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/*  $OpenBSD: shapes.c,v 1.8 2004/07/10 07:26:24 deraadt Exp $  */
/*  $NetBSD: shapes.c,v 1.2 1995/04/22 07:42:44 cgd Exp $   */

/*-
 * Copyright (c) 1992, 1993
 *  The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek and Darren F. Provine.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *  @(#)shapes.c    8.1 (Berkeley) 5/31/93
 */

/*
 * Tetris shapes and related routines.
 *
 * Note that the first 7 are `well known'.
 */

#include <unistd.h>
#include "tetris.h"

#define TL  -B_COLS-1   /* top left */
#define TC  -B_COLS     /* top center */
#define TR  -B_COLS+1   /* top right */
#define ML  -1      /* middle left */
#define MR  1       /* middle right */
#define BL  B_COLS-1    /* bottom left */
#define BC  B_COLS      /* bottom center */
#define BR  B_COLS+1    /* bottom right */

const struct shape shapes[] = {
    /* 0*/  { 7,    7,  { TL, TC, MR } },
    /* 1*/  { 8,    8,  { TC, TR, ML } },
    /* 2*/  { 9,    11, { ML, MR, BC } },
    /* 3*/  { 3,    3,  { TL, TC, ML } },
    /* 4*/  { 12,   14, { ML, BL, MR } },
    /* 5*/  { 15,   17, { ML, BR, MR } },
    /* 6*/  { 18,   18, { ML, MR, 2  } }, /* sticks out */
    /* 7*/  { 0,    0,  { TC, ML, BL } },
    /* 8*/  { 1,    1,  { TC, MR, BR } },
    /* 9*/  { 10,   2,  { TC, MR, BC } },
    /*10*/  { 11,   9,  { TC, ML, MR } },
    /*11*/  { 2,    10, { TC, ML, BC } },
    /*12*/  { 13,   4,  { TC, BC, BR } },
    /*13*/  { 14,   12, { TR, ML, MR } },
    /*14*/  { 4,    13, { TL, TC, BC } },
    /*15*/  { 16,   5,  { TR, TC, BC } },
    /*16*/  { 17,   15, { TL, MR, ML } },
    /*17*/  { 5,    16, { TC, BC, BL } },
    /*18*/  { 6,    6,  { TC, BC, 2*B_COLS } }/* sticks out */
};

/*
 * Return true iff the given shape fits in the given position,
 * taking the current board into account.
 */
int
fits_in(const struct shape *shape, int pos)
{
    int *o = shape->off;

    if (board[pos] || board[pos + *o++] || board[pos + *o++] ||
        board[pos + *o])
        return 0;
    return 1;
}

/*
 * Write the given shape into the current board, turning it on
 * if `onoff' is 1, and off if `onoff' is 0.
 */
void
place(const struct shape *shape, int pos, int onoff)
{
    int *o = shape->off;

    board[pos] = onoff;
    board[pos + *o++] = onoff;
    board[pos + *o++] = onoff;
    board[pos + *o] = onoff;
}