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/* 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.
*
*/
/*
* This code is based on original Mortville Manor DOS source code
* Copyright (c) 1987-1989 Lankhor
*/
#include "mortevielle/mortevielle.h"
#include "mortevielle/sound.h"
#include "common/scummsys.h"
namespace Mortevielle {
/**
* Constructor
*/
PCSpeaker::PCSpeaker(int rate) {
_rate = rate;
_oscLength = 0;
_oscSamples = 0;
_remainingSamples = 0;
_volume = 255;
}
/**
* Destructor
*/
PCSpeaker::~PCSpeaker() {
}
/**
* Adds a new note to the queue of notes to be played.
*/
void PCSpeaker::play(int freq, uint32 length) {
assert((freq > 0) && (length > 0));
Common::StackLock lock(_mutex);
_pendingNotes.push(SpeakerNote(freq, length));
}
/**
* Stops the currently playing song
*/
void PCSpeaker::stop() {
Common::StackLock lock(_mutex);
_remainingSamples = 0;
_pendingNotes.clear();
}
void PCSpeaker::setVolume(byte volume) {
_volume = volume;
}
/**
* Return true if a song is currently playing
*/
bool PCSpeaker::isPlaying() const {
return !_pendingNotes.empty() || (_remainingSamples != 0);
}
/**
* Method used by the mixer to pull off pending samples to play
*/
int PCSpeaker::readBuffer(int16 *buffer, const int numSamples) {
Common::StackLock lock(_mutex);
int i;
for (i = 0; (_remainingSamples || !_pendingNotes.empty()) && (i < numSamples); ++i) {
if (!_remainingSamples)
// Used up the current note, so queue the next one
dequeueNote();
buffer[i] = generateSquare(_oscSamples, _oscLength) * _volume;
if (_oscSamples++ >= _oscLength)
_oscSamples = 0;
_remainingSamples--;
}
// Clear the rest of the buffer
if (i < numSamples)
memset(buffer + i, 0, (numSamples - i) * sizeof(int16));
return numSamples;
}
/**
* Dequeues a note from the pending note list
*/
void PCSpeaker::dequeueNote() {
SpeakerNote note = _pendingNotes.pop();
_oscLength = _rate / note.freq;
_oscSamples = 0;
_remainingSamples = (_rate * note.length) / 1000000;
assert((_oscLength > 0) && (_remainingSamples > 0));
}
/**
* Support method for generating a square wave
*/
int8 PCSpeaker::generateSquare(uint32 x, uint32 oscLength) {
return (x < (oscLength / 2)) ? 127 : -128;
}
/*-------------------------------------------------------------------------*/
const int tab[16] = { -96, -72, -48, -32, -20, -12, -8, -4, 0, 4, 8, 12, 20, 32, 48, 72 };
// The PC timer chip works at a frequency of 1.19318Mhz
#define TIMER_FREQUENCY 1193180
SoundManager::SoundManager(Audio::Mixer *mixer) {
_mixer = mixer;
_speakerStream = new PCSpeaker(mixer->getOutputRate());
_mixer->playStream(Audio::Mixer::kSFXSoundType, &_speakerHandle,
_speakerStream, -1, Audio::Mixer::kMaxChannelVolume, 0, DisposeAfterUse::NO, true);
}
SoundManager::~SoundManager() {
_mixer->stopHandle(_speakerHandle);
delete _speakerStream;
}
/**
* Decode music data
*/
void SoundManager::decodeMusic(const byte *PSrc, byte *PDest, int NbreSeg) {
int seed = 128;
int v;
for (int idx1 = 0; idx1 < (NbreSeg * 2); ++idx1) {
for (int idx2 = 0; idx2 < 64; ++idx2) {
byte srcByte = *PSrc++;
v = tab[srcByte >> 4];
seed += v;
*PDest++ = seed & 0xff;
v = tab[srcByte & 0xf];
seed += v;
*PDest++ = seed & 0xff;
}
}
}
void SoundManager::litph(tablint &t, int typ, int tempo) {
return;
}
void SoundManager::playNote(int frequency, int32 length) {
_speakerStream->play(frequency, length);
}
void SoundManager::musyc(tablint &tb, int nbseg, int att) {
#ifdef DEBUG
const byte *pSrc = &_vm->_mem[kAdrMusic * 16];
// Convert the countdown amount to a tempo rate, and then to note length in microseconds
int tempo = TIMER_FREQUENCY / att;
int length = 1000000 / tempo;
for (int noteIndex = 0; noteIndex < (nbseg * 16); ++noteIndex) {
int lookupValue = *pSrc++;
int noteCountdown = tb[lookupValue];
int noteFrequency = TIMER_FREQUENCY / noteCountdown;
playNote(noteFrequency, length);
}
// Keep waiting until the song has been finished
while (_speakerStream->isPlaying() && !_vm->shouldQuit()) {
_vm->delay(10);
}
#endif
}
void SoundManager::setParent(MortevielleEngine *vm) {
_vm = vm;
}
} // End of namespace Mortevielle
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