scummvm/engines/agi/logic.cpp
2011-05-12 01:16:22 +02:00

110 lines
3.3 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "agi/agi.h"
namespace Agi {
/**
* Decode logic resource
* This function decodes messages from the specified raw logic resource
* into a message list.
* @param n The number of the logic resource to decode.
*/
int AgiEngine::decodeLogic(int n) {
int ec = errOK;
int mstart, mend, mc;
uint8 *m0;
// decrypt messages at end of logic + build message list
// report ("decoding logic #%d\n", n);
m0 = _game.logics[n].data;
mstart = READ_LE_UINT16(m0) + 2;
mc = *(m0 + mstart);
mend = READ_LE_UINT16(m0 + mstart + 1);
m0 += mstart + 3; // cover header info
mstart = mc << 1;
// if the logic was not compressed, decrypt the text messages
// only if there are more than 0 messages
if ((~_game.dirLogic[n].flags & RES_COMPRESSED) && mc > 0)
decrypt(m0 + mstart, mend - mstart); // decrypt messages
// build message list
m0 = _game.logics[n].data;
mstart = READ_LE_UINT16(m0) + 2; // +2 covers pointer
_game.logics[n].numTexts = *(m0 + mstart);
// resetp logic pointers
_game.logics[n].sIP = 2;
_game.logics[n].cIP = 2;
_game.logics[n].size = READ_LE_UINT16(m0) + 2; // logic end pointer
// allocate list of pointers to point into our data
_game.logics[n].texts = (const char **)calloc(1 + _game.logics[n].numTexts, sizeof(char *));
// cover header info
m0 += mstart + 3;
if (_game.logics[n].texts != NULL) {
// move list of strings into list to make real pointers
for (mc = 0; mc < _game.logics[n].numTexts; mc++) {
mend = READ_LE_UINT16(m0 + mc * 2);
_game.logics[n].texts[mc] = mend ? (const char *)m0 + mend - 2 : (const char *)"";
}
// set loaded flag now its all completly loaded
_game.dirLogic[n].flags |= RES_LOADED;
} else {
// unload data
// Note that not every logic has text
free(_game.logics[n].data);
ec = errNotEnoughMemory;
}
return ec;
}
/**
* Unload logic resource
* This function unloads the specified logic resource, freeing any
* memory chunks allocated for this resource.
* @param n The number of the logic resource to unload
*/
void AgiEngine::unloadLogic(int n) {
if (_game.dirLogic[n].flags & RES_LOADED) {
free(_game.logics[n].data);
if (_game.logics[n].numTexts)
free(_game.logics[n].texts);
_game.logics[n].numTexts = 0;
_game.dirLogic[n].flags &= ~RES_LOADED;
}
// if cached, we end up here
_game.logics[n].sIP = 2;
_game.logics[n].cIP = 2;
}
} // End of namespace Agi