/* 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 "audio/softsynth/pcspk.h" #include "audio/null.h" namespace Audio { const PCSpeaker::generatorFunc PCSpeaker::generateWave[] = {&PCSpeaker::generateSquare, &PCSpeaker::generateSine, &PCSpeaker::generateSaw, &PCSpeaker::generateTriangle}; PCSpeaker::PCSpeaker(int rate) { _rate = rate; _wave = kWaveFormSquare; _playForever = false; _oscLength = 0; _oscSamples = 0; _remainingSamples = 0; _mixedSamples = 0; _volume = 255; } PCSpeaker::~PCSpeaker() { } void PCSpeaker::play(WaveForm wave, int freq, int32 length) { Common::StackLock lock(_mutex); assert((wave >= kWaveFormSquare) && (wave <= kWaveFormTriangle)); _wave = wave; _oscLength = _rate / freq; _oscSamples = 0; if (length == -1) { _remainingSamples = 1; _playForever = true; } else { _remainingSamples = (_rate * length) / 1000; _playForever = false; } _mixedSamples = 0; } void PCSpeaker::stop(int32 delay) { Common::StackLock lock(_mutex); _remainingSamples = (_rate * delay) / 1000; _playForever = false; } void PCSpeaker::setVolume(byte volume) { _volume = volume; } bool PCSpeaker::isPlaying() const { return _remainingSamples != 0; } int PCSpeaker::readBuffer(int16 *buffer, const int numSamples) { Common::StackLock lock(_mutex); int i; for (i = 0; _remainingSamples && (i < numSamples); i++) { buffer[i] = generateWave[_wave](_oscSamples, _oscLength) * _volume; if (_oscSamples++ >= _oscLength) _oscSamples = 0; if (!_playForever) _remainingSamples--; _mixedSamples++; } // Clear the rest of the buffer if (i < numSamples) memset(buffer + i, 0, (numSamples - i) * sizeof(int16)); return numSamples; } int8 PCSpeaker::generateSquare(uint32 x, uint32 oscLength) { return (x < (oscLength / 2)) ? 127 : -128; } int8 PCSpeaker::generateSine(uint32 x, uint32 oscLength) { if (oscLength == 0) return 0; // TODO: Maybe using a look-up-table would be better? return CLIP<int16>((int16) (128 * sin(2.0 * M_PI * x / oscLength)), -128, 127); } int8 PCSpeaker::generateSaw(uint32 x, uint32 oscLength) { if (oscLength == 0) return 0; return ((x * (65536 / oscLength)) >> 8) - 128; } int8 PCSpeaker::generateTriangle(uint32 x, uint32 oscLength) { if (oscLength == 0) return 0; int y = ((x * (65536 / (oscLength / 2))) >> 8) - 128; return (x <= (oscLength / 2)) ? y : (256 - y); } } // End of namespace Audio // Plugin interface // (This can only create a null driver since pc speaker support is not part of the // midi driver architecture. But we need the plugin for the options menu in the launcher // and for MidiDriver::detectDevice() which is more or less used by all engines.) class PCSpeakerMusicPlugin : public NullMusicPlugin { public: const char *getName() const { return _s("PC Speaker Emulator"); } const char *getId() const { return "pcspk"; } MusicDevices getDevices() const; }; MusicDevices PCSpeakerMusicPlugin::getDevices() const { MusicDevices devices; devices.push_back(MusicDevice(this, "", MT_PCSPK)); return devices; } class PCjrMusicPlugin : public NullMusicPlugin { public: const char *getName() const { return _s("IBM PCjr Emulator"); } const char *getId() const { return "pcjr"; } MusicDevices getDevices() const; }; MusicDevices PCjrMusicPlugin::getDevices() const { MusicDevices devices; devices.push_back(MusicDevice(this, "", MT_PCJR)); return devices; } //#if PLUGIN_ENABLED_DYNAMIC(PCSPK) //REGISTER_PLUGIN_DYNAMIC(PCSPK, PLUGIN_TYPE_MUSIC, PCSpeakerMusicPlugin); //#else REGISTER_PLUGIN_STATIC(PCSPK, PLUGIN_TYPE_MUSIC, PCSpeakerMusicPlugin); //#endif //#if PLUGIN_ENABLED_DYNAMIC(PCJR) //REGISTER_PLUGIN_DYNAMIC(PCJR, PLUGIN_TYPE_MUSIC, PCjrMusicPlugin); //#else REGISTER_PLUGIN_STATIC(PCJR, PLUGIN_TYPE_MUSIC, PCjrMusicPlugin); //#endif