xref: /openbsd/games/tetris/screen.c (revision 8932bfb7)
1 /*	$OpenBSD: screen.c,v 1.14 2011/04/03 10:25:59 dcoppa 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 	*VIstr,			/* make cursor invisible */
85 	*VEstr;			/* make cursor appear normal */
86 char
87 	*SEstr,			/* end standout mode */
88 	*SOstr;			/* begin standout mode */
89 static int
90 	COnum,			/* co# value */
91 	LInum,			/* li# value */
92 	MSflag;			/* can move in standout mode */
93 
94 
95 struct tcsinfo {		/* termcap string info; some abbrevs above */
96 	char tcname[3];
97 	char **tcaddr;
98 } tcstrings[] = {
99 	{"bc", &bcstr},
100 	{"ce", &CEstr},
101 	{"cl", &CLstr},
102 	{"cm", &CMstr},
103 #ifdef unneeded
104 	{"cr", &CRstr},
105 #endif
106 	{"le", &BC},		/* move cursor left one space */
107 	{"pc", &pcstr},
108 	{"se", &SEstr},
109 	{"so", &SOstr},
110 	{"te", &TEstr},
111 	{"ti", &TIstr},
112 	{"vi", &VIstr},
113 	{"ve", &VEstr},
114 	{"up", &UP},		/* cursor up */
115 	{ {0}, NULL}
116 };
117 
118 /* This is where we will actually stuff the information */
119 
120 static char combuf[1024], tbuf[1024];
121 
122 
123 /*
124  * Routine used by tputs().
125  */
126 int
127 put(int c)
128 {
129 
130 	return (putchar(c));
131 }
132 
133 /*
134  * putstr() is for unpadded strings (either as in termcap(5) or
135  * simply literal strings); putpad() is for padded strings with
136  * count=1.  (See screen.h for putpad().)
137  */
138 #define	putstr(s)	(void)fputs(s, stdout)
139 #define	moveto(r, c)	putpad(tgoto(CMstr, c, r))
140 
141 /*
142  * Set up from termcap.
143  */
144 void
145 scr_init(void)
146 {
147 	static int bsflag, xsflag, sgnum;
148 #ifdef unneeded
149 	static int ncflag;
150 #endif
151 	char *term, *fill;
152 	static struct tcninfo {	/* termcap numeric and flag info */
153 		char tcname[3];
154 		int *tcaddr;
155 	} tcflags[] = {
156 		{"bs", &bsflag},
157 		{"ms", &MSflag},
158 #ifdef unneeded
159 		{"nc", &ncflag},
160 #endif
161 		{"xs", &xsflag},
162 		{ {0}, NULL}
163 	}, tcnums[] = {
164 		{"co", &COnum},
165 		{"li", &LInum},
166 		{"sg", &sgnum},
167 		{ {0}, NULL}
168 	};
169 
170 	if ((term = getenv("TERM")) == NULL)
171 		stop("you must set the TERM environment variable");
172 	if (tgetent(tbuf, term) <= 0)
173 		stop("cannot find your termcap");
174 	fill = combuf;
175 	{
176 		struct tcsinfo *p;
177 
178 		for (p = tcstrings; p->tcaddr; p++)
179 			*p->tcaddr = tgetstr(p->tcname, &fill);
180 	}
181 	if (classic)
182 		SOstr = SEstr = NULL;
183 	{
184 		struct tcninfo *p;
185 
186 		for (p = tcflags; p->tcaddr; p++)
187 			*p->tcaddr = tgetflag(p->tcname);
188 		for (p = tcnums; p->tcaddr; p++)
189 			*p->tcaddr = tgetnum(p->tcname);
190 	}
191 	if (bsflag)
192 		BC = "\b";
193 	else if (BC == NULL && bcstr != NULL)
194 		BC = bcstr;
195 	if (CLstr == NULL)
196 		stop("cannot clear screen");
197 	if (CMstr == NULL || UP == NULL || BC == NULL)
198 		stop("cannot do random cursor positioning via tgoto()");
199 	PC = pcstr ? *pcstr : 0;
200 	if (sgnum > 0 || xsflag)
201 		SOstr = SEstr = NULL;
202 #ifdef unneeded
203 	if (ncflag)
204 		CRstr = NULL;
205 	else if (CRstr == NULL)
206 		CRstr = "\r";
207 #endif
208 }
209 
210 /* this foolery is needed to modify tty state `atomically' */
211 static jmp_buf scr_onstop;
212 
213 static void
214 stopset(int sig)
215 {
216 	sigset_t sigset;
217 
218 	(void) signal(sig, SIG_DFL);
219 	(void) kill(getpid(), sig);
220 	sigemptyset(&sigset);
221 	sigaddset(&sigset, sig);
222 	(void) sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *)0);
223 	longjmp(scr_onstop, 1);
224 }
225 
226 static void
227 scr_stop(int sig)
228 {
229 	sigset_t sigset;
230 
231 	scr_end();
232 	(void) kill(getpid(), sig);
233 	sigemptyset(&sigset);
234 	sigaddset(&sigset, sig);
235 	(void) sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *)0);
236 	scr_set();
237 	scr_msg(key_msg, 1);
238 }
239 
240 /*
241  * Set up screen mode.
242  */
243 void
244 scr_set(void)
245 {
246 	struct winsize ws;
247 	struct termios newtt;
248 	sigset_t sigset, osigset;
249 	void (*ttou)(int);
250 
251 	sigemptyset(&sigset);
252 	sigaddset(&sigset, SIGTSTP);
253 	sigaddset(&sigset, SIGTTOU);
254 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
255 	if ((tstp = signal(SIGTSTP, stopset)) == SIG_IGN)
256 		(void) signal(SIGTSTP, SIG_IGN);
257 	if ((ttou = signal(SIGTTOU, stopset)) == SIG_IGN)
258 		(void) signal(SIGTTOU, SIG_IGN);
259 	/*
260 	 * At last, we are ready to modify the tty state.  If
261 	 * we stop while at it, stopset() above will longjmp back
262 	 * to the setjmp here and we will start over.
263 	 */
264 	(void) setjmp(scr_onstop);
265 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
266 	Rows = 0, Cols = 0;
267 	if (ioctl(0, TIOCGWINSZ, &ws) == 0) {
268 		Rows = ws.ws_row;
269 		Cols = ws.ws_col;
270 	}
271 	if (Rows == 0)
272 		Rows = LInum;
273 	if (Cols == 0)
274 	Cols = COnum;
275 	if (Rows < MINROWS || Cols < MINCOLS) {
276 		char smallscr[55];
277 
278 		(void)snprintf(smallscr, sizeof(smallscr),
279 		    "the screen is too small (must be at least %dx%d)",
280 		    MINROWS, MINCOLS);
281 		stop(smallscr);
282 	}
283 	if (tcgetattr(0, &oldtt) < 0)
284 		stop("tcgetattr() fails");
285 	newtt = oldtt;
286 	newtt.c_lflag &= ~(ICANON|ECHO);
287 	newtt.c_oflag &= ~OXTABS;
288 	if (tcsetattr(0, TCSADRAIN, &newtt) < 0)
289 		stop("tcsetattr() fails");
290 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
291 
292 	/*
293 	 * We made it.  We are now in screen mode, modulo TIstr
294 	 * (which we will fix immediately).
295 	 */
296 	if (TIstr)
297 		putstr(TIstr);	/* termcap(5) says this is not padded */
298 	if (VIstr)
299 		putstr(VIstr);	/* termcap(5) says this is not padded */
300 	if (tstp != SIG_IGN)
301 		(void) signal(SIGTSTP, scr_stop);
302 	if (ttou != SIG_IGN)
303 		(void) signal(SIGTTOU, ttou);
304 
305 	isset = 1;
306 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
307 	scr_clear();
308 }
309 
310 /*
311  * End screen mode.
312  */
313 void
314 scr_end(void)
315 {
316 	sigset_t sigset, osigset;
317 
318 	sigemptyset(&sigset);
319 	sigaddset(&sigset, SIGTSTP);
320 	sigaddset(&sigset, SIGTTOU);
321 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
322 	/* move cursor to last line */
323 	if (LLstr)
324 		putstr(LLstr);	/* termcap(5) says this is not padded */
325 	else
326 		moveto(Rows - 1, 0);
327 	/* exit screen mode */
328 	if (TEstr)
329 		putstr(TEstr);	/* termcap(5) says this is not padded */
330 	if (VEstr)
331 		putstr(VEstr);	/* termcap(5) says this is not padded */
332 	(void) fflush(stdout);
333 	(void) tcsetattr(0, TCSADRAIN, &oldtt);
334 	isset = 0;
335 	/* restore signals */
336 	(void) signal(SIGTSTP, tstp);
337 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
338 }
339 
340 void
341 stop(char *why)
342 {
343 
344 	if (isset)
345 		scr_end();
346 	errx(1, "aborting: %s", why);
347 }
348 
349 /*
350  * Clear the screen, forgetting the current contents in the process.
351  */
352 void
353 scr_clear(void)
354 {
355 
356 	putpad(CLstr);
357 	curscore = -1;
358 	memset((char *)curscreen, 0, sizeof(curscreen));
359 }
360 
361 #if vax && !__GNUC__
362 typedef int regcell;	/* pcc is bad at `register char', etc */
363 #else
364 typedef cell regcell;
365 #endif
366 
367 /*
368  * Update the screen.
369  */
370 void
371 scr_update(void)
372 {
373 	cell *bp, *sp;
374 	regcell so, cur_so = 0;
375 	int i, ccol, j;
376 	sigset_t sigset, osigset;
377 	static const struct shape *lastshape;
378 
379 	sigemptyset(&sigset);
380 	sigaddset(&sigset, SIGTSTP);
381 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
382 
383 	/* always leave cursor after last displayed point */
384 	curscreen[D_LAST * B_COLS - 1] = -1;
385 
386 	if (score != curscore) {
387 		if (HOstr)
388 			putpad(HOstr);
389 		else
390 			moveto(0, 0);
391 		(void) printf("Score: %d", score);
392 		curscore = score;
393 	}
394 
395 	/* draw preview of next pattern */
396 	if (showpreview && (nextshape != lastshape)) {
397 		int i;
398 		static int r=5, c=2;
399 		int tr, tc, t;
400 
401 		lastshape = nextshape;
402 
403 		/* clean */
404 		putpad(SEstr);
405 		moveto(r-1, c-1); putstr("          ");
406 		moveto(r,   c-1); putstr("          ");
407 		moveto(r+1, c-1); putstr("          ");
408 		moveto(r+2, c-1); putstr("          ");
409 
410 		moveto(r-3, c-2);
411 		putstr("Next shape:");
412 
413 		/* draw */
414 		if (SOstr)
415 			putpad(SOstr);
416 		moveto(r, 2 * c);
417 		putstr(SOstr ? "  " : "[]");
418 		for (i = 0; i < 3; i++) {
419 			t = c + r * B_COLS;
420 			t += nextshape->off[i];
421 
422 			tr = t / B_COLS;
423 			tc = t % B_COLS;
424 
425 			moveto(tr, 2*tc);
426 			putstr(SOstr ? "  " : "[]");
427 		}
428 		putpad(SEstr);
429 	}
430 
431 	bp = &board[D_FIRST * B_COLS];
432 	sp = &curscreen[D_FIRST * B_COLS];
433 	for (j = D_FIRST; j < D_LAST; j++) {
434 		ccol = -1;
435 		for (i = 0; i < B_COLS; bp++, sp++, i++) {
436 			if (*sp == (so = *bp))
437 				continue;
438 			*sp = so;
439 			if (i != ccol) {
440 				if (cur_so && MSflag) {
441 					putpad(SEstr);
442 					cur_so = 0;
443 				}
444 				moveto(RTOD(j), CTOD(i));
445 			}
446 			if (SOstr) {
447 				if (so != cur_so) {
448 					putpad(so ? SOstr : SEstr);
449 					cur_so = so;
450 				}
451 				putstr("  ");
452 			} else
453 				putstr(so ? "[]" : "  ");
454 			ccol = i + 1;
455 			/*
456 			 * Look ahead a bit, to avoid extra motion if
457 			 * we will be redrawing the cell after the next.
458 			 * Motion probably takes four or more characters,
459 			 * so we save even if we rewrite two cells
460 			 * `unnecessarily'.  Skip it all, though, if
461 			 * the next cell is a different color.
462 			 */
463 #define	STOP (B_COLS - 3)
464 			if (i > STOP || sp[1] != bp[1] || so != bp[1])
465 				continue;
466 			if (sp[2] != bp[2])
467 				sp[1] = -1;
468 			else if (i < STOP && so == bp[2] && sp[3] != bp[3]) {
469 				sp[2] = -1;
470 				sp[1] = -1;
471 			}
472 		}
473 	}
474 	if (cur_so)
475 		putpad(SEstr);
476 	(void) fflush(stdout);
477 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
478 }
479 
480 /*
481  * Write a message (set!=0), or clear the same message (set==0).
482  * (We need its length in case we have to overwrite with blanks.)
483  */
484 void
485 scr_msg(char *s, int set)
486 {
487 
488 	if (set || CEstr == NULL) {
489 		int l = strlen(s);
490 
491 		moveto(Rows - 2, ((Cols - l) >> 1) - 1);
492 		if (set)
493 			putstr(s);
494 		else
495 			while (--l >= 0)
496 				(void) putchar(' ');
497 	} else {
498 		moveto(Rows - 2, 0);
499 		putpad(CEstr);
500 	}
501 }
502