xref: /netbsd-src/games/tetris/screen.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: screen.c,v 1.19 2004/01/27 20:30:30 jsm Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Chris Torek and Darren F. Provine.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)screen.c	8.1 (Berkeley) 5/31/93
35  */
36 
37 /*
38  * Tetris screen control.
39  */
40 
41 #include <sys/ioctl.h>
42 
43 #include <setjmp.h>
44 #include <signal.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <termcap.h>
49 #include <termios.h>
50 #include <unistd.h>
51 
52 #ifndef sigmask
53 #define sigmask(s) (1 << ((s) - 1))
54 #endif
55 
56 #include "screen.h"
57 #include "tetris.h"
58 
59 static cell curscreen[B_SIZE];	/* 1 => standout (or otherwise marked) */
60 static int curscore;
61 static int isset;		/* true => terminal is in game mode */
62 static struct termios oldtt;
63 static void (*tstp)(int);
64 
65 static	void	scr_stop(int);
66 static	void	stopset(int) __attribute__((__noreturn__));
67 
68 
69 /*
70  * Capabilities from TERMCAP.
71  */
72 short	ospeed;
73 
74 static char
75 	*bcstr,			/* backspace char */
76 	*CEstr,			/* clear to end of line */
77 	*CLstr,			/* clear screen */
78 	*CMstr,			/* cursor motion string */
79 #ifdef unneeded
80 	*CRstr,			/* "\r" equivalent */
81 #endif
82 	*HOstr,			/* cursor home */
83 	*LLstr,			/* last line, first column */
84 	*pcstr,			/* pad character */
85 	*TEstr,			/* end cursor motion mode */
86 	*TIstr;			/* begin cursor motion mode */
87 char
88 	*SEstr,			/* end standout mode */
89 	*SOstr;			/* begin standout mode */
90 static int
91 	COnum,			/* co# value */
92 	LInum,			/* li# value */
93 	MSflag;			/* can move in standout mode */
94 
95 
96 struct tcsinfo {	/* termcap string info; some abbrevs above */
97 	char tcname[3];
98 	char **tcaddr;
99 } tcstrings[] = {
100 	{"bc", &bcstr},
101 	{"ce", &CEstr},
102 	{"cl", &CLstr},
103 	{"cm", &CMstr},
104 #ifdef unneeded
105 	{"cr", &CRstr},
106 #endif
107 	{"le", &BC},		/* move cursor left one space */
108 	{"pc", &pcstr},
109 	{"se", &SEstr},
110 	{"so", &SOstr},
111 	{"te", &TEstr},
112 	{"ti", &TIstr},
113 	{"up", &UP},		/* cursor up */
114 	{ {0}, NULL}
115 };
116 
117 /* This is where we will actually stuff the information */
118 
119 static struct tinfo *info;
120 
121 /*
122  * Routine used by tputs().
123  */
124 int
125 put(c)
126 	int c;
127 {
128 
129 	return (putchar(c));
130 }
131 
132 /*
133  * putstr() is for unpadded strings (either as in termcap(5) or
134  * simply literal strings); putpad() is for padded strings with
135  * count=1.  (See screen.h for putpad().)
136  */
137 #define	putstr(s)	(void)fputs(s, stdout)
138 
139 void
140 moveto(int r, int c)
141 {
142 	char buf[256];
143 
144 	if (t_goto(info, CMstr, c, r, buf, 255) == 0)
145 		putpad(buf);
146 }
147 
148 /*
149  * Set up from termcap.
150  */
151 void
152 scr_init()
153 {
154 	static int bsflag, xsflag, sgnum;
155 #ifdef unneeded
156 	static int ncflag;
157 #endif
158 	char *term;
159 	static struct tcninfo {	/* termcap numeric and flag info */
160 		char tcname[3];
161 		int *tcaddr;
162 	} tcflags[] = {
163 		{"bs", &bsflag},
164 		{"ms", &MSflag},
165 #ifdef unneeded
166 		{"nc", &ncflag},
167 #endif
168 		{"xs", &xsflag},
169 		{ {0}, NULL}
170 	}, tcnums[] = {
171 		{"co", &COnum},
172 		{"li", &LInum},
173 		{"sg", &sgnum},
174 		{ {0}, NULL}
175 	};
176 
177 	if ((term = getenv("TERM")) == NULL)
178 		stop("you must set the TERM environment variable");
179 	if (t_getent(&info, term) <= 0)
180 		stop("cannot find your termcap");
181 	{
182 		struct tcsinfo *p;
183 
184 		for (p = tcstrings; p->tcaddr; p++)
185 			*p->tcaddr = t_agetstr(info, p->tcname);
186 	}
187 	{
188 		struct tcninfo *p;
189 
190 		for (p = tcflags; p->tcaddr; p++)
191 			*p->tcaddr = t_getflag(info, p->tcname);
192 		for (p = tcnums; p->tcaddr; p++)
193 			*p->tcaddr = t_getnum(info, p->tcname);
194 	}
195 	if (bsflag)
196 		BC = "\b";
197 	else if (BC == NULL && bcstr != NULL)
198 		BC = bcstr;
199 	if (CLstr == NULL)
200 		stop("cannot clear screen");
201 	if (CMstr == NULL || UP == NULL || BC == NULL)
202 		stop("cannot do random cursor positioning via tgoto()");
203 	PC = pcstr ? *pcstr : 0;
204 	if (sgnum >= 0 || xsflag)
205 		SOstr = SEstr = NULL;
206 #ifdef unneeded
207 	if (ncflag)
208 		CRstr = NULL;
209 	else if (CRstr == NULL)
210 		CRstr = "\r";
211 #endif
212 }
213 
214 /* this foolery is needed to modify tty state `atomically' */
215 static jmp_buf scr_onstop;
216 
217 static void
218 stopset(sig)
219 	int sig;
220 {
221 	sigset_t sigset;
222 
223 	(void) signal(sig, SIG_DFL);
224 	(void) kill(getpid(), sig);
225 	sigemptyset(&sigset);
226 	sigaddset(&sigset, sig);
227 	(void) sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *)0);
228 	longjmp(scr_onstop, 1);
229 }
230 
231 static void
232 scr_stop(sig)
233 	int sig;
234 {
235 	sigset_t sigset;
236 
237 	scr_end();
238 	(void) kill(getpid(), sig);
239 	sigemptyset(&sigset);
240 	sigaddset(&sigset, sig);
241 	(void) sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *)0);
242 	scr_set();
243 	scr_msg(key_msg, 1);
244 }
245 
246 /*
247  * Set up screen mode.
248  */
249 void
250 scr_set()
251 {
252 	struct winsize ws;
253 	struct termios newtt;
254 	sigset_t sigset, osigset;
255 	void (*ttou)(int);
256 
257 	sigemptyset(&sigset);
258 	sigaddset(&sigset, SIGTSTP);
259 	sigaddset(&sigset, SIGTTOU);
260 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
261 	if ((tstp = signal(SIGTSTP, stopset)) == SIG_IGN)
262 		(void) signal(SIGTSTP, SIG_IGN);
263 	if ((ttou = signal(SIGTTOU, stopset)) == SIG_IGN)
264 		(void) signal(SIGTTOU, SIG_IGN);
265 	/*
266 	 * At last, we are ready to modify the tty state.  If
267 	 * we stop while at it, stopset() above will longjmp back
268 	 * to the setjmp here and we will start over.
269 	 */
270 	(void) setjmp(scr_onstop);
271 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
272 	Rows = 0, Cols = 0;
273 	if (ioctl(0, TIOCGWINSZ, &ws) == 0) {
274 		Rows = ws.ws_row;
275 		Cols = ws.ws_col;
276 	}
277 	if (Rows == 0)
278 		Rows = LInum;
279 	if (Cols == 0)
280 	Cols = COnum;
281 	if (Rows < MINROWS || Cols < MINCOLS) {
282 		(void) fprintf(stderr,
283 		    "the screen is too small: must be at least %dx%d, ",
284 		    MINCOLS, MINROWS);
285 		stop("");	/* stop() supplies \n */
286 	}
287 	if (tcgetattr(0, &oldtt) < 0)
288 		stop("tcgetattr() fails");
289 	newtt = oldtt;
290 	newtt.c_lflag &= ~(ICANON|ECHO);
291 	newtt.c_oflag &= ~OXTABS;
292 	if (tcsetattr(0, TCSADRAIN, &newtt) < 0)
293 		stop("tcsetattr() fails");
294 	ospeed = cfgetospeed(&newtt);
295 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
296 
297 	/*
298 	 * We made it.  We are now in screen mode, modulo TIstr
299 	 * (which we will fix immediately).
300 	 */
301 	if (TIstr)
302 		putstr(TIstr);	/* termcap(5) says this is not padded */
303 	if (tstp != SIG_IGN)
304 		(void) signal(SIGTSTP, scr_stop);
305 	if (ttou != SIG_IGN)
306 		(void) signal(SIGTTOU, ttou);
307 
308 	isset = 1;
309 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
310 	scr_clear();
311 }
312 
313 /*
314  * End screen mode.
315  */
316 void
317 scr_end()
318 {
319 	sigset_t sigset, osigset;
320 
321 	sigemptyset(&sigset);
322 	sigaddset(&sigset, SIGTSTP);
323 	sigaddset(&sigset, SIGTTOU);
324 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
325 	/* move cursor to last line */
326 	if (LLstr)
327 		putstr(LLstr);	/* termcap(5) says this is not padded */
328 	else
329 		moveto(Rows - 1, 0);
330 	/* exit screen mode */
331 	if (TEstr)
332 		putstr(TEstr);	/* termcap(5) says this is not padded */
333 	(void) fflush(stdout);
334 	(void) tcsetattr(0, TCSADRAIN, &oldtt);
335 	isset = 0;
336 	/* restore signals */
337 	(void) signal(SIGTSTP, tstp);
338 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
339 }
340 
341 void
342 stop(why)
343 	const char *why;
344 {
345 
346 	if (isset)
347 		scr_end();
348 	(void) fprintf(stderr, "aborting: %s\n", why);
349 	exit(1);
350 }
351 
352 /*
353  * Clear the screen, forgetting the current contents in the process.
354  */
355 void
356 scr_clear()
357 {
358 
359 	putpad(CLstr);
360 	curscore = -1;
361 	memset((char *)curscreen, 0, sizeof(curscreen));
362 }
363 
364 #if vax && !__GNUC__
365 typedef int regcell;	/* pcc is bad at `register char', etc */
366 #else
367 typedef cell regcell;
368 #endif
369 
370 /*
371  * Update the screen.
372  */
373 void
374 scr_update()
375 {
376 	cell *bp, *sp;
377 	regcell so, cur_so = 0;
378 	int i, ccol, j;
379 	sigset_t sigset, osigset;
380 	static const struct shape *lastshape;
381 
382 	sigemptyset(&sigset);
383 	sigaddset(&sigset, SIGTSTP);
384 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
385 
386 	/* always leave cursor after last displayed point */
387 	curscreen[D_LAST * B_COLS - 1] = -1;
388 
389 	if (score != curscore) {
390 		if (HOstr)
391 			putpad(HOstr);
392 		else
393 			moveto(0, 0);
394 		(void) printf("Score: %d", score);
395 		curscore = score;
396 	}
397 
398 	/* draw preview of nextpattern */
399 	if (showpreview && (nextshape != lastshape)) {
400 		int i;
401 		static int r=5, c=2;
402 		int tr, tc, t;
403 
404 		lastshape = nextshape;
405 
406 		/* clean */
407 		putpad(SEstr);
408 		moveto(r-1, c-1); putstr("          ");
409 		moveto(r,   c-1); putstr("          ");
410 		moveto(r+1, c-1); putstr("          ");
411 		moveto(r+2, c-1); putstr("          ");
412 
413 		moveto(r-3, c-2);
414 		putstr("Next shape:");
415 
416 		/* draw */
417 		putpad(SOstr);
418 		moveto(r, 2*c);
419 		putstr("  ");
420 		for(i=0; i<3; i++) {
421 			t = c + r*B_COLS;
422 			t += nextshape->off[i];
423 
424 			tr = t / B_COLS;
425 			tc = t % B_COLS;
426 
427 			moveto(tr, 2*tc);
428 			putstr("  ");
429 		}
430 		putpad(SEstr);
431 	}
432 
433 	bp = &board[D_FIRST * B_COLS];
434 	sp = &curscreen[D_FIRST * B_COLS];
435 	for (j = D_FIRST; j < D_LAST; j++) {
436 		ccol = -1;
437 		for (i = 0; i < B_COLS; bp++, sp++, i++) {
438 			if (*sp == (so = *bp))
439 				continue;
440 			*sp = so;
441 			if (i != ccol) {
442 				if (cur_so && MSflag) {
443 					putpad(SEstr);
444 					cur_so = 0;
445 				}
446 				moveto(RTOD(j), CTOD(i));
447 			}
448 			if (SOstr) {
449 				if (so != cur_so) {
450 					putpad(so ? SOstr : SEstr);
451 					cur_so = so;
452 				}
453 				putstr("  ");
454 			} else
455 				putstr(so ? "XX" : "  ");
456 			ccol = i + 1;
457 			/*
458 			 * Look ahead a bit, to avoid extra motion if
459 			 * we will be redrawing the cell after the next.
460 			 * Motion probably takes four or more characters,
461 			 * so we save even if we rewrite two cells
462 			 * `unnecessarily'.  Skip it all, though, if
463 			 * the next cell is a different color.
464 			 */
465 #define	STOP (B_COLS - 3)
466 			if (i > STOP || sp[1] != bp[1] || so != bp[1])
467 				continue;
468 			if (sp[2] != bp[2])
469 				sp[1] = -1;
470 			else if (i < STOP && so == bp[2] && sp[3] != bp[3]) {
471 				sp[2] = -1;
472 				sp[1] = -1;
473 			}
474 		}
475 	}
476 	if (cur_so)
477 		putpad(SEstr);
478 	(void) fflush(stdout);
479 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
480 }
481 
482 /*
483  * Write a message (set!=0), or clear the same message (set==0).
484  * (We need its length in case we have to overwrite with blanks.)
485  */
486 void
487 scr_msg(s, set)
488 	char *s;
489 	int set;
490 {
491 
492 	if (set || CEstr == NULL) {
493 		int l = strlen(s);
494 
495 		moveto(Rows - 2, ((Cols - l) >> 1) - 1);
496 		if (set)
497 			putstr(s);
498 		else
499 			while (--l >= 0)
500 				(void) putchar(' ');
501 	} else {
502 		moveto(Rows - 2, 0);
503 		putpad(CEstr);
504 	}
505 }
506