diff options
author | Max Horn | 2011-02-09 01:09:01 +0000 |
---|---|---|
committer | Max Horn | 2011-02-09 01:09:01 +0000 |
commit | 42ab839dd6c8a1570b232101eb97f4e54de57935 (patch) | |
tree | 3b763d8913a87482b793e0348c88b9a5f40eecc9 /audio/softsynth/emumidi.h | |
parent | 386203a3d6ce1abf457c9110d695408ec5f01b85 (diff) | |
download | scummvm-rg350-42ab839dd6c8a1570b232101eb97f4e54de57935.tar.gz scummvm-rg350-42ab839dd6c8a1570b232101eb97f4e54de57935.tar.bz2 scummvm-rg350-42ab839dd6c8a1570b232101eb97f4e54de57935.zip |
AUDIO: Rename sound/ dir to audio/
svn-id: r55850
Diffstat (limited to 'audio/softsynth/emumidi.h')
-rw-r--r-- | audio/softsynth/emumidi.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/audio/softsynth/emumidi.h b/audio/softsynth/emumidi.h new file mode 100644 index 0000000000..35c81490e4 --- /dev/null +++ b/audio/softsynth/emumidi.h @@ -0,0 +1,116 @@ +/* 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. + * + * $URL$ + * $Id$ + */ + +#ifndef SOUND_SOFTSYNTH_EMUMIDI_H +#define SOUND_SOFTSYNTH_EMUMIDI_H + +#include "audio/audiostream.h" +#include "audio/mididrv.h" +#include "audio/mixer.h" + +#define FIXP_SHIFT 16 + +class MidiDriver_Emulated : public Audio::AudioStream, public MidiDriver { +protected: + bool _isOpen; + Audio::Mixer *_mixer; + Audio::SoundHandle _mixerSoundHandle; + +private: + Common::TimerManager::TimerProc _timerProc; + void *_timerParam; + + int _nextTick; + int _samplesPerTick; + +protected: + virtual void generateSamples(int16 *buf, int len) = 0; + virtual void onTimer() {} + + int _baseFreq; + +public: + MidiDriver_Emulated(Audio::Mixer *mixer) : _mixer(mixer) { + _isOpen = false; + + _timerProc = 0; + _timerParam = 0; + + _nextTick = 0; + _samplesPerTick = 0; + + _baseFreq = 250; + } + + int open() { + _isOpen = true; + + int d = getRate() / _baseFreq; + int r = getRate() % _baseFreq; + + // This is equivalent to (getRate() << FIXP_SHIFT) / BASE_FREQ + // but less prone to arithmetic overflow. + + _samplesPerTick = (d << FIXP_SHIFT) + (r << FIXP_SHIFT) / _baseFreq; + return 0; + } + + void setTimerCallback(void *timer_param, Common::TimerManager::TimerProc timer_proc) { + _timerProc = timer_proc; + _timerParam = timer_param; + } + + uint32 getBaseTempo() { return 1000000 / _baseFreq; } + + + // AudioStream API + int readBuffer(int16 *data, const int numSamples) { + const int stereoFactor = isStereo() ? 2 : 1; + int len = numSamples / stereoFactor; + int step; + + do { + step = len; + if (step > (_nextTick >> FIXP_SHIFT)) + step = (_nextTick >> FIXP_SHIFT); + + generateSamples(data, step); + + _nextTick -= step << FIXP_SHIFT; + if (!(_nextTick >> FIXP_SHIFT)) { + if (_timerProc) + (*_timerProc)(_timerParam); + onTimer(); + _nextTick += _samplesPerTick; + } + data += step * stereoFactor; + len -= step; + } while (len); + + return numSamples; + } + bool endOfData() const { return false; } +}; + +#endif |