 		__CTRACE(" attr:");
836 		for (j = 0; j < curscr->maxx; j++)
837 			__CTRACE(" %x", curscr->lines[i]->line[j].attr);
838 		__CTRACE("\n");
839 		__CTRACE("W: %d:", i);
840 		__CTRACE(" 0x%x \n", __virtscr->lines[i]->hash);
841 		__CTRACE(" 0x%x ", __virtscr->lines[i]->flags);
842 		for (j = 0; j < __virtscr->maxx; j++)
843 			__CTRACE("%c", __virtscr->lines[i]->line[j].ch);
844 		__CTRACE("\n");
845 		__CTRACE(" attr:");
846 		for (j = 0; j < __virtscr->maxx; j++)
847 			__CTRACE(" %x", __virtscr->lines[i]->line[j].attr);
848 		__CTRACE("\n");
849 	}
850 #endif
851 
852 	if (buf[0].ch != ' ') {
853 		for (i = 0; i < BLANKSIZE; i++) {
854 			buf[i].ch = ' ';
855 			buf[i].bch = ' ';
856 			buf[i].attr = 0;
857 			buf[i].battr = 0;
858 		}
859 	}
860 
861 	if (__virtscr->maxx != last_hash_len) {
862 		blank_hash = 0;
863 		for (i = __virtscr->maxx; i > BLANKSIZE; i -= BLANKSIZE) {
864 			blank_hash = __hash_more((char *)(void *)buf, sizeof(buf),
865 			    blank_hash);
866 		}
867 		blank_hash = __hash_more((char *)(void *)buf,
868 		    i * sizeof(buf[0]), blank_hash);
869 		/* cache result in static data - screen width doesn't change often */
870 		last_hash_len = __virtscr->maxx;
871 		last_hash = blank_hash;
872 	} else
873 		blank_hash = last_hash;
874 
875 	/*
876 	 * Perform the rotation to maintain the consistency of curscr.
877 	 * This is hairy since we are doing an *in place* rotation.
878 	 * Invariants of the loop:
879 	 * - I is the index of the current line.
880 	 * - Target is the index of the target of line i.
881 	 * - Tmp1 points to current line (i).
882 	 * - Tmp2 and points to target line (target);
883 	 * - Cur_period is the index of the end of the current period.
884 	 *   (see below).
885 	 *
886 	 * There are 2 major issues here that make this rotation non-trivial:
887 	 * 1.  Scrolling in a scrolling region bounded by the top
888 	 *     and bottom regions determined (whose size is sc_region).
889 	 * 2.  As a result of the use of the mod function, there may be a
890 	 *     period introduced, i.e., 2 maps to 4, 4 to 6, n-2 to 0, and
891 	 *     0 to 2, which then causes all odd lines not to be rotated.
892 	 *     To remedy this, an index of the end ( = beginning) of the
893 	 *     current 'period' is kept, cur_period, and when it is reached,
894 	 *     the next period is started from cur_period + 1 which is
895 	 *     guaranteed not to have been reached since that would mean that
896 	 *     all records would have been reached. (think about it...).
897 	 *
898 	 * Lines in the rotation can have 3 attributes which are marked on the
899 	 * line so that curscr is consistent with the visual screen.
900 	 * 1.  Not dirty -- lines inside the scrolled block, top region or
901 	 *                  bottom region.
902 	 * 2.  Blank lines -- lines in the differential of the scrolling
903 	 *		      region adjacent to top and bot regions
904 	 *                    depending on scrolling direction.
905 	 * 3.  Dirty line -- all other lines are marked dirty.
906 	 */
907 	sc_region = bot - top + 1;
908 	i = top;
909 	tmp1 = curscr->lines[top];
910 	cur_period = top;
911 	for (j = top; j <= bot; j++) {
912 		target = (i - top + n + sc_region) % sc_region + top;
913 		tmp2 = curscr->lines[target];
914 		curscr->lines[target] = tmp1;
915 		/* Mark block as clean and blank out scrolled lines. */
916 		clp = curscr->lines[target];
917 #ifdef DEBUG
918 		__CTRACE("quickch: n=%d startw=%d curw=%d i = %d target=%d ",
919 		    n, startw, curw, i, target);
920 #endif
921 		if ((target >= startw && target < curw) || target < top
922 		    || target > bot) {
923 #ifdef DEBUG
924 			__CTRACE("-- notdirty\n");
925 #endif
926 			__virtscr->lines[target]->flags &= ~__ISDIRTY;
927 		} else
928 			if ((n > 0 && target >= top && target < top + n) ||
929 			    (n < 0 && target <= bot && target > bot + n)) {
930 				if (clp->hash != blank_hash || memcmp(clp->line,
931 				    clp->line + 1, (__virtscr->maxx - 1) *
932 				    __LDATASIZE) || memcmp(clp->line, buf,
933 				    __LDATASIZE)) {
934 					for (i = __virtscr->maxx; i > BLANKSIZE;
935 					    i -= BLANKSIZE) {
936 						(void)memcpy(clp->line + i -
937 						    BLANKSIZE, buf, sizeof(buf));
938 					}
939 					(void)memcpy(clp->line , buf, i *
940 					    sizeof(buf[0]));
941 #ifdef DEBUG
942 					__CTRACE("-- blanked out: dirty\n");
943 #endif
944 					clp->hash = blank_hash;
945 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
946 				} else {
947 #ifdef DEBUG
948 					__CTRACE(" -- blank line already: dirty\n");
949 #endif
950 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
951 				}
952 			} else {
953 #ifdef DEBUG
954 				__CTRACE(" -- dirty\n");
955 #endif
956 				__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
957 			}
958 		if (target == cur_period) {
959 			i = target + 1;
960 			tmp1 = curscr->lines[i];
961 			cur_period = i;
962 		} else {
963 			tmp1 = tmp2;
964 			i = target;
965 		}
966 	}
967 #ifdef DEBUG
968 	__CTRACE("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$\n");
969 	for (i = 0; i < curscr->maxy; i++) {
970 		__CTRACE("C: %d:", i);
971 		for (j = 0; j < curscr->maxx; j++)
972 			__CTRACE("%c", curscr->lines[i]->line[j].ch);
973 		__CTRACE("\n");
974 		__CTRACE("W: %d:", i);
975 		for (j = 0; j < __virtscr->maxx; j++)
976 			__CTRACE("%c", __virtscr->lines[i]->line[j].ch);
977 		__CTRACE("\n");
978 	}
979 #endif
980 	if (n != 0)
981 		scrolln(starts, startw, curs, bot, top);
982 }
983 
984 /*
985  * scrolln --
986  *	Scroll n lines, where n is starts - startw.
987  */
988 static void /* ARGSUSED */
989 scrolln(starts, startw, curs, bot, top)
990 	int	starts, startw, curs, bot, top;
991 {
992 	int	i, oy, ox, n;
993 
994 	oy = curscr->cury;
995 	ox = curscr->curx;
996 	n = starts - startw;
997 
998 	/*
999 	 * XXX
1000 	 * The initial tests that set __noqch don't let us reach here unless
1001 	 * we have either cs + ho + SF/sf/SR/sr, or AL + DL.  SF/sf and SR/sr
1002 	 * scrolling can only shift the entire scrolling region, not just a
1003 	 * part of it, which means that the quickch() routine is going to be
1004 	 * sadly disappointed in us if we don't have cs as well.
1005 	 *
1006 	 * If cs, ho and SF/sf are set, can use the scrolling region.  Because
1007 	 * the cursor position after cs is undefined, we need ho which gives us
1008 	 * the ability to move to somewhere without knowledge of the current
1009 	 * location of the cursor.  Still call __mvcur() anyway, to update its
1010 	 * idea of where the cursor is.
1011 	 *
1012 	 * When the scrolling region has been set, the cursor has to be at the
1013 	 * last line of the region to make the scroll happen.
1014 	 *
1015 	 * Doing SF/SR or AL/DL appears faster on the screen than either sf/sr
1016 	 * or AL/DL, and, some terminals have AL/DL, sf/sr, and cs, but not
1017 	 * SF/SR.  So, if we're scrolling almost all of the screen, try and use
1018 	 * AL/DL, otherwise use the scrolling region.  The "almost all" is a
1019 	 * shameless hack for vi.
1020 	 */
1021 	if (n > 0) {
1022 		if (__tc_cs != NULL && __tc_ho != NULL && (__tc_SF != NULL ||
1023 		    ((__tc_AL == NULL || __tc_DL == NULL ||
1024 		    top > 3 || bot + 3 < __virtscr->maxy) &&
1025 		    __tc_sf != NULL))) {
1026 			tputs(__tscroll(__tc_cs, top, bot + 1), 0, __cputchar);
1027 			__mvcur(oy, ox, 0, 0, 1);
1028 			tputs(__tc_ho, 0, __cputchar);
1029 			__mvcur(0, 0, bot, 0, 1);
1030 			if (__tc_SF != NULL)
1031 				tputs(__tscroll(__tc_SF, n, 0), 0, __cputchar);
1032 			else
1033 				for (i = 0; i < n; i++)
1034 					tputs(__tc_sf, 0, __cputchar);
1035 			tputs(__tscroll(__tc_cs, 0, (int) __virtscr->maxy), 0,
1036 			    __cputchar);
1037 			__mvcur(bot, 0, 0, 0, 1);
1038 			tputs(__tc_ho, 0, __cputchar);
1039 			__mvcur(0, 0, oy, ox, 1);
1040 			return;
1041 		}
1042 
1043 		/* Scroll up the block. */
1044 		if (__tc_SF != NULL && top == 0) {
1045 			__mvcur(oy, ox, bot, 0, 1);
1046 			tputs(__tscroll(__tc_SF, n, 0), 0, __cputchar);
1047 		} else
1048 			if (__tc_DL != NULL) {
1049 				__mvcur(oy, ox, top, 0, 1);
1050 				tputs(__tscroll(__tc_DL, n, 0), 0, __cputchar);
1051 			} else
1052 				if (__tc_dl != NULL) {
1053 					__mvcur(oy, ox, top, 0, 1);
1054 					for (i = 0; i < n; i++)
1055 						tputs(__tc_dl, 0, __cputchar);
1056 				} else
1057 					if (__tc_sf != NULL && top == 0) {
1058 						__mvcur(oy, ox, bot, 0, 1);
1059 						for (i = 0; i < n; i++)
1060 							tputs(__tc_sf, 0,
1061 							    __cputchar);
1062 					} else
1063 						abort();
1064 
1065 		/* Push down the bottom region. */
1066 		__mvcur(top, 0, bot - n + 1, 0, 1);
1067 		if (__tc_AL != NULL)
1068 			tputs(__tscroll(__tc_AL, n, 0), 0, __cputchar);
1069 		else
1070 			if (__tc_al != NULL)
1071 				for (i = 0; i < n; i++)
1072 					tputs(__tc_al, 0, __cputchar);
1073 			else
1074 				abort();
1075 		__mvcur(bot - n + 1, 0, oy, ox, 1);
1076 	} else {
1077 		/*
1078 		 * !!!
1079 		 * n < 0
1080 		 *
1081 		 * If cs, ho and SR/sr are set, can use the scrolling region.
1082 		 * See the above comments for details.
1083 		 */
1084 		if (__tc_cs != NULL && __tc_ho != NULL && (__tc_SR != NULL ||
1085 		    ((__tc_AL == NULL || __tc_DL == NULL || top > 3 ||
1086 		    bot + 3 < __virtscr->maxy) && __tc_sr != NULL))) {
1087 			tputs(__tscroll(__tc_cs, top, bot + 1), 0, __cputchar);
1088 			__mvcur(oy, ox, 0, 0, 1);
1089 			tputs(__tc_ho, 0, __cputchar);
1090 			__mvcur(0, 0, top, 0, 1);
1091 
1092 			if (__tc_SR != NULL)
1093 				tputs(__tscroll(__tc_SR, -n, 0), 0, __cputchar);
1094 			else
1095 				for (i = n; i < 0; i++)
1096 					tputs(__tc_sr, 0, __cputchar);
1097 			tputs(__tscroll(__tc_cs, 0, (int) __virtscr->maxy), 0,
1098 			    __cputchar);
1099 			__mvcur(top, 0, 0, 0, 1);
1100 			tputs(__tc_ho, 0, __cputchar);
1101 			__mvcur(0, 0, oy, ox, 1);
1102 			return;
1103 		}
1104 
1105 		/* Preserve the bottom lines. */
1106 		__mvcur(oy, ox, bot + n + 1, 0, 1);
1107 		if (__tc_SR != NULL && bot == __virtscr->maxy)
1108 			tputs(__tscroll(__tc_SR, -n, 0), 0, __cputchar);
1109 		else
1110 			if (__tc_DL != NULL)
1111 				tputs(__tscroll(__tc_DL, -n, 0), 0, __cputchar);
1112 			else
1113 				if (__tc_dl != NULL)
1114 					for (i = n; i < 0; i++)
1115 						tputs(__tc_dl, 0, __cputchar);
1116 				else
1117 					if (__tc_sr != NULL &&
1118 					    bot == __virtscr->maxy)
1119 						for (i = n; i < 0; i++)
1120 							tputs(__tc_sr, 0,
1121 							    __cputchar);
1122 					else
1123 						abort();
1124 
1125 		/* Scroll the block down. */
1126 		__mvcur(bot + n + 1, 0, top, 0, 1);
1127 		if (__tc_AL != NULL)
1128 			tputs(__tscroll(__tc_AL, -n, 0), 0, __cputchar);
1129 		else
1130 			if (__tc_al != NULL)
1131 				for (i = n; i < 0; i++)
1132 					tputs(__tc_al, 0, __cputchar);
1133 			else
1134 				abort();
1135 		__mvcur(top, 0, oy, ox, 1);
1136 	}
1137 }
1138 
1139 /*
1140  * __unsetattr --
1141  *	Unset attributes on curscr.  Leave standout, attribute and colour
1142  *	modes if necessary (!ms).  Always leave altcharset (xterm at least
1143  *	ignores a cursor move if we don't).
1144  */
1145 void /* ARGSUSED */
1146 __unsetattr(int checkms)
1147 {
1148 	int	isms;
1149 
1150 	if (checkms)
1151 		if (!__tc_ms) {
1152 			isms = 1;
1153 		} else {
1154 			isms = 0;
1155 		}
1156 	else
1157 		isms = 1;
1158 #ifdef DEBUG
1159 	__CTRACE("__unsetattr: checkms = %d, ms = %s, wattr = %08x\n",
1160 	    checkms, __tc_ms ? "TRUE" : "FALSE", curscr->wattr);
1161 #endif
1162 
1163 	/*
1164          * Don't leave the screen in standout mode (check against ms).  Check
1165 	 * to see if we also turn off underscore, attributes and colour.
1166 	 */
1167 	if (curscr->wattr & __STANDOUT && isms) {
1168 		tputs(__tc_se, 0, __cputchar);
1169 		curscr->wattr &= __mask_se;
1170 	}
1171 	/*
1172 	 * Don't leave the screen in underscore mode (check against ms).
1173 	 * Check to see if we also turn off attributes.  Assume that we
1174 	 * also turn off colour.
1175 	 */
1176 	if (curscr->wattr & __UNDERSCORE && isms) {
1177 		tputs(__tc_ue, 0, __cputchar);
1178 		curscr->wattr &= __mask_ue;
1179 	}
1180 	/*
1181 	 * Don't leave the screen with attributes set (check against ms).
1182 	 * Assume that also turn off colour.
1183 	 */
1184 	if (curscr->wattr & __TERMATTR && isms) {
1185 		tputs(__tc_me, 0, __cputchar);
1186 		curscr->wattr &= __mask_me;
1187 	}
1188 	/* Don't leave the screen with altcharset set (don't check ms). */
1189 	if (curscr->wattr & __ALTCHARSET) {
1190 		tputs(__tc_ae, 0, __cputchar);
1191 		curscr->wattr &= ~__ALTCHARSET;
1192 	}
1193 	/* Don't leave the screen with colour set (check against ms). */
1194 	if (__using_color && isms)
1195 		__unset_color(curscr);
1196 }
1197