scummvm/engines/sky/music/adlibmusic.cpp

125 lines
3.4 KiB
C++

/* ScummVM - Scumm Interpreter
* Copyright (C) 2003-2006 The ScummVM project
*
* 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.
*
* $URL$
* $Id$
*
*/
#include "common/stdafx.h"
#include "common/endian.h"
#include "sky/music/adlibmusic.h"
#include "sky/music/adlibchannel.h"
#include "sound/mixer.h"
#include "sky/sky.h"
namespace Sky {
AdlibMusic::AdlibMusic(Audio::Mixer *pMixer, Disk *pDisk)
: MusicBase(pDisk) {
_driverFileBase = 60202;
_mixer = pMixer;
_sampleRate = pMixer->getOutputRate();
_opl = makeAdlibOPL(_sampleRate);
_mixer->setupPremix(this);
}
AdlibMusic::~AdlibMusic(void) {
_mixer->setupPremix(0);
}
void AdlibMusic::premixerCall(int16 *data, uint len) {
if (_musicData == NULL) {
// no music loaded
memset(data, 0, 2 * len * sizeof(int16));
} else if ((_currentMusic == 0) || (_numberOfChannels == 0)) {
// music loaded but not played as of yet
memset(data, 0, 2 * len * sizeof(int16));
// poll anyways as pollMusic() can activate the music
pollMusic();
_nextMusicPoll = _sampleRate/50;
} else {
uint32 render;
int16 *origData = data;
uint origLen = len;
while (len) {
render = (len > _nextMusicPoll) ? (_nextMusicPoll) : (len);
len -= render;
_nextMusicPoll -= render;
YM3812UpdateOne(_opl, data, render);
data += render;
if (_nextMusicPoll == 0) {
pollMusic();
_nextMusicPoll = _sampleRate/50;
}
}
// Convert mono data to stereo
for (int i = (origLen - 1); i >= 0; i--) {
origData[2 * i] = origData[2 * i + 1] = origData[i];
}
}
}
void AdlibMusic::setupPointers(void) {
if (SkyEngine::_systemVars.gameVersion == 109) {
// disk demo uses a different adlib driver version, some offsets have changed
//_musicDataLoc = (_musicData[0x11CC] << 8) | _musicData[0x11CB];
//_initSequence = _musicData + 0xEC8;
_musicDataLoc = READ_LE_UINT16(_musicData + 0x1200);
_initSequence = _musicData + 0xEFB;
} else if (SkyEngine::_systemVars.gameVersion == 267) {
_musicDataLoc = READ_LE_UINT16(_musicData + 0x11F7);
_initSequence = _musicData + 0xE87;
} else {
_musicDataLoc = READ_LE_UINT16(_musicData + 0x1201);
_initSequence = _musicData + 0xE91;
}
_nextMusicPoll = 0;
}
void AdlibMusic::setupChannels(uint8 *channelData) {
_numberOfChannels = channelData[0];
channelData++;
for (uint8 cnt = 0; cnt < _numberOfChannels; cnt++) {
uint16 chDataStart = ((channelData[(cnt << 1) | 1] << 8) | channelData[cnt << 1]) + _musicDataLoc;
_channels[cnt] = new AdlibChannel(_opl, _musicData, chDataStart);
_channels[cnt]->updateVolume(_musicVolume);
}
}
void AdlibMusic::startDriver(void) {
uint16 cnt = 0;
while (_initSequence[cnt] || _initSequence[cnt+1]) {
OPLWriteReg (_opl, _initSequence[cnt], _initSequence[cnt+1]);
cnt += 2;
}
_allowedCommands = 0xD;
}
} // End of namespace Sky