1/*	$NetBSD: twinkle1.c,v 1.7 2023/05/04 11:30:25 uwe Exp $	*/
2
3/*
4 *
5 *  Copyright (c) 1980, 1993
6 * 	 The Regents of the University of California.  All rights reserved.
7 *
8 *  Redistribution and use in source and binary forms, with or without
9 *  modification, are permitted provided that the following conditions
10 *  are met:
11 *  1. Redistributions of source code must retain the above copyright
12 *     notice, this list of conditions and the following disclaimer.
13 *  2. Redistributions in binary form must reproduce the above copyright
14 *     notice, this list of conditions and the following disclaimer in the
15 *     documentation and/or other materials provided with the distribution.
16 *  3. Neither the name of the University nor the names of its contributors
17 *     may be used to endorse or promote products derived from this software
18 *     without specific prior written permission.
19 *
20 *  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 *  ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 *  SUCH DAMAGE.
31 *
32 * 	@(#)twinkle1.c	8.1 (Berkeley) 6/8/93
33 */
34#include	<curses.h>
35#include	<signal.h>
36
37/*
38 * the idea for this program was a product of the imagination of
39 * Kurt Shoens.  Not responsible for minds lost or stolen.
40 */
41
42#define	NCOLS	80
43#define	NLINES	24
44#define	MAXPATTERNS	4
45
46typedef struct {
47	int	y, x;
48} LOCS;
49
50static LOCS	Layout[NCOLS * NLINES];	/* current board layout */
51
52static int	Pattern,		/* current pattern number */
53		Numstars;		/* number of stars in pattern */
54
55static void puton(char);
56static void makeboard(void);
57static int ison(int, int);
58static void die(int);
59
60int
61main(void)
62{
63	srand(getpid());		/* initialize random sequence */
64
65	initscr();
66	signal(SIGINT, die);
67	noecho();
68	nonl();
69	leaveok(stdscr, TRUE);
70	scrollok(stdscr, FALSE);
71
72	for (;;) {
73		makeboard();		/* make the board setup */
74		puton('*');		/* put on '*'s */
75		puton(' ');		/* cover up with ' 's */
76	}
77}
78
79/*
80 * On program exit, move the cursor to the lower left corner by
81 * direct addressing, since current location is not guaranteed.
82 * We lie and say we used to be at the upper right corner to guarantee
83 * absolute addressing.
84 */
85static void
86die(int n)
87{
88	signal(SIGINT, SIG_IGN);
89	mvcur(0, COLS - 1, LINES - 1, 0);
90	endwin();
91	exit(n);
92}
93
94
95/*
96 * Make the current board setup.  It picks a random pattern and
97 * calls ison() to determine if the character is on that pattern
98 * or not.
99 */
100static void
101makeboard(void)
102{
103	int		y, x;
104	LOCS	*lp;
105
106	Pattern = rand() % MAXPATTERNS;
107	lp = Layout;
108	for (y = 0; y < NLINES; y++)
109		for (x = 0; x < NCOLS; x++)
110			if (ison(y, x)) {
111				lp->y = y;
112				lp->x = x;
113				lp++;
114			}
115	Numstars = lp - Layout;
116}
117
118/*
119 * Return TRUE if (y, x) is on the current pattern.
120 */
121static int
122ison(int y, int x)
123{
124	switch (Pattern) {
125	  case 0:	/* alternating lines */
126		return !(y & 01);
127	  case 1:	/* box */
128		if (x >= LINES && y >= NCOLS)
129			return FALSE;
130		if (y < 3 || y >= NLINES - 3)
131			return TRUE;
132		return (x < 3 || x >= NCOLS - 3);
133	  case 2:	/* holy pattern! */
134		return ((x + y) & 01);
135	  case 3:	/* bar across center */
136		return (y >= 9 && y <= 15);
137	}
138	/* NOTREACHED */
139}
140
141static void
142puton(char ch)
143{
144	LOCS	*lp;
145	int	r;
146	LOCS	*end;
147	LOCS	temp;
148
149	end = &Layout[Numstars];
150	for (lp = Layout; lp < end; lp++) {
151		r = rand() % Numstars;
152		temp = *lp;
153		*lp = Layout[r];
154		Layout[r] = temp;
155	}
156
157	for (lp = Layout; lp < end; lp++) {
158		mvaddch(lp->y, lp->x, ch);
159		refresh();
160	}
161}
162