xref: /freebsd/sys/dev/vt/vt_buf.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2009, 2013 The FreeBSD Foundation
5  *
6  * This software was developed by Ed Schouten under sponsorship from the
7  * FreeBSD Foundation.
8  *
9  * Portions of this software were developed by Oleksandr Rybalko
10  * under sponsorship from the FreeBSD Foundation.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/mutex.h>
43 #include <sys/reboot.h>
44 
45 #include <dev/vt/vt.h>
46 
47 static MALLOC_DEFINE(M_VTBUF, "vtbuf", "vt buffer");
48 
49 #define	VTBUF_LOCK(vb)		mtx_lock_spin(&(vb)->vb_lock)
50 #define	VTBUF_UNLOCK(vb)	mtx_unlock_spin(&(vb)->vb_lock)
51 
52 #define POS_INDEX(c, r) (((r) << 12) + (c))
53 #define	POS_COPY(d, s)	do {	\
54 	(d).tp_col = (s).tp_col;	\
55 	(d).tp_row = (s).tp_row;	\
56 } while (0)
57 
58 #ifndef SC_NO_CUTPASTE
59 static int vtbuf_htw(const struct vt_buf *vb, int row);
60 static int vtbuf_wth(const struct vt_buf *vb, int row);
61 static int vtbuf_in_this_range(int begin, int test, int end, int sz);
62 #endif
63 
64 /*
65  * line4
66  * line5 <--- curroffset (terminal output to that line)
67  * line0
68  * line1                  <--- roffset (history display from that point)
69  * line2
70  * line3
71  */
72 int
73 vthistory_seek(struct vt_buf *vb, int offset, int whence)
74 {
75 	int diff, top, bottom, roffset;
76 
77 	/* No scrolling if not enabled. */
78 	if ((vb->vb_flags & VBF_SCROLL) == 0) {
79 		if (vb->vb_roffset != vb->vb_curroffset) {
80 			vb->vb_roffset = vb->vb_curroffset;
81 			return (0xffff);
82 		}
83 		return (0); /* No changes */
84 	}
85 
86 	/* "top" may be a negative integer. */
87 	bottom = vb->vb_curroffset;
88 	top = (vb->vb_flags & VBF_HISTORY_FULL) ?
89 	    bottom + vb->vb_scr_size.tp_row - vb->vb_history_size :
90 	    0;
91 
92 	roffset = 0; /* Make gcc happy. */
93 	switch (whence) {
94 	case VHS_SET:
95 		if (offset < 0)
96 			offset = 0;
97 		roffset = top + offset;
98 		break;
99 	case VHS_CUR:
100 		/*
101 		 * Operate on copy of offset value, since it temporary
102 		 * can be bigger than amount of rows in buffer.
103 		 */
104 		roffset = vb->vb_roffset;
105 		if (roffset >= bottom + vb->vb_scr_size.tp_row)
106 			roffset -= vb->vb_history_size;
107 
108 		roffset += offset;
109 		roffset = MAX(roffset, top);
110 		roffset = MIN(roffset, bottom);
111 
112 		if (roffset < 0)
113 			roffset = vb->vb_history_size + roffset;
114 
115 		break;
116 	case VHS_END:
117 		/* Go to current offset. */
118 		roffset = vb->vb_curroffset;
119 		break;
120 	}
121 
122 	diff = vb->vb_roffset != roffset;
123 	vb->vb_roffset = roffset;
124 
125 	return (diff);
126 }
127 
128 void
129 vthistory_addlines(struct vt_buf *vb, int offset)
130 {
131 #ifndef SC_NO_CUTPASTE
132 	int cur, sz;
133 #endif
134 
135 	vb->vb_curroffset += offset;
136 	if (vb->vb_curroffset + vb->vb_scr_size.tp_row >= vb->vb_history_size) {
137 		vb->vb_flags |= VBF_HISTORY_FULL;
138 		vb->vb_curroffset %= vb->vb_history_size;
139 	}
140 	if ((vb->vb_flags & VBF_SCROLL) == 0) {
141 		vb->vb_roffset = vb->vb_curroffset;
142 	}
143 
144 #ifndef SC_NO_CUTPASTE
145 	sz = vb->vb_history_size;
146 	cur = vb->vb_roffset + vb->vb_scr_size.tp_row + sz - 1;
147 	if (vtbuf_in_this_range(cur, vb->vb_mark_start.tp_row, cur + offset, sz) ||
148 	    vtbuf_in_this_range(cur, vb->vb_mark_end.tp_row, cur + offset, sz)) {
149 		/* clear screen selection */
150 		vb->vb_mark_start.tp_row = vb->vb_mark_end.tp_row;
151 		vb->vb_mark_start.tp_col = vb->vb_mark_end.tp_col;
152 	}
153 #endif
154 }
155 
156 void
157 vthistory_getpos(const struct vt_buf *vb, unsigned int *offset)
158 {
159 
160 	*offset = vb->vb_roffset;
161 }
162 
163 #ifndef SC_NO_CUTPASTE	/* Only mouse support use it now. */
164 /* Translate history row to current view row number. */
165 static int
166 vtbuf_htw(const struct vt_buf *vb, int row)
167 {
168 
169 	/*
170 	 * total 1000 rows.
171 	 * History offset	roffset	winrow
172 	 *	205		200	((205 - 200 + 1000) % 1000) = 5
173 	 *	90		990	((90 - 990 + 1000) % 1000) = 100
174 	 */
175 	return ((row - vb->vb_roffset + vb->vb_history_size) %
176 	    vb->vb_history_size);
177 }
178 
179 /* Translate current view row number to history row. */
180 static int
181 vtbuf_wth(const struct vt_buf *vb, int row)
182 {
183 
184 	return ((vb->vb_roffset + row) % vb->vb_history_size);
185 }
186 
187 /*
188  * Test if an index in a circular buffer is within a range.
189  *
190  * begin - start index
191  * end - end index
192  * test - test index
193  * sz - size of circular buffer when it turns over
194  */
195 static int
196 vtbuf_in_this_range(int begin, int test, int end, int sz)
197 {
198 
199 	begin %= sz;
200 	end %= sz;
201 
202 	/* check for inversion */
203 	if (begin > end)
204 		return (test >= begin || test < end);
205 	else
206 		return (test >= begin && test < end);
207 }
208 #endif
209 
210 int
211 vtbuf_iscursor(const struct vt_buf *vb, int row, int col)
212 {
213 #ifndef SC_NO_CUTPASTE
214 	int sc, sr, sz, ec, er, tmp;
215 #endif
216 
217 	if ((vb->vb_flags & (VBF_CURSOR|VBF_SCROLL)) == VBF_CURSOR &&
218 	    (vb->vb_cursor.tp_row == row) && (vb->vb_cursor.tp_col == col))
219 		return (1);
220 
221 #ifndef SC_NO_CUTPASTE
222 	/* Mark cut/paste region. */
223 	if (vb->vb_mark_start.tp_col == vb->vb_mark_end.tp_col &&
224 	    vb->vb_mark_start.tp_row == vb->vb_mark_end.tp_row)
225 		return (0);
226 
227 	sc = vb->vb_mark_start.tp_col;
228 	sr = vb->vb_mark_start.tp_row;
229 	ec = vb->vb_mark_end.tp_col;
230 	er = vb->vb_mark_end.tp_row;
231 
232 	/*
233 	 * Information about if the selection was made bottom-top or
234 	 * top-bottom is lost due to modulo arithmetics and needs to
235 	 * be recovered:
236 	 */
237 	sz = vb->vb_history_size;
238 	tmp = (sz + er - sr) % sz;
239 	row = vtbuf_wth(vb, row);
240 
241 	/* Swap start and end if start > end */
242 	if ((2 * tmp) > sz || (tmp == 0 && sc > ec)) {
243 		tmp = sc; sc = ec; ec = tmp;
244 		tmp = sr; sr = er; er = tmp;
245 	}
246 
247 	if (vtbuf_in_this_range(POS_INDEX(sc, sr), POS_INDEX(col, row),
248 	    POS_INDEX(ec, er), POS_INDEX(0, sz)))
249 		return (1);
250 #endif
251 
252 	return (0);
253 }
254 
255 void
256 vtbuf_lock(struct vt_buf *vb)
257 {
258 
259 	VTBUF_LOCK(vb);
260 }
261 
262 void
263 vtbuf_unlock(struct vt_buf *vb)
264 {
265 
266 	VTBUF_UNLOCK(vb);
267 }
268 
269 void
270 vtbuf_dirty(struct vt_buf *vb, const term_rect_t *area)
271 {
272 
273 	if (vb->vb_dirtyrect.tr_begin.tp_row > area->tr_begin.tp_row)
274 		vb->vb_dirtyrect.tr_begin.tp_row = area->tr_begin.tp_row;
275 	if (vb->vb_dirtyrect.tr_begin.tp_col > area->tr_begin.tp_col)
276 		vb->vb_dirtyrect.tr_begin.tp_col = area->tr_begin.tp_col;
277 	if (vb->vb_dirtyrect.tr_end.tp_row < area->tr_end.tp_row)
278 		vb->vb_dirtyrect.tr_end.tp_row = area->tr_end.tp_row;
279 	if (vb->vb_dirtyrect.tr_end.tp_col < area->tr_end.tp_col)
280 		vb->vb_dirtyrect.tr_end.tp_col = area->tr_end.tp_col;
281 }
282 
283 static inline void
284 vtbuf_dirty_cell(struct vt_buf *vb, const term_pos_t *p)
285 {
286 	term_rect_t area;
287 
288 	area.tr_begin = *p;
289 	area.tr_end.tp_row = p->tp_row + 1;
290 	area.tr_end.tp_col = p->tp_col + 1;
291 	vtbuf_dirty(vb, &area);
292 }
293 
294 static void
295 vtbuf_make_undirty(struct vt_buf *vb)
296 {
297 
298 	vb->vb_dirtyrect.tr_begin = vb->vb_scr_size;
299 	vb->vb_dirtyrect.tr_end.tp_row = vb->vb_dirtyrect.tr_end.tp_col = 0;
300 }
301 
302 void
303 vtbuf_undirty(struct vt_buf *vb, term_rect_t *r)
304 {
305 
306 	*r = vb->vb_dirtyrect;
307 	vtbuf_make_undirty(vb);
308 }
309 
310 void
311 vtbuf_copy(struct vt_buf *vb, const term_rect_t *r, const term_pos_t *p2)
312 {
313 	const term_pos_t *p1 = &r->tr_begin;
314 	term_rect_t area;
315 	unsigned int rows, cols;
316 	int pr, rdiff;
317 
318 	KASSERT(r->tr_begin.tp_row < vb->vb_scr_size.tp_row,
319 	    ("vtbuf_copy begin.tp_row %d must be less than screen width %d",
320 		r->tr_begin.tp_row, vb->vb_scr_size.tp_row));
321 	KASSERT(r->tr_begin.tp_col < vb->vb_scr_size.tp_col,
322 	    ("vtbuf_copy begin.tp_col %d must be less than screen height %d",
323 		r->tr_begin.tp_col, vb->vb_scr_size.tp_col));
324 
325 	KASSERT(r->tr_end.tp_row <= vb->vb_scr_size.tp_row,
326 	    ("vtbuf_copy end.tp_row %d must be less than screen width %d",
327 		r->tr_end.tp_row, vb->vb_scr_size.tp_row));
328 	KASSERT(r->tr_end.tp_col <= vb->vb_scr_size.tp_col,
329 	    ("vtbuf_copy end.tp_col %d must be less than screen height %d",
330 		r->tr_end.tp_col, vb->vb_scr_size.tp_col));
331 
332 	KASSERT(p2->tp_row < vb->vb_scr_size.tp_row,
333 	    ("vtbuf_copy tp_row %d must be less than screen width %d",
334 		p2->tp_row, vb->vb_scr_size.tp_row));
335 	KASSERT(p2->tp_col < vb->vb_scr_size.tp_col,
336 	    ("vtbuf_copy tp_col %d must be less than screen height %d",
337 		p2->tp_col, vb->vb_scr_size.tp_col));
338 
339 	rows = r->tr_end.tp_row - r->tr_begin.tp_row;
340 	rdiff = r->tr_begin.tp_row - p2->tp_row;
341 	cols = r->tr_end.tp_col - r->tr_begin.tp_col;
342 	if (r->tr_begin.tp_row > p2->tp_row && r->tr_begin.tp_col == 0 &&
343 	    r->tr_end.tp_col == vb->vb_scr_size.tp_col && /* Full row. */
344 	    (rows + rdiff) == vb->vb_scr_size.tp_row && /* Whole screen. */
345 	    rdiff > 0) { /* Only forward direction. Do not eat history. */
346 		vthistory_addlines(vb, rdiff);
347 	} else if (p2->tp_row < p1->tp_row) {
348 		/* Handle overlapping copies of line segments. */
349 		/* Move data up. */
350 		for (pr = 0; pr < rows; pr++)
351 			memmove(
352 			    &VTBUF_FIELD(vb, p2->tp_row + pr, p2->tp_col),
353 			    &VTBUF_FIELD(vb, p1->tp_row + pr, p1->tp_col),
354 			    cols * sizeof(term_char_t));
355 	} else {
356 		/* Move data down. */
357 		for (pr = rows - 1; pr >= 0; pr--)
358 			memmove(
359 			    &VTBUF_FIELD(vb, p2->tp_row + pr, p2->tp_col),
360 			    &VTBUF_FIELD(vb, p1->tp_row + pr, p1->tp_col),
361 			    cols * sizeof(term_char_t));
362 	}
363 
364 	area.tr_begin = *p2;
365 	area.tr_end.tp_row = MIN(p2->tp_row + rows, vb->vb_scr_size.tp_row);
366 	area.tr_end.tp_col = MIN(p2->tp_col + cols, vb->vb_scr_size.tp_col);
367 	vtbuf_dirty(vb, &area);
368 }
369 
370 static void
371 vtbuf_do_fill(struct vt_buf *vb, const term_rect_t *r, term_char_t c)
372 {
373 	unsigned int pr, pc;
374 	term_char_t *row;
375 
376 	for (pr = r->tr_begin.tp_row; pr < r->tr_end.tp_row; pr++) {
377 		row = vb->vb_rows[(vb->vb_curroffset + pr) %
378 		    VTBUF_MAX_HEIGHT(vb)];
379 		for (pc = r->tr_begin.tp_col; pc < r->tr_end.tp_col; pc++) {
380 			row[pc] = c;
381 		}
382 	}
383 }
384 
385 void
386 vtbuf_fill(struct vt_buf *vb, const term_rect_t *r, term_char_t c)
387 {
388 
389 	KASSERT(r->tr_begin.tp_row < vb->vb_scr_size.tp_row,
390 	    ("vtbuf_fill begin.tp_row %d must be < screen height %d",
391 		r->tr_begin.tp_row, vb->vb_scr_size.tp_row));
392 	KASSERT(r->tr_begin.tp_col < vb->vb_scr_size.tp_col,
393 	    ("vtbuf_fill begin.tp_col %d must be < screen width %d",
394 		r->tr_begin.tp_col, vb->vb_scr_size.tp_col));
395 
396 	KASSERT(r->tr_end.tp_row <= vb->vb_scr_size.tp_row,
397 	    ("vtbuf_fill end.tp_row %d must be <= screen height %d",
398 		r->tr_end.tp_row, vb->vb_scr_size.tp_row));
399 	KASSERT(r->tr_end.tp_col <= vb->vb_scr_size.tp_col,
400 	    ("vtbuf_fill end.tp_col %d must be <= screen width %d",
401 		r->tr_end.tp_col, vb->vb_scr_size.tp_col));
402 
403 	vtbuf_do_fill(vb, r, c);
404 	vtbuf_dirty(vb, r);
405 }
406 
407 static void
408 vtbuf_init_rows(struct vt_buf *vb)
409 {
410 	int r;
411 
412 	vb->vb_history_size = MAX(vb->vb_history_size, vb->vb_scr_size.tp_row);
413 
414 	for (r = 0; r < vb->vb_history_size; r++)
415 		vb->vb_rows[r] = &vb->vb_buffer[r * vb->vb_scr_size.tp_col];
416 }
417 
418 static void
419 vtbuf_do_clearhistory(struct vt_buf *vb)
420 {
421 	term_rect_t rect;
422 	const teken_attr_t *a;
423 	term_char_t ch;
424 
425 	a = teken_get_curattr(&vb->vb_terminal->tm_emulator);
426 	ch = TCOLOR_FG(a->ta_fgcolor) | TCOLOR_BG(a->ta_bgcolor);
427 
428 	rect.tr_begin.tp_row = rect.tr_begin.tp_col = 0;
429 	rect.tr_end.tp_col = vb->vb_scr_size.tp_col;
430 	rect.tr_end.tp_row = vb->vb_history_size;
431 
432 	vtbuf_do_fill(vb, &rect, VTBUF_SPACE_CHAR(ch));
433 }
434 
435 static void
436 vtbuf_reset_scrollback(struct vt_buf *vb)
437 {
438 	vb->vb_roffset = 0;
439 	vb->vb_curroffset = 0;
440 	vb->vb_mark_start.tp_row = 0;
441 	vb->vb_mark_start.tp_col = 0;
442 	vb->vb_mark_end.tp_row = 0;
443 	vb->vb_mark_end.tp_col = 0;
444 }
445 
446 void
447 vtbuf_init_early(struct vt_buf *vb)
448 {
449 	vb->vb_flags |= VBF_CURSOR;
450 	vtbuf_reset_scrollback(vb);
451 	vtbuf_init_rows(vb);
452 	vtbuf_do_clearhistory(vb);
453 	vtbuf_make_undirty(vb);
454 	if ((vb->vb_flags & VBF_MTX_INIT) == 0) {
455 		mtx_init(&vb->vb_lock, "vtbuf", NULL, MTX_SPIN);
456 		vb->vb_flags |= VBF_MTX_INIT;
457 	}
458 }
459 
460 void
461 vtbuf_init(struct vt_buf *vb, const term_pos_t *p)
462 {
463 	int sz;
464 
465 	vb->vb_scr_size = *p;
466 	vb->vb_history_size = VBF_DEFAULT_HISTORY_SIZE;
467 
468 	if ((vb->vb_flags & VBF_STATIC) == 0) {
469 		sz = vb->vb_history_size * p->tp_col * sizeof(term_char_t);
470 		vb->vb_buffer = malloc(sz, M_VTBUF, M_WAITOK | M_ZERO);
471 
472 		sz = vb->vb_history_size * sizeof(term_char_t *);
473 		vb->vb_rows = malloc(sz, M_VTBUF, M_WAITOK | M_ZERO);
474 	}
475 
476 	vtbuf_init_early(vb);
477 }
478 
479 void
480 vtbuf_clearhistory(struct vt_buf *vb)
481 {
482 	VTBUF_LOCK(vb);
483 	vtbuf_do_clearhistory(vb);
484 	vtbuf_reset_scrollback(vb);
485 	vb->vb_flags &= ~VBF_HISTORY_FULL;
486 	VTBUF_UNLOCK(vb);
487 }
488 
489 void
490 vtbuf_sethistory_size(struct vt_buf *vb, unsigned int size)
491 {
492 	term_pos_t p;
493 
494 	/* With same size */
495 	p.tp_row = vb->vb_scr_size.tp_row;
496 	p.tp_col = vb->vb_scr_size.tp_col;
497 	vtbuf_grow(vb, &p, size);
498 }
499 
500 void
501 vtbuf_grow(struct vt_buf *vb, const term_pos_t *p, unsigned int history_size)
502 {
503 	term_char_t *old, *new, **rows, **oldrows, **copyrows, *row, *oldrow;
504 	unsigned int w, h, c, r, old_history_size;
505 	size_t bufsize, rowssize;
506 	int history_full;
507 	const teken_attr_t *a;
508 	term_char_t ch;
509 
510 	a = teken_get_curattr(&vb->vb_terminal->tm_emulator);
511 	ch = TCOLOR_FG(a->ta_fgcolor) | TCOLOR_BG(a->ta_bgcolor);
512 
513 	history_size = MAX(history_size, p->tp_row);
514 
515 	/* Allocate new buffer. */
516 	bufsize = history_size * p->tp_col * sizeof(term_char_t);
517 	new = malloc(bufsize, M_VTBUF, M_WAITOK | M_ZERO);
518 	rowssize = history_size * sizeof(term_pos_t *);
519 	rows = malloc(rowssize, M_VTBUF, M_WAITOK | M_ZERO);
520 
521 	/* Toggle it. */
522 	VTBUF_LOCK(vb);
523 	old = vb->vb_flags & VBF_STATIC ? NULL : vb->vb_buffer;
524 	oldrows = vb->vb_flags & VBF_STATIC ? NULL : vb->vb_rows;
525 	copyrows = vb->vb_rows;
526 
527 	w = vb->vb_scr_size.tp_col;
528 	h = vb->vb_scr_size.tp_row;
529 	old_history_size = vb->vb_history_size;
530 	history_full = vb->vb_flags & VBF_HISTORY_FULL ||
531 	    vb->vb_curroffset + h >= history_size;
532 
533 	vb->vb_history_size = history_size;
534 	vb->vb_buffer = new;
535 	vb->vb_rows = rows;
536 	vb->vb_flags &= ~VBF_STATIC;
537 	vb->vb_scr_size = *p;
538 	vtbuf_init_rows(vb);
539 
540 	/*
541 	 * Copy rows to the new buffer. The first row in the history
542 	 * is back to index 0, ie. the new buffer doesn't cycle.
543 	 */
544 	if (history_size > old_history_size) {
545 		for (r = 0; r < old_history_size; r++) {
546 			row = rows[r];
547 
548 			/* Compute the corresponding row in the old buffer. */
549 			if (history_full)
550 				/*
551 				 * The buffer is full, the "top" row is
552 				 * the one just after the viewable area
553 				 * (curroffset + viewable height) in the
554 				 * cycling buffer. The corresponding row
555 				 * is computed from this top row.
556 				 */
557 				oldrow = copyrows[
558 				    (vb->vb_curroffset + h + r) %
559 				    old_history_size];
560 			else
561 				/*
562 				 * The buffer is not full, therefore,
563 				 * we didn't cycle already. The
564 				 * corresponding rows are the same in
565 				 * both buffers.
566 				 */
567 				oldrow = copyrows[r];
568 
569 			memmove(row, oldrow,
570 			    MIN(p->tp_col, w) * sizeof(term_char_t));
571 
572 			/*
573 			 * XXX VTBUF_SPACE_CHAR(TERMINAL_NORM_ATTR) will
574 			 * extended lines of kernel text using the wrong
575 			 * background color.
576 			 */
577 			for (c = MIN(p->tp_col, w); c < p->tp_col; c++) {
578 				row[c] = VTBUF_SPACE_CHAR(ch);
579 			}
580 		}
581 
582 		/* Fill remaining rows. */
583 		for (r = old_history_size; r < history_size; r++) {
584 			row = rows[r];
585 			for (c = MIN(p->tp_col, w); c < p->tp_col; c++) {
586 				row[c] = VTBUF_SPACE_CHAR(ch);
587 			}
588 		}
589 
590 		vb->vb_flags &= ~VBF_HISTORY_FULL;
591 
592 		/*
593 		 * If the screen is already filled (there are non-visible lines
594 		 * above the current viewable area), adjust curroffset to the
595 		 * new viewable area.
596 		 *
597 		 * If the old buffer was full, set curroffset to the
598 		 * <h>th most recent line of history in the new, non-cycled
599 		 * buffer. Otherwise, it didn't cycle, so the old curroffset
600 		 * is the same in the new buffer.
601 		 */
602 		if (history_full)
603 			vb->vb_curroffset = old_history_size - h;
604 	} else {
605 		/*
606 		 * (old_history_size - history_size) lines of history are
607 		 * dropped.
608 		 */
609 		for (r = 0; r < history_size; r++) {
610 			row = rows[r];
611 
612 			/*
613 			 * Compute the corresponding row in the old buffer.
614 			 *
615 			 * See the equivalent if{} block above for an
616 			 * explanation.
617 			 */
618 			if (history_full)
619 				oldrow = copyrows[
620 				    (vb->vb_curroffset + h + r +
621 				     (old_history_size - history_size)) %
622 				    old_history_size];
623 			else
624 				oldrow = copyrows[r];
625 
626 			memmove(row, oldrow,
627 			    MIN(p->tp_col, w) * sizeof(term_char_t));
628 
629 			/*
630 			 * XXX VTBUF_SPACE_CHAR(TERMINAL_NORM_ATTR) will
631 			 * extended lines of kernel text using the wrong
632 			 * background color.
633 			 */
634 			for (c = MIN(p->tp_col, w); c < p->tp_col; c++) {
635 				row[c] = VTBUF_SPACE_CHAR(ch);
636 			}
637 		}
638 
639 		if (history_full) {
640 			vb->vb_curroffset = history_size - h;
641 			vb->vb_flags |= VBF_HISTORY_FULL;
642 		}
643 	}
644 
645 	vb->vb_roffset = vb->vb_curroffset;
646 
647 	/* Adjust cursor position. */
648 	if (vb->vb_cursor.tp_col > p->tp_col - 1)
649 		/*
650 		 * Move cursor to the last column, in case its previous
651 		 * position is outside of the new screen area.
652 		 */
653 		vb->vb_cursor.tp_col = p->tp_col - 1;
654 
655 	if (vb->vb_curroffset > 0 || vb->vb_cursor.tp_row > p->tp_row - 1)
656 		/* Move cursor to the last line on the screen. */
657 		vb->vb_cursor.tp_row = p->tp_row - 1;
658 
659 	VTBUF_UNLOCK(vb);
660 
661 	/* Deallocate old buffer. */
662 	free(old, M_VTBUF);
663 	free(oldrows, M_VTBUF);
664 }
665 
666 void
667 vtbuf_putchar(struct vt_buf *vb, const term_pos_t *p, term_char_t c)
668 {
669 	term_char_t *row;
670 
671 	KASSERT(p->tp_row < vb->vb_scr_size.tp_row,
672 	    ("vtbuf_putchar tp_row %d must be less than screen width %d",
673 		p->tp_row, vb->vb_scr_size.tp_row));
674 	KASSERT(p->tp_col < vb->vb_scr_size.tp_col,
675 	    ("vtbuf_putchar tp_col %d must be less than screen height %d",
676 		p->tp_col, vb->vb_scr_size.tp_col));
677 
678 	row = vb->vb_rows[(vb->vb_curroffset + p->tp_row) %
679 	    VTBUF_MAX_HEIGHT(vb)];
680 	if (row[p->tp_col] != c) {
681 		row[p->tp_col] = c;
682 		vtbuf_dirty_cell(vb, p);
683 	}
684 }
685 
686 void
687 vtbuf_cursor_position(struct vt_buf *vb, const term_pos_t *p)
688 {
689 	if (vb->vb_flags & VBF_CURSOR) {
690 		vtbuf_dirty_cell(vb, &vb->vb_cursor);
691 		vb->vb_cursor = *p;
692 		vtbuf_dirty_cell(vb, &vb->vb_cursor);
693 	} else {
694 		vb->vb_cursor = *p;
695 	}
696 }
697 
698 #ifndef SC_NO_CUTPASTE
699 static void
700 vtbuf_flush_mark(struct vt_buf *vb)
701 {
702 	term_rect_t area;
703 	int s, e;
704 
705 	/* Notify renderer to update marked region. */
706 	if ((vb->vb_mark_start.tp_col != vb->vb_mark_end.tp_col) ||
707 	    (vb->vb_mark_start.tp_row != vb->vb_mark_end.tp_row)) {
708 		s = vtbuf_htw(vb, vb->vb_mark_start.tp_row);
709 		e = vtbuf_htw(vb, vb->vb_mark_end.tp_row);
710 
711 		area.tr_begin.tp_col = 0;
712 		area.tr_begin.tp_row = MIN(s, e);
713 
714 		area.tr_end.tp_col = vb->vb_scr_size.tp_col;
715 		area.tr_end.tp_row = MAX(s, e) + 1;
716 
717 		VTBUF_LOCK(vb);
718 		vtbuf_dirty(vb, &area);
719 		VTBUF_UNLOCK(vb);
720 	}
721 }
722 
723 int
724 vtbuf_get_marked_len(struct vt_buf *vb)
725 {
726 	int ei, si, sz;
727 	term_pos_t s, e;
728 
729 	/* Swap according to window coordinates. */
730 	if (POS_INDEX(vtbuf_htw(vb, vb->vb_mark_start.tp_row),
731 	    vb->vb_mark_start.tp_col) >
732 	    POS_INDEX(vtbuf_htw(vb, vb->vb_mark_end.tp_row),
733 	    vb->vb_mark_end.tp_col)) {
734 		POS_COPY(e, vb->vb_mark_start);
735 		POS_COPY(s, vb->vb_mark_end);
736 	} else {
737 		POS_COPY(s, vb->vb_mark_start);
738 		POS_COPY(e, vb->vb_mark_end);
739 	}
740 
741 	si = s.tp_row * vb->vb_scr_size.tp_col + s.tp_col;
742 	ei = e.tp_row * vb->vb_scr_size.tp_col + e.tp_col;
743 
744 	/* Number symbols and number of rows to inject \r */
745 	sz = ei - si + (1 + e.tp_row - s.tp_row);
746 
747 	return (sz * sizeof(term_char_t));
748 }
749 
750 static bool
751 tchar_is_word_separator(term_char_t ch)
752 {
753 	/* List of unicode word separator characters: */
754 	switch (TCHAR_CHARACTER(ch)) {
755 	case 0x0020: /* SPACE */
756 	case 0x180E: /* MONGOLIAN VOWEL SEPARATOR */
757 	case 0x2002: /* EN SPACE (nut) */
758 	case 0x2003: /* EM SPACE (mutton) */
759 	case 0x2004: /* THREE-PER-EM SPACE (thick space) */
760 	case 0x2005: /* FOUR-PER-EM SPACE (mid space) */
761 	case 0x2006: /* SIX-PER-EM SPACE */
762 	case 0x2008: /* PUNCTUATION SPACE */
763 	case 0x2009: /* THIN SPACE */
764 	case 0x200A: /* HAIR SPACE */
765 	case 0x200B: /* ZERO WIDTH SPACE */
766 	case 0x3000: /* IDEOGRAPHIC SPACE */
767 		return (true);
768 	default:
769 		return (false);
770 	}
771 }
772 
773 void
774 vtbuf_extract_marked(struct vt_buf *vb, term_char_t *buf, int sz, int mark)
775 {
776 	int i, j, r, c, cs, ce;
777 	term_pos_t s, e;
778 
779 	/* Swap according to window coordinates. */
780 	if (POS_INDEX(vtbuf_htw(vb, vb->vb_mark_start.tp_row),
781 	    vb->vb_mark_start.tp_col) >
782 	    POS_INDEX(vtbuf_htw(vb, vb->vb_mark_end.tp_row),
783 	    vb->vb_mark_end.tp_col)) {
784 		POS_COPY(e, vb->vb_mark_start);
785 		POS_COPY(s, vb->vb_mark_end);
786 	} else {
787 		POS_COPY(s, vb->vb_mark_start);
788 		POS_COPY(e, vb->vb_mark_end);
789 	}
790 
791 	i = 0;
792 	for (r = s.tp_row; r <= e.tp_row; r++) {
793 		cs = (r == s.tp_row)?s.tp_col:0;
794 		ce = (r == e.tp_row)?e.tp_col:vb->vb_scr_size.tp_col;
795 
796 		/* Copy characters from terminal window. */
797 		j = i;
798 		for (c = cs; c < ce; c++)
799 			buf[i++] = vb->vb_rows[r][c];
800 
801 		/* For all rows, but the last one. */
802 		if (r != e.tp_row || mark == VTB_MARK_ROW) {
803 			/* Trim trailing word separators, if any. */
804 			for (; i != j; i--) {
805 				if (!tchar_is_word_separator(buf[i - 1]))
806 					break;
807 			}
808 			/* Add newline character as expected by TTY. */
809 			buf[i++] = '\r';
810 		}
811 	}
812 	/* Zero rest of expected buffer size, if any. */
813 	while ((i * sizeof(buf[0])) < sz)
814 		buf[i++] = '\0';
815 
816 	MPASS((i * sizeof(buf[0])) == sz);
817 }
818 
819 int
820 vtbuf_set_mark(struct vt_buf *vb, int type, int col, int row)
821 {
822 	term_char_t *r;
823 	int i;
824 
825 	switch (type) {
826 	case VTB_MARK_END:	/* B1 UP */
827 		if (vb->vb_mark_last != VTB_MARK_MOVE)
828 			return (0);
829 		/* FALLTHROUGH */
830 	case VTB_MARK_MOVE:
831 	case VTB_MARK_EXTEND:
832 		vtbuf_flush_mark(vb); /* Clean old mark. */
833 		vb->vb_mark_end.tp_col = col;
834 		vb->vb_mark_end.tp_row = vtbuf_wth(vb, row);
835 		break;
836 	case VTB_MARK_START:
837 		vtbuf_flush_mark(vb); /* Clean old mark. */
838 		vb->vb_mark_start.tp_col = col;
839 		vb->vb_mark_start.tp_row = vtbuf_wth(vb, row);
840 		/* Start again, so clear end point. */
841 		vb->vb_mark_end.tp_col = col;
842 		vb->vb_mark_end.tp_row = vtbuf_wth(vb, row);
843 		break;
844 	case VTB_MARK_WORD:
845 		vtbuf_flush_mark(vb); /* Clean old mark. */
846 		vb->vb_mark_start.tp_row = vb->vb_mark_end.tp_row =
847 		    vtbuf_wth(vb, row);
848 		r = vb->vb_rows[vb->vb_mark_start.tp_row];
849 		for (i = col; i >= 0; i --) {
850 			if (tchar_is_word_separator(r[i])) {
851 				vb->vb_mark_start.tp_col = i + 1;
852 				break;
853 			}
854 		}
855 		/* No space - word extends to beginning of line. */
856 		if (i == -1)
857 			vb->vb_mark_start.tp_col = 0;
858 		for (i = col; i < vb->vb_scr_size.tp_col; i++) {
859 			if (tchar_is_word_separator(r[i])) {
860 				vb->vb_mark_end.tp_col = i;
861 				break;
862 			}
863 		}
864 		/* No space - word extends to end of line. */
865 		if (i == vb->vb_scr_size.tp_col)
866 			vb->vb_mark_end.tp_col = i;
867 
868 		if (vb->vb_mark_start.tp_col > vb->vb_mark_end.tp_col)
869 			vb->vb_mark_start.tp_col = vb->vb_mark_end.tp_col;
870 		break;
871 	case VTB_MARK_ROW:
872 		vtbuf_flush_mark(vb); /* Clean old mark. */
873 		vb->vb_mark_start.tp_col = 0;
874 		vb->vb_mark_end.tp_col = vb->vb_scr_size.tp_col;
875 		vb->vb_mark_start.tp_row = vb->vb_mark_end.tp_row =
876 		    vtbuf_wth(vb, row);
877 		break;
878 	case VTB_MARK_NONE:
879 		vb->vb_mark_last = type;
880 		/* FALLTHROUGH */
881 	default:
882 		/* panic? */
883 		return (0);
884 	}
885 
886 	vb->vb_mark_last = type;
887 	/* Draw new marked region. */
888 	vtbuf_flush_mark(vb);
889 	return (1);
890 }
891 #endif
892 
893 void
894 vtbuf_cursor_visibility(struct vt_buf *vb, int yes)
895 {
896 	int oflags, nflags;
897 
898 	oflags = vb->vb_flags;
899 	if (yes)
900 		vb->vb_flags |= VBF_CURSOR;
901 	else
902 		vb->vb_flags &= ~VBF_CURSOR;
903 	nflags = vb->vb_flags;
904 
905 	if (oflags != nflags)
906 		vtbuf_dirty_cell(vb, &vb->vb_cursor);
907 }
908 
909 void
910 vtbuf_scroll_mode(struct vt_buf *vb, int yes)
911 {
912 	int oflags, nflags;
913 
914 	VTBUF_LOCK(vb);
915 	oflags = vb->vb_flags;
916 	if (yes)
917 		vb->vb_flags |= VBF_SCROLL;
918 	else
919 		vb->vb_flags &= ~VBF_SCROLL;
920 	nflags = vb->vb_flags;
921 
922 	if (oflags != nflags)
923 		vtbuf_dirty_cell(vb, &vb->vb_cursor);
924 	VTBUF_UNLOCK(vb);
925 }
926