apps/plugins/doom/m_cheat.c

   1 // Emacs style mode select   -*- C++ -*-
   2 //-----------------------------------------------------------------------------
   3 //
   4 // $Id$
   5 //
   6 // Copyright (C) 1993-1996 by id Software, Inc.
   7 //
   8 // This program is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU General Public License
  10 // as published by the Free Software Foundation; either version 2
  11 // of the License, or (at your option) any later version.
  12 //
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17 //
  18 // $Log$
  19 // Revision 1.1  2006/03/28 15:44:01  dave
  20 // Patch #2969 - Doom!  Currently only working on the H300.
  21 //
  22 //
  23 // DESCRIPTION:
  24 // Cheat sequence checking.
  25 //
  26 //-----------------------------------------------------------------------------
  27
  28 #include "m_cheat.h"
  29
  30 //
  31 // CHEAT SEQUENCE PACKAGE
  32 //
  33
  34 static int  firsttime = 1;
  35 static unsigned char cheat_xlate_table[20];
  36
  37
  38 //
  39 // Called in st_stuff module, which handles the input.
  40 // Returns a 1 if the cheat was successful, 0 if failed.
  41 //
  42 int
  43 cht_CheckCheat
  44 ( cheatseq_t* cht,
  45   char  key )
  46 {
  47    int i;
  48    int rc = 0;
  49
  50    if (firsttime)
  51    {
  52       firsttime = 0;
  53       for (i=0;i<256;i++)
  54          cheat_xlate_table[i] = SCRAMBLE(i);
  55    }
  56
  57    if (!cht->p)
  58       cht->p = cht->sequence; // initialize if first time
  59
  60    if (*cht->p == 0)
  61       *(cht->p++) = key;
  62    else if
  63    (cheat_xlate_table[(unsigned char)key] == *cht->p)
  64       cht->p++;
  65    else
  66       cht->p = cht->sequence;
  67
  68    if (*cht->p == 1)
  69       cht->p++;
  70    else if (*cht->p == 0xff) // end of sequence character
  71    {
  72       cht->p = cht->sequence;
  73       rc = 1;
  74    }
  75
  76    return rc;
  77 }
  78
  79 void
  80 cht_GetParam
  81 ( cheatseq_t* cht,
  82   char*  buffer )
  83 {
  84
  85    unsigned char *p, c;
  86
  87    p = cht->sequence;
  88    while (*(p++) != 1)
  89       ;
  90
  91    do
  92    {
  93       c = *p;
  94       *(buffer++) = c;
  95       *(p++) = 0;
  96    }
  97    while (c && *p!=0xff );
  98
  99    if (*p==0xff)
 100       *buffer = 0;
 101
 102 }
 103
 104