xref: /netbsd-src/lib/libcurses/refresh.c (revision 7cc2f76925f078d01ddc9e640a98f4ccfc9f8c3b)
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