games/tetris/shapes.c

   1 /*      $OpenBSD: shapes.c,v 1.10 2016/01/04 17:33:24 mestre Exp $      */
   2 /*      $NetBSD: shapes.c,v 1.2 1995/04/22 07:42:44 cgd Exp $   */
   3
   4 /*-
   5  * Copyright (c) 1992, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Chris Torek and Darren F. Provine.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  *      @(#)shapes.c    8.1 (Berkeley) 5/31/93
  36  */
  37
  38 /*
  39  * Tetris shapes and related routines.
  40  *
  41  * Note that the first 7 are `well known'.
  42  */
  43
  44 #include <unistd.h>
  45
  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 const struct shape shapes[] = {
  58         /* 0*/  { 7,    7,      { TL, TC, MR } },
  59         /* 1*/  { 8,    8,      { TC, TR, ML } },
  60         /* 2*/  { 9,    11,     { ML, MR, BC } },
  61         /* 3*/  { 3,    3,      { TL, TC, ML } },
  62         /* 4*/  { 12,   14,     { ML, BL, MR } },
  63         /* 5*/  { 15,   17,     { ML, BR, MR } },
  64         /* 6*/  { 18,   18,     { ML, MR, 2  } }, /* sticks out */
  65         /* 7*/  { 0,    0,      { TC, ML, BL } },
  66         /* 8*/  { 1,    1,      { TC, MR, BR } },
  67         /* 9*/  { 10,   2,      { TC, MR, BC } },
  68         /*10*/  { 11,   9,      { TC, ML, MR } },
  69         /*11*/  { 2,    10,     { TC, ML, BC } },
  70         /*12*/  { 13,   4,      { TC, BC, BR } },
  71         /*13*/  { 14,   12,     { TR, ML, MR } },
  72         /*14*/  { 4,    13,     { TL, TC, BC } },
  73         /*15*/  { 16,   5,      { TR, TC, BC } },
  74         /*16*/  { 17,   15,     { TL, MR, ML } },
  75         /*17*/  { 5,    16,     { TC, BC, BL } },
  76         /*18*/  { 6,    6,      { TC, BC, 2*B_COLS } }/* sticks out */
  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(const struct shape *shape, int pos)
  85 {
  86         const int *o = shape->off;
  87
  88         if (board[pos] || board[pos + *o++] || board[pos + *o++] ||
  89             board[pos + *o])
  90                 return 0;
  91         return 1;
  92 }
  93
  94 /*
  95  * Write the given shape into the current board, turning it on
  96  * if `onoff' is 1, and off if `onoff' is 0.
  97  */
  98 void
  99 place(const struct shape *shape, int pos, int onoff)
 100 {
 101         const int *o = shape->off;
 102
 103         board[pos] = onoff;
 104         board[pos + *o++] = onoff;
 105         board[pos + *o++] = onoff;
 106         board[pos + *o] = onoff;
 107 }