1 /****************************************************************************
2  * Copyright 2018-2020,2021 Thomas E. Dickey                                *
3  * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
4  *                                                                          *
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6  * copy of this software and associated documentation files (the            *
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12  *                                                                          *
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15  *                                                                          *
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23  *                                                                          *
24  * Except as contained in this notice, the name(s) of the above copyright   *
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29 
30 /****************************************************************************
31  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
32  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
33  *     and: Thomas E. Dickey                        1996-on                 *
34  *     and: Juergen Pfeifer                         2009                    *
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(sp, fy, fx, ty, tx)	((tx > LONG_DIST) \
115 		 && (tx < screen_columns(sp) - 1 - LONG_DIST) \
116 		 && (abs(ty-fy) + abs(tx-fx) > LONG_DIST))
117 
118 /****************************************************************************
119  *
120  * External interfaces
121  *
122  ****************************************************************************/
123 
124 /*
125  * For this code to work OK, the following components must live in the
126  * screen structure:
127  *
128  *	int		_char_padding;	// cost of character put
129  *	int		_cr_cost;	// cost of (carriage_return)
130  *	int		_cup_cost;	// cost of (cursor_address)
131  *	int		_home_cost;	// cost of (cursor_home)
132  *	int		_ll_cost;	// cost of (cursor_to_ll)
133  *#if USE_HARD_TABS
134  *	int		_ht_cost;	// cost of (tab)
135  *	int		_cbt_cost;	// cost of (back_tab)
136  *#endif USE_HARD_TABS
137  *	int		_cub1_cost;	// cost of (cursor_left)
138  *	int		_cuf1_cost;	// cost of (cursor_right)
139  *	int		_cud1_cost;	// cost of (cursor_down)
140  *	int		_cuu1_cost;	// cost of (cursor_up)
141  *	int		_cub_cost;	// cost of (parm_cursor_left)
142  *	int		_cuf_cost;	// cost of (parm_cursor_right)
143  *	int		_cud_cost;	// cost of (parm_cursor_down)
144  *	int		_cuu_cost;	// cost of (parm_cursor_up)
145  *	int		_hpa_cost;	// cost of (column_address)
146  *	int		_vpa_cost;	// cost of (row_address)
147  *	int		_ech_cost;	// cost of (erase_chars)
148  *	int		_rep_cost;	// cost of (repeat_char)
149  *
150  * The USE_HARD_TABS switch controls whether it is reliable to use tab/backtabs
151  * for local motions.  On many systems, it's not, due to uncertainties about
152  * tab delays and whether or not tabs will be expanded in raw mode.  If you
153  * have parm_right_cursor, tab motions don't win you a lot anyhow.
154  */
155 
156 #include <curses.priv.h>
157 #include <ctype.h>
158 
159 #ifndef CUR
160 #define CUR SP_TERMTYPE
161 #endif
162 
163 MODULE_ID("$Id: lib_mvcur.c,v 1.155 2021/02/06 13:53:41 tom Exp $")
164 
165 #define WANT_CHAR(sp, y, x) NewScreen(sp)->_line[y].text[x]	/* desired state */
166 
167 #if NCURSES_SP_FUNCS
168 #define BAUDRATE(sp)	sp->_term->_baudrate	/* bits per second */
169 #else
170 #define BAUDRATE(sp)	cur_term->_baudrate	/* bits per second */
171 #endif
172 
173 #if defined(MAIN) || defined(NCURSES_TEST)
174 #include <sys/time.h>
175 
176 static bool profiling = FALSE;
177 static float diff;
178 #endif /* MAIN */
179 
180 #undef NCURSES_OUTC_FUNC
181 #define NCURSES_OUTC_FUNC myOutCh
182 
183 #define OPT_SIZE 512
184 
185 static int normalized_cost(NCURSES_SP_DCLx const char *const cap, int affcnt);
186 
187 /****************************************************************************
188  *
189  * Initialization/wrapup (including cost pre-computation)
190  *
191  ****************************************************************************/
192 
193 #ifdef TRACE
194 static int
195 trace_cost_of(NCURSES_SP_DCLx const char *capname, const char *cap, int affcnt)
196 {
197     int result = NCURSES_SP_NAME(_nc_msec_cost) (NCURSES_SP_ARGx cap, affcnt);
198     TR(TRACE_CHARPUT | TRACE_MOVE,
199        ("CostOf %s %d %s", capname, result, _nc_visbuf(cap)));
200     return result;
201 }
202 #define CostOf(cap,affcnt) trace_cost_of(NCURSES_SP_ARGx #cap, cap, affcnt)
203 
204 static int
205 trace_normalized_cost(NCURSES_SP_DCLx const char *capname, const char *cap, int affcnt)
206 {
207     int result = normalized_cost(NCURSES_SP_ARGx cap, affcnt);
208     TR(TRACE_CHARPUT | TRACE_MOVE,
209        ("NormalizedCost %s %d %s", capname, result, _nc_visbuf(cap)));
210     return result;
211 }
212 #define NormalizedCost(cap,affcnt) trace_normalized_cost(NCURSES_SP_ARGx #cap, cap, affcnt)
213 
214 #else
215 
216 #define CostOf(cap,affcnt) NCURSES_SP_NAME(_nc_msec_cost)(NCURSES_SP_ARGx cap, affcnt)
217 #define NormalizedCost(cap,affcnt) normalized_cost(NCURSES_SP_ARGx cap, affcnt)
218 
219 #endif
220 
221 NCURSES_EXPORT(int)
222 NCURSES_SP_NAME(_nc_msec_cost) (NCURSES_SP_DCLx const char *const cap, int affcnt)
223 /* compute the cost of a given operation */
224 {
225     if (cap == 0)
226 	return (INFINITY);
227     else {
228 	const char *cp;
229 	float cum_cost = 0.0;
230 
231 	for (cp = cap; *cp; cp++) {
232 	    /* extract padding, either mandatory or required */
233 	    if (cp[0] == '$' && cp[1] == '<' && strchr(cp, '>')) {
234 		float number = 0.0;
235 
236 		for (cp += 2; *cp != '>'; cp++) {
237 		    if (isdigit(UChar(*cp)))
238 			number = number * 10 + (float) (*cp - '0');
239 		    else if (*cp == '*')
240 			number *= (float) affcnt;
241 		    else if (*cp == '.' && (*++cp != '>') && isdigit(UChar(*cp)))
242 			number += (float) ((*cp - '0') / 10.0);
243 		}
244 
245 #if NCURSES_NO_PADDING
246 		if (!GetNoPadding(SP_PARM))
247 #endif
248 		    cum_cost += number * 10;
249 	    } else if (SP_PARM) {
250 		cum_cost += (float) SP_PARM->_char_padding;
251 	    }
252 	}
253 
254 	return ((int) cum_cost);
255     }
256 }
257 
258 #if NCURSES_SP_FUNCS
259 NCURSES_EXPORT(int)
260 _nc_msec_cost(const char *const cap, int affcnt)
261 {
262     return NCURSES_SP_NAME(_nc_msec_cost) (CURRENT_SCREEN, cap, affcnt);
263 }
264 #endif
265 
266 static int
267 normalized_cost(NCURSES_SP_DCLx const char *const cap, int affcnt)
268 /* compute the effective character-count for an operation (round up) */
269 {
270     int cost = NCURSES_SP_NAME(_nc_msec_cost) (NCURSES_SP_ARGx cap, affcnt);
271     if (cost != INFINITY)
272 	cost = (cost + SP_PARM->_char_padding - 1) / SP_PARM->_char_padding;
273     return cost;
274 }
275 
276 static void
277 reset_scroll_region(NCURSES_SP_DCL0)
278 /* Set the scroll-region to a known state (the default) */
279 {
280     if (change_scroll_region) {
281 	NCURSES_PUTP2("change_scroll_region",
282 		      TIPARM_2(change_scroll_region,
283 			       0, screen_lines(SP_PARM) - 1));
284     }
285 }
286 
287 NCURSES_EXPORT(void)
288 NCURSES_SP_NAME(_nc_mvcur_resume) (NCURSES_SP_DCL0)
289 /* what to do at initialization time and after each shellout */
290 {
291     if (!SP_PARM || !IsTermInfo(SP_PARM))
292 	return;
293 
294     /* initialize screen for cursor access */
295     if (enter_ca_mode) {
296 	NCURSES_PUTP2("enter_ca_mode", enter_ca_mode);
297     }
298 
299     /*
300      * Doing this here rather than in _nc_mvcur_wrap() ensures that
301      * ncurses programs will see a reset scroll region even if a
302      * program that messed with it died ungracefully.
303      *
304      * This also undoes the effects of terminal init strings that assume
305      * they know the screen size.  This is useful when you're running
306      * a vt100 emulation through xterm.
307      */
308     reset_scroll_region(NCURSES_SP_ARG);
309     SP_PARM->_cursrow = SP_PARM->_curscol = -1;
310 
311     /* restore cursor shape */
312     if (SP_PARM->_cursor != -1) {
313 	int cursor = SP_PARM->_cursor;
314 	SP_PARM->_cursor = -1;
315 	NCURSES_SP_NAME(curs_set) (NCURSES_SP_ARGx cursor);
316     }
317 }
318 
319 #if NCURSES_SP_FUNCS
320 NCURSES_EXPORT(void)
321 _nc_mvcur_resume(void)
322 {
323     NCURSES_SP_NAME(_nc_mvcur_resume) (CURRENT_SCREEN);
324 }
325 #endif
326 
327 NCURSES_EXPORT(void)
328 NCURSES_SP_NAME(_nc_mvcur_init) (NCURSES_SP_DCL0)
329 /* initialize the cost structure */
330 {
331     if (SP_PARM->_ofp && NC_ISATTY(fileno(SP_PARM->_ofp))) {
332 	SP_PARM->_char_padding = ((BAUDBYTE * 1000 * 10)
333 				  / (BAUDRATE(SP_PARM) > 0
334 				     ? BAUDRATE(SP_PARM)
335 				     : 9600));
336     } else {
337 	SP_PARM->_char_padding = 1;	/* must be nonzero */
338     }
339     if (SP_PARM->_char_padding <= 0)
340 	SP_PARM->_char_padding = 1;	/* must be nonzero */
341     TR(TRACE_CHARPUT | TRACE_MOVE, ("char_padding %d msecs", SP_PARM->_char_padding));
342 
343     /* non-parameterized local-motion strings */
344     SP_PARM->_cr_cost = CostOf(carriage_return, 0);
345     SP_PARM->_home_cost = CostOf(cursor_home, 0);
346     SP_PARM->_ll_cost = CostOf(cursor_to_ll, 0);
347 #if USE_HARD_TABS
348     if (getenv("NCURSES_NO_HARD_TABS") == 0
349 	&& dest_tabs_magic_smso == 0
350 	&& HasHardTabs()) {
351 	SP_PARM->_ht_cost = CostOf(tab, 0);
352 	SP_PARM->_cbt_cost = CostOf(back_tab, 0);
353     } else {
354 	SP_PARM->_ht_cost = INFINITY;
355 	SP_PARM->_cbt_cost = INFINITY;
356     }
357 #endif /* USE_HARD_TABS */
358     SP_PARM->_cub1_cost = CostOf(cursor_left, 0);
359     SP_PARM->_cuf1_cost = CostOf(cursor_right, 0);
360     SP_PARM->_cud1_cost = CostOf(cursor_down, 0);
361     SP_PARM->_cuu1_cost = CostOf(cursor_up, 0);
362 
363     SP_PARM->_smir_cost = CostOf(enter_insert_mode, 0);
364     SP_PARM->_rmir_cost = CostOf(exit_insert_mode, 0);
365     SP_PARM->_ip_cost = 0;
366     if (insert_padding) {
367 	SP_PARM->_ip_cost = CostOf(insert_padding, 0);
368     }
369 
370     /*
371      * Assumption: if the terminal has memory_relative addressing, the
372      * initialization strings or smcup will set single-page mode so we
373      * can treat it like absolute screen addressing.  This seems to be true
374      * for all cursor_mem_address terminal types in the terminfo database.
375      */
376     SP_PARM->_address_cursor = cursor_address ? cursor_address : cursor_mem_address;
377 
378     /*
379      * Parametrized local-motion strings.  This static cost computation
380      * depends on the following assumptions:
381      *
382      * (1) They never have * padding.  In the entire master terminfo database
383      *     as of March 1995, only the obsolete Zenith Z-100 pc violates this.
384      *     (Proportional padding is found mainly in insert, delete and scroll
385      *     capabilities).
386      *
387      * (2) The average case of cup has two two-digit parameters.  Strictly,
388      *     the average case for a 24 * 80 screen has ((10*10*(1 + 1)) +
389      *     (14*10*(1 + 2)) + (10*70*(2 + 1)) + (14*70*4)) / (24*80) = 3.458
390      *     digits of parameters.  On a 25x80 screen the average is 3.6197.
391      *     On larger screens the value gets much closer to 4.
392      *
393      * (3) The average case of cub/cuf/hpa/ech/rep has 2 digits of parameters
394      *     (strictly, (((10 * 1) + (70 * 2)) / 80) = 1.8750).
395      *
396      * (4) The average case of cud/cuu/vpa has 2 digits of parameters
397      *     (strictly, (((10 * 1) + (14 * 2)) / 24) = 1.5833).
398      *
399      * All these averages depend on the assumption that all parameter values
400      * are equally probable.
401      */
402     SP_PARM->_cup_cost = CostOf(TIPARM_2(SP_PARM->_address_cursor, 23, 23), 1);
403     SP_PARM->_cub_cost = CostOf(TIPARM_1(parm_left_cursor, 23), 1);
404     SP_PARM->_cuf_cost = CostOf(TIPARM_1(parm_right_cursor, 23), 1);
405     SP_PARM->_cud_cost = CostOf(TIPARM_1(parm_down_cursor, 23), 1);
406     SP_PARM->_cuu_cost = CostOf(TIPARM_1(parm_up_cursor, 23), 1);
407     SP_PARM->_hpa_cost = CostOf(TIPARM_1(column_address, 23), 1);
408     SP_PARM->_vpa_cost = CostOf(TIPARM_1(row_address, 23), 1);
409 
410     /* non-parameterized screen-update strings */
411     SP_PARM->_ed_cost = NormalizedCost(clr_eos, 1);
412     SP_PARM->_el_cost = NormalizedCost(clr_eol, 1);
413     SP_PARM->_el1_cost = NormalizedCost(clr_bol, 1);
414     SP_PARM->_dch1_cost = NormalizedCost(delete_character, 1);
415     SP_PARM->_ich1_cost = NormalizedCost(insert_character, 1);
416 
417     /*
418      * If this is a bce-terminal, we want to bias the choice so we use clr_eol
419      * rather than spaces at the end of a line.
420      */
421     if (back_color_erase)
422 	SP_PARM->_el_cost = 0;
423 
424     /* parameterized screen-update strings */
425     SP_PARM->_dch_cost = NormalizedCost(TIPARM_1(parm_dch, 23), 1);
426     SP_PARM->_ich_cost = NormalizedCost(TIPARM_1(parm_ich, 23), 1);
427     SP_PARM->_ech_cost = NormalizedCost(TIPARM_1(erase_chars, 23), 1);
428     SP_PARM->_rep_cost = NormalizedCost(TIPARM_2(repeat_char, ' ', 23), 1);
429 
430     SP_PARM->_cup_ch_cost = NormalizedCost(TIPARM_2(SP_PARM->_address_cursor,
431 						    23, 23),
432 					   1);
433     SP_PARM->_hpa_ch_cost = NormalizedCost(TIPARM_1(column_address, 23), 1);
434     SP_PARM->_cuf_ch_cost = NormalizedCost(TIPARM_1(parm_right_cursor, 23), 1);
435     SP_PARM->_inline_cost = min(SP_PARM->_cup_ch_cost,
436 				min(SP_PARM->_hpa_ch_cost,
437 				    SP_PARM->_cuf_ch_cost));
438 
439     /*
440      * If save_cursor is used within enter_ca_mode, we should not use it for
441      * scrolling optimization, since the corresponding restore_cursor is not
442      * nested on the various terminals (vt100, xterm, etc.) which use this
443      * feature.
444      */
445     if (save_cursor != 0
446 	&& enter_ca_mode != 0
447 	&& strstr(enter_ca_mode, save_cursor) != 0) {
448 	T(("...suppressed sc/rc capability due to conflict with smcup/rmcup"));
449 	save_cursor = 0;
450 	restore_cursor = 0;
451     }
452 
453     /*
454      * A different, possibly better way to arrange this would be to set the
455      * SCREEN's _endwin at window initialization time and let this be called by
456      * doupdate's return-from-shellout code.
457      */
458     NCURSES_SP_NAME(_nc_mvcur_resume) (NCURSES_SP_ARG);
459 }
460 
461 #if NCURSES_SP_FUNCS
462 NCURSES_EXPORT(void)
463 _nc_mvcur_init(void)
464 {
465     NCURSES_SP_NAME(_nc_mvcur_init) (CURRENT_SCREEN);
466 }
467 #endif
468 
469 NCURSES_EXPORT(void)
470 NCURSES_SP_NAME(_nc_mvcur_wrap) (NCURSES_SP_DCL0)
471 /* wrap up cursor-addressing mode */
472 {
473     /* leave cursor at screen bottom */
474     TINFO_MVCUR(NCURSES_SP_ARGx -1, -1, screen_lines(SP_PARM) - 1, 0);
475 
476     if (!SP_PARM || !IsTermInfo(SP_PARM))
477 	return;
478 
479     /* set cursor to normal mode */
480     if (SP_PARM->_cursor != -1) {
481 	int cursor = SP_PARM->_cursor;
482 	NCURSES_SP_NAME(curs_set) (NCURSES_SP_ARGx 1);
483 	SP_PARM->_cursor = cursor;
484     }
485 
486     if (exit_ca_mode) {
487 	NCURSES_PUTP2("exit_ca_mode", exit_ca_mode);
488     }
489     /*
490      * Reset terminal's tab counter.  There's a long-time bug that
491      * if you exit a "curses" program such as vi or more, tab
492      * forward, and then backspace, the cursor doesn't go to the
493      * right place.  The problem is that the kernel counts the
494      * escape sequences that reset things as column positions.
495      * Utter a \r to reset this invisibly.
496      */
497     NCURSES_SP_NAME(_nc_outch) (NCURSES_SP_ARGx '\r');
498 }
499 
500 #if NCURSES_SP_FUNCS
501 NCURSES_EXPORT(void)
502 _nc_mvcur_wrap(void)
503 {
504     NCURSES_SP_NAME(_nc_mvcur_wrap) (CURRENT_SCREEN);
505 }
506 #endif
507 
508 /****************************************************************************
509  *
510  * Optimized cursor movement
511  *
512  ****************************************************************************/
513 
514 /*
515  * Perform repeated-append, returning cost
516  */
517 static NCURSES_INLINE int
518 repeated_append(string_desc * target, int total, int num, int repeat, const char *src)
519 {
520     size_t need = (size_t) repeat * strlen(src);
521 
522     if (need < target->s_size) {
523 	while (repeat-- > 0) {
524 	    if (_nc_safe_strcat(target, src)) {
525 		total += num;
526 	    } else {
527 		total = INFINITY;
528 		break;
529 	    }
530 	}
531     } else {
532 	total = INFINITY;
533     }
534     return total;
535 }
536 
537 #ifndef NO_OPTIMIZE
538 #define NEXTTAB(fr)	(fr + init_tabs - (fr % init_tabs))
539 
540 /*
541  * Assume back_tab (CBT) does not wrap backwards at the left margin, return
542  * a negative value at that point to simplify the loop.
543  */
544 #define LASTTAB(fr)	((fr > 0) ? ((fr - 1) / init_tabs) * init_tabs : -1)
545 
546 static int
547 relative_move(NCURSES_SP_DCLx
548 	      string_desc * target,
549 	      int from_y,
550 	      int from_x,
551 	      int to_y,
552 	      int to_x,
553 	      int ovw)
554 /* move via local motions (cuu/cuu1/cud/cud1/cub1/cub/cuf1/cuf/vpa/hpa) */
555 {
556     string_desc save;
557     int n, vcost = 0, hcost = 0;
558 
559     (void) _nc_str_copy(&save, target);
560 
561     if (to_y != from_y) {
562 	vcost = INFINITY;
563 
564 	if (row_address != 0
565 	    && _nc_safe_strcat(target, TIPARM_1(row_address, to_y))) {
566 	    vcost = SP_PARM->_vpa_cost;
567 	}
568 
569 	if (to_y > from_y) {
570 	    n = (to_y - from_y);
571 
572 	    if (parm_down_cursor
573 		&& SP_PARM->_cud_cost < vcost
574 		&& _nc_safe_strcat(_nc_str_copy(target, &save),
575 				   TIPARM_1(parm_down_cursor, n))) {
576 		vcost = SP_PARM->_cud_cost;
577 	    }
578 
579 	    if (cursor_down
580 		&& (*cursor_down != '\n')
581 		&& (n * SP_PARM->_cud1_cost < vcost)) {
582 		vcost = repeated_append(_nc_str_copy(target, &save), 0,
583 					SP_PARM->_cud1_cost, n, cursor_down);
584 	    }
585 	} else {		/* (to_y < from_y) */
586 	    n = (from_y - to_y);
587 
588 	    if (parm_up_cursor
589 		&& SP_PARM->_cuu_cost < vcost
590 		&& _nc_safe_strcat(_nc_str_copy(target, &save),
591 				   TIPARM_1(parm_up_cursor, n))) {
592 		vcost = SP_PARM->_cuu_cost;
593 	    }
594 
595 	    if (cursor_up && (n * SP_PARM->_cuu1_cost < vcost)) {
596 		vcost = repeated_append(_nc_str_copy(target, &save), 0,
597 					SP_PARM->_cuu1_cost, n, cursor_up);
598 	    }
599 	}
600 
601 	if (vcost == INFINITY)
602 	    return (INFINITY);
603     }
604 
605     save = *target;
606 
607     if (to_x != from_x) {
608 	char str[OPT_SIZE];
609 	string_desc check;
610 
611 	hcost = INFINITY;
612 
613 	if (column_address
614 	    && _nc_safe_strcat(_nc_str_copy(target, &save),
615 			       TIPARM_1(column_address, to_x))) {
616 	    hcost = SP_PARM->_hpa_cost;
617 	}
618 
619 	if (to_x > from_x) {
620 	    n = to_x - from_x;
621 
622 	    if (parm_right_cursor
623 		&& SP_PARM->_cuf_cost < hcost
624 		&& _nc_safe_strcat(_nc_str_copy(target, &save),
625 				   TIPARM_1(parm_right_cursor, n))) {
626 		hcost = SP_PARM->_cuf_cost;
627 	    }
628 
629 	    if (cursor_right) {
630 		int lhcost = 0;
631 
632 		(void) _nc_str_init(&check, str, sizeof(str));
633 
634 #if USE_HARD_TABS
635 		/* use hard tabs, if we have them, to do as much as possible */
636 		if (init_tabs > 0 && tab) {
637 		    int nxt, fr;
638 
639 		    for (fr = from_x; (nxt = NEXTTAB(fr)) <= to_x; fr = nxt) {
640 			lhcost = repeated_append(&check, lhcost,
641 						 SP_PARM->_ht_cost, 1, tab);
642 			if (lhcost == INFINITY)
643 			    break;
644 		    }
645 
646 		    n = to_x - fr;
647 		    from_x = fr;
648 		}
649 #endif /* USE_HARD_TABS */
650 
651 		if (n <= 0 || n >= (int) check.s_size)
652 		    ovw = FALSE;
653 #if BSD_TPUTS
654 		/*
655 		 * If we're allowing BSD-style padding in tputs, don't generate
656 		 * a string with a leading digit.  Otherwise, that will be
657 		 * interpreted as a padding value rather than sent to the
658 		 * screen.
659 		 */
660 		if (ovw
661 		    && n > 0
662 		    && n < (int) check.s_size
663 		    && vcost == 0
664 		    && str[0] == '\0') {
665 		    int wanted = CharOf(WANT_CHAR(SP_PARM, to_y, from_x));
666 		    if (is8bits(wanted) && isdigit(wanted))
667 			ovw = FALSE;
668 		}
669 #endif
670 		/*
671 		 * If we have no attribute changes, overwrite is cheaper.
672 		 * Note: must suppress this by passing in ovw = FALSE whenever
673 		 * WANT_CHAR would return invalid data.  In particular, this
674 		 * is true between the time a hardware scroll has been done
675 		 * and the time the structure WANT_CHAR would access has been
676 		 * updated.
677 		 */
678 		if (ovw) {
679 		    int i;
680 
681 		    for (i = 0; i < n; i++) {
682 			NCURSES_CH_T ch = WANT_CHAR(SP_PARM, to_y, from_x + i);
683 			if (!SameAttrOf(ch, SCREEN_ATTRS(SP_PARM))
684 #if USE_WIDEC_SUPPORT
685 			    || !Charable(ch)
686 #endif
687 			    ) {
688 			    ovw = FALSE;
689 			    break;
690 			}
691 		    }
692 		}
693 		if (ovw) {
694 		    int i;
695 
696 		    for (i = 0; i < n; i++)
697 			*check.s_tail++ = (char) CharOf(WANT_CHAR(SP_PARM, to_y,
698 								  from_x + i));
699 		    *check.s_tail = '\0';
700 		    check.s_size -= (size_t) n;
701 		    lhcost += n * SP_PARM->_char_padding;
702 		} else {
703 		    lhcost = repeated_append(&check, lhcost, SP_PARM->_cuf1_cost,
704 					     n, cursor_right);
705 		}
706 
707 		if (lhcost < hcost
708 		    && _nc_safe_strcat(_nc_str_copy(target, &save), str)) {
709 		    hcost = lhcost;
710 		}
711 	    }
712 	} else {		/* (to_x < from_x) */
713 	    n = from_x - to_x;
714 
715 	    if (parm_left_cursor
716 		&& SP_PARM->_cub_cost < hcost
717 		&& _nc_safe_strcat(_nc_str_copy(target, &save),
718 				   TIPARM_1(parm_left_cursor, n))) {
719 		hcost = SP_PARM->_cub_cost;
720 	    }
721 
722 	    if (cursor_left) {
723 		int lhcost = 0;
724 
725 		(void) _nc_str_init(&check, str, sizeof(str));
726 
727 #if USE_HARD_TABS
728 		if (init_tabs > 0 && back_tab) {
729 		    int nxt, fr;
730 
731 		    for (fr = from_x; (nxt = LASTTAB(fr)) >= to_x; fr = nxt) {
732 			lhcost = repeated_append(&check, lhcost,
733 						 SP_PARM->_cbt_cost,
734 						 1, back_tab);
735 			if (lhcost == INFINITY)
736 			    break;
737 		    }
738 
739 		    n = fr - to_x;
740 		}
741 #endif /* USE_HARD_TABS */
742 
743 		lhcost = repeated_append(&check, lhcost,
744 					 SP_PARM->_cub1_cost,
745 					 n, cursor_left);
746 
747 		if (lhcost < hcost
748 		    && _nc_safe_strcat(_nc_str_copy(target, &save), str)) {
749 		    hcost = lhcost;
750 		}
751 	    }
752 	}
753 
754 	if (hcost == INFINITY)
755 	    return (INFINITY);
756     }
757 
758     return (vcost + hcost);
759 }
760 #endif /* !NO_OPTIMIZE */
761 
762 /*
763  * With the machinery set up above, it's conceivable that
764  * onscreen_mvcur could be modified into a recursive function that does
765  * an alpha-beta search of motion space, as though it were a chess
766  * move tree, with the weight function being boolean and the search
767  * depth equated to length of string.  However, this would jack up the
768  * computation cost a lot, especially on terminals without a cup
769  * capability constraining the search tree depth.  So we settle for
770  * the simpler method below.
771  */
772 
773 static NCURSES_INLINE int
774 onscreen_mvcur(NCURSES_SP_DCLx
775 	       int yold, int xold,
776 	       int ynew, int xnew, int ovw,
777 	       NCURSES_SP_OUTC myOutCh)
778 /* onscreen move from (yold, xold) to (ynew, xnew) */
779 {
780     string_desc result;
781     char buffer[OPT_SIZE];
782     int tactic = 0, newcost, usecost = INFINITY;
783     int t5_cr_cost;
784 
785 #if defined(MAIN) || defined(NCURSES_TEST)
786     struct timeval before, after;
787 
788     gettimeofday(&before, NULL);
789 #endif /* MAIN */
790 
791 #define NullResult _nc_str_null(&result, sizeof(buffer))
792 #define InitResult _nc_str_init(&result, buffer, sizeof(buffer))
793 
794     /* tactic #0: use direct cursor addressing */
795     if (_nc_safe_strcpy(InitResult, TIPARM_2(SP_PARM->_address_cursor,
796 					     ynew, xnew))) {
797 	tactic = 0;
798 	usecost = SP_PARM->_cup_cost;
799 
800 #if defined(TRACE) || defined(NCURSES_TEST)
801 	if (!(_nc_optimize_enable & OPTIMIZE_MVCUR))
802 	    goto nonlocal;
803 #endif /* TRACE */
804 
805 	/*
806 	 * We may be able to tell in advance that the full optimization
807 	 * will probably not be worth its overhead.  Also, don't try to
808 	 * use local movement if the current attribute is anything but
809 	 * A_NORMAL...there are just too many ways this can screw up
810 	 * (like, say, local-movement \n getting mapped to some obscure
811 	 * character because A_ALTCHARSET is on).
812 	 */
813 	if (yold == -1 || xold == -1 || NOT_LOCAL(SP_PARM, yold, xold, ynew, xnew)) {
814 #if defined(MAIN) || defined(NCURSES_TEST)
815 	    if (!profiling) {
816 		(void) fputs("nonlocal\n", stderr);
817 		goto nonlocal;	/* always run the optimizer if profiling */
818 	    }
819 #else
820 	    goto nonlocal;
821 #endif /* MAIN */
822 	}
823     }
824 #ifndef NO_OPTIMIZE
825     /* tactic #1: use local movement */
826     if (yold != -1 && xold != -1
827 	&& ((newcost = relative_move(NCURSES_SP_ARGx
828 				     NullResult,
829 				     yold, xold,
830 				     ynew, xnew, ovw)) != INFINITY)
831 	&& newcost < usecost) {
832 	tactic = 1;
833 	usecost = newcost;
834     }
835 
836     /* tactic #2: use carriage-return + local movement */
837     if (yold != -1 && carriage_return
838 	&& ((newcost = relative_move(NCURSES_SP_ARGx
839 				     NullResult,
840 				     yold, 0,
841 				     ynew, xnew, ovw)) != INFINITY)
842 	&& SP_PARM->_cr_cost + newcost < usecost) {
843 	tactic = 2;
844 	usecost = SP_PARM->_cr_cost + newcost;
845     }
846 
847     /* tactic #3: use home-cursor + local movement */
848     if (cursor_home
849 	&& ((newcost = relative_move(NCURSES_SP_ARGx
850 				     NullResult,
851 				     0, 0,
852 				     ynew, xnew, ovw)) != INFINITY)
853 	&& SP_PARM->_home_cost + newcost < usecost) {
854 	tactic = 3;
855 	usecost = SP_PARM->_home_cost + newcost;
856     }
857 
858     /* tactic #4: use home-down + local movement */
859     if (cursor_to_ll
860 	&& ((newcost = relative_move(NCURSES_SP_ARGx
861 				     NullResult,
862 				     screen_lines(SP_PARM) - 1, 0,
863 				     ynew, xnew, ovw)) != INFINITY)
864 	&& SP_PARM->_ll_cost + newcost < usecost) {
865 	tactic = 4;
866 	usecost = SP_PARM->_ll_cost + newcost;
867     }
868 
869     /*
870      * tactic #5: use left margin for wrap to right-hand side,
871      * unless strange wrap behavior indicated by xenl might hose us.
872      */
873     t5_cr_cost = (xold > 0 ? SP_PARM->_cr_cost : 0);
874     if (auto_left_margin && !eat_newline_glitch
875 	&& yold > 0 && cursor_left
876 	&& ((newcost = relative_move(NCURSES_SP_ARGx
877 				     NullResult,
878 				     yold - 1, screen_columns(SP_PARM) - 1,
879 				     ynew, xnew, ovw)) != INFINITY)
880 	&& t5_cr_cost + SP_PARM->_cub1_cost + newcost < usecost) {
881 	tactic = 5;
882 	usecost = t5_cr_cost + SP_PARM->_cub1_cost + newcost;
883     }
884 
885     /*
886      * These cases are ordered by estimated relative frequency.
887      */
888     if (tactic)
889 	InitResult;
890     switch (tactic) {
891     case 1:
892 	(void) relative_move(NCURSES_SP_ARGx
893 			     &result,
894 			     yold, xold,
895 			     ynew, xnew, ovw);
896 	break;
897     case 2:
898 	(void) _nc_safe_strcpy(&result, carriage_return);
899 	(void) relative_move(NCURSES_SP_ARGx
900 			     &result,
901 			     yold, 0,
902 			     ynew, xnew, ovw);
903 	break;
904     case 3:
905 	(void) _nc_safe_strcpy(&result, cursor_home);
906 	(void) relative_move(NCURSES_SP_ARGx
907 			     &result, 0, 0,
908 			     ynew, xnew, ovw);
909 	break;
910     case 4:
911 	(void) _nc_safe_strcpy(&result, cursor_to_ll);
912 	(void) relative_move(NCURSES_SP_ARGx
913 			     &result,
914 			     screen_lines(SP_PARM) - 1, 0,
915 			     ynew, xnew, ovw);
916 	break;
917     case 5:
918 	if (xold > 0)
919 	    (void) _nc_safe_strcat(&result, carriage_return);
920 	(void) _nc_safe_strcat(&result, cursor_left);
921 	(void) relative_move(NCURSES_SP_ARGx
922 			     &result,
923 			     yold - 1, screen_columns(SP_PARM) - 1,
924 			     ynew, xnew, ovw);
925 	break;
926     }
927 #endif /* !NO_OPTIMIZE */
928 
929   nonlocal:
930 #if defined(MAIN) || defined(NCURSES_TEST)
931     gettimeofday(&after, NULL);
932     diff = after.tv_usec - before.tv_usec
933 	+ (after.tv_sec - before.tv_sec) * 1000000;
934     if (!profiling)
935 	(void) fprintf(stderr,
936 		       "onscreen: %d microsec, %f 28.8Kbps char-equivalents\n",
937 		       (int) diff, diff / 288);
938 #endif /* MAIN */
939 
940     if (usecost != INFINITY) {
941 	TR(TRACE_MOVE, ("mvcur tactic %d", tactic));
942 	TPUTS_TRACE("mvcur");
943 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
944 				buffer, 1, myOutCh);
945 	SP_PARM->_cursrow = ynew;
946 	SP_PARM->_curscol = xnew;
947 	return (OK);
948     } else
949 	return (ERR);
950 }
951 
952 /*
953  * optimized cursor move from (yold, xold) to (ynew, xnew)
954  */
955 static int
956 _nc_real_mvcur(NCURSES_SP_DCLx
957 	       int yold, int xold,
958 	       int ynew, int xnew,
959 	       NCURSES_SP_OUTC myOutCh,
960 	       int ovw)
961 {
962     NCURSES_CH_T oldattr;
963     int code;
964 
965     TR(TRACE_CALLS | TRACE_MOVE, (T_CALLED("_nc_real_mvcur(%p,%d,%d,%d,%d)"),
966 				  (void *) SP_PARM, yold, xold, ynew, xnew));
967 
968     if (SP_PARM == 0) {
969 	code = ERR;
970     } else if (yold == ynew && xold == xnew) {
971 	code = OK;
972     } else {
973 
974 	/*
975 	 * Most work here is rounding for terminal boundaries getting the
976 	 * column position implied by wraparound or the lack thereof and
977 	 * rolling up the screen to get ynew on the screen.
978 	 */
979 	if (xnew >= screen_columns(SP_PARM)) {
980 	    ynew += xnew / screen_columns(SP_PARM);
981 	    xnew %= screen_columns(SP_PARM);
982 	}
983 
984 	/*
985 	 * Force restore even if msgr is on when we're in an alternate
986 	 * character set -- these have a strong tendency to screw up the CR &
987 	 * LF used for local character motions!
988 	 */
989 	oldattr = SCREEN_ATTRS(SP_PARM);
990 	if ((AttrOf(oldattr) & A_ALTCHARSET)
991 	    || (AttrOf(oldattr) && !move_standout_mode)) {
992 	    TR(TRACE_CHARPUT, ("turning off (%#lx) %s before move",
993 			       (unsigned long) AttrOf(oldattr),
994 			       _traceattr(AttrOf(oldattr))));
995 	    VIDPUTS(SP_PARM, A_NORMAL, 0);
996 	}
997 
998 	if (xold >= screen_columns(SP_PARM)) {
999 
1000 	    int l = (xold + 1) / screen_columns(SP_PARM);
1001 
1002 	    yold += l;
1003 	    if (yold >= screen_lines(SP_PARM))
1004 		l -= (yold - screen_lines(SP_PARM) - 1);
1005 
1006 	    if (l > 0) {
1007 		if (carriage_return) {
1008 		    NCURSES_PUTP2("carriage_return", carriage_return);
1009 		} else {
1010 		    myOutCh(NCURSES_SP_ARGx '\r');
1011 		}
1012 		xold = 0;
1013 
1014 		while (l > 0) {
1015 		    if (newline) {
1016 			NCURSES_PUTP2("newline", newline);
1017 		    } else {
1018 			myOutCh(NCURSES_SP_ARGx '\n');
1019 		    }
1020 		    l--;
1021 		}
1022 	    }
1023 	}
1024 
1025 	if (yold > screen_lines(SP_PARM) - 1)
1026 	    yold = screen_lines(SP_PARM) - 1;
1027 	if (ynew > screen_lines(SP_PARM) - 1)
1028 	    ynew = screen_lines(SP_PARM) - 1;
1029 
1030 	/* destination location is on screen now */
1031 	code = onscreen_mvcur(NCURSES_SP_ARGx yold, xold, ynew, xnew, ovw, myOutCh);
1032 
1033 	/*
1034 	 * Restore attributes if we disabled them before moving.
1035 	 */
1036 	if (!SameAttrOf(oldattr, SCREEN_ATTRS(SP_PARM))) {
1037 	    TR(TRACE_CHARPUT, ("turning on (%#lx) %s after move",
1038 			       (unsigned long) AttrOf(oldattr),
1039 			       _traceattr(AttrOf(oldattr))));
1040 	    VIDPUTS(SP_PARM, AttrOf(oldattr), GetPair(oldattr));
1041 	}
1042     }
1043     returnCode(code);
1044 }
1045 
1046 /*
1047  * These entrypoints are used within the library.
1048  */
1049 NCURSES_EXPORT(int)
1050 NCURSES_SP_NAME(_nc_mvcur) (NCURSES_SP_DCLx
1051 			    int yold, int xold,
1052 			    int ynew, int xnew)
1053 {
1054     int rc;
1055     rc = _nc_real_mvcur(NCURSES_SP_ARGx yold, xold, ynew, xnew,
1056 			NCURSES_SP_NAME(_nc_outch),
1057 			TRUE);
1058     /*
1059      * With the terminal-driver, we cannot distinguish between internal and
1060      * external calls.  Flush the output if the screen has not been
1061      * initialized, e.g., when used from low-level terminfo programs.
1062      */
1063     if ((SP_PARM != 0) && (SP_PARM->_endwin == ewInitial))
1064 	NCURSES_SP_NAME(_nc_flush) (NCURSES_SP_ARG);
1065     return rc;
1066 }
1067 
1068 #if NCURSES_SP_FUNCS
1069 NCURSES_EXPORT(int)
1070 _nc_mvcur(int yold, int xold,
1071 	  int ynew, int xnew)
1072 {
1073     return NCURSES_SP_NAME(_nc_mvcur) (CURRENT_SCREEN, yold, xold, ynew, xnew);
1074 }
1075 #endif
1076 
1077 #if defined(USE_TERM_DRIVER)
1078 /*
1079  * The terminal driver does not support the external "mvcur()".
1080  */
1081 NCURSES_EXPORT(int)
1082 TINFO_MVCUR(NCURSES_SP_DCLx int yold, int xold, int ynew, int xnew)
1083 {
1084     int rc;
1085     rc = _nc_real_mvcur(NCURSES_SP_ARGx
1086 			yold, xold,
1087 			ynew, xnew,
1088 			NCURSES_SP_NAME(_nc_outch),
1089 			TRUE);
1090     if ((SP_PARM != 0) && (SP_PARM->_endwin == ewInitial))
1091 	NCURSES_SP_NAME(_nc_flush) (NCURSES_SP_ARG);
1092     NCURSES_SP_NAME(_nc_flush) (NCURSES_SP_ARG);
1093     return rc;
1094 }
1095 
1096 #else /* !USE_TERM_DRIVER */
1097 
1098 /*
1099  * These entrypoints support users of the library.
1100  */
1101 NCURSES_EXPORT(int)
1102 NCURSES_SP_NAME(mvcur) (NCURSES_SP_DCLx int yold, int xold, int ynew,
1103 			int xnew)
1104 {
1105     return _nc_real_mvcur(NCURSES_SP_ARGx
1106 			  yold, xold,
1107 			  ynew, xnew,
1108 			  NCURSES_SP_NAME(_nc_putchar),
1109 			  FALSE);
1110 }
1111 
1112 #if NCURSES_SP_FUNCS
1113 NCURSES_EXPORT(int)
1114 mvcur(int yold, int xold, int ynew, int xnew)
1115 {
1116     return NCURSES_SP_NAME(mvcur) (CURRENT_SCREEN, yold, xold, ynew, xnew);
1117 }
1118 #endif
1119 #endif /* USE_TERM_DRIVER */
1120 
1121 #if defined(TRACE) || defined(NCURSES_TEST)
1122 NCURSES_EXPORT_VAR(int) _nc_optimize_enable = OPTIMIZE_ALL;
1123 #endif
1124 
1125 #if defined(MAIN) || defined(NCURSES_TEST)
1126 /****************************************************************************
1127  *
1128  * Movement optimizer test code
1129  *
1130  ****************************************************************************/
1131 
1132 #include <tic.h>
1133 #include <dump_entry.h>
1134 #include <time.h>
1135 
1136 NCURSES_EXPORT_VAR(const char *) _nc_progname = "mvcur";
1137 
1138 static unsigned long xmits;
1139 
1140 /* these override lib_tputs.c */
1141 NCURSES_EXPORT(int)
1142 tputs(const char *string, int affcnt GCC_UNUSED, int (*outc) (int) GCC_UNUSED)
1143 /* stub tputs() that dumps sequences in a visible form */
1144 {
1145     if (profiling)
1146 	xmits += strlen(string);
1147     else
1148 	(void) fputs(_nc_visbuf(string), stdout);
1149     return (OK);
1150 }
1151 
1152 NCURSES_EXPORT(int)
1153 putp(const char *string)
1154 {
1155     return (tputs(string, 1, _nc_outch));
1156 }
1157 
1158 NCURSES_EXPORT(int)
1159 _nc_outch(int ch)
1160 {
1161     putc(ch, stdout);
1162     return OK;
1163 }
1164 
1165 NCURSES_EXPORT(int)
1166 delay_output(int ms GCC_UNUSED)
1167 {
1168     return OK;
1169 }
1170 
1171 static char tname[PATH_MAX];
1172 
1173 static void
1174 load_term(void)
1175 {
1176     (void) setupterm(tname, STDOUT_FILENO, NULL);
1177 }
1178 
1179 static int
1180 roll(int n)
1181 {
1182     int i, j;
1183 
1184     i = (RAND_MAX / n) * n;
1185     while ((j = rand()) >= i)
1186 	continue;
1187     return (j % n);
1188 }
1189 
1190 int
1191 main(int argc GCC_UNUSED, char *argv[]GCC_UNUSED)
1192 {
1193     _nc_STRCPY(tname, getenv("TERM"), sizeof(tname));
1194     load_term();
1195     _nc_setupscreen(lines, columns, stdout, FALSE, 0);
1196     baudrate();
1197 
1198     _nc_mvcur_init();
1199 
1200     (void) puts("The mvcur tester.  Type ? for help");
1201 
1202     fputs("smcup:", stdout);
1203     putchar('\n');
1204 
1205     for (;;) {
1206 	int fy, fx, ty, tx, n, i;
1207 	char buf[BUFSIZ], capname[BUFSIZ];
1208 
1209 	if (fputs("> ", stdout) == EOF)
1210 	    break;
1211 	if (fgets(buf, sizeof(buf), stdin) == 0)
1212 	    break;
1213 
1214 #define PUTS(s)   (void) puts(s)
1215 #define PUTF(s,t) (void) printf(s,t)
1216 	if (buf[0] == '?') {
1217 	    PUTS("?                -- display this help message");
1218 	    PUTS("fy fx ty tx      -- (4 numbers) display (fy,fx)->(ty,tx) move");
1219 	    PUTS("s[croll] n t b m -- display scrolling sequence");
1220 	    PUTF("r[eload]         -- reload terminal info for %s\n",
1221 		 termname());
1222 	    PUTS("l[oad] <term>    -- load terminal info for type <term>");
1223 	    PUTS("d[elete] <cap>   -- delete named capability");
1224 	    PUTS("i[nspect]        -- display terminal capabilities");
1225 	    PUTS("c[ost]           -- dump cursor-optimization cost table");
1226 	    PUTS("o[optimize]      -- toggle movement optimization");
1227 	    PUTS("t[orture] <num>  -- torture-test with <num> random moves");
1228 	    PUTS("q[uit]           -- quit the program");
1229 	} else if (sscanf(buf, "%d %d %d %d", &fy, &fx, &ty, &tx) == 4) {
1230 	    struct timeval before, after;
1231 
1232 	    putchar('"');
1233 
1234 	    gettimeofday(&before, NULL);
1235 	    mvcur(fy, fx, ty, tx);
1236 	    gettimeofday(&after, NULL);
1237 
1238 	    printf("\" (%ld msec)\n",
1239 		   (long) (after.tv_usec - before.tv_usec
1240 			   + (after.tv_sec - before.tv_sec)
1241 			   * 1000000));
1242 	} else if (sscanf(buf, "s %d %d %d %d", &fy, &fx, &ty, &tx) == 4) {
1243 	    struct timeval before, after;
1244 
1245 	    putchar('"');
1246 
1247 	    gettimeofday(&before, NULL);
1248 	    _nc_scrolln(fy, fx, ty, tx);
1249 	    gettimeofday(&after, NULL);
1250 
1251 	    printf("\" (%ld msec)\n",
1252 		   (long) (after.tv_usec - before.tv_usec + (after.tv_sec -
1253 							     before.tv_sec)
1254 			   * 1000000));
1255 	} else if (buf[0] == 'r') {
1256 	    _nc_STRCPY(tname, termname(), sizeof(tname));
1257 	    load_term();
1258 	} else if (sscanf(buf, "l %s", tname) == 1) {
1259 	    load_term();
1260 	} else if (sscanf(buf, "d %s", capname) == 1) {
1261 	    struct name_table_entry const *np = _nc_find_entry(capname,
1262 							       _nc_get_hash_table(FALSE));
1263 
1264 	    if (np == NULL)
1265 		(void) printf("No such capability as \"%s\"\n", capname);
1266 	    else {
1267 		switch (np->nte_type) {
1268 		case BOOLEAN:
1269 		    cur_term->type.Booleans[np->nte_index] = FALSE;
1270 		    (void)
1271 			printf("Boolean capability `%s' (%d) turned off.\n",
1272 			       np->nte_name, np->nte_index);
1273 		    break;
1274 
1275 		case NUMBER:
1276 		    cur_term->type.Numbers[np->nte_index] = ABSENT_NUMERIC;
1277 		    (void) printf("Number capability `%s' (%d) set to -1.\n",
1278 				  np->nte_name, np->nte_index);
1279 		    break;
1280 
1281 		case STRING:
1282 		    cur_term->type.Strings[np->nte_index] = ABSENT_STRING;
1283 		    (void) printf("String capability `%s' (%d) deleted.\n",
1284 				  np->nte_name, np->nte_index);
1285 		    break;
1286 		}
1287 	    }
1288 	} else if (buf[0] == 'i') {
1289 	    dump_init(NULL, F_TERMINFO, S_TERMINFO,
1290 		      FALSE, 70, 0, 0, FALSE, FALSE, 0);
1291 	    dump_entry(&TerminalType(cur_term), FALSE, TRUE, 0, 0);
1292 	    putchar('\n');
1293 	} else if (buf[0] == 'o') {
1294 	    if (_nc_optimize_enable & OPTIMIZE_MVCUR) {
1295 		_nc_optimize_enable &= ~OPTIMIZE_MVCUR;
1296 		(void) puts("Optimization is now off.");
1297 	    } else {
1298 		_nc_optimize_enable |= OPTIMIZE_MVCUR;
1299 		(void) puts("Optimization is now on.");
1300 	    }
1301 	}
1302 	/*
1303 	 * You can use the `t' test to profile and tune the movement
1304 	 * optimizer.  Use iteration values in three digits or more.
1305 	 * At above 5000 iterations the profile timing averages are stable
1306 	 * to within a millisecond or three.
1307 	 *
1308 	 * The `overhead' field of the report will help you pick a
1309 	 * COMPUTE_OVERHEAD figure appropriate for your processor and
1310 	 * expected line speed.  The `total estimated time' is
1311 	 * computation time plus a character-transmission time
1312 	 * estimate computed from the number of transmits and the baud
1313 	 * rate.
1314 	 *
1315 	 * Use this together with the `o' command to get a read on the
1316 	 * optimizer's effectiveness.  Compare the total estimated times
1317 	 * for `t' runs of the same length in both optimized and un-optimized
1318 	 * modes.  As long as the optimized times are less, the optimizer
1319 	 * is winning.
1320 	 */
1321 	else if (sscanf(buf, "t %d", &n) == 1) {
1322 	    float cumtime = 0.0, perchar;
1323 	    int speeds[] =
1324 	    {2400, 9600, 14400, 19200, 28800, 38400, 0};
1325 
1326 	    srand((unsigned) (getpid() + time((time_t *) 0)));
1327 	    profiling = TRUE;
1328 	    xmits = 0;
1329 	    for (i = 0; i < n; i++) {
1330 		/*
1331 		 * This does a move test between two random locations,
1332 		 * Random moves probably short-change the optimizer,
1333 		 * which will work better on the short moves probably
1334 		 * typical of doupdate()'s usage pattern.  Still,
1335 		 * until we have better data...
1336 		 */
1337 #ifdef FIND_COREDUMP
1338 		int from_y = roll(lines);
1339 		int to_y = roll(lines);
1340 		int from_x = roll(columns);
1341 		int to_x = roll(columns);
1342 
1343 		printf("(%d,%d) -> (%d,%d)\n", from_y, from_x, to_y, to_x);
1344 		mvcur(from_y, from_x, to_y, to_x);
1345 #else
1346 		mvcur(roll(lines), roll(columns), roll(lines), roll(columns));
1347 #endif /* FIND_COREDUMP */
1348 		if (diff)
1349 		    cumtime += diff;
1350 	    }
1351 	    profiling = FALSE;
1352 
1353 	    /*
1354 	     * Average milliseconds per character optimization time.
1355 	     * This is the key figure to watch when tuning the optimizer.
1356 	     */
1357 	    perchar = cumtime / n;
1358 
1359 	    (void) printf("%d moves (%ld chars) in %d msec, %f msec each:\n",
1360 			  n, xmits, (int) cumtime, perchar);
1361 
1362 	    for (i = 0; speeds[i]; i++) {
1363 		/*
1364 		 * Total estimated time for the moves, computation and
1365 		 * transmission both. Transmission time is an estimate
1366 		 * assuming 9 bits/char, 8 bits + 1 stop bit.
1367 		 */
1368 		float totalest = cumtime + xmits * 9 * 1e6 / speeds[i];
1369 
1370 		/*
1371 		 * Per-character optimization overhead in character transmits
1372 		 * at the current speed.  Round this to the nearest integer
1373 		 * to figure COMPUTE_OVERHEAD for the speed.
1374 		 */
1375 		float overhead = speeds[i] * perchar / 1e6;
1376 
1377 		(void)
1378 		    printf("%6d bps: %3.2f char-xmits overhead; total estimated time %15.2f\n",
1379 			   speeds[i], overhead, totalest);
1380 	    }
1381 	} else if (buf[0] == 'c') {
1382 	    (void) printf("char padding: %d\n", CURRENT_SCREEN->_char_padding);
1383 	    (void) printf("cr cost: %d\n", CURRENT_SCREEN->_cr_cost);
1384 	    (void) printf("cup cost: %d\n", CURRENT_SCREEN->_cup_cost);
1385 	    (void) printf("home cost: %d\n", CURRENT_SCREEN->_home_cost);
1386 	    (void) printf("ll cost: %d\n", CURRENT_SCREEN->_ll_cost);
1387 #if USE_HARD_TABS
1388 	    (void) printf("ht cost: %d\n", CURRENT_SCREEN->_ht_cost);
1389 	    (void) printf("cbt cost: %d\n", CURRENT_SCREEN->_cbt_cost);
1390 #endif /* USE_HARD_TABS */
1391 	    (void) printf("cub1 cost: %d\n", CURRENT_SCREEN->_cub1_cost);
1392 	    (void) printf("cuf1 cost: %d\n", CURRENT_SCREEN->_cuf1_cost);
1393 	    (void) printf("cud1 cost: %d\n", CURRENT_SCREEN->_cud1_cost);
1394 	    (void) printf("cuu1 cost: %d\n", CURRENT_SCREEN->_cuu1_cost);
1395 	    (void) printf("cub cost: %d\n", CURRENT_SCREEN->_cub_cost);
1396 	    (void) printf("cuf cost: %d\n", CURRENT_SCREEN->_cuf_cost);
1397 	    (void) printf("cud cost: %d\n", CURRENT_SCREEN->_cud_cost);
1398 	    (void) printf("cuu cost: %d\n", CURRENT_SCREEN->_cuu_cost);
1399 	    (void) printf("hpa cost: %d\n", CURRENT_SCREEN->_hpa_cost);
1400 	    (void) printf("vpa cost: %d\n", CURRENT_SCREEN->_vpa_cost);
1401 	} else if (buf[0] == 'x' || buf[0] == 'q')
1402 	    break;
1403 	else
1404 	    (void) puts("Invalid command.");
1405     }
1406 
1407     (void) fputs("rmcup:", stdout);
1408     _nc_mvcur_wrap();
1409     putchar('\n');
1410 
1411     return (0);
1412 }
1413 
1414 #endif /* MAIN */
1415 
1416 /* lib_mvcur.c ends here */
1417