xref: /openbsd-src/lib/libcurses/tty/lib_mvcur.c (revision 24dc1c5e148b865950fd90786c4d6bbc53d0845d)
1 /*	$OpenBSD: lib_mvcur.c,v 1.3 1999/06/27 08:14:21 millert Exp $	*/
2 
3 /****************************************************************************
4  * Copyright (c) 1998 Free Software Foundation, Inc.                        *
5  *                                                                          *
6  * Permission is hereby granted, free of charge, to any person obtaining a  *
7  * copy of this software and associated documentation files (the            *
8  * "Software"), to deal in the Software without restriction, including      *
9  * without limitation the rights to use, copy, modify, merge, publish,      *
10  * distribute, distribute with modifications, sublicense, and/or sell       *
11  * copies of the Software, and to permit persons to whom the Software is    *
12  * furnished to do so, subject to the following conditions:                 *
13  *                                                                          *
14  * The above copyright notice and this permission notice shall be included  *
15  * in all copies or substantial portions of the Software.                   *
16  *                                                                          *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
20  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
21  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
22  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
23  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
24  *                                                                          *
25  * Except as contained in this notice, the name(s) of the above copyright   *
26  * holders shall not be used in advertising or otherwise to promote the     *
27  * sale, use or other dealings in this Software without prior written       *
28  * authorization.                                                           *
29  ****************************************************************************/
30 
31 /****************************************************************************
32  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
33  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
34  ****************************************************************************/
35 
36 
37 /*
38 **	lib_mvcur.c
39 **
40 **	The routines for moving the physical cursor and scrolling:
41 **
42 **		void _nc_mvcur_init(void)
43 **
44 **		void _nc_mvcur_resume(void)
45 **
46 **		int mvcur(int old_y, int old_x, int new_y, int new_x)
47 **
48 **		void _nc_mvcur_wrap(void)
49 **
50 ** Comparisons with older movement optimizers:
51 **    SVr3 curses mvcur() can't use cursor_to_ll or auto_left_margin.
52 **    4.4BSD curses can't use cuu/cud/cuf/cub/hpa/vpa/tab/cbt for local
53 ** motions.  It doesn't use tactics based on auto_left_margin.  Weirdly
54 ** enough, it doesn't use its own hardware-scrolling routine to scroll up
55 ** destination lines for out-of-bounds addresses!
56 **    old ncurses optimizer: less accurate cost computations (in fact,
57 ** it was broken and had to be commented out!).
58 **
59 ** Compile with -DMAIN to build an interactive tester/timer for the movement
60 ** optimizer.  You can use it to investigate the optimizer's behavior.
61 ** You can also use it for tuning the formulas used to determine whether
62 ** or not full optimization is attempted.
63 **
64 ** This code has a nasty tendency to find bugs in terminfo entries, because it
65 ** exercises the non-cup movement capabilities heavily.  If you think you've
66 ** found a bug, try deleting subsets of the following capabilities (arranged
67 ** in decreasing order of suspiciousness): it, tab, cbt, hpa, vpa, cuu, cud,
68 ** cuf, cub, cuu1, cud1, cuf1, cub1.  It may be that one or more are wrong.
69 **
70 ** Note: you should expect this code to look like a resource hog in a profile.
71 ** That's because it does a lot of I/O, through the tputs() calls.  The I/O
72 ** cost swamps the computation overhead (and as machines get faster, this
73 ** will become even more true).  Comments in the test exerciser at the end
74 ** go into detail about tuning and how you can gauge the optimizer's
75 ** effectiveness.
76 **/
77 
78 /****************************************************************************
79  *
80  * Constants and macros for optimizer tuning.
81  *
82  ****************************************************************************/
83 
84 /*
85  * The average overhead of a full optimization computation in character
86  * transmission times.  If it's too high, the algorithm will be a bit
87  * over-biased toward using cup rather than local motions; if it's too
88  * low, the algorithm may spend more time than is strictly optimal
89  * looking for non-cup motions.  Profile the optimizer using the `t'
90  * command of the exerciser (see below), and round to the nearest integer.
91  *
92  * Yes, I (esr) thought about computing expected overhead dynamically, say
93  * by derivation from a running average of optimizer times.  But the
94  * whole point of this optimization is to *decrease* the frequency of
95  * system calls. :-)
96  */
97 #define COMPUTE_OVERHEAD	1	/* I use a 90MHz Pentium @ 9.6Kbps */
98 
99 /*
100  * LONG_DIST is the distance we consider to be just as costly to move over as a
101  * cup sequence is to emit.  In other words, it's the length of a cup sequence
102  * adjusted for average computation overhead.  The magic number is the length
103  * of "\033[yy;xxH", the typical cup sequence these days.
104  */
105 #define LONG_DIST		(8 - COMPUTE_OVERHEAD)
106 
107 /*
108  * Tell whether a motion is optimizable by local motions.  Needs to be cheap to
109  * compute. In general, all the fast moves go to either the right or left edge
110  * of the screen.  So any motion to a location that is (a) further away than
111  * LONG_DIST and (b) further inward from the right or left edge than LONG_DIST,
112  * we'll consider nonlocal.
113  */
114 #define NOT_LOCAL(fy, fx, ty, tx)	((tx > LONG_DIST) && (tx < screen_lines - 1 - LONG_DIST) && (abs(ty-fy) + abs(tx-fx) > LONG_DIST))
115 
116 /****************************************************************************
117  *
118  * External interfaces
119  *
120  ****************************************************************************/
121 
122 /*
123  * For this code to work OK, the following components must live in the
124  * screen structure:
125  *
126  *	int		_char_padding;	// cost of character put
127  *	int		_cr_cost;	// cost of (carriage_return)
128  *	int		_cup_cost;	// cost of (cursor_address)
129  *	int		_home_cost;	// cost of (cursor_home)
130  *	int		_ll_cost;	// cost of (cursor_to_ll)
131  *#if USE_HARD_TABS
132  *	int		_ht_cost;	// cost of (tab)
133  *	int		_cbt_cost;	// cost of (back_tab)
134  *#endif USE_HARD_TABS
135  *	int		_cub1_cost;	// cost of (cursor_left)
136  *	int		_cuf1_cost;	// cost of (cursor_right)
137  *	int		_cud1_cost;	// cost of (cursor_down)
138  *	int		_cuu1_cost;	// cost of (cursor_up)
139  *	int		_cub_cost;	// cost of (parm_cursor_left)
140  *	int		_cuf_cost;	// cost of (parm_cursor_right)
141  *	int		_cud_cost;	// cost of (parm_cursor_down)
142  *	int		_cuu_cost;	// cost of (parm_cursor_up)
143  *	int		_hpa_cost;	// cost of (column_address)
144  *	int		_vpa_cost;	// cost of (row_address)
145  *	int		_ech_cost;	// cost of (erase_chars)
146  *	int		_rep_cost;	// cost of (repeat_char)
147  *
148  * The USE_HARD_TABS switch controls whether it is reliable to use tab/backtabs
149  * for local motions.  On many systems, it's not, due to uncertainties about
150  * tab delays and whether or not tabs will be expanded in raw mode.  If you
151  * have parm_right_cursor, tab motions don't win you a lot anyhow.
152  */
153 
154 #include <curses.priv.h>
155 #include <term.h>
156 #include <ctype.h>
157 
158 MODULE_ID("$From: lib_mvcur.c,v 1.57 1999/06/26 22:16:04 tom Exp $")
159 
160 #define STRLEN(s)       (s != 0) ? strlen(s) : 0
161 
162 #define CURRENT_ATTR	SP->_current_attr	/* current phys attribute */
163 #define CURRENT_ROW	SP->_cursrow		/* phys cursor row */
164 #define CURRENT_COLUMN	SP->_curscol		/* phys cursor column */
165 #define REAL_ATTR	SP->_current_attr	/* phys current attribute */
166 #define WANT_CHAR(y, x)	SP->_newscr->_line[y].text[x]	/* desired state */
167 #define BAUDRATE	cur_term->_baudrate	/* bits per second */
168 
169 #if defined(MAIN) || defined(NCURSES_TEST)
170 #include <sys/time.h>
171 
172 static bool profiling = FALSE;
173 static float diff;
174 #endif /* MAIN */
175 
176 #define OPT_SIZE 512
177 
178 static int normalized_cost(const char *const cap, int affcnt);
179 
180 #if !HAVE_STRSTR
181 char * _nc_strstr(const char *haystack, const char *needle)
182 {
183 	size_t len1 = strlen(haystack);
184 	size_t len2 = strlen(needle);
185 	char *result = 0;
186 
187 	while ((len1 != 0) && (len1-- >= len2)) {
188 		if (!strncmp(haystack, needle, len2)) {
189 			result = haystack;
190 			break;
191 		}
192 		haystack++;
193 	}
194 	return result;
195 }
196 #endif
197 
198 /****************************************************************************
199  *
200  * Initialization/wrapup (including cost pre-computation)
201  *
202  ****************************************************************************/
203 
204 #ifdef TRACE
205 static int
206 trace_cost_of(const char *capname, const char *cap, int affcnt)
207 {
208 	int result = _nc_msec_cost(cap,affcnt);
209 	TR(TRACE_CHARPUT|TRACE_MOVE, ("CostOf %s %d", capname, result));
210 	return result;
211 }
212 #define CostOf(cap,affcnt) trace_cost_of(#cap,cap,affcnt);
213 
214 static int
215 trace_normalized_cost(const char *capname, const char *cap, int affcnt)
216 {
217 	int result = normalized_cost(cap,affcnt);
218 	TR(TRACE_CHARPUT|TRACE_MOVE, ("NormalizedCost %s %d", capname, result));
219 	return result;
220 }
221 #define NormalizedCost(cap,affcnt) trace_normalized_cost(#cap,cap,affcnt);
222 
223 #else
224 
225 #define CostOf(cap,affcnt) _nc_msec_cost(cap,affcnt);
226 #define NormalizedCost(cap,affcnt) normalized_cost(cap,affcnt);
227 
228 #endif
229 
230 int _nc_msec_cost(const char *const cap, int affcnt)
231 /* compute the cost of a given operation */
232 {
233     if (cap == 0)
234 	return(INFINITY);
235     else
236     {
237 	const	char	*cp;
238 	float	cum_cost = 0;
239 
240 	for (cp = cap; *cp; cp++)
241 	{
242 	    /* extract padding, either mandatory or required */
243 	    if (cp[0] == '$' && cp[1] == '<' && strchr(cp, '>'))
244 	    {
245 		float	number = 0;
246 
247 		for (cp += 2; *cp != '>'; cp++)
248 		{
249 		    if (isdigit(*cp))
250 			number = number * 10 + (*cp - '0');
251 		    else if (*cp == '.')
252 			number += (*++cp - 10) / 10.0;
253 		    else if (*cp == '*')
254 			number *= affcnt;
255 		}
256 
257 		cum_cost += number * 10;
258 	    }
259 	    else
260 		cum_cost += SP->_char_padding;
261 	}
262 
263 	return((int)cum_cost);
264     }
265 }
266 
267 static int normalized_cost(const char *const cap, int affcnt)
268 /* compute the effective character-count for an operation (round up) */
269 {
270 	int cost = _nc_msec_cost(cap, affcnt);
271 	if (cost != INFINITY)
272 		cost = (cost + SP->_char_padding - 1) / SP->_char_padding;
273 	return cost;
274 }
275 
276 static void reset_scroll_region(void)
277 /* Set the scroll-region to a known state (the default) */
278 {
279     if (change_scroll_region)
280     {
281 	TPUTS_TRACE("change_scroll_region");
282 	putp(tparm(change_scroll_region, 0, screen_lines - 1));
283     }
284 }
285 
286 void _nc_mvcur_resume(void)
287 /* what to do at initialization time and after each shellout */
288 {
289     /* initialize screen for cursor access */
290     if (enter_ca_mode)
291     {
292 	TPUTS_TRACE("enter_ca_mode");
293 	putp(enter_ca_mode);
294     }
295 
296     /*
297      * Doing this here rather than in _nc_mvcur_wrap() ensures that
298      * ncurses programs will see a reset scroll region even if a
299      * program that messed with it died ungracefully.
300      *
301      * This also undoes the effects of terminal init strings that assume
302      * they know the screen size.  This is useful when you're running
303      * a vt100 emulation through xterm.
304      */
305     reset_scroll_region();
306     SP->_cursrow = SP->_curscol = -1;
307 
308     /* restore cursor shape */
309     if (SP->_cursor != -1)
310     {
311 	int cursor = SP->_cursor;
312 	SP->_cursor = -1;
313 	curs_set (cursor);
314     }
315 }
316 
317 void _nc_mvcur_init(void)
318 /* initialize the cost structure */
319 {
320     /*
321      * 9 = 7 bits + 1 parity + 1 stop.
322      */
323     SP->_char_padding = (9 * 1000 * 10) / (BAUDRATE > 0 ? BAUDRATE : 9600);
324     if (SP->_char_padding <= 0)
325 	SP->_char_padding = 1;	/* must be nonzero */
326     TR(TRACE_CHARPUT|TRACE_MOVE, ("char_padding %d msecs", SP->_char_padding));
327 
328     /* non-parameterized local-motion strings */
329     SP->_cr_cost   = CostOf(carriage_return, 0);
330     SP->_home_cost = CostOf(cursor_home, 0);
331     SP->_ll_cost   = CostOf(cursor_to_ll, 0);
332 #if USE_HARD_TABS
333     SP->_ht_cost   = CostOf(tab, 0);
334     SP->_cbt_cost  = CostOf(back_tab, 0);
335 #endif /* USE_HARD_TABS */
336     SP->_cub1_cost = CostOf(cursor_left, 0);
337     SP->_cuf1_cost = CostOf(cursor_right, 0);
338     SP->_cud1_cost = CostOf(cursor_down, 0);
339     SP->_cuu1_cost = CostOf(cursor_up, 0);
340 
341     SP->_smir_cost = CostOf(enter_insert_mode, 0);
342     SP->_rmir_cost = CostOf(exit_insert_mode, 0);
343     SP->_ip_cost = 0;
344     if (insert_padding) {
345 	SP->_ip_cost = CostOf(insert_padding, 0);
346     }
347 
348     /*
349      * Assumption: if the terminal has memory_relative addressing, the
350      * initialization strings or smcup will set single-page mode so we
351      * can treat it like absolute screen addressing.  This seems to be true
352      * for all cursor_mem_address terminal types in the terminfo database.
353      */
354     SP->_address_cursor = cursor_address ? cursor_address : cursor_mem_address;
355 
356     /*
357      * Parametrized local-motion strings.  This static cost computation
358      * depends on the following assumptions:
359      *
360      * (1) They never have * padding.  In the entire master terminfo database
361      *     as of March 1995, only the obsolete Zenith Z-100 pc violates this.
362      *	   (Proportional padding is found mainly in insert, delete and scroll
363      *     capabilities).
364      *
365      * (2) The average case of cup has two two-digit parameters.  Strictly,
366      *     the average case for a 24 * 80 screen has ((10*10*(1 + 1)) +
367      *     (14*10*(1 + 2)) + (10*70*(2 + 1)) + (14*70*4)) / (24*80) = 3.458
368      *     digits of parameters.  On a 25x80 screen the average is 3.6197.
369      *     On larger screens the value gets much closer to 4.
370      *
371      * (3) The average case of cub/cuf/hpa/ech/rep has 2 digits of parameters
372      *     (strictly, (((10 * 1) + (70 * 2)) / 80) = 1.8750).
373      *
374      * (4) The average case of cud/cuu/vpa has 2 digits of parameters
375      *     (strictly, (((10 * 1) + (14 * 2)) / 24) = 1.5833).
376      *
377      * All these averages depend on the assumption that all parameter values
378      * are equally probable.
379      */
380     SP->_cup_cost  = CostOf(tparm(SP->_address_cursor, 23, 23), 1);
381     SP->_cub_cost  = CostOf(tparm(parm_left_cursor, 23), 1);
382     SP->_cuf_cost  = CostOf(tparm(parm_right_cursor, 23), 1);
383     SP->_cud_cost  = CostOf(tparm(parm_down_cursor, 23), 1);
384     SP->_cuu_cost  = CostOf(tparm(parm_up_cursor, 23), 1);
385     SP->_hpa_cost  = CostOf(tparm(column_address, 23), 1);
386     SP->_vpa_cost  = CostOf(tparm(row_address, 23), 1);
387 
388     /* non-parameterized screen-update strings */
389     SP->_ed_cost   = NormalizedCost(clr_eos, 1);
390     SP->_el_cost   = NormalizedCost(clr_eol, 1);
391     SP->_el1_cost  = NormalizedCost(clr_bol, 1);
392     SP->_dch1_cost = NormalizedCost(delete_character, 1);
393     SP->_ich1_cost = NormalizedCost(insert_character, 1);
394 
395     /* parameterized screen-update strings */
396     SP->_dch_cost  = NormalizedCost(tparm(parm_dch, 23), 1);
397     SP->_ich_cost  = NormalizedCost(tparm(parm_ich, 23), 1);
398     SP->_ech_cost  = NormalizedCost(tparm(erase_chars, 23), 1);
399     SP->_rep_cost  = NormalizedCost(tparm(repeat_char, ' ', 23), 1);
400 
401     SP->_cup_ch_cost = NormalizedCost(tparm(SP->_address_cursor, 23, 23), 1);
402     SP->_hpa_ch_cost = NormalizedCost(tparm(column_address, 23), 1);
403 
404     /* pre-compute some capability lengths */
405     SP->_carriage_return_length = STRLEN(carriage_return);
406     SP->_cursor_home_length     = STRLEN(cursor_home);
407     SP->_cursor_to_ll_length    = STRLEN(cursor_to_ll);
408 
409     /*
410      * If save_cursor is used within enter_ca_mode, we should not use it for
411      * scrolling optimization, since the corresponding restore_cursor is not
412      * nested on the various terminals (vt100, xterm, etc.) which use this
413      * feature.
414      */
415     if (save_cursor != 0
416      && enter_ca_mode != 0
417      && strstr(enter_ca_mode, save_cursor) != 0) {
418 	T(("...suppressed sc/rc capability due to conflict with smcup/rmcup"));
419 	save_cursor = 0;
420 	restore_cursor = 0;
421     }
422 
423     /*
424      * A different, possibly better way to arrange this would be to set
425      * SP->_endwin = TRUE at window initialization time and let this be
426      * called by doupdate's return-from-shellout code.
427      */
428     _nc_mvcur_resume();
429 }
430 
431 void _nc_mvcur_wrap(void)
432 /* wrap up cursor-addressing mode */
433 {
434     /* leave cursor at screen bottom */
435     mvcur(-1, -1, screen_lines - 1, 0);
436 
437     /* set cursor to normal mode */
438     if (SP->_cursor != -1)
439 	curs_set(1);
440 
441     if (exit_ca_mode)
442     {
443 	TPUTS_TRACE("exit_ca_mode");
444 	putp(exit_ca_mode);
445     }
446     /*
447      * Reset terminal's tab counter.  There's a long-time bug that
448      * if you exit a "curses" program such as vi or more, tab
449      * forward, and then backspace, the cursor doesn't go to the
450      * right place.  The problem is that the kernel counts the
451      * escape sequences that reset things as column positions.
452      * Utter a \r to reset this invisibly.
453      */
454     _nc_outch('\r');
455 }
456 
457 /****************************************************************************
458  *
459  * Optimized cursor movement
460  *
461  ****************************************************************************/
462 
463 /*
464  * Perform repeated-append, returning cost
465  */
466 static inline int
467 repeated_append (int total, int num, int repeat, char *dst, const char *src)
468 {
469 	register size_t src_len = strlen(src);
470 	register size_t dst_len = STRLEN(dst);
471 
472 	if ((dst_len + repeat * src_len) < OPT_SIZE-1) {
473 		total += (num * repeat);
474 		if (dst) {
475 		    dst += dst_len;
476 		    while (repeat-- > 0) {
477 			(void) strcpy(dst, src);
478 			dst += src_len;
479 		    }
480 		}
481 	} else {
482 		total = INFINITY;
483 	}
484 	return total;
485 }
486 
487 #ifndef NO_OPTIMIZE
488 #define NEXTTAB(fr)	(fr + init_tabs - (fr % init_tabs))
489 
490 /*
491  * Assume back_tab (CBT) does not wrap backwards at the left margin, return
492  * a negative value at that point to simplify the loop.
493  */
494 #define LASTTAB(fr)	((fr > 0) ? ((fr - 1) / init_tabs) * init_tabs : -1)
495 
496 /* Note: we'd like to inline this for speed, but GNU C barfs on the attempt. */
497 
498 static int
499 relative_move(char *result, int from_y,int from_x,int to_y,int to_x, bool ovw)
500 /* move via local motions (cuu/cuu1/cud/cud1/cub1/cub/cuf1/cuf/vpa/hpa) */
501 {
502     int		n, vcost = 0, hcost = 0;
503 
504     if (result)
505 	result[0] = '\0';
506 
507     if (to_y != from_y)
508     {
509 	vcost = INFINITY;
510 
511 	if (row_address)
512 	{
513 	    if (result)
514 		(void) strcpy(result, tparm(row_address, to_y));
515 	    vcost = SP->_vpa_cost;
516 	}
517 
518 	if (to_y > from_y)
519 	{
520 	    n = (to_y - from_y);
521 
522 	    if (parm_down_cursor && SP->_cud_cost < vcost)
523 	    {
524 		if (result)
525 		    (void) strcpy(result, tparm(parm_down_cursor, n));
526 		vcost = SP->_cud_cost;
527 	    }
528 
529 	    if (cursor_down && (n * SP->_cud1_cost < vcost))
530 	    {
531 		if (result)
532 		    result[0] = '\0';
533 		vcost = repeated_append(0, SP->_cud1_cost, n, result, cursor_down);
534 	    }
535 	}
536 	else /* (to_y < from_y) */
537 	{
538 	    n = (from_y - to_y);
539 
540 	    if (parm_up_cursor && SP->_cup_cost < vcost)
541 	    {
542 		if (result)
543 		    (void) strcpy(result, tparm(parm_up_cursor, n));
544 		vcost = SP->_cup_cost;
545 	    }
546 
547 	    if (cursor_up && (n * SP->_cuu1_cost < vcost))
548 	    {
549 		if (result)
550 		    result[0] = '\0';
551 		vcost = repeated_append(0, SP->_cuu1_cost, n, result, cursor_up);
552 	    }
553 	}
554 
555 	if (vcost == INFINITY)
556 	    return(INFINITY);
557     }
558 
559     if (result)
560 	result += strlen(result);
561 
562     if (to_x != from_x)
563     {
564 	char	str[OPT_SIZE];
565 
566 	hcost = INFINITY;
567 
568 	if (column_address)
569 	{
570 	    if (result)
571 		(void) strcpy(result, tparm(column_address, to_x));
572 	    hcost = SP->_hpa_cost;
573 	}
574 
575 	if (to_x > from_x)
576 	{
577 	    n = to_x - from_x;
578 
579 	    if (parm_right_cursor && SP->_cuf_cost < hcost)
580 	    {
581 		if (result)
582 		    (void) strcpy(result, tparm(parm_right_cursor, n));
583 		hcost = SP->_cuf_cost;
584 	    }
585 
586 	    if (cursor_right)
587 	    {
588 		int	lhcost = 0;
589 
590 		str[0] = '\0';
591 
592 #if USE_HARD_TABS
593 		/* use hard tabs, if we have them, to do as much as possible */
594 		if (init_tabs > 0 && tab)
595 		{
596 		    int	nxt, fr;
597 
598 		    for (fr = from_x; (nxt = NEXTTAB(fr)) <= to_x; fr = nxt)
599 		    {
600 			lhcost = repeated_append(lhcost, SP->_ht_cost, 1, str, tab);
601 			if (lhcost == INFINITY)
602 				break;
603 		    }
604 
605 		    n = to_x - fr;
606 		    from_x = fr;
607 		}
608 #endif /* USE_HARD_TABS */
609 
610 #if defined(REAL_ATTR) && defined(WANT_CHAR)
611 #ifdef BSD_TPUTS
612 		/*
613 		 * If we're allowing BSD-style padding in tputs, don't generate
614 		 * a string with a leading digit.  Otherwise, that will be
615 		 * interpreted as a padding value rather than sent to the
616 		 * screen.
617 		 */
618 		if (ovw
619 		 && n > 0
620 		 && vcost == 0
621 		 && str[0] == '\0'
622 		 && isdigit(TextOf(WANT_CHAR(to_y, from_x))))
623 			ovw = FALSE;
624 #endif
625 		/*
626 		 * If we have no attribute changes, overwrite is cheaper.
627 		 * Note: must suppress this by passing in ovw = FALSE whenever
628 		 * WANT_CHAR would return invalid data.  In particular, this
629 		 * is true between the time a hardware scroll has been done
630 		 * and the time the structure WANT_CHAR would access has been
631 		 * updated.
632 		 */
633 		if (ovw)
634 		{
635 		    int	i;
636 
637 		    for (i = 0; i < n; i++)
638 			if ((WANT_CHAR(to_y, from_x + i) & A_ATTRIBUTES) != CURRENT_ATTR)
639 			{
640 			    ovw = FALSE;
641 			    break;
642 			}
643 		}
644 		if (ovw)
645 		{
646 		    char	*sp;
647 		    int	i;
648 
649 		    sp = str + strlen(str);
650 
651 		    for (i = 0; i < n; i++)
652 			*sp++ = WANT_CHAR(to_y, from_x + i);
653 		    *sp = '\0';
654 		    lhcost += n * SP->_char_padding;
655 		}
656 		else
657 #endif /* defined(REAL_ATTR) && defined(WANT_CHAR) */
658 		{
659 		    lhcost = repeated_append(lhcost, SP->_cuf1_cost, n, str, cursor_right);
660 		}
661 
662 		if (lhcost < hcost)
663 		{
664 		    if (result)
665 			(void) strcpy(result, str);
666 		    hcost = lhcost;
667 		}
668 	    }
669 	}
670 	else /* (to_x < from_x) */
671 	{
672 	    n = from_x - to_x;
673 
674 	    if (parm_left_cursor && SP->_cub_cost < hcost)
675 	    {
676 		if (result)
677 		    (void) strcpy(result, tparm(parm_left_cursor, n));
678 		hcost = SP->_cub_cost;
679 	    }
680 
681 	    if (cursor_left)
682 	    {
683 		int	lhcost = 0;
684 
685 		str[0] = '\0';
686 
687 #if USE_HARD_TABS
688 		if (init_tabs > 0 && back_tab)
689 		{
690 		    int	nxt, fr;
691 
692 		    for (fr = from_x; (nxt = LASTTAB(fr)) >= to_x; fr = nxt)
693 		    {
694 			lhcost = repeated_append(lhcost, SP->_cbt_cost, 1, str, back_tab);
695 			if (lhcost == INFINITY)
696 				break;
697 		    }
698 
699 		    n = fr - to_x;
700 		}
701 #endif /* USE_HARD_TABS */
702 
703 		lhcost = repeated_append(lhcost, SP->_cub1_cost, n, str, cursor_left);
704 
705 		if (lhcost < hcost)
706 		{
707 		    if (result)
708 			(void) strcpy(result, str);
709 		    hcost = lhcost;
710 		}
711 	    }
712 	}
713 
714 	if (hcost == INFINITY)
715 	    return(INFINITY);
716     }
717 
718     return(vcost + hcost);
719 }
720 #endif /* !NO_OPTIMIZE */
721 
722 /*
723  * With the machinery set up above, it's conceivable that
724  * onscreen_mvcur could be modified into a recursive function that does
725  * an alpha-beta search of motion space, as though it were a chess
726  * move tree, with the weight function being boolean and the search
727  * depth equated to length of string.  However, this would jack up the
728  * computation cost a lot, especially on terminals without a cup
729  * capability constraining the search tree depth.  So we settle for
730  * the simpler method below.
731  */
732 
733 static inline int
734 onscreen_mvcur(int yold,int xold,int ynew,int xnew, bool ovw)
735 /* onscreen move from (yold, xold) to (ynew, xnew) */
736 {
737     char	use[OPT_SIZE], *sp;
738     int		tactic = 0, newcost, usecost = INFINITY;
739 
740 #if defined(MAIN) || defined(NCURSES_TEST)
741     struct timeval before, after;
742 
743     gettimeofday(&before, NULL);
744 #endif /* MAIN */
745 
746     /* tactic #0: use direct cursor addressing */
747     sp = tparm(SP->_address_cursor, ynew, xnew);
748     if (sp)
749     {
750 	tactic = 0;
751 	(void) strcpy(use, sp);
752 	usecost = SP->_cup_cost;
753 
754 #if defined(TRACE) || defined(NCURSES_TEST)
755 	if (!(_nc_optimize_enable & OPTIMIZE_MVCUR))
756 	    goto nonlocal;
757 #endif /* TRACE */
758 
759 	/*
760 	 * We may be able to tell in advance that the full optimization
761 	 * will probably not be worth its overhead.  Also, don't try to
762 	 * use local movement if the current attribute is anything but
763 	 * A_NORMAL...there are just too many ways this can screw up
764 	 * (like, say, local-movement \n getting mapped to some obscure
765 	 * character because A_ALTCHARSET is on).
766 	 */
767 	if (yold == -1 || xold == -1 || NOT_LOCAL(yold, xold, ynew, xnew))
768 	{
769 #if defined(MAIN) || defined(NCURSES_TEST)
770 	    if (!profiling)
771 	    {
772 		(void) fputs("nonlocal\n", stderr);
773 		goto nonlocal;	/* always run the optimizer if profiling */
774 	    }
775 #else
776 	    goto nonlocal;
777 #endif /* MAIN */
778 	}
779     }
780 
781 #ifndef NO_OPTIMIZE
782     /* tactic #1: use local movement */
783     if (yold != -1 && xold != -1
784 		&& ((newcost=relative_move(NULL, yold, xold, ynew, xnew, ovw))!=INFINITY)
785 		&& newcost < usecost)
786     {
787 	tactic = 1;
788 	usecost = newcost;
789     }
790 
791     /* tactic #2: use carriage-return + local movement */
792     if (yold != -1 && carriage_return
793 		&& ((newcost=relative_move(NULL, yold,0,ynew,xnew, ovw)) != INFINITY)
794 		&& SP->_cr_cost + newcost < usecost)
795     {
796 	tactic = 2;
797 	usecost = SP->_cr_cost + newcost;
798     }
799 
800     /* tactic #3: use home-cursor + local movement */
801     if (cursor_home
802 	&& ((newcost=relative_move(NULL, 0, 0, ynew, xnew, ovw)) != INFINITY)
803 	&& SP->_home_cost + newcost < usecost)
804     {
805 	tactic = 3;
806 	usecost = SP->_home_cost + newcost;
807     }
808 
809     /* tactic #4: use home-down + local movement */
810     if (cursor_to_ll
811 	&& ((newcost=relative_move(NULL, screen_lines-1, 0, ynew, xnew, ovw)) != INFINITY)
812 	&& SP->_ll_cost + newcost < usecost)
813     {
814 	tactic = 4;
815 	usecost = SP->_ll_cost + newcost;
816     }
817 
818     /*
819      * tactic #5: use left margin for wrap to right-hand side,
820      * unless strange wrap behavior indicated by xenl might hose us.
821      */
822     if (auto_left_margin && !eat_newline_glitch
823 	&& yold > 0 && cursor_left
824 	&& ((newcost=relative_move(NULL, yold-1, screen_columns-1, ynew, xnew, ovw)) != INFINITY)
825 	&& SP->_cr_cost + SP->_cub1_cost + newcost + newcost < usecost)
826     {
827 	tactic = 5;
828 	usecost = SP->_cr_cost + SP->_cub1_cost + newcost;
829     }
830 
831     /*
832      * These cases are ordered by estimated relative frequency.
833      */
834     if (tactic)
835     {
836 	if (tactic == 1)
837 	    (void) relative_move(use, yold, xold, ynew, xnew, ovw);
838 	else if (tactic == 2)
839 	{
840 	    (void) strcpy(use, carriage_return);
841 	    (void) relative_move(use + SP->_carriage_return_length,
842 				 yold,0,ynew,xnew, ovw);
843 	}
844 	else if (tactic == 3)
845 	{
846 	    (void) strcpy(use, cursor_home);
847 	    (void) relative_move(use + SP->_cursor_home_length,
848 				 0, 0, ynew, xnew, ovw);
849 	}
850 	else if (tactic == 4)
851 	{
852 	    (void) strcpy(use, cursor_to_ll);
853 	    (void) relative_move(use + SP->_cursor_to_ll_length,
854 				 screen_lines-1, 0, ynew, xnew, ovw);
855 	}
856 	else /* if (tactic == 5) */
857 	{
858 	    use[0] = '\0';
859 	    if (xold > 0)
860 		(void) strcat(use, carriage_return);
861 	    (void) strcat(use, cursor_left);
862 	    (void) relative_move(use + strlen(use),
863 				 yold-1, screen_columns-1, ynew, xnew, ovw);
864 	}
865     }
866 #endif /* !NO_OPTIMIZE */
867 
868 #if defined(MAIN) || defined(NCURSES_TEST)
869     gettimeofday(&after, NULL);
870     diff = after.tv_usec - before.tv_usec
871 	+ (after.tv_sec - before.tv_sec) * 1000000;
872     if (!profiling)
873 	(void) fprintf(stderr, "onscreen: %d msec, %f 28.8Kbps char-equivalents\n",
874 		       (int)diff, diff/288);
875 #endif /* MAIN */
876 
877  nonlocal:
878     if (usecost != INFINITY)
879     {
880 	TPUTS_TRACE("mvcur");
881 	tputs(use, 1, _nc_outch);
882 	return(OK);
883     }
884     else
885 	return(ERR);
886 }
887 
888 int mvcur(int yold, int xold, int ynew, int xnew)
889 /* optimized cursor move from (yold, xold) to (ynew, xnew) */
890 {
891     TR(TRACE_MOVE, ("mvcur(%d,%d,%d,%d) called", yold, xold, ynew, xnew));
892 
893     if (yold == ynew && xold == xnew)
894 	return(OK);
895 
896     /*
897      * Most work here is rounding for terminal boundaries getting the
898      * column position implied by wraparound or the lack thereof and
899      * rolling up the screen to get ynew on the screen.
900      */
901 
902     if (xnew >= screen_columns)
903     {
904 	ynew += xnew / screen_columns;
905 	xnew %= screen_columns;
906     }
907     if (xold >= screen_columns)
908     {
909 	int	l;
910 
911 	l = (xold + 1) / screen_columns;
912 	yold += l;
913 	if (yold >= screen_lines)
914 		l -= (yold - screen_lines - 1);
915 
916 	while (l > 0) {
917 		if (newline)
918 		{
919 			TPUTS_TRACE("newline");
920 			tputs(newline, 0, _nc_outch);
921 		}
922 		else
923 			putchar('\n');
924 		l--;
925 		if (xold > 0)
926 		{
927 			if (carriage_return)
928 			{
929 				TPUTS_TRACE("carriage_return");
930 				tputs(carriage_return, 0, _nc_outch);
931 			}
932 			else
933 				putchar('\r');
934 			xold = 0;
935 		}
936 	}
937     }
938 
939     if (yold > screen_lines - 1)
940 	yold = screen_lines - 1;
941     if (ynew > screen_lines - 1)
942 	ynew = screen_lines - 1;
943 
944     /* destination location is on screen now */
945     return(onscreen_mvcur(yold, xold, ynew, xnew, TRUE));
946 }
947 
948 #if defined(TRACE) || defined(NCURSES_TEST)
949 int _nc_optimize_enable = OPTIMIZE_ALL;
950 #endif
951 
952 #if defined(MAIN) || defined(NCURSES_TEST)
953 /****************************************************************************
954  *
955  * Movement optimizer test code
956  *
957  ****************************************************************************/
958 
959 #include <tic.h>
960 #include <dump_entry.h>
961 
962 const char *_nc_progname = "mvcur";
963 
964 static unsigned long xmits;
965 
966 int tputs(const char *string, int affcnt GCC_UNUSED, int (*outc)(int) GCC_UNUSED)
967 /* stub tputs() that dumps sequences in a visible form */
968 {
969     if (profiling)
970 	xmits += strlen(string);
971     else
972 	(void) fputs(_nc_visbuf(string), stdout);
973     return(OK);
974 }
975 
976 int putp(const char *string)
977 {
978     return(tputs(string, 1, _nc_outch));
979 }
980 
981 int _nc_outch(int ch)
982 {
983     putc(ch, stdout);
984     return OK;
985 }
986 
987 static char	tname[MAX_ALIAS];
988 
989 static void load_term(void)
990 {
991     (void) setupterm(tname, STDOUT_FILENO, NULL);
992 }
993 
994 static int roll(int n)
995 {
996     int i, j;
997 
998     i = (RAND_MAX / n) * n;
999     while ((j = rand()) >= i)
1000 	continue;
1001     return (j % n);
1002 }
1003 
1004 int main(int argc GCC_UNUSED, char *argv[] GCC_UNUSED)
1005 {
1006     (void) strcpy(tname, termname());
1007     load_term();
1008     _nc_setupscreen(lines, columns, stdout);
1009     baudrate();
1010 
1011     _nc_mvcur_init();
1012     NC_BUFFERED(FALSE);
1013 
1014     (void) puts("The mvcur tester.  Type ? for help");
1015 
1016     fputs("smcup:", stdout);
1017     putchar('\n');
1018 
1019     for (;;)
1020     {
1021 	int	fy, fx, ty, tx, n, i;
1022 	char	buf[BUFSIZ], capname[BUFSIZ];
1023 
1024 	(void) fputs("> ", stdout);
1025 	(void) fgets(buf, sizeof(buf), stdin);
1026 
1027 	if (buf[0] == '?')
1028 	{
1029 (void) puts("?                -- display this help message");
1030 (void) puts("fy fx ty tx      -- (4 numbers) display (fy,fx)->(ty,tx) move");
1031 (void) puts("s[croll] n t b m -- display scrolling sequence");
1032 (void) printf("r[eload]         -- reload terminal info for %s\n", termname());
1033 (void) puts("l[oad] <term>    -- load terminal info for type <term>");
1034 (void) puts("d[elete] <cap>   -- delete named capability");
1035 (void) puts("i[nspect]        -- display terminal capabilities");
1036 (void) puts("c[ost]           -- dump cursor-optimization cost table");
1037 (void) puts("o[optimize]      -- toggle movement optimization");
1038 (void) puts("t[orture] <num>  -- torture-test with <num> random moves");
1039 (void) puts("q[uit]           -- quit the program");
1040 	}
1041 	else if (sscanf(buf, "%d %d %d %d", &fy, &fx, &ty, &tx) == 4)
1042 	{
1043 	    struct timeval before, after;
1044 
1045 	    putchar('"');
1046 
1047 	    gettimeofday(&before, NULL);
1048 	    mvcur(fy, fx, ty, tx);
1049 	    gettimeofday(&after, NULL);
1050 
1051 	    printf("\" (%ld msec)\n",
1052 		(long)(after.tv_usec - before.tv_usec + (after.tv_sec - before.tv_sec) * 1000000));
1053 	}
1054 	else if (sscanf(buf, "s %d %d %d %d", &fy, &fx, &ty, &tx) == 4)
1055 	{
1056 	    struct timeval before, after;
1057 
1058 	    putchar('"');
1059 
1060 	    gettimeofday(&before, NULL);
1061 	    _nc_scrolln(fy, fx, ty, tx);
1062 	    gettimeofday(&after, NULL);
1063 
1064 	    printf("\" (%ld msec)\n",
1065 		(long)(after.tv_usec - before.tv_usec + (after.tv_sec - before.tv_sec) * 1000000));
1066 	}
1067 	else if (buf[0] == 'r')
1068 	{
1069 	    (void) strcpy(tname, termname());
1070 	    load_term();
1071 	}
1072 	else if (sscanf(buf, "l %s", tname) == 1)
1073 	{
1074 	    load_term();
1075 	}
1076 	else if (sscanf(buf, "d %s", capname) == 1)
1077 	{
1078 	    struct name_table_entry const	*np = _nc_find_entry(capname,
1079 							 _nc_info_hash_table);
1080 
1081 	    if (np == NULL)
1082 		(void) printf("No such capability as \"%s\"\n", capname);
1083 	    else
1084 	    {
1085 		switch(np->nte_type)
1086 		{
1087 		case BOOLEAN:
1088 		    cur_term->type.Booleans[np->nte_index] = FALSE;
1089 		    (void) printf("Boolean capability `%s' (%d) turned off.\n",
1090 				  np->nte_name, np->nte_index);
1091 		    break;
1092 
1093 		case NUMBER:
1094 		    cur_term->type.Numbers[np->nte_index] = -1;
1095 		    (void) printf("Number capability `%s' (%d) set to -1.\n",
1096 				  np->nte_name, np->nte_index);
1097 		    break;
1098 
1099 		case STRING:
1100 		    cur_term->type.Strings[np->nte_index] = (char *)NULL;
1101 		    (void) printf("String capability `%s' (%d) deleted.\n",
1102 				  np->nte_name, np->nte_index);
1103 		    break;
1104 		}
1105 	    }
1106 	}
1107 	else if (buf[0] == 'i')
1108 	{
1109 	     dump_init((char *)NULL, F_TERMINFO, S_TERMINFO, 70, 0, FALSE);
1110 	     dump_entry(&cur_term->type, FALSE, TRUE, 0);
1111 	     putchar('\n');
1112 	}
1113 	else if (buf[0] == 'o')
1114 	{
1115 	     if (_nc_optimize_enable & OPTIMIZE_MVCUR)
1116 	     {
1117 		 _nc_optimize_enable &=~ OPTIMIZE_MVCUR;
1118 		 (void) puts("Optimization is now off.");
1119 	     }
1120 	     else
1121 	     {
1122 		 _nc_optimize_enable |= OPTIMIZE_MVCUR;
1123 		 (void) puts("Optimization is now on.");
1124 	     }
1125 	}
1126 	/*
1127 	 * You can use the `t' test to profile and tune the movement
1128 	 * optimizer.  Use iteration values in three digits or more.
1129 	 * At above 5000 iterations the profile timing averages are stable
1130 	 * to within a millisecond or three.
1131 	 *
1132 	 * The `overhead' field of the report will help you pick a
1133 	 * COMPUTE_OVERHEAD figure appropriate for your processor and
1134 	 * expected line speed.  The `total estimated time' is
1135 	 * computation time plus a character-transmission time
1136 	 * estimate computed from the number of transmits and the baud
1137 	 * rate.
1138 	 *
1139 	 * Use this together with the `o' command to get a read on the
1140 	 * optimizer's effectiveness.  Compare the total estimated times
1141 	 * for `t' runs of the same length in both optimized and un-optimized
1142 	 * modes.  As long as the optimized times are less, the optimizer
1143 	 * is winning.
1144 	 */
1145 	else if (sscanf(buf, "t %d", &n) == 1)
1146 	{
1147 	    float cumtime = 0, perchar;
1148 	    int speeds[] = {2400, 9600, 14400, 19200, 28800, 38400, 0};
1149 
1150 	    srand((unsigned)(getpid() + time((time_t *)0)));
1151 	    profiling = TRUE;
1152 	    xmits = 0;
1153 	    for (i = 0; i < n; i++)
1154 	    {
1155 		/*
1156 		 * This does a move test between two random locations,
1157 		 * Random moves probably short-change the optimizer,
1158 		 * which will work better on the short moves probably
1159 		 * typical of doupdate()'s usage pattern.  Still,
1160 		 * until we have better data...
1161 		 */
1162 #ifdef FIND_COREDUMP
1163 		int from_y = roll(lines);
1164 		int to_y = roll(lines);
1165 		int from_x = roll(columns);
1166 		int to_x = roll(columns);
1167 
1168 		printf("(%d,%d) -> (%d,%d)\n", from_y, from_x, to_y, to_x);
1169 		mvcur(from_y, from_x, to_y, to_x);
1170 #else
1171 		mvcur(roll(lines), roll(columns), roll(lines), roll(columns));
1172 #endif /* FIND_COREDUMP */
1173 		if (diff)
1174 		    cumtime += diff;
1175 	    }
1176 	    profiling = FALSE;
1177 
1178 	    /*
1179 	     * Average milliseconds per character optimization time.
1180 	     * This is the key figure to watch when tuning the optimizer.
1181 	     */
1182 	    perchar = cumtime / n;
1183 
1184 	    (void) printf("%d moves (%ld chars) in %d msec, %f msec each:\n",
1185 			  n, xmits, (int)cumtime, perchar);
1186 
1187 	    for (i = 0; speeds[i]; i++)
1188 	    {
1189 		/*
1190 		 * Total estimated time for the moves, computation and
1191 		 * transmission both. Transmission time is an estimate
1192 		 * assuming 9 bits/char, 8 bits + 1 stop bit.
1193 		 */
1194 		float totalest = cumtime + xmits * 9 * 1e6 / speeds[i];
1195 
1196 		/*
1197 		 * Per-character optimization overhead in character transmits
1198 		 * at the current speed.  Round this to the nearest integer
1199 		 * to figure COMPUTE_OVERHEAD for the speed.
1200 		 */
1201 		float overhead = speeds[i] * perchar / 1e6;
1202 
1203 		(void) printf("%6d bps: %3.2f char-xmits overhead; total estimated time %15.2f\n",
1204 			      speeds[i], overhead, totalest);
1205 	    }
1206 	}
1207 	else if (buf[0] == 'c')
1208 	{
1209 	    (void) printf("char padding: %d\n", SP->_char_padding);
1210 	    (void) printf("cr cost: %d\n", SP->_cr_cost);
1211 	    (void) printf("cup cost: %d\n", SP->_cup_cost);
1212 	    (void) printf("home cost: %d\n", SP->_home_cost);
1213 	    (void) printf("ll cost: %d\n", SP->_ll_cost);
1214 #if USE_HARD_TABS
1215 	    (void) printf("ht cost: %d\n", SP->_ht_cost);
1216 	    (void) printf("cbt cost: %d\n", SP->_cbt_cost);
1217 #endif /* USE_HARD_TABS */
1218 	    (void) printf("cub1 cost: %d\n", SP->_cub1_cost);
1219 	    (void) printf("cuf1 cost: %d\n", SP->_cuf1_cost);
1220 	    (void) printf("cud1 cost: %d\n", SP->_cud1_cost);
1221 	    (void) printf("cuu1 cost: %d\n", SP->_cuu1_cost);
1222 	    (void) printf("cub cost: %d\n", SP->_cub_cost);
1223 	    (void) printf("cuf cost: %d\n", SP->_cuf_cost);
1224 	    (void) printf("cud cost: %d\n", SP->_cud_cost);
1225 	    (void) printf("cuu cost: %d\n", SP->_cuu_cost);
1226 	    (void) printf("hpa cost: %d\n", SP->_hpa_cost);
1227 	    (void) printf("vpa cost: %d\n", SP->_vpa_cost);
1228 	}
1229 	else if (buf[0] == 'x' || buf[0] == 'q')
1230 	    break;
1231 	else
1232 	    (void) puts("Invalid command.");
1233     }
1234 
1235     (void) fputs("rmcup:", stdout);
1236     _nc_mvcur_wrap();
1237     putchar('\n');
1238 
1239     return(0);
1240 }
1241 
1242 #endif /* MAIN */
1243 
1244 /* lib_mvcur.c ends here */
1245