/* * NanoBreaker, a Nano-X Breakout clone by Alex Holden. * * The contents of this file are subject to the Mozilla Public License * Version 1.1 (the "License"); you may not use this file except in * compliance with the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the * License for the specific language governing rights and limitations * under the License. * * The Original Code is NanoBreaker. * * The Initial Developer of the Original Code is Alex Holden. * Portions created by Alex Holden are Copyright (C) 2002 * Alex Holden . All Rights Reserved. * * Contributor(s): * * Alternatively, the contents of this file may be used under the terms * of the GNU General Public license (the "[GNU] License"), in which case the * provisions of [GNU] License are applicable instead of those * above. If you wish to allow use of your version of this file only * under the terms of the [GNU] License and not to allow others to use * your version of this file under the MPL, indicate your decision by * deleting the provisions above and replace them with the notice and * other provisions required by the [GNU] License. If you do not delete * the provisions above, a recipient may use your version of this file * under either the MPL or the [GNU] License. */ /* cheat.c contains do_cheat() which is used to handle the cheat sequences. */ #include #include #include #include #include #include "nbreaker.h" /* Used by do_cheat to compare each of the cheat sequences in turn to the * current cheat state. It differs from strcmp() in that it returns 0 * ("no match") if the second parameter is null (ie. that cheat sequence is * undefined), it returns 1 ("match") if there is a definite match, and it * returns 2 ("partial match") if the first string is shorter than the second * string but the letters which are there match the initial portion of the * second string. This latter is used to determine when the current cheat * state has no chance of matching any of the cheat sequences so it can throw * away the current cheat state and start again. */ static int cheatcmp(char *a, char *b) { int m = 0; /* If the cheat sequence is undefined, return "no match": */ if(!b) return 0; /* While the current character of the cheat sequence matches the * current character of the cheat state: */ while(*a == *b) { /* If they are 0 (ie. the end of the strings) then both strings * must match for their entire length, so return "match": */ if(!*a) return 1; /* Since we got past the first comparison, at least the first * character must match, so set the "match found" flag: */ m = 1; /* Increment to the next letter in the strings: */ a++; b++; } /* If we have reached the end of the cheat state but not the end of the * cheat sequence and at least one matching character was found, return * "partial match": */ if(!*a && *b && m) return 2; else return 0; /* Otherwise return "no match". */ } /* This is called by handle_keystroke_event() when it gets a key down event * for a key that it isn't interested in. This includes all ascii characters. * We maintain a buffer with the current list of letters received by this * function, and every time we get a new letter the entire buffer is compared * against all of the cheat sequences. If it fully matches one of the cheat * sequences, that cheat is activated and the buffer reset. If it matches only * the initial portion of at least one of the cheat sequences, the buffer is * kept as is. If it doesn't match the initial portion of any of the cheat * sequences, the buffer is emptied. */ void do_cheat(nbstate *state, GR_KEY key) { int i, len, partial_match = 0; /* We aren't interested in any non-ascii keystrokes: */ if(key > 127) return; /* Find the end of the buffer and paste the new letter on the end. * We know the buffer can't overrun because the cheat sequences are * limited to one less than the size of the buffer, and the buffer * cannot grow to longer than the longest cheat sequence because it * will either match one of the cheat sequences and get reset, or fail * to match any of them and also get reset. */ len = strlen(state->cheatstate); state->cheatstate[len] = key; /* Check for a match against the SolidFloor cheat: */ if((i = cheatcmp(state->cheatstate, state->cheats[SFCHEAT]))) { if(i == 1) { /* A complete match. */ /* Toggle the SolidFloor flag: */ state->flags.sf ^= 1; /* Reset the cheat state and return: */ memset(state->cheatstate, 0, MAXCHEATLEN + 1); return; } else partial_match = 1; /* It was at least a partial match. */ } /* Check for a match against the TelePort cheat: */ if((i = cheatcmp(state->cheatstate, state->cheats[TPCHEAT]))) { if(i == 1) { /* Teleport to the next level: */ increment_level(state); memset(state->cheatstate, 0, MAXCHEATLEN + 1); return; } else partial_match = 1; } /* Check for a match against the NoBounce cheat: */ if((i = cheatcmp(state->cheatstate, state->cheats[NBCHEAT]))) { if(i == 1) { /* Toggle the NoBounce flag: */ state->flags.nb ^= 1; memset(state->cheatstate, 0, MAXCHEATLEN + 1); return; } else partial_match = 1; } /* Check for a match against the NoPowerDown cheat: */ if((i = cheatcmp(state->cheatstate, state->cheats[NPDCHEAT]))) { if(i == 1) { /* Toggle the NoPowerDown flag: */ state->flags.npd ^= 1; memset(state->cheatstate, 0, MAXCHEATLEN + 1); return; } else partial_match = 1; } /* Check for a match against the NoPowerUpTimeOut cheat: */ if((i = cheatcmp(state->cheatstate, state->cheats[NPUTOCHEAT]))) { if(i == 1) { /* Toggle the NoPowerUpTimeOut flag: */ state->flags.nputo ^= 1; memset(state->cheatstate, 0, MAXCHEATLEN + 1); return; } else partial_match = 1; } /* If there wasn't even a partial match against any of the cheat * sequences, reset the cheat state: */ if(!partial_match) memset(state->cheatstate, 0, MAXCHEATLEN + 1); }