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screen.c revision 1.13 
      1 /*	$NetBSD: screen.c,v 1.13 1999/10/04 23:27:03 lukem 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 <termcap.h>
     53 #include <termios.h>
     54 #include <unistd.h>
     55 
     56 #ifndef sigmask
     57 #define sigmask(s) (1 << ((s) - 1))
     58 #endif
     59 
     60 #include "screen.h"
     61 #include "tetris.h"
     62 
     63 static cell curscreen[B_SIZE];	/* 1 => standout (or otherwise marked) */
     64 static int curscore;
     65 static int isset;		/* true => terminal is in game mode */
     66 static struct termios oldtt;
     67 static void (*tstp) __P((int));
     68 
     69 static	void	scr_stop __P((int));
     70 static	void	stopset __P((int)) __attribute__((__noreturn__));
     71 
     72 
     73 /*
     74  * Capabilities from TERMCAP.
     75  */
     76 char	PC, *BC, *UP;		/* tgoto requires globals: ugh! */
     77 short	ospeed;
     78 
     79 static char
     80 	*bcstr,			/* backspace char */
     81 	*CEstr,			/* clear to end of line */
     82 	*CLstr,			/* clear screen */
     83 	*CMstr,			/* cursor motion string */
     84 #ifdef unneeded
     85 	*CRstr,			/* "\r" equivalent */
     86 #endif
     87 	*HOstr,			/* cursor home */
     88 	*LLstr,			/* last line, first column */
     89 	*pcstr,			/* pad character */
     90 	*TEstr,			/* end cursor motion mode */
     91 	*TIstr;			/* begin cursor motion mode */
     92 char
     93 	*SEstr,			/* end standout mode */
     94 	*SOstr;			/* begin standout mode */
     95 static int
     96 	COnum,			/* co# value */
     97 	LInum,			/* li# value */
     98 	MSflag;			/* can move in standout mode */
     99 
    100 
    101 struct tcsinfo {	/* termcap string info; some abbrevs above */
    102 	char tcname[3];
    103 	char **tcaddr;
    104 } tcstrings[] = {
    105 	{"bc", &bcstr},
    106 	{"ce", &CEstr},
    107 	{"cl", &CLstr},
    108 	{"cm", &CMstr},
    109 #ifdef unneeded
    110 	{"cr", &CRstr},
    111 #endif
    112 	{"le", &BC},		/* move cursor left one space */
    113 	{"pc", &pcstr},
    114 	{"se", &SEstr},
    115 	{"so", &SOstr},
    116 	{"te", &TEstr},
    117 	{"ti", &TIstr},
    118 	{"up", &UP},		/* cursor up */
    119 	{ {0}, NULL}
    120 };
    121 
    122 /* This is where we will actually stuff the information */
    123 
    124 static char combuf[1024], tbuf[1024];
    125 
    126 
    127 /*
    128  * Routine used by tputs().
    129  */
    130 int
    131 put(c)
    132 	int c;
    133 {
    134 
    135 	return (putchar(c));
    136 }
    137 
    138 /*
    139  * putstr() is for unpadded strings (either as in termcap(5) or
    140  * simply literal strings); putpad() is for padded strings with
    141  * count=1.  (See screen.h for putpad().)
    142  */
    143 #define	putstr(s)	(void)fputs(s, stdout)
    144 #define	moveto(r, c)	putpad(tgoto(CMstr, c, r))
    145 
    146 /*
    147  * Set up from termcap.
    148  */
    149 void
    150 scr_init()
    151 {
    152 	static int bsflag, xsflag, sgnum;
    153 #ifdef unneeded
    154 	static int ncflag;
    155 #endif
    156 	char *term, *fill;
    157 	static struct tcninfo {	/* termcap numeric and flag info */
    158 		char tcname[3];
    159 		int *tcaddr;
    160 	} tcflags[] = {
    161 		{"bs", &bsflag},
    162 		{"ms", &MSflag},
    163 #ifdef unneeded
    164 		{"nc", &ncflag},
    165 #endif
    166 		{"xs", &xsflag},
    167 		{ {0}, NULL}
    168 	}, tcnums[] = {
    169 		{"co", &COnum},
    170 		{"li", &LInum},
    171 		{"sg", &sgnum},
    172 		{ {0}, NULL}
    173 	};
    174 
    175 	if ((term = getenv("TERM")) == NULL)
    176 		stop("you must set the TERM environment variable");
    177 	if (tgetent(tbuf, term) <= 0)
    178 		stop("cannot find your termcap");
    179 	fill = combuf;
    180 	{
    181 		register struct tcsinfo *p;
    182 
    183 		for (p = tcstrings; p->tcaddr; p++)
    184 			*p->tcaddr = tgetstr(p->tcname, &fill);
    185 	}
    186 	{
    187 		register struct tcninfo *p;
    188 
    189 		for (p = tcflags; p->tcaddr; p++)
    190 			*p->tcaddr = tgetflag(p->tcname);
    191 		for (p = tcnums; p->tcaddr; p++)
    192 			*p->tcaddr = tgetnum(p->tcname);
    193 	}
    194 	if (bsflag)
    195 		BC = "\b";
    196 	else if (BC == NULL && bcstr != NULL)
    197 		BC = bcstr;
    198 	if (CLstr == NULL)
    199 		stop("cannot clear screen");
    200 	if (CMstr == NULL || UP == NULL || BC == NULL)
    201 		stop("cannot do random cursor positioning via tgoto()");
    202 	PC = pcstr ? *pcstr : 0;
    203 	if (sgnum >= 0 || xsflag)
    204 		SOstr = SEstr = NULL;
    205 #ifdef unneeded
    206 	if (ncflag)
    207 		CRstr = NULL;
    208 	else if (CRstr == NULL)
    209 		CRstr = "\r";
    210 #endif
    211 }
    212 
    213 /* this foolery is needed to modify tty state `atomically' */
    214 static jmp_buf scr_onstop;
    215 
    216 static void
    217 stopset(sig)
    218 	int sig;
    219 {
    220 	sigset_t sigset;
    221 
    222 	(void) signal(sig, SIG_DFL);
    223 	(void) kill(getpid(), sig);
    224 	sigemptyset(&sigset);
    225 	sigaddset(&sigset, sig);
    226 	(void) sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *)0);
    227 	longjmp(scr_onstop, 1);
    228 }
    229 
    230 static void
    231 scr_stop(sig)
    232 	int sig;
    233 {
    234 	sigset_t sigset;
    235 
    236 	scr_end();
    237 	(void) kill(getpid(), sig);
    238 	sigemptyset(&sigset);
    239 	sigaddset(&sigset, sig);
    240 	(void) sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *)0);
    241 	scr_set();
    242 	scr_msg(key_msg, 1);
    243 }
    244 
    245 /*
    246  * Set up screen mode.
    247  */
    248 void
    249 scr_set()
    250 {
    251 	struct winsize ws;
    252 	struct termios newtt;
    253 	sigset_t sigset, osigset;
    254 	void (*ttou) __P((int));
    255 
    256 	sigemptyset(&sigset);
    257 	sigaddset(&sigset, SIGTSTP);
    258 	sigaddset(&sigset, SIGTTOU);
    259 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
    260 	if ((tstp = signal(SIGTSTP, stopset)) == SIG_IGN)
    261 		(void) signal(SIGTSTP, SIG_IGN);
    262 	if ((ttou = signal(SIGTTOU, stopset)) == SIG_IGN)
    263 		(void) signal(SIGTTOU, SIG_IGN);
    264 	/*
    265 	 * At last, we are ready to modify the tty state.  If
    266 	 * we stop while at it, stopset() above will longjmp back
    267 	 * to the setjmp here and we will start over.
    268 	 */
    269 	(void) setjmp(scr_onstop);
    270 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
    271 	Rows = 0, Cols = 0;
    272 	if (ioctl(0, TIOCGWINSZ, &ws) == 0) {
    273 		Rows = ws.ws_row;
    274 		Cols = ws.ws_col;
    275 	}
    276 	if (Rows == 0)
    277 		Rows = LInum;
    278 	if (Cols == 0)
    279 	Cols = COnum;
    280 	if (Rows < MINROWS || Cols < MINCOLS) {
    281 		(void) fprintf(stderr,
    282 		    "the screen is too small: must be at least %dx%d, ",
    283 		    MINCOLS, MINROWS);
    284 		stop("");	/* stop() supplies \n */
    285 	}
    286 	if (tcgetattr(0, &oldtt) < 0)
    287 		stop("tcgetattr() fails");
    288 	newtt = oldtt;
    289 	newtt.c_lflag &= ~(ICANON|ECHO);
    290 	newtt.c_oflag &= ~OXTABS;
    291 	if (tcsetattr(0, TCSADRAIN, &newtt) < 0)
    292 		stop("tcsetattr() fails");
    293 	ospeed = cfgetospeed(&newtt);
    294 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
    295 
    296 	/*
    297 	 * We made it.  We are now in screen mode, modulo TIstr
    298 	 * (which we will fix immediately).
    299 	 */
    300 	if (TIstr)
    301 		putstr(TIstr);	/* termcap(5) says this is not padded */
    302 	if (tstp != SIG_IGN)
    303 		(void) signal(SIGTSTP, scr_stop);
    304 	if (ttou != SIG_IGN)
    305 		(void) signal(SIGTTOU, ttou);
    306 
    307 	isset = 1;
    308 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
    309 	scr_clear();
    310 }
    311 
    312 /*
    313  * End screen mode.
    314  */
    315 void
    316 scr_end()
    317 {
    318 	sigset_t sigset, osigset;
    319 
    320 	sigemptyset(&sigset);
    321 	sigaddset(&sigset, SIGTSTP);
    322 	sigaddset(&sigset, SIGTTOU);
    323 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
    324 	/* move cursor to last line */
    325 	if (LLstr)
    326 		putstr(LLstr);	/* termcap(5) says this is not padded */
    327 	else
    328 		moveto(Rows - 1, 0);
    329 	/* exit screen mode */
    330 	if (TEstr)
    331 		putstr(TEstr);	/* 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(why)
    342 	const char *why;
    343 {
    344 
    345 	if (isset)
    346 		scr_end();
    347 	(void) fprintf(stderr, "aborting: %s\n", why);
    348 	exit(1);
    349 }
    350 
    351 /*
    352  * Clear the screen, forgetting the current contents in the process.
    353  */
    354 void
    355 scr_clear()
    356 {
    357 
    358 	putpad(CLstr);
    359 	curscore = -1;
    360 	memset((char *)curscreen, 0, sizeof(curscreen));
    361 }
    362 
    363 #if vax && !__GNUC__
    364 typedef int regcell;	/* pcc is bad at `register char', etc */
    365 #else
    366 typedef cell regcell;
    367 #endif
    368 
    369 /*
    370  * Update the screen.
    371  */
    372 void
    373 scr_update()
    374 {
    375 	register cell *bp, *sp;
    376 	register regcell so, cur_so = 0;
    377 	register int i, ccol, j;
    378 	sigset_t sigset, osigset;
    379 	static const struct shape *lastshape;
    380 
    381 	sigemptyset(&sigset);
    382 	sigaddset(&sigset, SIGTSTP);
    383 	(void) sigprocmask(SIG_BLOCK, &sigset, &osigset);
    384 
    385 	/* always leave cursor after last displayed point */
    386 	curscreen[D_LAST * B_COLS - 1] = -1;
    387 
    388 	if (score != curscore) {
    389 		if (HOstr)
    390 			putpad(HOstr);
    391 		else
    392 			moveto(0, 0);
    393 		(void) printf("Score: %d", score);
    394 		curscore = score;
    395 	}
    396 
    397 	/* draw preview of nextpattern */
    398 	if (showpreview && (nextshape != lastshape)) {
    399 		int i;
    400 		static int r=5, c=2;
    401 		int tr, tc, t;
    402 
    403 		lastshape = nextshape;
    404 
    405 		/* clean */
    406 		putpad(SEstr);
    407 		moveto(r-1, c-1); putstr("          ");
    408 		moveto(r,   c-1); putstr("          ");
    409 		moveto(r+1, c-1); putstr("          ");
    410 		moveto(r+2, c-1); putstr("          ");
    411 
    412 		moveto(r-3, c-2);
    413 		putstr("Next shape:");
    414 
    415 		/* draw */
    416 		putpad(SOstr);
    417 		moveto(r, 2*c);
    418 		putstr("  ");
    419 		for(i=0; i<3; i++) {
    420 			t = c + r*B_COLS;
    421 			t += nextshape->off[i];
    422 
    423 			tr = t / B_COLS;
    424 			tc = t % B_COLS;
    425 
    426 			moveto(tr, 2*tc);
    427 			putstr("  ");
    428 		}
    429 		putpad(SEstr);
    430 	}
    431 
    432 	bp = &board[D_FIRST * B_COLS];
    433 	sp = &curscreen[D_FIRST * B_COLS];
    434 	for (j = D_FIRST; j < D_LAST; j++) {
    435 		ccol = -1;
    436 		for (i = 0; i < B_COLS; bp++, sp++, i++) {
    437 			if (*sp == (so = *bp))
    438 				continue;
    439 			*sp = so;
    440 			if (i != ccol) {
    441 				if (cur_so && MSflag) {
    442 					putpad(SEstr);
    443 					cur_so = 0;
    444 				}
    445 				moveto(RTOD(j), CTOD(i));
    446 			}
    447 			if (SOstr) {
    448 				if (so != cur_so) {
    449 					putpad(so ? SOstr : SEstr);
    450 					cur_so = so;
    451 				}
    452 				putstr("  ");
    453 			} else
    454 				putstr(so ? "XX" : "  ");
    455 			ccol = i + 1;
    456 			/*
    457 			 * Look ahead a bit, to avoid extra motion if
    458 			 * we will be redrawing the cell after the next.
    459 			 * Motion probably takes four or more characters,
    460 			 * so we save even if we rewrite two cells
    461 			 * `unnecessarily'.  Skip it all, though, if
    462 			 * the next cell is a different color.
    463 			 */
    464 #define	STOP (B_COLS - 3)
    465 			if (i > STOP || sp[1] != bp[1] || so != bp[1])
    466 				continue;
    467 			if (sp[2] != bp[2])
    468 				sp[1] = -1;
    469 			else if (i < STOP && so == bp[2] && sp[3] != bp[3]) {
    470 				sp[2] = -1;
    471 				sp[1] = -1;
    472 			}
    473 		}
    474 	}
    475 	if (cur_so)
    476 		putpad(SEstr);
    477 	(void) fflush(stdout);
    478 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
    479 }
    480 
    481 /*
    482  * Write a message (set!=0), or clear the same message (set==0).
    483  * (We need its length in case we have to overwrite with blanks.)
    484  */
    485 void
    486 scr_msg(s, set)
    487 	register char *s;
    488 	int set;
    489 {
    490 
    491 	if (set || CEstr == NULL) {
    492 		register int l = strlen(s);
    493 
    494 		moveto(Rows - 2, ((Cols - l) >> 1) - 1);
    495 		if (set)
    496 			putstr(s);
    497 		else
    498 			while (--l >= 0)
    499 				(void) putchar(' ');
    500 	} else {
    501 		moveto(Rows - 2, 0);
    502 		putpad(CEstr);
    503 	}
    504 }
    505