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:   Ping-Pong Delay: stereo delay alternating between channels
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: PingPongDelayAudioProcessor::PingPongDelayAudioProcessor() : delayBuffer_ (2, 1)
andrewm@0: {
andrewm@0:     // Set default values:
andrewm@0:     delayLengthLeft_ = delayLengthRight_ = 0.5;
andrewm@0:     wetMix_ = 0.5;
andrewm@0:     feedback_ = 0.75;
andrewm@0:     delayBufferLength_ = 1;
andrewm@0:     reverseChannels_ = false;
andrewm@0:     
andrewm@0:     // Start the circular buffer pointers at the beginning
andrewm@0:     delayReadPositionLeft_ = delayReadPositionRight_ = 0;
andrewm@0:     delayWritePosition_ = 0;
andrewm@0:     
andrewm@0:     lastUIWidth_ = 500;
andrewm@0:     lastUIHeight_ = 140;
andrewm@0: }
andrewm@0: 
andrewm@0: PingPongDelayAudioProcessor::~PingPongDelayAudioProcessor()
andrewm@0: {
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: const String PingPongDelayAudioProcessor::getName() const
andrewm@0: {
andrewm@0:     return JucePlugin_Name;
andrewm@0: }
andrewm@0: 
andrewm@0: int PingPongDelayAudioProcessor::getNumParameters()
andrewm@0: {
andrewm@0:     return kNumParameters;
andrewm@0: }
andrewm@0: 
andrewm@0: float PingPongDelayAudioProcessor::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 kWetMixParam:           return wetMix_;
andrewm@0:         case kFeedbackParam:         return feedback_;
andrewm@0:         case kDelayLengthLeftParam:  return delayLengthLeft_;
andrewm@0:         case kDelayLengthRightParam: return delayLengthRight_;
andrewm@0:         case kReverseChannelsParam:  return (reverseChannels_ ? 1.0f : 0.0f);
andrewm@0:         default:                     return 0.0f;
andrewm@0:     }
andrewm@0: }
andrewm@0: 
andrewm@0: void PingPongDelayAudioProcessor::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 kWetMixParam:
andrewm@0:             wetMix_ = newValue;
andrewm@0:             break;
andrewm@0:         case kFeedbackParam:
andrewm@0:             feedback_ = newValue;
andrewm@0:             break;
andrewm@0:         case kDelayLengthLeftParam:
andrewm@0:             delayLengthLeft_ = newValue;
andrewm@0:             delayReadPositionLeft_ = (int)(delayWritePosition_ - (delayLengthLeft_ * getSampleRate())
andrewm@0:                                        + delayBufferLength_) % delayBufferLength_;
andrewm@0:             break;
andrewm@0:         case kDelayLengthRightParam:
andrewm@0:             delayLengthRight_ = newValue;
andrewm@0:             delayReadPositionRight_ = (int)(delayWritePosition_ - (delayLengthRight_ * getSampleRate())
andrewm@0:                                            + delayBufferLength_) % delayBufferLength_;
andrewm@0:             break;
andrewm@0:         case kReverseChannelsParam:
andrewm@0:             reverseChannels_ = (newValue != 0.0f);
andrewm@0:             break;
andrewm@0:         default:
andrewm@0:             break;
andrewm@0:     }
andrewm@0: }
andrewm@0: 
andrewm@0: const String PingPongDelayAudioProcessor::getParameterName (int index)
andrewm@0: {
andrewm@0:     switch (index)
andrewm@0:     {
andrewm@0:         case kWetMixParam:           return "wet mix";
andrewm@0:         case kFeedbackParam:         return "feedback";
andrewm@0:         case kDelayLengthLeftParam:  return "delay left";
andrewm@0:         case kDelayLengthRightParam: return "delay right";
andrewm@0:         case kReverseChannelsParam:  return "reverse channels";
andrewm@0:         default:                     break;
andrewm@0:     }
andrewm@0:     
andrewm@0:     return String::empty;
andrewm@0: }
andrewm@0: 
andrewm@0: const String PingPongDelayAudioProcessor::getParameterText (int index)
andrewm@0: {
andrewm@0:     return String (getParameter (index), 2);
andrewm@0: }
andrewm@0: 
andrewm@0: const String PingPongDelayAudioProcessor::getInputChannelName (int channelIndex) const
andrewm@0: {
andrewm@0:     return String (channelIndex + 1);
andrewm@0: }
andrewm@0: 
andrewm@0: const String PingPongDelayAudioProcessor::getOutputChannelName (int channelIndex) const
andrewm@0: {
andrewm@0:     return String (channelIndex + 1);
andrewm@0: }
andrewm@0: 
andrewm@0: bool PingPongDelayAudioProcessor::isInputChannelStereoPair (int index) const
andrewm@0: {
andrewm@0:     return true;
andrewm@0: }
andrewm@0: 
andrewm@0: bool PingPongDelayAudioProcessor::isOutputChannelStereoPair (int index) const
andrewm@0: {
andrewm@0:     return true;
andrewm@0: }
andrewm@0: 
andrewm@0: bool PingPongDelayAudioProcessor::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: 
andrewm@0: double PingPongDelayAudioProcessor::getTailLengthSeconds() const
andrewm@0: {
andrewm@0:     return 0.0;
andrewm@0: }
andrewm@0: 
andrewm@0: bool PingPongDelayAudioProcessor::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 PingPongDelayAudioProcessor::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 PingPongDelayAudioProcessor::getNumPrograms()
andrewm@0: {
andrewm@0:     return 0;
andrewm@0: }
andrewm@0: 
andrewm@0: int PingPongDelayAudioProcessor::getCurrentProgram()
andrewm@0: {
andrewm@0:     return 0;
andrewm@0: }
andrewm@0: 
andrewm@0: void PingPongDelayAudioProcessor::setCurrentProgram (int index)
andrewm@0: {
andrewm@0: }
andrewm@0: 
andrewm@0: const String PingPongDelayAudioProcessor::getProgramName (int index)
andrewm@0: {
andrewm@0:     return String::empty;
andrewm@0: }
andrewm@0: 
andrewm@0: void PingPongDelayAudioProcessor::changeProgramName (int index, const String& newName)
andrewm@0: {
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: void PingPongDelayAudioProcessor::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:     delayReadPositionLeft_ = (int)(delayWritePosition_ - (delayLengthLeft_ * getSampleRate())
andrewm@0:                                + delayBufferLength_) % delayBufferLength_;
andrewm@0:     delayReadPositionRight_ = (int)(delayWritePosition_ - (delayLengthRight_ * getSampleRate())
andrewm@0:                                    + delayBufferLength_) % delayBufferLength_;
andrewm@0: }
andrewm@0: 
andrewm@0: void PingPongDelayAudioProcessor::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 PingPongDelayAudioProcessor::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 PingPongDelayAudioProcessor::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:     // This shouldn't happen, but we need a sanity check: this effect only makes sense
andrewm@0:     // if there are at least 2 channels to work with (and in this case only 2...)
andrewm@0:     if(buffer.getNumChannels() < 2)
andrewm@0:         return;
andrewm@0:     
andrewm@0:     // If there is one input only, the second channel may not contain anything useful.
andrewm@0:     // start with a blank buffer in this case
andrewm@0:     if(numInputChannels < 2)
andrewm@0:         buffer.clear(1, 0, numSamples);
andrewm@0:     
andrewm@0:     // channelDataL and channelDataR are arrays of length numSamples which contain
andrewm@0:     // the audio for one channel
b@1:     float *channelDataL = buffer.getWritePointer(0);
b@1:     float *channelDataR = buffer.getWritePointer(1);
andrewm@0:         
andrewm@0:     // delayDataL and delayDataR are the circular buffers for implementing delay
b@1:     float* delayDataL = delayBuffer_.getWritePointer(0);
b@1:     float* delayDataR = delayBuffer_.getWritePointer(1);
andrewm@0:     
andrewm@0:     for (int i = 0; i < numSamples; ++i)
andrewm@0:     {
andrewm@0:         const float inL = channelDataL[i];
andrewm@0:         const float inR = channelDataR[i];
andrewm@0:         float outL, outR;
andrewm@0:         
andrewm@0:         if(reverseChannels_)
andrewm@0:         {
andrewm@0:             outL = (inL + wetMix_ * delayDataR[delayReadPositionLeft_]);
andrewm@0:             outR = (inR + wetMix_ * delayDataL[delayReadPositionRight_]);
andrewm@0:         }
andrewm@0:         else
andrewm@0:         {
andrewm@0:             outL = (inL + wetMix_ * delayDataL[delayReadPositionLeft_]);
andrewm@0:             outR = (inR + wetMix_ * delayDataR[delayReadPositionRight_]);
andrewm@0:         }
andrewm@0:             
andrewm@0:         // Store the output of one delay buffer into the other, producing
andrewm@0:         // the ping-pong effect
andrewm@0:         delayDataR[delayWritePosition_] = inR + (delayDataL[delayReadPositionLeft_] * feedback_);
andrewm@0:         delayDataL[delayWritePosition_] = inL + (delayDataR[delayReadPositionRight_] * feedback_);
andrewm@0:         
andrewm@0:         if (++delayReadPositionLeft_ >= delayBufferLength_)
andrewm@0:             delayReadPositionLeft_ = 0;
andrewm@0:         if (++delayReadPositionRight_ >= delayBufferLength_)
andrewm@0:             delayReadPositionRight_ = 0;
andrewm@0:         if (++delayWritePosition_ >= delayBufferLength_)
andrewm@0:             delayWritePosition_ = 0;
andrewm@0:         
andrewm@0:         // Store the output samples in the buffer, replacing the input
andrewm@0:         channelDataL[i] = outL;
andrewm@0:         channelDataR[i] = outR;
andrewm@0:     }
andrewm@0:     
andrewm@0:     // Clear any channels above 2 (stereo)
andrewm@0:     for (int i = 2; i < numOutputChannels; ++i)
andrewm@0:     {
andrewm@0:         buffer.clear (i, 0, buffer.getNumSamples());
andrewm@0:     }
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: bool PingPongDelayAudioProcessor::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* PingPongDelayAudioProcessor::createEditor()
andrewm@0: {
andrewm@0:     return new PingPongDelayAudioProcessorEditor (this);
andrewm@0: }
andrewm@0: 
andrewm@0: //==============================================================================
andrewm@0: void PingPongDelayAudioProcessor::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("delayLengthLeft", delayLengthLeft_);
andrewm@0:     xml.setAttribute("delayLengthRight", delayLengthRight_);
andrewm@0:     xml.setAttribute("feedback", feedback_);
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 PingPongDelayAudioProcessor::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:             delayLengthLeft_  = (float)xmlState->getDoubleAttribute("delayLengthLeft", delayLengthLeft_);
andrewm@0:             delayLengthRight_ = (float)xmlState->getDoubleAttribute("delayLengthRight", delayLengthRight_);
andrewm@0:             feedback_     = (float)xmlState->getDoubleAttribute("feedback", feedback_);
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 PingPongDelayAudioProcessor();
andrewm@0: }