diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/simpl/synthesis.cpp | 109 | ||||
| -rw-r--r-- | src/simpl/synthesis.h | 21 |
2 files changed, 130 insertions, 0 deletions
diff --git a/src/simpl/synthesis.cpp b/src/simpl/synthesis.cpp index 3f48c78..c5d3570 100644 --- a/src/simpl/synthesis.cpp +++ b/src/simpl/synthesis.cpp @@ -59,6 +59,115 @@ Frames Synthesis::synth(Frames frames) { // --------------------------------------------------------------------------- +// MQSynthesis +// --------------------------------------------------------------------------- +MQSynthesis::MQSynthesis() { + _prev_amps = NULL; + _prev_freqs = NULL; + _prev_phases = NULL; + reset(); +} + +MQSynthesis::~MQSynthesis() { + if(_prev_amps) delete [] _prev_amps; + if(_prev_freqs) delete [] _prev_freqs; + if(_prev_phases) delete [] _prev_phases; + + _prev_amps = NULL; + _prev_freqs = NULL; + _prev_phases = NULL; +} + +void MQSynthesis::reset() { + if(_prev_amps) delete [] _prev_amps; + if(_prev_freqs) delete [] _prev_freqs; + if(_prev_phases) delete [] _prev_phases; + + _prev_amps = new sample[_max_partials]; + _prev_freqs = new sample[_max_partials]; + _prev_phases = new sample[_max_partials]; + + memset(_prev_amps, 0.0, sizeof(sample) * _max_partials); + memset(_prev_freqs, 0.0, sizeof(sample) * _max_partials); + memset(_prev_phases, 0.0, sizeof(sample) * _max_partials); +} + +sample MQSynthesis::hz_to_radians(sample f) { + return (f * 2 * M_PI) / _sampling_rate; +} + +void MQSynthesis::max_partials(int new_max_partials) { + _max_partials = new_max_partials; + reset(); +} + +void MQSynthesis::synth_frame(Frame* frame) { + int num_partials = frame->num_partials(); + if(num_partials > _max_partials) { + num_partials = _max_partials; + } + + for(int n = 0; n < _hop_size; n++) { + frame->synth()[n] = 0.f; + } + + for(int i = 0; i < num_partials; i++) { + sample amp = frame->partial(i)->amplitude; + sample freq = hz_to_radians(frame->partial(i)->frequency); + sample phase = frame->partial(i)->phase; + + // get values for last amplitude, frequency and phase + // these are the initial values of the instantaneous + // amplitude/frequency/phase + sample prev_amp = _prev_amps[i]; + sample prev_freq = _prev_freqs[i]; + sample prev_phase = _prev_phases[i]; + + if(prev_amp == 0) { + prev_freq = freq; + prev_phase = frame->partial(i)->phase - (freq * _hop_size); + while(prev_phase >= M_PI) { + prev_phase -= (2.0 * M_PI); + } + while(prev_phase < -M_PI) { + prev_phase += (2.0 * M_PI); + } + } + + // amplitudes are linearly interpolated between frames + sample inst_amp = prev_amp; + sample amp_inc = (frame->partial(i)->amplitude - prev_amp) / _hop_size; + + // freqs/phases are calculated by cubic interpolation + sample freq_diff = freq - prev_freq; + sample x = (prev_phase + (prev_freq * _hop_size) - phase) + + (freq_diff * (_hop_size / 2.0)); + x /= (2.0 * M_PI); + int m = floor(x + 0.5); + sample phase_diff = phase - prev_phase - (prev_freq * _hop_size) + + (2.0 * M_PI * m); + sample alpha = ((3.0 / pow(_hop_size, 2.0)) * phase_diff) - + (freq_diff / _hop_size); + sample beta = ((-2.0 / pow(_hop_size, 3.0)) * phase_diff) + + (freq_diff / pow(_hop_size, 2.0)); + + // calculate output samples + sample inst_phase = 0.f; + for(int n = 0; n < _hop_size; n++) { + inst_amp += amp_inc; + inst_phase = prev_phase + (prev_freq * n) + + (alpha * pow((sample)n, 2.0)) + + (beta * pow((sample)n, 3.0)); + frame->synth()[n] += (2.f * inst_amp) * cos(inst_phase); + } + + _prev_amps[i] = amp; + _prev_freqs[i] = freq; + _prev_phases[i] = phase; + } +} + +// --------------------------------------------------------------------------- // SMSSynthesis // --------------------------------------------------------------------------- diff --git a/src/simpl/synthesis.h b/src/simpl/synthesis.h index e93669f..64f6f7b 100644 --- a/src/simpl/synthesis.h +++ b/src/simpl/synthesis.h @@ -1,6 +1,8 @@ #ifndef SYNTHESIS_H #define SYNTHESIS_H +#include <math.h> + #include "base.h" extern "C" { @@ -51,6 +53,25 @@ class Synthesis { // --------------------------------------------------------------------------- +// MQSynthesis +// --------------------------------------------------------------------------- +class MQSynthesis : public Synthesis { + private: + sample* _prev_amps; + sample* _prev_freqs; + sample* _prev_phases; + void reset(); + sample hz_to_radians(sample f); + + public: + MQSynthesis(); + ~MQSynthesis(); + void max_partials(int new_max_partials); + void synth_frame(Frame* frame); +}; + + +// --------------------------------------------------------------------------- // SMSSynthesis // --------------------------------------------------------------------------- class SMSSynthesis : public Synthesis { |