andrewm@0: /*
andrewm@0:   This code accompanies the textbook:
andrewm@0:  
andrewm@0:   Digital Audio Effects: Theory, Implementation and Application
andrewm@0:   Joshua D. Reiss and Andrew P. McPherson
andrewm@0:  
andrewm@0:   ---
andrewm@0:  
andrewm@0:   Delay: basic delay effect with feedback
andrewm@0:   See textbook Chapter 2: Delay Line Effects
andrewm@0:  
andrewm@0:   Code by Andrew McPherson, Brecht de Man and Joshua Reiss
andrewm@0:  
andrewm@0:   ---
andrewm@0: 
andrewm@0:   This program is free software: you can redistribute it and/or modify
andrewm@0:   it under the terms of the GNU General Public License as published by
andrewm@0:   the Free Software Foundation, either version 3 of the License, or
andrewm@0:   (at your option) any later version.
andrewm@0:  
andrewm@0:   This program is distributed in the hope that it will be useful,
andrewm@0:   but WITHOUT ANY WARRANTY; without even the implied warranty of
andrewm@0:   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
andrewm@0:   GNU General Public License for more details.
andrewm@0: 
andrewm@0:   You should have received a copy of the GNU General Public License
andrewm@0:   along with this program.  If not, see <http://www.gnu.org/licenses/>.
andrewm@0: */
andrewm@0: 
andrewm@0: #include "PluginProcessor.h"
andrewm@0: #include "PluginEditor.h"
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: DelayAudioProcessor::DelayAudioProcessor() : delayBuffer_ (2, 1)
andrewm@0: {
andrewm@0:     // Set default values:
andrewm@0:     delayLength_ = 0.5;
andrewm@0:     dryMix_ = 1.0;
andrewm@0:     wetMix_ = 0.5;
andrewm@0:     feedback_ = 0.75;
andrewm@0:     delayBufferLength_ = 1;
andrewm@0:     
andrewm@0:     // Start the circular buffer pointers at the beginning
andrewm@0:     delayReadPosition_ = 0;
andrewm@0:     delayWritePosition_ = 0;
andrewm@0:     
andrewm@0:     lastUIWidth_ = 370;
andrewm@0:     lastUIHeight_ = 140;
andrewm@0: }
andrewm@0: 
andrewm@0: DelayAudioProcessor::~DelayAudioProcessor()
andrewm@0: {
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: const String DelayAudioProcessor::getName() const
andrewm@0: {
andrewm@0:     return JucePlugin_Name;
andrewm@0: }
andrewm@0: 
andrewm@0: int DelayAudioProcessor::getNumParameters()
andrewm@0: {
andrewm@0:     return kNumParameters;
andrewm@0: }
andrewm@0: 
andrewm@0: float DelayAudioProcessor::getParameter (int index)
andrewm@0: {
andrewm@0:     // This method will be called by the host, probably on the audio thread, so
andrewm@0:     // it's absolutely time-critical. Don't use critical sections or anything
andrewm@0:     // UI-related, or anything at all that may block in any way!
andrewm@0:     switch (index)
andrewm@0:     {
andrewm@0:         case kDryMixParam:     return dryMix_;
andrewm@0:         case kWetMixParam:     return wetMix_;
andrewm@0:         case kFeedbackParam:   return feedback_;
andrewm@0:         case kDelayLengthParam:return delayLength_;
andrewm@0:         default:               return 0.0f;
andrewm@0:     }
andrewm@0: }
andrewm@0: 
andrewm@0: void DelayAudioProcessor::setParameter (int index, float newValue)
andrewm@0: {
andrewm@0:     // This method will be called by the host, probably on the audio thread, so
andrewm@0:     // it's absolutely time-critical. Don't use critical sections or anything
andrewm@0:     // UI-related, or anything at all that may block in any way!
andrewm@0:     switch (index)
andrewm@0:     {
andrewm@0:         case kDryMixParam:
andrewm@0:             dryMix_ = newValue;
andrewm@0:             break;
andrewm@0:         case kWetMixParam:
andrewm@0:             wetMix_ = newValue;
andrewm@0:             break;
andrewm@0:         case kFeedbackParam:
andrewm@0:             feedback_ = newValue;
andrewm@0:             break;
andrewm@0:         case kDelayLengthParam:
andrewm@0:             delayLength_ = newValue;
andrewm@0:             delayReadPosition_ = (int)(delayWritePosition_ - (delayLength_ * getSampleRate())
andrewm@0:                                        + delayBufferLength_) % delayBufferLength_;
andrewm@0:             break;
andrewm@0:         default:
andrewm@0:             break;
andrewm@0:     }
andrewm@0: }
andrewm@0: 
andrewm@0: const String DelayAudioProcessor::getParameterName (int index)
andrewm@0: {
andrewm@0:     switch (index)
andrewm@0:     {
andrewm@0:         case kDryMixParam:     return "dry mix";
andrewm@0:         case kWetMixParam:     return "wet mix";
andrewm@0:         case kFeedbackParam:   return "feedback";
andrewm@0:         case kDelayLengthParam:return "delay";
andrewm@0:         default:               break;
andrewm@0:     }
andrewm@0:     
andrewm@0:     return String::empty;
andrewm@0: }
andrewm@0: 
andrewm@0: const String DelayAudioProcessor::getParameterText (int index)
andrewm@0: {
andrewm@0:     return String (getParameter (index), 2);
andrewm@0: }
andrewm@0: 
andrewm@0: const String DelayAudioProcessor::getInputChannelName (int channelIndex) const
andrewm@0: {
andrewm@0:     return String (channelIndex + 1);
andrewm@0: }
andrewm@0: 
andrewm@0: const String DelayAudioProcessor::getOutputChannelName (int channelIndex) const
andrewm@0: {
andrewm@0:     return String (channelIndex + 1);
andrewm@0: }
andrewm@0: 
andrewm@0: bool DelayAudioProcessor::isInputChannelStereoPair (int index) const
andrewm@0: {
andrewm@0:     return true;
andrewm@0: }
andrewm@0: 
andrewm@0: bool DelayAudioProcessor::isOutputChannelStereoPair (int index) const
andrewm@0: {
andrewm@0:     return true;
andrewm@0: }
andrewm@0: 
andrewm@0: bool DelayAudioProcessor::silenceInProducesSilenceOut() const
andrewm@0: {
andrewm@0: #if JucePlugin_SilenceInProducesSilenceOut
andrewm@0:     return true;
andrewm@0: #else
andrewm@0:     return false;
andrewm@0: #endif
andrewm@0: }
andrewm@0: double DelayAudioProcessor::getTailLengthSeconds() const
andrewm@0: {
andrewm@0:     return 0.0;
andrewm@0: }
andrewm@0: bool DelayAudioProcessor::acceptsMidi() const
andrewm@0: {
andrewm@0: #if JucePlugin_WantsMidiInput
andrewm@0:     return true;
andrewm@0: #else
andrewm@0:     return false;
andrewm@0: #endif
andrewm@0: }
andrewm@0: 
andrewm@0: bool DelayAudioProcessor::producesMidi() const
andrewm@0: {
andrewm@0: #if JucePlugin_ProducesMidiOutput
andrewm@0:     return true;
andrewm@0: #else
andrewm@0:     return false;
andrewm@0: #endif
andrewm@0: }
andrewm@0: 
andrewm@0: int DelayAudioProcessor::getNumPrograms()
andrewm@0: {
andrewm@0:     return 0;
andrewm@0: }
andrewm@0: 
andrewm@0: int DelayAudioProcessor::getCurrentProgram()
andrewm@0: {
andrewm@0:     return 0;
andrewm@0: }
andrewm@0: 
andrewm@0: void DelayAudioProcessor::setCurrentProgram (int index)
andrewm@0: {
andrewm@0: }
andrewm@0: 
andrewm@0: const String DelayAudioProcessor::getProgramName (int index)
andrewm@0: {
andrewm@0:     return String::empty;
andrewm@0: }
andrewm@0: 
andrewm@0: void DelayAudioProcessor::changeProgramName (int index, const String& newName)
andrewm@0: {
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: void DelayAudioProcessor::prepareToPlay (double sampleRate, int samplesPerBlock)
andrewm@0: {
andrewm@0:     // Allocate and zero the delay buffer (size will depend on current sample rate)
andrewm@0:     // Sanity check the result so we don't end up with any zero-length calculations
andrewm@0:     delayBufferLength_ = (int)(2.0*sampleRate);
andrewm@0:     if(delayBufferLength_ < 1)
andrewm@0:         delayBufferLength_ = 1;
andrewm@0:     delayBuffer_.setSize(2, delayBufferLength_);
andrewm@0:     delayBuffer_.clear();
andrewm@0:     
andrewm@0:     // This method gives us the sample rate. Use this to figure out what the delay position
andrewm@0:     // offset should be (since it is specified in seconds, and we need to convert it to a number
andrewm@0:     // of samples)
andrewm@0:     delayReadPosition_ = (int)(delayWritePosition_ - (delayLength_ * getSampleRate())
andrewm@0:                                + delayBufferLength_) % delayBufferLength_;
andrewm@0: }
andrewm@0: 
andrewm@0: void DelayAudioProcessor::releaseResources()
andrewm@0: {
andrewm@0:     // When playback stops, you can use this as an opportunity to free up any
andrewm@0:     // spare memory, etc.
andrewm@0:     
andrewm@0:     // The delay buffer will stay in memory until the effect is unloaded.
andrewm@0: }
andrewm@0: 
andrewm@0: void DelayAudioProcessor::reset()
andrewm@0: {
andrewm@0:     // Use this method as the place to clear any delay lines, buffers, etc, as it
andrewm@0:     // means there's been a break in the audio's continuity.
andrewm@0:     
andrewm@0:     delayBuffer_.clear();
andrewm@0: }
andrewm@0: 
andrewm@0: 
andrewm@0: void DelayAudioProcessor::processBlock (AudioSampleBuffer& buffer, MidiBuffer& midiMessages)
andrewm@0: {
andrewm@0:     // Helpful information about this block of samples:
andrewm@0:     const int numInputChannels = getNumInputChannels();     // How many input channels for our effect?
andrewm@0:     const int numOutputChannels = getNumOutputChannels();   // How many output channels for our effect?
andrewm@0:     const int numSamples = buffer.getNumSamples();          // How many samples in the buffer for this block?
andrewm@0:     
andrewm@0:     int channel, dpr, dpw; // dpr = delay read pointer; dpw = delay write pointer
andrewm@0:     
andrewm@0:     // Go through each channel of audio that's passed in. In this example we apply identical
andrewm@0:     // effects to each channel, regardless of how many input channels there are. For some effects, like
andrewm@0:     // a stereo chorus or panner, you might do something different for each channel.
andrewm@0:     
andrewm@0:     for (channel = 0; channel < numInputChannels; ++channel)
andrewm@0:     {
andrewm@0:         // channelData is an array of length numSamples which contains the audio for one channel
b@1:         float* channelData = buffer.getWritePointer(channel);
andrewm@0:         
andrewm@0:         // delayData is the circular buffer for implementing delay on this channel
b@1:         float* delayData = delayBuffer_.getWritePointer (jmin (channel, delayBuffer_.getNumChannels() - 1));
andrewm@0:         
andrewm@0:         // Make a temporary copy of any state variables declared in PluginProcessor.h which need to be
andrewm@0:         // maintained between calls to processBlock(). Each channel needs to be processed identically
andrewm@0:         // which means that the activity of processing one channel can't affect the state variable for
andrewm@0:         // the next channel.
andrewm@0:         
andrewm@0:         dpr = delayReadPosition_;
andrewm@0:         dpw = delayWritePosition_;
andrewm@0:         
andrewm@0:         for (int i = 0; i < numSamples; ++i)
andrewm@0:         {
andrewm@0:             const float in = channelData[i];
andrewm@0:             float out = 0.0;
andrewm@0:             
andrewm@0:             // In this example, the output is the input plus the contents of the delay buffer (weighted by delayMix)
andrewm@0:             // The last term implements a tremolo (variable amplitude) on the whole thing.
andrewm@0:             
andrewm@0:             out = (dryMix_ * in + wetMix_ * delayData[dpr]);
andrewm@0:             
andrewm@0:             // Store the current information in the delay buffer. delayData[dpr] is the delay sample we just read,
andrewm@0:             // i.e. what came out of the buffer. delayData[dpw] is what we write to the buffer, i.e. what goes in
andrewm@0:             
andrewm@0:             delayData[dpw] = in + (delayData[dpr] * feedback_);
andrewm@0:             
andrewm@0:             if (++dpr >= delayBufferLength_)
andrewm@0:                 dpr = 0;
andrewm@0:             if (++dpw >= delayBufferLength_)
andrewm@0:                 dpw = 0;
andrewm@0:             
andrewm@0:             // Store the output sample in the buffer, replacing the input
andrewm@0:             channelData[i] = out;
andrewm@0:         }
andrewm@0:     }
andrewm@0:     
andrewm@0:     // Having made a local copy of the state variables for each channel, now transfer the result
andrewm@0:     // back to the main state variable so they will be preserved for the next call of processBlock()
andrewm@0:     
andrewm@0:     delayReadPosition_ = dpr;
andrewm@0:     delayWritePosition_ = dpw;
andrewm@0:     
andrewm@0:     // In case we have more outputs than inputs, we'll clear any output
andrewm@0:     // channels that didn't contain input data, (because these aren't
andrewm@0:     // guaranteed to be empty - they may contain garbage).
andrewm@0:     for (int i = numInputChannels; i < numOutputChannels; ++i)
andrewm@0:     {
andrewm@0:         buffer.clear (i, 0, buffer.getNumSamples());
andrewm@0:     }
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: bool DelayAudioProcessor::hasEditor() const
andrewm@0: {
andrewm@0:     return true; // (change this to false if you choose to not supply an editor)
andrewm@0: }
andrewm@0: 
andrewm@0: AudioProcessorEditor* DelayAudioProcessor::createEditor()
andrewm@0: {
andrewm@0:     return new DelayAudioProcessorEditor (this);
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: void DelayAudioProcessor::getStateInformation (MemoryBlock& destData)
andrewm@0: {
andrewm@0:     // You should use this method to store your parameters in the memory block.
andrewm@0:     // You could do that either as raw data, or use the XML or ValueTree classes
andrewm@0:     // as intermediaries to make it easy to save and load complex data.
andrewm@0:     
andrewm@0:     // Create an outer XML element..
andrewm@0:     XmlElement xml("C4DMPLUGINSETTINGS");
andrewm@0:     
andrewm@0:     // add some attributes to it..
andrewm@0:     xml.setAttribute("uiWidth", lastUIWidth_);
andrewm@0:     xml.setAttribute("uiHeight", lastUIHeight_);
andrewm@0:     xml.setAttribute("delayLength", delayLength_);
andrewm@0:     xml.setAttribute("feedback", feedback_);
andrewm@0:     xml.setAttribute("dryMix", dryMix_);
andrewm@0:     xml.setAttribute("wetMix", wetMix_);
andrewm@0:     
andrewm@0:     // then use this helper function to stuff it into the binary blob and return it..
andrewm@0:     copyXmlToBinary(xml, destData);
andrewm@0: }
andrewm@0: 
andrewm@0: void DelayAudioProcessor::setStateInformation (const void* data, int sizeInBytes)
andrewm@0: {
andrewm@0:     // You should use this method to restore your parameters from this memory block,
andrewm@0:     // whose contents will have been created by the getStateInformation() call.
andrewm@0:     
andrewm@0:     // This getXmlFromBinary() helper function retrieves our XML from the binary blob..
andrewm@0:     ScopedPointer<XmlElement> xmlState (getXmlFromBinary (data, sizeInBytes));
andrewm@0:     
andrewm@0:     if(xmlState != 0)
andrewm@0:     {
andrewm@0:         // make sure that it's actually our type of XML object..
andrewm@0:         if(xmlState->hasTagName("C4DMPLUGINSETTINGS"))
andrewm@0:         {
andrewm@0:             // ok, now pull out our parameters..
andrewm@0:             lastUIWidth_  = xmlState->getIntAttribute("uiWidth", lastUIWidth_);
andrewm@0:             lastUIHeight_ = xmlState->getIntAttribute("uiHeight", lastUIHeight_);
andrewm@0:             
andrewm@0:             delayLength_  = (float)xmlState->getDoubleAttribute("delayLength", delayLength_);
andrewm@0:             feedback_     = (float)xmlState->getDoubleAttribute("feedback", feedback_);
andrewm@0:             dryMix_       = (float)xmlState->getDoubleAttribute("dryMix", dryMix_);
andrewm@0:             wetMix_       = (float)xmlState->getDoubleAttribute("wetMix", wetMix_);
andrewm@0:         }
andrewm@0:     }
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: // This creates new instances of the plugin..
andrewm@0: AudioProcessor* JUCE_CALLTYPE createPluginFilter()
andrewm@0: {
andrewm@0:     return new DelayAudioProcessor();
andrewm@0: }