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shapes.c revision 1.3 
      1 /*	$NetBSD: shapes.c,v 1.3 1997/10/12 02:03:47 lukem 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. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  *
     38  *	@(#)shapes.c	8.1 (Berkeley) 5/31/93
     39  */
     40 
     41 /*
     42  * Tetris shapes and related routines.
     43  *
     44  * Note that the first 7 are `well known'.
     45  */
     46 
     47 #include <sys/cdefs.h>
     48 #include "tetris.h"
     49 
     50 #define	TL	-B_COLS-1	/* top left */
     51 #define	TC	-B_COLS		/* top center */
     52 #define	TR	-B_COLS+1	/* top right */
     53 #define	ML	-1		/* middle left */
     54 #define	MR	1		/* middle right */
     55 #define	BL	B_COLS-1	/* bottom left */
     56 #define	BC	B_COLS		/* bottom center */
     57 #define	BR	B_COLS+1	/* bottom right */
     58 
     59 struct shape shapes[] = {
     60 	/* 0*/	{ 7,	{ TL, TC, MR, } },
     61 	/* 1*/	{ 8,	{ TC, TR, ML, } },
     62 	/* 2*/	{ 9,	{ ML, MR, BC, } },
     63 	/* 3*/	{ 3,	{ TL, TC, ML, } },
     64 	/* 4*/	{ 12,	{ ML, BL, MR, } },
     65 	/* 5*/	{ 15,	{ ML, BR, MR, } },
     66 	/* 6*/	{ 18,	{ ML, MR, 2   } },	/* sticks out */
     67 	/* 7*/	{ 0,	{ TC, ML, BL, } },
     68 	/* 8*/	{ 1,	{ TC, MR, BR, } },
     69 	/* 9*/	{ 10,	{ TC, MR, BC, } },
     70 	/*10*/	{ 11,	{ TC, ML, MR, } },
     71 	/*11*/	{ 2,	{ TC, ML, BC, } },
     72 	/*12*/	{ 13,	{ TC, BC, BR, } },
     73 	/*13*/	{ 14,	{ TR, ML, MR, } },
     74 	/*14*/	{ 4,	{ TL, TC, BC, } },
     75 	/*15*/	{ 16,	{ TR, TC, BC, } },
     76 	/*16*/	{ 17,	{ TL, MR, ML, } },
     77 	/*17*/	{ 5,	{ TC, BC, BL, } },
     78 	/*18*/	{ 6,	{ TC, BC, 2*B_COLS } }	/* sticks out */
     79 };
     80 
     81 /*
     82  * Return true iff the given shape fits in the given position,
     83  * taking the current board into account.
     84  */
     85 int
     86 fits_in(shape, pos)
     87 	struct shape *shape;
     88 	register int pos;
     89 {
     90 	register int *o = shape->off;
     91 
     92 	if (board[pos] || board[pos + *o++] || board[pos + *o++] ||
     93 	    board[pos + *o])
     94 		return 0;
     95 	return 1;
     96 }
     97 
     98 /*
     99  * Write the given shape into the current board, turning it on
    100  * if `onoff' is 1, and off if `onoff' is 0.
    101  */
    102 void
    103 place(shape, pos, onoff)
    104 	struct shape *shape;
    105 	register int pos, onoff;
    106 {
    107 	register int *o = shape->off;
    108 
    109 	board[pos] = onoff;
    110 	board[pos + *o++] = onoff;
    111 	board[pos + *o++] = onoff;
    112 	board[pos + *o] = onoff;
    113 }
    114