homeburger/metabalus
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

add oscillator class

Browse Source
This commit is contained in:
Blitblank
2026-01-16 22:55:28 -06:00
parent 2e8953e489
commit 198b7f0dde
4 changed files with 122 additions and 58 deletions
Download Patch File Download Diff File Expand all files Collapse all files

54
src/synth/Voice.cpp
View File

@@ -21,12 +21,9 @@ void Voice::setSampleRate(float sampleRate) {
filter2_.setSampleRate(sampleRate);
// then foreach oscillator
//osc1_.setSampleRate(sampleRate);
}
// calculates oscillator frequency based on midi note
inline float Voice::noteToFrequency(uint8_t note) {
return SYNTH_PITCH_STANDARD * pow(2.0f, static_cast<float>(note - SYNTH_MIDI_HOME) / static_cast<float>(SYNTH_NOTES_PER_OCTAVE));
for(Oscillator& o : oscillators_) {
o.setSampleRate(sampleRate);
}
}
inline float Voice::getParam(ParamId id) {
@@ -36,13 +33,13 @@ inline float Voice::getParam(ParamId id) {
void Voice::noteOn(int midiNote, float velocity) {
note_ = midiNote;
velocity_ = velocity;
frequency_ = noteToFrequency(midiNote);
active_ = true;
// TODO: for each envelope ...
gainEnvelope_.noteOn();
cutoffEnvelope_.noteOn();
resonanceEnvelope_.noteOn();
}
void Voice::noteOff() {
@@ -77,57 +74,26 @@ float Voice::process(float* params, bool& scopeTrigger) {
float cutoffEnv = cutoffEnvelope_.process();
float resonanceEnv = resonanceEnvelope_.process();
// TODO: make pitchOffset variable for each oscillator (maybe three values like octave, semitone offset, and pitch offset in cents)
float pitchOffset = 1.0f;
float phaseInc = pitchOffset * 2.0f * M_PI * frequency_ / static_cast<float>(sampleRate_);
// calculate the change that the velocity will make
// TODO: make velocity parameters configurable, probably also for filterCutoff and filterResonance
float velocityGain = std::lerp(velocityCenter, velocity_, velocitySensitivity);
float gain = gainEnv * getParam(ParamId::Osc1VolumeDepth) * velocityGain;
float sampleOut = 0.0f;
// sample generation
// TODO: move this into the oscillator class
// TODO: wavetables
// TODO: wavetables should be scaled by their RMS for equal loudness (prelim standard = 0.707)
float sineSample = std::sin(phase_);
float squareSample = (phase_ >= M_PI) ? 0.707f : -0.707f;
float sawSample = ((phase_ / M_PI) - 1.0f) / 0.577f * 0.707f;
// switch statement will be replaced with an array index for our array of wavetables
switch (static_cast<int32_t>(std::round(getParam(ParamId::Osc1WaveSelector1)))) {
case 0:
sampleOut = sineSample * gain;
break;
case 1:
sampleOut = squareSample * gain;
break;
case 2:
sampleOut = sawSample * gain;
break;
case 3:
// TODO: no triable wave yet :(
sampleOut = sineSample * gain;
break;
default: // unreachable
break;
}
uint8_t osc1Wave = (static_cast<uint8_t>(std::round(getParam(ParamId::Osc1WaveSelector1))));
oscillators_[0].setWavetable(osc1Wave);
float sampleOut = oscillators_[0].process(note_, scopeTrigger) * gain;
// filter sample
float cutoffFreq = cutoffEnv * pow(2.0f, getParam(ParamId::FilterCutoffDepth)) * frequency_ * velocityGain;
float baseFreq = oscillators_[0].frequency();
float cutoffFreq = cutoffEnv * pow(2.0f, getParam(ParamId::FilterCutoffDepth)) * baseFreq * velocityGain;
float resonance = resonanceEnv * getParam(ParamId::FilterResonanceDepth) * velocityGain;
filter1_.setParams(Filter::Type::BiquadLowpass, cutoffFreq, resonance);
filter2_.setParams(Filter::Type::BiquadLowpass, cutoffFreq, resonance);
sampleOut = filter1_.biquadProcess(sampleOut);
sampleOut = filter2_.biquadProcess(sampleOut);
// state tracking, may keep this here even if oscillators store their own phase because it might help with scope triggering
phase_ += phaseInc;
if (phase_ > 2.0f * M_PI) {
scopeTrigger = true;
phase_ -= 2.0f * M_PI;
}
return sampleOut;
}