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      1 /*	$NetBSD: shapes.c,v 1.9 2014/06/11 16:47:39 christos 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  *	@(#)shapes.c	8.1 (Berkeley) 5/31/93
     35  */
     36 
     37 /*
     38  * Tetris shapes and related routines.
     39  *
     40  * Note that the first 7 are `well known'.
     41  */
     42 
     43 #include <sys/cdefs.h>
     44 #include "tetris.h"
     45 
     46 #define	TL	-B_COLS-1	/* top left */
     47 #define	TC	-B_COLS		/* top center */
     48 #define	TR	-B_COLS+1	/* top right */
     49 #define	ML	-1		/* middle left */
     50 #define	MR	1		/* middle right */
     51 #define	BL	B_COLS-1	/* bottom left */
     52 #define	BC	B_COLS		/* bottom center */
     53 #define	BR	B_COLS+1	/* bottom right */
     54 
     55 const struct shape shapes[] = {
     56 	/* 0*/	{ 7,  7,	{ TL, TC, MR, } },
     57 	/* 1*/	{ 1,  8,	{ TC, TR, ML, } },
     58 	/* 2*/	{ 2,  9,	{ ML, MR, BC, } },
     59 	/* 3*/	{ 3,  3,	{ TL, TC, ML, } },
     60 	/* 4*/	{ 4, 12,	{ ML, BL, MR, } },
     61 	/* 5*/	{ 5, 15,	{ ML, BR, MR, } },
     62 	/* 6*/	{ 6, 18,	{ ML, MR, 2   } },	/* sticks out */
     63 	/* 7*/	{ 7,  0,	{ TC, ML, BL, } },
     64 	/* 8*/	{ 1,  1,	{ TC, MR, BR, } },
     65 	/* 9*/	{ 2, 10,	{ TC, MR, BC, } },
     66 	/*10*/	{ 2, 11,	{ TC, ML, MR, } },
     67 	/*11*/	{ 2,  2,	{ TC, ML, BC, } },
     68 	/*12*/	{ 4, 13,	{ TC, BC, BR, } },
     69 	/*13*/	{ 4, 14,	{ TR, ML, MR, } },
     70 	/*14*/	{ 4,  4,	{ TL, TC, BC, } },
     71 	/*15*/	{ 5, 16,	{ TR, TC, BC, } },
     72 	/*16*/	{ 5, 17,	{ TL, MR, ML, } },
     73 	/*17*/	{ 5,  5,	{ TC, BC, BL, } },
     74 	/*18*/	{ 6,  6,	{ TC, BC, 2*B_COLS } }	/* sticks out */
     75 };
     76 
     77 /*
     78  * Return true iff the given shape fits in the given position,
     79  * taking the current board into account.
     80  */
     81 int
     82 fits_in(const struct shape *shape, int pos)
     83 {
     84 	const int *o = shape->off;
     85 
     86 	if (board[pos] || board[pos + *o++] || board[pos + *o++] ||
     87 	    board[pos + *o])
     88 		return 0;
     89 	return 1;
     90 }
     91 
     92 /*
     93  * Write the given shape into the current board, turning it on
     94  * if `onoff' is 1, and off if `onoff' is 0.
     95  */
     96 void
     97 place(const struct shape *shape, int pos, int onoff)
     98 {
     99 	const int *o = shape->off;
    100 	onoff = onoff ? shape->color : 0;
    101 
    102 	board[pos] = onoff;
    103 	board[pos + *o++] = onoff;
    104 	board[pos + *o++] = onoff;
    105 	board[pos + *o] = onoff;
    106 }
    107