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      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 
     46 typedef struct {
     47 	int	y, x;
     48 } LOCS;
     49 
     50 static LOCS	Layout[NCOLS * NLINES];	/* current board layout */
     51 
     52 static int	Pattern,		/* current pattern number */
     53 		Numstars;		/* number of stars in pattern */
     54 
     55 static void puton(char);
     56 static void makeboard(void);
     57 static int ison(int, int);
     58 static void die(int);
     59 
     60 int
     61 main(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  */
     85 static void
     86 die(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  */
    100 static void
    101 makeboard(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  */
    121 static int
    122 ison(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 
    141 static void
    142 puton(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