xref: /netbsd-src/games/tetris/tetris.h (revision 413d532bcc3f62d122e56d92e13ac64825a40baf)
1 /*	$NetBSD: tetris.h,v 1.12 2009/08/12 08:51:21 dholland 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  *	@(#)tetris.h	8.1 (Berkeley) 5/31/93
35  */
36 
37 #include <sys/types.h>
38 
39 /*
40  * Definitions for Tetris.
41  */
42 
43 /*
44  * The display (`board') is composed of 23 rows of 12 columns of characters
45  * (numbered 0..22 and 0..11), stored in a single array for convenience.
46  * Columns 1 to 10 of rows 1 to 20 are the actual playing area, where
47  * shapes appear.  Columns 0 and 11 are always occupied, as are all
48  * columns of rows 21 and 22.  Rows 0 and 22 exist as boundary areas
49  * so that regions `outside' the visible area can be examined without
50  * worrying about addressing problems.
51  */
52 
53 	/* the board */
54 #define	B_COLS	12
55 #define	B_ROWS	23
56 #define	B_SIZE	(B_ROWS * B_COLS)
57 
58 typedef unsigned char cell;
59 extern cell	board[B_SIZE];	/* 1 => occupied, 0 => empty */
60 
61 	/* the displayed area (rows) */
62 #define	D_FIRST	1
63 #define	D_LAST	22
64 
65 	/* the active area (rows) */
66 #define	A_FIRST	1
67 #define	A_LAST	21
68 
69 /*
70  * Minimum display size.
71  */
72 #define	MINROWS	23
73 #define	MINCOLS	40
74 
75 extern int	Rows, Cols;	/* current screen size */
76 
77 /*
78  * Translations from board coordinates to display coordinates.
79  * As with board coordinates, display coordiates are zero origin.
80  */
81 #define	RTOD(x)	((x) - 1)
82 #define	CTOD(x)	((x) * 2 + (((Cols - 2 * B_COLS) >> 1) - 1))
83 
84 /*
85  * A `shape' is the fundamental thing that makes up the game.  There
86  * are 7 basic shapes, each consisting of four `blots':
87  *
88  *	X.X	  X.X		X.X
89  *	  X.X	X.X	X.X.X	X.X	X.X.X	X.X.X	X.X.X.X
90  *			  X		X	    X
91  *
92  *	  0	  1	  2	  3	  4	  5	  6
93  *
94  * Except for 3 and 6, the center of each shape is one of the blots.
95  * This blot is designated (0,0).  The other three blots can then be
96  * described as offsets from the center.  Shape 3 is the same under
97  * rotation, so its center is effectively irrelevant; it has been chosen
98  * so that it `sticks out' upward and leftward.  Except for shape 6,
99  * all the blots are contained in a box going from (-1,-1) to (+1,+1);
100  * shape 6's center `wobbles' as it rotates, so that while it `sticks out'
101  * rightward, its rotation---a vertical line---`sticks out' downward.
102  * The containment box has to include the offset (2,0), making the overall
103  * containment box range from offset (-1,-1) to (+2,+1).  (This is why
104  * there is only one row above, but two rows below, the display area.)
105  *
106  * The game works by choosing one of these shapes at random and putting
107  * its center at the middle of the first display row (row 1, column 5).
108  * The shape is moved steadily downward until it collides with something:
109  * either  another shape, or the bottom of the board.  When the shape can
110  * no longer be moved downwards, it is merged into the current board.
111  * At this time, any completely filled rows are elided, and blots above
112  * these rows move down to make more room.  A new random shape is again
113  * introduced at the top of the board, and the whole process repeats.
114  * The game ends when the new shape will not fit at (1,5).
115  *
116  * While the shapes are falling, the user can rotate them counterclockwise
117  * 90 degrees (in addition to moving them left or right), provided that the
118  * rotation puts the blots in empty spaces.  The table of shapes is set up
119  * so that each shape contains the index of the new shape obtained by
120  * rotating the current shape.  Due to symmetry, each shape has exactly
121  * 1, 2, or 4 rotations total; the first 7 entries in the table represent
122  * the primary shapes, and the remaining 12 represent their various
123  * rotated forms.
124  */
125 struct shape {
126 	int	rot;	/* index of rotated version of this shape */
127 	int	off[3];	/* offsets to other blots if center is at (0,0) */
128 };
129 
130 extern const struct shape shapes[];
131 #define	randshape() (&shapes[random() % 7])
132 
133 extern const struct shape *nextshape;
134 
135 /*
136  * Shapes fall at a rate faster than once per second.
137  *
138  * The initial rate is determined by dividing 1 million microseconds
139  * by the game `level'.  (This is at most 1 million, or one second.)
140  * Each time the fall-rate is used, it is decreased a little bit,
141  * depending on its current value, via the `faster' macro below.
142  * The value eventually reaches a limit, and things stop going faster,
143  * but by then the game is utterly impossible.
144  */
145 extern long	fallrate;	/* less than 1 million; smaller => faster */
146 #define	faster() (fallrate -= fallrate / 3000)
147 
148 /*
149  * Game level must be between 1 and 9.  This controls the initial fall rate
150  * and affects scoring.
151  */
152 #define	MINLEVEL	1
153 #define	MAXLEVEL	9
154 
155 /*
156  * Scoring is as follows:
157  *
158  * When the shape comes to rest, and is integrated into the board,
159  * we score one point.  If the shape is high up (at a low-numbered row),
160  * and the user hits the space bar, the shape plummets all the way down,
161  * and we score a point for each row it falls (plus one more as soon as
162  * we find that it is at rest and integrate it---until then, it can
163  * still be moved or rotated).
164  */
165 extern int	score;		/* the obvious thing */
166 extern gid_t	gid, egid;
167 
168 extern char	key_msg[100];
169 extern int	showpreview;
170 
171 int	fits_in(const struct shape *, int);
172 void	place(const struct shape *, int, int);
173 void	stop(const char *) __dead;
174