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