source: mainline/tetris/shapes.c@ 854387b

/*      $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;
}