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 #if defined(__linux__) && !defined(XTABS)
58 # define OXTABS 0x01800
59 #endif
60 
61 #include "screen.h"
62 #include "tetris.h"
63 
64 static cell curscreen[B_SIZE];	/* 1 => standout (or otherwise marked) */
65 static int curscore;
66 static int isset;		/* true => terminal is in game mode */
67 static struct termios oldtt;
68 static void (*tstp)(int);
69 
70 static	void	scr_stop(int);
71 static	void	stopset(int) __dead;
72 
73 extern int ospeed;
74 
75 
76 /*
77  * Routine used by tputs().
78  */
79 int
80 put(int c)
81 {
82 
83 	return (putchar(c));
84 }
85 
86 /*
87  * putstr() is for unpadded strings (either as in termcap(5) or
88  * simply literal strings); putpad() is for padded strings with
89  * count=1.  (See screen.h for putpad().)
90  */
91 #define	putstr(s)	(void)fputs(s, stdout)
92 
93 static void
94 moveto(int r, int c)
95 {
96 	char *buf;
97 
98 	buf = tiparm(cursor_address, r, c);
99 	if (buf != NULL)
100 		putpad(buf);
101 }
102 
103 static void
104 setcolor(int c)
105 {
106 	char *buf;
107 	char monochrome[] = "\033[0m";
108 	if (nocolor == 1)
109 		return;
110 	if (set_a_foreground == NULL)
111 		return;
112 
113 	if (c == 0 || c == 7)
114 		buf = monochrome;
115 	else
116 		buf = tiparm(set_a_foreground, c);
117 	if (buf != NULL)
118 		putpad(buf);
119 }
120 
121 /*
122  * Set up from termcap.
123  */
124 void
125 scr_init(void)
126 {
127 
128 	setupterm(NULL, 0, NULL);
129 	if (clear_screen == NULL)
130 		stop("cannot clear screen");
131 	if (cursor_address == NULL || cursor_up == NULL)
132 		stop("cannot do random cursor positioning");
133 }
134 
135 /* this foolery is needed to modify tty state `atomically' */
136 static jmp_buf scr_onstop;
137 
138 static void
139 stopset(int sig)
140 {
141 	sigset_t set;
142 
143 	(void) signal(sig, SIG_DFL);
144 	(void) kill(getpid(), sig);
145 	sigemptyset(&set);
146 	sigaddset(&set, sig);
147 	(void) sigprocmask(SIG_UNBLOCK, &set, (sigset_t *)0);
148 	longjmp(scr_onstop, 1);
149 }
150 
151 static void
152 scr_stop(int sig)
153 {
154 	sigset_t set;
155 
156 	scr_end();
157 	(void) kill(getpid(), sig);
158 	sigemptyset(&set);
159 	sigaddset(&set, sig);
160 	(void) sigprocmask(SIG_UNBLOCK, &set, (sigset_t *)0);
161 	scr_set();
162 	scr_msg(key_msg, 1);
163 }
164 
165 /*
166  * Set up screen mode.
167  */
168 void
169 scr_set(void)
170 {
171 	struct winsize ws;
172 	struct termios newtt;
173 	sigset_t nsigset, osigset;
174 	void (*ttou)(int);
175 
176 	sigemptyset(&nsigset);
177 	sigaddset(&nsigset, SIGTSTP);
178 	sigaddset(&nsigset, SIGTTOU);
179 	(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
180 	if ((tstp = signal(SIGTSTP, stopset)) == SIG_IGN)
181 		(void) signal(SIGTSTP, SIG_IGN);
182 	if ((ttou = signal(SIGTTOU, stopset)) == SIG_IGN)
183 		(void) signal(SIGTTOU, SIG_IGN);
184 	/*
185 	 * At last, we are ready to modify the tty state.  If
186 	 * we stop while at it, stopset() above will longjmp back
187 	 * to the setjmp here and we will start over.
188 	 */
189 	(void) setjmp(scr_onstop);
190 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
191 	Rows = 0, Cols = 0;
192 	if (ioctl(0, TIOCGWINSZ, &ws) == 0) {
193 		Rows = ws.ws_row;
194 		Cols = ws.ws_col;
195 	}
196 	if (Rows == 0)
197 		Rows = lines;
198 	if (Cols == 0)
199 	    Cols = columns;
200 	if (Rows < MINROWS || Cols < MINCOLS) {
201 		(void) fprintf(stderr,
202 		    "the screen is too small: must be at least %dx%d, ",
203 		    MINCOLS, MINROWS);
204 		stop("");	/* stop() supplies \n */
205 	}
206 	Offset = (Rows - D_LAST + D_FIRST - 2) / 2;
207 	if (tcgetattr(0, &oldtt) < 0)
208 		stop("tcgetattr() fails");
209 	newtt = oldtt;
210 	newtt.c_lflag &= ~(ICANON|ECHO);
211 	newtt.c_oflag &= ~OXTABS;
212 	if (tcsetattr(0, TCSADRAIN, &newtt) < 0)
213 		stop("tcsetattr() fails");
214 	ospeed = cfgetospeed(&newtt);
215 	(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
216 
217 	/*
218 	 * We made it.  We are now in screen mode, modulo TIstr
219 	 * (which we will fix immediately).
220 	 */
221 	const char *tstr;
222 	if ((tstr = enter_ca_mode) != NULL)
223 		putstr(tstr);
224 	if ((tstr = cursor_invisible) != NULL)
225 		putstr(tstr);
226 	if (tstp != SIG_IGN)
227 		(void) signal(SIGTSTP, scr_stop);
228 	if (ttou != SIG_IGN)
229 		(void) signal(SIGTTOU, ttou);
230 
231 	isset = 1;
232 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
233 	scr_clear();
234 }
235 
236 /*
237  * End screen mode.
238  */
239 void
240 scr_end(void)
241 {
242 	sigset_t nsigset, osigset;
243 
244 	sigemptyset(&nsigset);
245 	sigaddset(&nsigset, SIGTSTP);
246 	sigaddset(&nsigset, SIGTTOU);
247 	(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
248 	/* move cursor to last line */
249 	const char *tstr;
250 	if ((tstr = cursor_to_ll) != NULL)
251 		putstr(tstr);
252 	else
253 		moveto(Rows - 1, 0);
254 	/* exit screen mode */
255 	if ((tstr = exit_ca_mode) != NULL)
256 		putstr(tstr);
257 	if ((tstr = cursor_normal) != NULL)
258 		putstr(tstr);
259 	(void) fflush(stdout);
260 	(void) tcsetattr(0, TCSADRAIN, &oldtt);
261 	isset = 0;
262 	/* restore signals */
263 	(void) signal(SIGTSTP, tstp);
264 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
265 }
266 
267 void
268 stop(const char *why)
269 {
270 
271 	if (isset)
272 		scr_end();
273 	(void) fprintf(stderr, "aborting: %s\n", why);
274 	exit(1);
275 }
276 
277 /*
278  * Clear the screen, forgetting the current contents in the process.
279  */
280 void
281 scr_clear(void)
282 {
283 
284 	putpad(clear_screen);
285 	curscore = -1;
286 	memset((char *)curscreen, 0, sizeof(curscreen));
287 }
288 
289 #if vax && !__GNUC__
290 typedef int regcell;	/* pcc is bad at `register char', etc */
291 #else
292 typedef cell regcell;
293 #endif
294 
295 /*
296  * Update the screen.
297  */
298 void
299 scr_update(void)
300 {
301 	cell *bp, *sp;
302 	regcell so, cur_so = 0;
303 	int i, ccol, j;
304 	sigset_t nsigset, osigset;
305 	static const struct shape *lastshape;
306 
307 	sigemptyset(&nsigset);
308 	sigaddset(&nsigset, SIGTSTP);
309 	(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
310 
311 	/* always leave cursor after last displayed point */
312 	curscreen[D_LAST * B_COLS - 1] = -1;
313 
314 	if (score != curscore) {
315 		if (cursor_home)
316 			putpad(cursor_home);
317 		else
318 			moveto(0, 0);
319 		setcolor(0);
320 		(void) printf("Score: %d", score);
321 		curscore = score;
322 	}
323 
324 	/* draw preview of nextpattern */
325 	if (showpreview && (nextshape != lastshape)) {
326 		static int r=5, c=2;
327 		int tr, tc, t;
328 
329 		lastshape = nextshape;
330 
331 		/* clean */
332 		putpad(exit_standout_mode);
333 		moveto(r-1, c-1); putstr("          ");
334 		moveto(r,   c-1); putstr("          ");
335 		moveto(r+1, c-1); putstr("          ");
336 		moveto(r+2, c-1); putstr("          ");
337 
338 		moveto(r-3, c-2);
339 		putstr("Next shape:");
340 
341 		/* draw */
342 		setcolor(nextshape->color);
343 		putpad(enter_standout_mode);
344 		moveto(r, 2*c);
345 		putstr("  ");
346 		for(i=0; i<3; i++) {
347 			t = c + r*B_COLS;
348 			t += nextshape->off[i];
349 
350 			tr = t / B_COLS;
351 			tc = t % B_COLS;
352 
353 			moveto(tr, 2*tc);
354 			putstr("  ");
355 		}
356 		putpad(exit_standout_mode);
357 	}
358 
359 	bp = &board[D_FIRST * B_COLS];
360 	sp = &curscreen[D_FIRST * B_COLS];
361 	for (j = D_FIRST; j < D_LAST; j++) {
362 		ccol = -1;
363 		for (i = 0; i < B_COLS; bp++, sp++, i++) {
364 			if (*sp == (so = *bp))
365 				continue;
366 			*sp = so;
367 			if (i != ccol) {
368 				if (cur_so && move_standout_mode) {
369 					putpad(exit_standout_mode);
370 					cur_so = 0;
371 				}
372 				moveto(RTOD(j + Offset), CTOD(i));
373 			}
374 			if (enter_standout_mode) {
375 				if (so != cur_so) {
376 					setcolor(so);
377 					putpad(so ?
378 					    enter_standout_mode :
379 					    exit_standout_mode);
380 					cur_so = so;
381 				}
382 #ifdef DEBUG
383 				char buf[3];
384 				snprintf(buf, sizeof(buf), "%d%d", so, so);
385 				putstr(buf);
386 #else
387 				putstr("  ");
388 #endif
389 			} else
390 				putstr(so ? "XX" : "  ");
391 			ccol = i + 1;
392 			/*
393 			 * Look ahead a bit, to avoid extra motion if
394 			 * we will be redrawing the cell after the next.
395 			 * Motion probably takes four or more characters,
396 			 * so we save even if we rewrite two cells
397 			 * `unnecessarily'.  Skip it all, though, if
398 			 * the next cell is a different color.
399 			 */
400 #define	STOP (B_COLS - 3)
401 			if (i > STOP || sp[1] != bp[1] || so != bp[1])
402 				continue;
403 			if (sp[2] != bp[2])
404 				sp[1] = -1;
405 			else if (i < STOP && so == bp[2] && sp[3] != bp[3]) {
406 				sp[2] = -1;
407 				sp[1] = -1;
408 			}
409 		}
410 	}
411 	if (cur_so)
412 		putpad(exit_standout_mode);
413 	(void) fflush(stdout);
414 	(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
415 }
416 
417 /*
418  * Write a message (set!=0), or clear the same message (set==0).
419  * (We need its length in case we have to overwrite with blanks.)
420  */
421 void
422 scr_msg(char *s, int set)
423 {
424 
425 	if (set || clr_eol == NULL) {
426 		int l = strlen(s);
427 
428 		moveto(Rows - 2, ((Cols - l) >> 1) - 1);
429 		if (set)
430 			putstr(s);
431 		else
432 			while (--l >= 0)
433 				(void) putchar(' ');
434 	} else {
435 		moveto(Rows - 2, 0);
436 		putpad(clr_eol);
437 	}
438 }