1 /*	$OpenBSD: screen.c,v 1.11 2003/06/03 03:01:41 millert Exp $	*/
2 /*	$NetBSD: screen.c,v 1.4 1995/04/29 01:11:36 mycroft Exp $	*/
3 
4 /*-
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Chris Torek and Darren F. Provine.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)screen.c	8.1 (Berkeley) 5/31/93
36  */
37 
38 /*
39  * Tetris screen control.
40  */
41 
42 #include <sys/ioctl.h>
43 
44 #include <err.h>
45 #include <setjmp.h>
46 #include <signal.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <term.h>
51 #include <termios.h>
52 #include <unistd.h>
53 
54 #include "screen.h"
55 #include "tetris.h"
56 
57 static cell curscreen[B_SIZE];	/* 1 => standout (or otherwise marked) */
58 static int curscore;
59 static int isset;		/* true => terminal is in game mode */
60 static struct termios oldtt;
61 static void (*tstp)(int);
62 
63 static void	scr_stop(int);
64 static void	stopset(int);
65 
66 /*
67  * Capabilities from TERMCAP.
68  */
69 char	PC, *BC, *UP;		/* tgoto requires globals: ugh! */
70 
71 static char
72 	*bcstr,			/* backspace char */
73 	*CEstr,			/* clear to end of line */
74 	*CLstr,			/* clear screen */
75 	*CMstr,			/* cursor motion string */
76 #ifdef unneeded
77 	*CRstr,			/* "\r" equivalent */
78 #endif
79 	*HOstr,			/* cursor home */
80 	*LLstr,			/* last line, first column */
81 	*pcstr,			/* pad character */
82 	*TEstr,			/* end cursor motion mode */
83 	*TIstr;			/* begin cursor motion mode */
84 char
85 	*SEstr,			/* end standout mode */
86 	*SOstr;			/* begin standout mode */
87 static int
88 	COnum,			/* co# value */
89 	LInum,			/* li# value */
90 	MSflag;			/* can move in standout mode */
91 
92 
93 struct tcsinfo {		/* termcap string info; some abbrevs above */
94 	char tcname[3];
95 	char **tcaddr;
96 } tcstrings[] = {
97 	{"bc", &bcstr},
98 	{"ce", &CEstr},
99 	{"cl", &CLstr},
100 	{"cm", &CMstr},
101 #ifdef unneeded
102 	{"cr", &CRstr},
103 #endif
104 	{"le", &BC},		/* move cursor left one space */
105 	{"pc", &pcstr},
106 	{"se", &SEstr},
107 	{"so", &SOstr},
108 	{"te", &TEstr},
109 	{"ti", &TIstr},
110 	{"up", &UP},		/* cursor up */
111 	{ {0}, NULL}
112 };
113 
114 /* This is where we will actually stuff the information */
115 
116 static char combuf[1024], tbuf[1024];
117 
118 
119 /*
120  * Routine used by tputs().
121  */
122 int
put(c)123 put(c)
124 	int c;
125 {
126 
127 	return (putchar(c));
128 }
129 
130 /*
131  * putstr() is for unpadded strings (either as in termcap(5) or
132  * simply literal strings); putpad() is for padded strings with
133  * count=1.  (See screen.h for putpad().)
134  */
135 #define	putstr(s)	(void)fputs(s, stdout)
136 #define	moveto(r, c)	putpad(tgoto(CMstr, c, r))
137 
138 /*
139  * Set up from termcap.
140  */
141 void
scr_init()142 scr_init()
143 {
144 	static int bsflag, xsflag, sgnum;
145 #ifdef unneeded
146 	static int ncflag;
147 #endif
148 	char *term, *fill;
149 	static struct tcninfo {	/* termcap numeric and flag info */
150 		char tcname[3];
151 		int *tcaddr;
152 	} tcflags[] = {
153 		{"bs", &bsflag},
154 		{"ms", &MSflag},
155 #ifdef unneeded
156 		{"nc", &ncflag},
157 #endif
158 		{"xs", &xsflag},
159 		{ {0}, NULL}
160 	}, tcnums[] = {
161 		{"co", &COnum},
162 		{"li", &LInum},
163 		{"sg", &sgnum},
164 		{ {0}, NULL}
165 	};
166 
167 	if ((term = getenv("TERM")) == NULL)
168 		stop("you must set the TERM environment variable");
169 	if (tgetent(tbuf, term) <= 0)
170 		stop("cannot find your termcap");
171 	fill = combuf;
172 	{
173 		struct tcsinfo *p;
174 
175 		for (p = tcstrings; p->tcaddr; p++)
176 			*p->tcaddr = tgetstr(p->tcname, &fill);
177 	}
178 	if (classic)
179 		SOstr = SEstr = NULL;
180 	{
181 		struct tcninfo *p;
182 
183 		for (p = tcflags; p->tcaddr; p++)
184 			*p->tcaddr = tgetflag(p->tcname);
185 		for (p = tcnums; p->tcaddr; p++)
186 			*p->tcaddr = tgetnum(p->tcname);
187 	}
188 	if (bsflag)
189 		BC = "\b";
190 	else if (BC == NULL && bcstr != NULL)
191 		BC = bcstr;
192 	if (CLstr == NULL)
193 		stop("cannot clear screen");
194 	if (CMstr == NULL || UP == NULL || BC == NULL)
195 		stop("cannot do random cursor positioning via tgoto()");
196 	PC = pcstr ? *pcstr : 0;
197 	if (sgnum > 0 || xsflag)
198 		SOstr = SEstr = NULL;
199 #ifdef unneeded
200 	if (ncflag)
201 		CRstr = NULL;
202 	else if (CRstr == NULL)
203 		CRstr = "\r";
204 #endif
205 }
206 
207 /* this foolery is needed to modify tty state `atomically' */
208 static jmp_buf scr_onstop;
209 
210 static void
stopset(sig)211 stopset(sig)
212 	int sig;
213 {
214 	sigset_t sigset;
215 
216 	(void) signal(sig, SIG_DFL);
217 	(void) kill(getpid(), sig);
218 	sigemptyset(&sigset);
219 	sigaddset(&sigset, sig);
220 	(void) sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *)0);
221 	longjmp(scr_onstop, 1);
222 }
223 
224 static void
scr_stop(sig)225 scr_stop(sig)
226 	int sig;
227 {
228 	sigset_t sigset;
229 
230 	scr_end();
231 	(void) kill(getpid(), sig);
232 	sigemptyset(&sigset);
233 	sigaddset(&sigset, sig);
234 	(void) sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *)0);
235 	scr_set();
236 	scr_msg(key_msg, 1);
237 }
238 
239 /*
240  * Set up screen mode.
241  */
242 void
scr_set()243 scr_set()
244 {
245 	struct winsize ws;
246 	struct termios newtt;
247 	sigset_t sigset, osigset;
248 	void (*ttou)(int);
249 
250 	sigemptyset(&sigset);
251 	sigaddset(&sigset, SIGTSTP);
252 	sigaddset(&sigset, SIGTTOU);
253 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
254 	if ((tstp = signal(SIGTSTP, stopset)) == SIG_IGN)
255 		(void) signal(SIGTSTP, SIG_IGN);
256 	if ((ttou = signal(SIGTTOU, stopset)) == SIG_IGN)
257 		(void) signal(SIGTTOU, SIG_IGN);
258 	/*
259 	 * At last, we are ready to modify the tty state.  If
260 	 * we stop while at it, stopset() above will longjmp back
261 	 * to the setjmp here and we will start over.
262 	 */
263 	(void) setjmp(scr_onstop);
264 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
265 	Rows = 0, Cols = 0;
266 	if (ioctl(0, TIOCGWINSZ, &ws) == 0) {
267 		Rows = ws.ws_row;
268 		Cols = ws.ws_col;
269 	}
270 	if (Rows == 0)
271 		Rows = LInum;
272 	if (Cols == 0)
273 	Cols = COnum;
274 	if (Rows < MINROWS || Cols < MINCOLS) {
275 		char smallscr[55];
276 
277 		(void) snprintf(smallscr, 55,
278 		    "the screen is too small (must be at least %dx%d)",
279 		    MINROWS, MINCOLS);
280 		stop(smallscr);
281 	}
282 	if (tcgetattr(0, &oldtt) < 0)
283 		stop("tcgetattr() fails");
284 	newtt = oldtt;
285 	newtt.c_lflag &= ~(ICANON|ECHO);
286 	newtt.c_oflag &= ~OXTABS;
287 	if (tcsetattr(0, TCSADRAIN, &newtt) < 0)
288 		stop("tcsetattr() fails");
289 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
290 
291 	/*
292 	 * We made it.  We are now in screen mode, modulo TIstr
293 	 * (which we will fix immediately).
294 	 */
295 	if (TIstr)
296 		putstr(TIstr);	/* termcap(5) says this is not padded */
297 	if (tstp != SIG_IGN)
298 		(void) signal(SIGTSTP, scr_stop);
299 	if (ttou != SIG_IGN)
300 		(void) signal(SIGTTOU, ttou);
301 
302 	isset = 1;
303 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
304 	scr_clear();
305 }
306 
307 /*
308  * End screen mode.
309  */
310 void
scr_end()311 scr_end()
312 {
313 	sigset_t sigset, osigset;
314 
315 	sigemptyset(&sigset);
316 	sigaddset(&sigset, SIGTSTP);
317 	sigaddset(&sigset, SIGTTOU);
318 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
319 	/* move cursor to last line */
320 	if (LLstr)
321 		putstr(LLstr);	/* termcap(5) says this is not padded */
322 	else
323 		moveto(Rows - 1, 0);
324 	/* exit screen mode */
325 	if (TEstr)
326 		putstr(TEstr);	/* termcap(5) says this is not padded */
327 	(void) fflush(stdout);
328 	(void) tcsetattr(0, TCSADRAIN, &oldtt);
329 	isset = 0;
330 	/* restore signals */
331 	(void) signal(SIGTSTP, tstp);
332 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
333 }
334 
335 void
stop(why)336 stop(why)
337 	char *why;
338 {
339 
340 	if (isset)
341 		scr_end();
342 	errx(1, "aborting: %s", why);
343 }
344 
345 /*
346  * Clear the screen, forgetting the current contents in the process.
347  */
348 void
scr_clear()349 scr_clear()
350 {
351 
352 	putpad(CLstr);
353 	curscore = -1;
354 	memset((char *)curscreen, 0, sizeof(curscreen));
355 }
356 
357 #if vax && !__GNUC__
358 typedef int regcell;	/* pcc is bad at `register char', etc */
359 #else
360 typedef cell regcell;
361 #endif
362 
363 /*
364  * Update the screen.
365  */
366 void
scr_update()367 scr_update()
368 {
369 	cell *bp, *sp;
370 	regcell so, cur_so = 0;
371 	int i, ccol, j;
372 	sigset_t sigset, osigset;
373 	static const struct shape *lastshape;
374 
375 	sigemptyset(&sigset);
376 	sigaddset(&sigset, SIGTSTP);
377 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
378 
379 	/* always leave cursor after last displayed point */
380 	curscreen[D_LAST * B_COLS - 1] = -1;
381 
382 	if (score != curscore) {
383 		if (HOstr)
384 			putpad(HOstr);
385 		else
386 			moveto(0, 0);
387 		(void) printf("Score: %d", score);
388 		curscore = score;
389 	}
390 
391 	/* draw preview of next pattern */
392 	if (showpreview && (nextshape != lastshape)) {
393 		int i;
394 		static int r=5, c=2;
395 		int tr, tc, t;
396 
397 		lastshape = nextshape;
398 
399 		/* clean */
400 		putpad(SEstr);
401 		moveto(r-1, c-1); putstr("          ");
402 		moveto(r,   c-1); putstr("          ");
403 		moveto(r+1, c-1); putstr("          ");
404 		moveto(r+2, c-1); putstr("          ");
405 
406 		moveto(r-3, c-2);
407 		putstr("Next shape:");
408 
409 		/* draw */
410 		if (SOstr)
411 			putpad(SOstr);
412 		moveto(r, 2 * c);
413 		putstr(SOstr ? "  " : "[]");
414 		for (i = 0; i < 3; i++) {
415 			t = c + r * B_COLS;
416 			t += nextshape->off[i];
417 
418 			tr = t / B_COLS;
419 			tc = t % B_COLS;
420 
421 			moveto(tr, 2*tc);
422 			putstr(SOstr ? "  " : "[]");
423 		}
424 		putpad(SEstr);
425 	}
426 
427 	bp = &board[D_FIRST * B_COLS];
428 	sp = &curscreen[D_FIRST * B_COLS];
429 	for (j = D_FIRST; j < D_LAST; j++) {
430 		ccol = -1;
431 		for (i = 0; i < B_COLS; bp++, sp++, i++) {
432 			if (*sp == (so = *bp))
433 				continue;
434 			*sp = so;
435 			if (i != ccol) {
436 				if (cur_so && MSflag) {
437 					putpad(SEstr);
438 					cur_so = 0;
439 				}
440 				moveto(RTOD(j), CTOD(i));
441 			}
442 			if (SOstr) {
443 				if (so != cur_so) {
444 					putpad(so ? SOstr : SEstr);
445 					cur_so = so;
446 				}
447 				putstr("  ");
448 			} else
449 				putstr(so ? "[]" : "  ");
450 			ccol = i + 1;
451 			/*
452 			 * Look ahead a bit, to avoid extra motion if
453 			 * we will be redrawing the cell after the next.
454 			 * Motion probably takes four or more characters,
455 			 * so we save even if we rewrite two cells
456 			 * `unnecessarily'.  Skip it all, though, if
457 			 * the next cell is a different color.
458 			 */
459 #define	STOP (B_COLS - 3)
460 			if (i > STOP || sp[1] != bp[1] || so != bp[1])
461 				continue;
462 			if (sp[2] != bp[2])
463 				sp[1] = -1;
464 			else if (i < STOP && so == bp[2] && sp[3] != bp[3]) {
465 				sp[2] = -1;
466 				sp[1] = -1;
467 			}
468 		}
469 	}
470 	if (cur_so)
471 		putpad(SEstr);
472 	(void) fflush(stdout);
473 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
474 }
475 
476 /*
477  * Write a message (set!=0), or clear the same message (set==0).
478  * (We need its length in case we have to overwrite with blanks.)
479  */
480 void
scr_msg(s,set)481 scr_msg(s, set)
482 	char *s;
483 	int set;
484 {
485 
486 	if (set || CEstr == NULL) {
487 		int l = strlen(s);
488 
489 		moveto(Rows - 2, ((Cols - l) >> 1) - 1);
490 		if (set)
491 			putstr(s);
492 		else
493 			while (--l >= 0)
494 				(void) putchar(' ');
495 	} else {
496 		moveto(Rows - 2, 0);
497 		putpad(CEstr);
498 	}
499 }
500