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