Mercurial > hg > audio_effects_textbook_code
view effects/ringmod/Source/PluginProcessor.cpp @ 0:e32fe563e124
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author | Andrew McPherson <andrewm@eecs.qmul.ac.uk> |
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date | Fri, 10 Oct 2014 15:41:23 +0100 |
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children | 04e171d2a747 |
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/* This code accompanies the textbook: Digital Audio Effects: Theory, Implementation and Application Joshua D. Reiss and Andrew P. McPherson --- Ring Modulator: modulation using a carrier oscillator See textbook Chapter 5: Amplitude Modulation Code by Andrew McPherson, Brecht De Man and Joshua Reiss --- 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 3 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, see <http://www.gnu.org/licenses/>. */ #include "PluginProcessor.h" #include "PluginEditor.h" #include <math.h> //============================================================================== RingModulatorAudioProcessor::RingModulatorAudioProcessor() { // Set default values: carrierFrequency_ = 100.0; sweepWidth_ = 0.0; lfoFrequency_ = 1.0; waveform_ = kWaveformSine; lfoPhase_ = carrierPhase_ = 0.0; inverseSampleRate_ = 1.0/44100.0; lastUIWidth_ = 370; lastUIHeight_ = 160; } RingModulatorAudioProcessor::~RingModulatorAudioProcessor() { } //============================================================================== const String RingModulatorAudioProcessor::getName() const { return JucePlugin_Name; } int RingModulatorAudioProcessor::getNumParameters() { return kNumParameters; } float RingModulatorAudioProcessor::getParameter (int index) { // This method will be called by the host, probably on the audio thread, so // it's absolutely time-critical. Don't use critical sections or anything // UI-related, or anything at all that may block in any way! switch (index) { case kCarrierFrequencyParam: return carrierFrequency_; case kSweepWidthParam: return sweepWidth_; case kLFOFrequencyParam: return lfoFrequency_; case kWaveformParam: return (float)waveform_; default: return 0.0f; } } void RingModulatorAudioProcessor::setParameter (int index, float newValue) { // This method will be called by the host, probably on the audio thread, so // it's absolutely time-critical. Don't use critical sections or anything // UI-related, or anything at all that may block in any way! switch (index) { case kCarrierFrequencyParam: carrierFrequency_ = newValue; break; case kSweepWidthParam: sweepWidth_ = newValue; break; case kLFOFrequencyParam: lfoFrequency_ = newValue; break; case kWaveformParam: waveform_ = (int)newValue; break; default: break; } } const String RingModulatorAudioProcessor::getParameterName (int index) { switch (index) { case kCarrierFrequencyParam: return "carrier frequency"; case kSweepWidthParam: return "LFO sweep width"; case kLFOFrequencyParam: return "LFO frequency"; case kWaveformParam: return "LFO waveform"; default: break; } return String::empty; } const String RingModulatorAudioProcessor::getParameterText (int index) { return String (getParameter (index), 2); } const String RingModulatorAudioProcessor::getInputChannelName (int channelIndex) const { return String (channelIndex + 1); } const String RingModulatorAudioProcessor::getOutputChannelName (int channelIndex) const { return String (channelIndex + 1); } bool RingModulatorAudioProcessor::isInputChannelStereoPair (int index) const { return true; } bool RingModulatorAudioProcessor::isOutputChannelStereoPair (int index) const { return true; } bool RingModulatorAudioProcessor::silenceInProducesSilenceOut() const { #if JucePlugin_SilenceInProducesSilenceOut return true; #else return false; #endif } double RingModulatorAudioProcessor::getTailLengthSeconds() const { return 0.0; } bool RingModulatorAudioProcessor::acceptsMidi() const { #if JucePlugin_WantsMidiInput return true; #else return false; #endif } bool RingModulatorAudioProcessor::producesMidi() const { #if JucePlugin_ProducesMidiOutput return true; #else return false; #endif } int RingModulatorAudioProcessor::getNumPrograms() { return 0; } int RingModulatorAudioProcessor::getCurrentProgram() { return 0; } void RingModulatorAudioProcessor::setCurrentProgram (int index) { } const String RingModulatorAudioProcessor::getProgramName (int index) { return String::empty; } void RingModulatorAudioProcessor::changeProgramName (int index, const String& newName) { } //============================================================================== void RingModulatorAudioProcessor::prepareToPlay (double sampleRate, int samplesPerBlock) { // Calculations that happen before play begins. Pretty simple in this effect, just // reset the previous state. lfoPhase_ = 0.0; carrierPhase_ = 0.0; inverseSampleRate_ = 1.0/sampleRate; } void RingModulatorAudioProcessor::releaseResources() { // When playback stops, you can use this as an opportunity to free up any // spare memory, etc. } void RingModulatorAudioProcessor::reset() { // Use this method as the place to clear any delay lines, buffers, etc, as it // means there's been a break in the audio's continuity. lfoPhase_ = 0.0; carrierPhase_ = 0.0; } void RingModulatorAudioProcessor::processBlock (AudioSampleBuffer& buffer, MidiBuffer& midiMessages) { // Helpful information about this block of samples: const int numInputChannels = getNumInputChannels(); // How many input channels for our effect? const int numOutputChannels = getNumOutputChannels(); // How many output channels for our effect? const int numSamples = buffer.getNumSamples(); // How many samples in the buffer for this block? int channel; float cph, lph; // Go through each channel of audio that's passed in. In this example we apply identical // effects to each channel, regardless of how many input channels there are. For some effects, like // a stereo chorus or panner, you might do something different for each channel. for (channel = 0; channel < numInputChannels; ++channel) { // channelData is an array of length numSamples which contains the audio for one channel float* channelData = buffer.getSampleData(channel); // Make a temporary copy of any state variables declared in PluginProcessor.h which need to be // maintained between calls to processBlock(). Each channel needs to be processed identically // which means that the activity of processing one channel can't affect the state variable for // the next channel. cph = carrierPhase_; lph = lfoPhase_; for (int i = 0; i < numSamples; ++i) { const float in = channelData[i]; // Ring modulation is easy! Just multiply the waveform by a periodic carrier channelData[i] = in * sinf(2.0 * M_PI * cph); // Update the carrier and LFO phases, keeping them in the range 0-1 lph += lfoFrequency_*inverseSampleRate_; if(lph >= 1.0) lph -= 1.0; cph += (carrierFrequency_ + sweepWidth_*lfo(lfoPhase_, waveform_))*inverseSampleRate_; if(cph >= 1.0) cph -= 1.0; } } // Having made a local copy of the state variables for each channel, now transfer the result // back to the main state variable so they will be preserved for the next call of processBlock() carrierPhase_ = cph; lfoPhase_ = lph; // In case we have more outputs than inputs, we'll clear any output // channels that didn't contain input data, (because these aren't // guaranteed to be empty - they may contain garbage). for (int i = numInputChannels; i < numOutputChannels; ++i) { buffer.clear (i, 0, buffer.getNumSamples()); } } //============================================================================== bool RingModulatorAudioProcessor::hasEditor() const { return true; // (change this to false if you choose to not supply an editor) } AudioProcessorEditor* RingModulatorAudioProcessor::createEditor() { return new RingModulatorAudioProcessorEditor (this); } //============================================================================== void RingModulatorAudioProcessor::getStateInformation (MemoryBlock& destData) { // You should use this method to store your parameters in the memory block. // You could do that either as raw data, or use the XML or ValueTree classes // as intermediaries to make it easy to save and load complex data. // Create an outer XML element.. XmlElement xml("C4DMPLUGINSETTINGS"); // add some attributes to it.. xml.setAttribute("uiWidth", lastUIWidth_); xml.setAttribute("uiHeight", lastUIHeight_); xml.setAttribute("carrierFrequency", carrierFrequency_); xml.setAttribute("sweepWidth", sweepWidth_); xml.setAttribute("lfoFrequency", lfoFrequency_); xml.setAttribute("waveform", waveform_); // then use this helper function to stuff it into the binary blob and return it.. copyXmlToBinary(xml, destData); } void RingModulatorAudioProcessor::setStateInformation (const void* data, int sizeInBytes) { // You should use this method to restore your parameters from this memory block, // whose contents will have been created by the getStateInformation() call. // This getXmlFromBinary() helper function retrieves our XML from the binary blob.. ScopedPointer<XmlElement> xmlState (getXmlFromBinary (data, sizeInBytes)); if(xmlState != 0) { // make sure that it's actually our type of XML object.. if(xmlState->hasTagName("C4DMPLUGINSETTINGS")) { // ok, now pull out our parameters.. lastUIWidth_ = xmlState->getIntAttribute("uiWidth", lastUIWidth_); lastUIHeight_ = xmlState->getIntAttribute("uiHeight", lastUIHeight_); carrierFrequency_ = (float)xmlState->getDoubleAttribute("carrierFrequency", carrierFrequency_); sweepWidth_ = (float)xmlState->getDoubleAttribute("sweepWidth", sweepWidth_); lfoFrequency_ = (float)xmlState->getDoubleAttribute("lfoFrequency", lfoFrequency_); waveform_ = xmlState->getIntAttribute("waveform", waveform_); } } } //============================================================================== // Function for calculating LFO waveforms. Phase runs from 0-1, output is scaled // from -1 to 1 (note: not 0 to 1 as in delay-based effects) float RingModulatorAudioProcessor::lfo(float phase, int waveform) { switch(waveform) { case kWaveformTriangle: if(phase < 0.25f) return 4.0f*phase; else if(phase < 0.75f) return 1.0f - 4.0f*(phase - 0.25f); else return -1.0f + 4.0f*(phase - 0.75f); case kWaveformSquare: if(phase < 0.5f) return 1.0f; else return -1.0f; case kWaveformSawtooth: if(phase < 0.5f) return 2.0f*phase; else return 2.0f*phase - 2.0f; case kWaveformInverseSawtooth: if(phase < 0.5f) return -2.0f*phase; else return 2.0f - 2.0f*phase; case kWaveformSine: default: return sinf(2.0 * M_PI * phase); } } //============================================================================== // This creates new instances of the plugin.. AudioProcessor* JUCE_CALLTYPE createPluginFilter() { return new RingModulatorAudioProcessor(); }