1 /*	$NetBSD: screen.c,v 1.34 2021/05/02 12:50:46 rillig 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/cdefs.h>
42 #include <sys/ioctl.h>
43 
44 #include <setjmp.h>
45 #include <signal.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <term.h>
50 #include <termios.h>
51 #include <unistd.h>
52 
53 #ifndef sigmask
54 #define sigmask(s) (1 << ((s) - 1))
55 #endif
56 
57 #include "screen.h"
58 #include "tetris.h"
59 
60 static cell curscreen[B_SIZE];	/* 1 => standout (or otherwise marked) */
61 static int curscore;
62 static int isset;		/* true => terminal is in game mode */
63 static struct termios oldtt;
64 static void (*tstp)(int);
65 
66 static	void	scr_stop(int);
67 static	void	stopset(int) __dead;
68 
69 extern int ospeed;
70 
71 
72 /*
73  * Routine used by tputs().
74  */
75 int
76 put(int c)
77 {
78 
79 	return (putchar(c));
80 }
81 
82 /*
83  * putstr() is for unpadded strings (either as in termcap(5) or
84  * simply literal strings); putpad() is for padded strings with
85  * count=1.  (See screen.h for putpad().)
86  */
87 #define	putstr(s)	(void)fputs(s, stdout)
88 
89 static void
90 moveto(int r, int c)
91 {
92 	char *buf;
93 
94 	buf = tiparm(cursor_address, r, c);
95 	if (buf != NULL)
96 		putpad(buf);
97 }
98 
99 static void
100 setcolor(int c)
101 {
102 	char *buf;
103 	char monochrome[] = "\033[0m";
104 	if (nocolor == 1)
105 		return;
106 	if (set_a_foreground == NULL)
107 		return;
108 
109 	if (c == 0 || c == 7)
110 		buf = monochrome;
111 	else
112 		buf = tiparm(set_a_foreground, c);
113 	if (buf != NULL)
114 		putpad(buf);
115 }
116 
117 /*
118  * Set up from termcap.
119  */
120 void
121 scr_init(void)
122 {
123 
124 	setupterm(NULL, 0, NULL);
125 	if (clear_screen == NULL)
126 		stop("cannot clear screen");
127 	if (cursor_address == NULL || cursor_up == NULL)
128 		stop("cannot do random cursor positioning");
129 }
130 
131 /* this foolery is needed to modify tty state `atomically' */
132 static jmp_buf scr_onstop;
133 
134 static void
135 stopset(int sig)
136 {
137 	sigset_t set;
138 
139 	(void) signal(sig, SIG_DFL);
140 	(void) kill(getpid(), sig);
141 	sigemptyset(&set);
142 	sigaddset(&set, sig);
143 	(void) sigprocmask(SIG_UNBLOCK, &set, (sigset_t *)0);
144 	longjmp(scr_onstop, 1);
145 }
146 
147 static void
148 scr_stop(int sig)
149 {
150 	sigset_t set;
151 
152 	scr_end();
153 	(void) kill(getpid(), sig);
154 	sigemptyset(&set);
155 	sigaddset(&set, sig);
156 	(void) sigprocmask(SIG_UNBLOCK, &set, (sigset_t *)0);
157 	scr_set();
158 	scr_msg(key_msg, 1);
159 }
160 
161 /*
162  * Set up screen mode.
163  */
164 void
165 scr_set(void)
166 {
167 	struct winsize ws;
168 	struct termios newtt;
169 	sigset_t nsigset, osigset;
170 	void (*ttou)(int);
171 
172 	sigemptyset(&nsigset);
173 	sigaddset(&nsigset, SIGTSTP);
174 	sigaddset(&nsigset, SIGTTOU);
175 	(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
176 	if ((tstp = signal(SIGTSTP, stopset)) == SIG_IGN)
177 		(void) signal(SIGTSTP, SIG_IGN);
178 	if ((ttou = signal(SIGTTOU, stopset)) == SIG_IGN)
179 		(void) signal(SIGTTOU, SIG_IGN);
180 	/*
181 	 * At last, we are ready to modify the tty state.  If
182 	 * we stop while at it, stopset() above will longjmp back
183 	 * to the setjmp here and we will start over.
184 	 */
185 	(void) setjmp(scr_onstop);
186 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
187 	Rows = 0, Cols = 0;
188 	if (ioctl(0, TIOCGWINSZ, &ws) == 0) {
189 		Rows = ws.ws_row;
190 		Cols = ws.ws_col;
191 	}
192 	if (Rows == 0)
193 		Rows = lines;
194 	if (Cols == 0)
195 	    Cols = columns;
196 	if (Rows < MINROWS || Cols < MINCOLS) {
197 		(void) fprintf(stderr,
198 		    "the screen is too small: must be at least %dx%d, ",
199 		    MINCOLS, MINROWS);
200 		stop("");	/* stop() supplies \n */
201 	}
202 	Offset = (Rows - D_LAST + D_FIRST - 2) / 2;
203 	if (tcgetattr(0, &oldtt) < 0)
204 		stop("tcgetattr() fails");
205 	newtt = oldtt;
206 	newtt.c_lflag &= ~(ICANON|ECHO);
207 	newtt.c_oflag &= ~OXTABS;
208 	if (tcsetattr(0, TCSADRAIN, &newtt) < 0)
209 		stop("tcsetattr() fails");
210 	ospeed = cfgetospeed(&newtt);
211 	(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
212 
213 	/*
214 	 * We made it.  We are now in screen mode, modulo TIstr
215 	 * (which we will fix immediately).
216 	 */
217 	const char *tstr;
218 	if ((tstr = enter_ca_mode) != NULL)
219 		putstr(tstr);
220 	if ((tstr = cursor_invisible) != NULL)
221 		putstr(tstr);
222 	if (tstp != SIG_IGN)
223 		(void) signal(SIGTSTP, scr_stop);
224 	if (ttou != SIG_IGN)
225 		(void) signal(SIGTTOU, ttou);
226 
227 	isset = 1;
228 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
229 	scr_clear();
230 }
231 
232 /*
233  * End screen mode.
234  */
235 void
236 scr_end(void)
237 {
238 	sigset_t nsigset, osigset;
239 
240 	sigemptyset(&nsigset);
241 	sigaddset(&nsigset, SIGTSTP);
242 	sigaddset(&nsigset, SIGTTOU);
243 	(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
244 	/* move cursor to last line */
245 	const char *tstr;
246 	if ((tstr = cursor_to_ll) != NULL)
247 		putstr(tstr);
248 	else
249 		moveto(Rows - 1, 0);
250 	/* exit screen mode */
251 	if ((tstr = exit_ca_mode) != NULL)
252 		putstr(tstr);
253 	if ((tstr = cursor_normal) != NULL)
254 		putstr(tstr);
255 	(void) fflush(stdout);
256 	(void) tcsetattr(0, TCSADRAIN, &oldtt);
257 	isset = 0;
258 	/* restore signals */
259 	(void) signal(SIGTSTP, tstp);
260 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
261 }
262 
263 void
264 stop(const char *why)
265 {
266 
267 	if (isset)
268 		scr_end();
269 	(void) fprintf(stderr, "aborting: %s\n", why);
270 	exit(1);
271 }
272 
273 /*
274  * Clear the screen, forgetting the current contents in the process.
275  */
276 void
277 scr_clear(void)
278 {
279 
280 	putpad(clear_screen);
281 	curscore = -1;
282 	memset((char *)curscreen, 0, sizeof(curscreen));
283 }
284 
285 #if vax && !__GNUC__
286 typedef int regcell;	/* pcc is bad at `register char', etc */
287 #else
288 typedef cell regcell;
289 #endif
290 
291 /*
292  * Update the screen.
293  */
294 void
295 scr_update(void)
296 {
297 	cell *bp, *sp;
298 	regcell so, cur_so = 0;
299 	int i, ccol, j;
300 	sigset_t nsigset, osigset;
301 	static const struct shape *lastshape;
302 
303 	sigemptyset(&nsigset);
304 	sigaddset(&nsigset, SIGTSTP);
305 	(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
306 
307 	/* always leave cursor after last displayed point */
308 	curscreen[D_LAST * B_COLS - 1] = -1;
309 
310 	if (score != curscore) {
311 		if (cursor_home)
312 			putpad(cursor_home);
313 		else
314 			moveto(0, 0);
315 		setcolor(0);
316 		(void) printf("Score: %d", score);
317 		curscore = score;
318 	}
319 
320 	/* draw preview of nextpattern */
321 	if (showpreview && (nextshape != lastshape)) {
322 		static int r=5, c=2;
323 		int tr, tc, t;
324 
325 		lastshape = nextshape;
326 
327 		/* clean */
328 		putpad(exit_standout_mode);
329 		moveto(r-1, c-1); putstr("          ");
330 		moveto(r,   c-1); putstr("          ");
331 		moveto(r+1, c-1); putstr("          ");
332 		moveto(r+2, c-1); putstr("          ");
333 
334 		moveto(r-3, c-2);
335 		putstr("Next shape:");
336 
337 		/* draw */
338 		setcolor(nextshape->color);
339 		putpad(enter_standout_mode);
340 		moveto(r, 2*c);
341 		putstr("  ");
342 		for(i=0; i<3; i++) {
343 			t = c + r*B_COLS;
344 			t += nextshape->off[i];
345 
346 			tr = t / B_COLS;
347 			tc = t % B_COLS;
348 
349 			moveto(tr, 2*tc);
350 			putstr("  ");
351 		}
352 		putpad(exit_standout_mode);
353 	}
354 
355 	bp = &board[D_FIRST * B_COLS];
356 	sp = &curscreen[D_FIRST * B_COLS];
357 	for (j = D_FIRST; j < D_LAST; j++) {
358 		ccol = -1;
359 		for (i = 0; i < B_COLS; bp++, sp++, i++) {
360 			if (*sp == (so = *bp))
361 				continue;
362 			*sp = so;
363 			if (i != ccol) {
364 				if (cur_so && move_standout_mode) {
365 					putpad(exit_standout_mode);
366 					cur_so = 0;
367 				}
368 				moveto(RTOD(j + Offset), CTOD(i));
369 			}
370 			if (enter_standout_mode) {
371 				if (so != cur_so) {
372 					setcolor(so);
373 					putpad(so ?
374 					    enter_standout_mode :
375 					    exit_standout_mode);
376 					cur_so = so;
377 				}
378 #ifdef DEBUG
379 				char buf[3];
380 				snprintf(buf, sizeof(buf), "%d%d", so, so);
381 				putstr(buf);
382 #else
383 				putstr("  ");
384 #endif
385 			} else
386 				putstr(so ? "XX" : "  ");
387 			ccol = i + 1;
388 			/*
389 			 * Look ahead a bit, to avoid extra motion if
390 			 * we will be redrawing the cell after the next.
391 			 * Motion probably takes four or more characters,
392 			 * so we save even if we rewrite two cells
393 			 * `unnecessarily'.  Skip it all, though, if
394 			 * the next cell is a different color.
395 			 */
396 #define	STOP (B_COLS - 3)
397 			if (i > STOP || sp[1] != bp[1] || so != bp[1])
398 				continue;
399 			if (sp[2] != bp[2])
400 				sp[1] = -1;
401 			else if (i < STOP && so == bp[2] && sp[3] != bp[3]) {
402 				sp[2] = -1;
403 				sp[1] = -1;
404 			}
405 		}
406 	}
407 	if (cur_so)
408 		putpad(exit_standout_mode);
409 	(void) fflush(stdout);
410 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
411 }
412 
413 /*
414  * Write a message (set!=0), or clear the same message (set==0).
415  * (We need its length in case we have to overwrite with blanks.)
416  */
417 void
418 scr_msg(char *s, int set)
419 {
420 
421 	if (set || clr_eol == NULL) {
422 		int l = strlen(s);
423 
424 		moveto(Rows - 2, ((Cols - l) >> 1) - 1);
425 		if (set)
426 			putstr(s);
427 		else
428 			while (--l >= 0)
429 				(void) putchar(' ');
430 	} else {
431 		moveto(Rows - 2, 0);
432 		putpad(clr_eol);
433 	}
434 }