screen.c revision 1.34 
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
60static cell curscreen[B_SIZE];	/* 1 => standout (or otherwise marked) */
61static int curscore;
62static int isset;		/* true => terminal is in game mode */
63static struct termios oldtt;
64static void (*tstp)(int);
65
66static	void	scr_stop(int);
67static	void	stopset(int) __dead;
68
69
70/*
71 * Routine used by tputs().
72 */
73int
74put(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
87static void
88moveto(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
97static void
98setcolor(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 */
118void
119scr_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' */
130static jmp_buf scr_onstop;
131
132static void
133stopset(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
145static void
146scr_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 */
162void
163scr_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 */
233void
234scr_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
261void
262stop(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 */
274void
275scr_clear(void)
276{
277
278	putpad(clear_screen);
279	curscore = -1;
280	memset((char *)curscreen, 0, sizeof(curscreen));
281}
282
283#if vax && !__GNUC__
284typedef int regcell;	/* pcc is bad at `register char', etc */
285#else
286typedef cell regcell;
287#endif
288
289/*
290 * Update the screen.
291 */
292void
293scr_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 */
415void
416scr_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}
433