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shapes.c revision 1.1 
      1 /*-
      2  * Copyright (c) 1992, 1993
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * Chris Torek and Darren F. Provine.
      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. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  *	@(#)shapes.c	8.1 (Berkeley) 5/31/93
     37  */
     38 
     39 /*
     40  * Tetris shapes and related routines.
     41  *
     42  * Note that the first 7 are `well known'.
     43  */
     44 
     45 #include <sys/cdefs.h>
     46 #include "tetris.h"
     47 
     48 #define	TL	-B_COLS-1	/* top left */
     49 #define	TC	-B_COLS		/* top center */
     50 #define	TR	-B_COLS+1	/* top right */
     51 #define	ML	-1		/* middle left */
     52 #define	MR	1		/* middle right */
     53 #define	BL	B_COLS-1	/* bottom left */
     54 #define	BC	B_COLS		/* bottom center */
     55 #define	BR	B_COLS+1	/* bottom right */
     56 
     57 struct shape shapes[] = {
     58 	/* 0*/	7,	TL, TC, MR,
     59 	/* 1*/	8,	TC, TR, ML,
     60 	/* 2*/	9,	ML, MR, BC,
     61 	/* 3*/	3,	TL, TC, ML,
     62 	/* 4*/	12,	ML, BL, MR,
     63 	/* 5*/	15,	ML, BR, MR,
     64 	/* 6*/	18,	ML, MR, /* sticks out */ 2,
     65 	/* 7*/	0,	TC, ML, BL,
     66 	/* 8*/	1,	TC, MR, BR,
     67 	/* 9*/	10,	TC, MR, BC,
     68 	/*10*/	11,	TC, ML, MR,
     69 	/*11*/	2,	TC, ML, BC,
     70 	/*12*/	13,	TC, BC, BR,
     71 	/*13*/	14,	TR, ML, MR,
     72 	/*14*/	4,	TL, TC, BC,
     73 	/*15*/	16,	TR, TC, BC,
     74 	/*16*/	17,	TL, MR, ML,
     75 	/*17*/	5,	TC, BC, BL,
     76 	/*18*/	6,	TC, BC, /* sticks out */ 2*B_COLS,
     77 };
     78 
     79 /*
     80  * Return true iff the given shape fits in the given position,
     81  * taking the current board into account.
     82  */
     83 int
     84 fits_in(shape, pos)
     85 	struct shape *shape;
     86 	register int pos;
     87 {
     88 	register int *o = shape->off;
     89 
     90 	if (board[pos] || board[pos + *o++] || board[pos + *o++] ||
     91 	    board[pos + *o])
     92 		return 0;
     93 	return 1;
     94 }
     95 
     96 /*
     97  * Write the given shape into the current board, turning it on
     98  * if `onoff' is 1, and off if `onoff' is 0.
     99  */
    100 void
    101 place(shape, pos, onoff)
    102 	struct shape *shape;
    103 	register int pos, onoff;
    104 {
    105 	register int *o = shape->off;
    106 
    107 	board[pos] = onoff;
    108 	board[pos + *o++] = onoff;
    109 	board[pos + *o++] = onoff;
    110 	board[pos + *o] = onoff;
    111 }
    112