b8d70d26fa
This update uses upstream commit f88ef828a600ce66d1f730c8fb2a7f580f6f6165. This update switches to use the new Munt C++ interface, which will allow ScummVM to link to an external Munt library instead of requiring it to be built-in in the future. For the moment, the emulator is still built-in, since it is not available from most package repositories. The Munt driver in ScummVM now uses writeSysex instead of the (now-private) playSysexWithoutFraming, per recommendation from the Munt team <https://github.com/munt/munt/pull/30>. This changeset also removes direct modifications that used to be made to Munt code, to ease future updates. To update Munt code in the future: 1. Replace all source files in the `softsynth/mt32` directory with new files from the upstream `mt32emu/src` directory; 2. Update `config.h` with the correct version number for the new version of Munt; 3. Update `module.mk` to add any new source files that need to be built.
132 lines
5.1 KiB
C++
Executable file
132 lines
5.1 KiB
C++
Executable file
/* Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009 Dean Beeler, Jerome Fisher
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* Copyright (C) 2011-2016 Dean Beeler, Jerome Fisher, Sergey V. Mikayev
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 2.1 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef MT32EMU_LA32_WAVE_GENERATOR_H
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#error This file should be included from LA32WaveGenerator.h only.
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#endif
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namespace MT32Emu {
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/**
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* LA32WaveGenerator is aimed to represent the exact model of LA32 wave generator.
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* The output square wave is created by adding high / low linear segments in-between
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* the rising and falling cosine segments. Basically, it's very similar to the phase distortion synthesis.
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* Behaviour of a true resonance filter is emulated by adding decaying sine wave.
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* The beginning and the ending of the resonant sine is multiplied by a cosine window.
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* To synthesise sawtooth waves, the resulting square wave is multiplied by synchronous cosine wave.
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*/
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class LA32WaveGenerator {
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//***************************************************************************
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// The local copy of partial parameters below
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//***************************************************************************
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bool active;
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// True means the resulting square wave is to be multiplied by the synchronous cosine
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bool sawtoothWaveform;
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// Values in range [1..31]
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// Value 1 correspong to the minimum resonance
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Bit8u resonance;
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// Processed value in range [0..255]
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// Values in range [0..128] have no effect and the resulting wave remains symmetrical
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// Value 255 corresponds to the maximum possible asymmetric of the resulting wave
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Bit8u pulseWidth;
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// Logarithmic PCM sample start address
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const Bit16s *pcmWaveAddress;
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// Logarithmic PCM sample length
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Bit32u pcmWaveLength;
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// true for looped logarithmic PCM samples
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bool pcmWaveLooped;
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// false for slave PCM partials in the structures with the ring modulation
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bool pcmWaveInterpolated;
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//***************************************************************************
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// Internal variables below
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//***************************************************************************
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float wavePos;
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float lastFreq;
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float pcmPosition;
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float getPCMSample(unsigned int position);
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public:
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// Initialise the WG engine for generation of synth partial samples and set up the invariant parameters
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void initSynth(const bool sawtoothWaveform, const Bit8u pulseWidth, const Bit8u resonance);
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// Initialise the WG engine for generation of PCM partial samples and set up the invariant parameters
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void initPCM(const Bit16s * const pcmWaveAddress, const Bit32u pcmWaveLength, const bool pcmWaveLooped, const bool pcmWaveInterpolated);
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// Update parameters with respect to TVP, TVA and TVF, and generate next sample
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float generateNextSample(const Bit32u amp, const Bit16u pitch, const Bit32u cutoff);
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// Deactivate the WG engine
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void deactivate();
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// Return active state of the WG engine
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bool isActive() const;
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// Return true if the WG engine generates PCM wave samples
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bool isPCMWave() const;
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}; // class LA32WaveGenerator
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// LA32PartialPair contains a structure of two partials being mixed / ring modulated
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class LA32PartialPair {
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LA32WaveGenerator master;
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LA32WaveGenerator slave;
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bool ringModulated;
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bool mixed;
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float masterOutputSample;
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float slaveOutputSample;
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public:
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enum PairType {
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MASTER,
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SLAVE
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};
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// ringModulated should be set to false for the structures with mixing or stereo output
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// ringModulated should be set to true for the structures with ring modulation
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// mixed is used for the structures with ring modulation and indicates whether the master partial output is mixed to the ring modulator output
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void init(const bool ringModulated, const bool mixed);
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// Initialise the WG engine for generation of synth partial samples and set up the invariant parameters
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void initSynth(const PairType master, const bool sawtoothWaveform, const Bit8u pulseWidth, const Bit8u resonance);
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// Initialise the WG engine for generation of PCM partial samples and set up the invariant parameters
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void initPCM(const PairType master, const Bit16s * const pcmWaveAddress, const Bit32u pcmWaveLength, const bool pcmWaveLooped);
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// Update parameters with respect to TVP, TVA and TVF, and generate next sample
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void generateNextSample(const PairType master, const Bit32u amp, const Bit16u pitch, const Bit32u cutoff);
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// Perform mixing / ring modulation and return the result
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float nextOutSample();
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// Deactivate the WG engine
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void deactivate(const PairType master);
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// Return active state of the WG engine
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bool isActive(const PairType master) const;
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}; // class LA32PartialPair
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} // namespace MT32Emu
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