SimplePanner.cpp

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//
//  SimplePanner.cpp -- Basic panner using a filter.
//  See the copyright notice and acknowledgment of authors in the file COPYRIGHT
//

#include "SimplePanner.h"

namespace csl {

// Default constructor

SimplePanner::SimplePanner() :
        mDryMix(2),                             // set up stereo mixers for the graph
        mFiltMix(2), 
        mRevMix(2), 
         
        mFiltSplit(mFiltMix),                   // splitter for filters
        mRLPF(mFiltSplit, BW_LOW_PASS, 800.0f), // 2 lo-pass filters
        mLLPF(mFiltSplit, BW_LOW_PASS, 800.0f),  
        mFiltJoin(mLLPF, mRLPF),                // joiner for filters
        
        mReverb(mRevMix),                       // stereoverb
        mOutMix(2)                              // grand output mixer
{
    mOutMix.addInput(mDryMix);
    mOutMix.addInput(mFiltJoin);
    mOutMix.addInput(mReverb);                  // add processing paths to out mixer

    mOutMix.scaleInput(mDryMix,  0.4f);         // scale out mix levels
    mOutMix.scaleInput(mFiltJoin, 0.4f);
    mOutMix.scaleInput(mReverb,  0.4f);

    mReverb.setWetLevel(1.0f);                  // set up reverb
    mReverb.setDryLevel(0.0f);
//  mReverb.setRoomSize(0.99f);                 // long reverb time
}

SimplePanner::~SimplePanner() {
    // no-op
}

// Add a new source, creating the in-panner as a fan-out

void SimplePanner::addSource(SpatialSource &soundSource) {
    mSources.push_back(&soundSource);           // remember the source
    Panner * inPan = new Panner(soundSource);   // add a panner on the source
    mPanners.push_back(inPan);                  // store panner in vector

    mDryMix.addInput(inPan);                    // add panner to mixers
    mFiltMix.addInput(inPan);
    mRevMix.addInput(inPan);
}

// delete from the list, shifting if necessary

void SimplePanner::removeSource(SpatialSource &soundSource) {
                            // find the source's panner and fanout
    for (unsigned i = 0; i < mSources.size(); i++) {
        if (mSources[i] == &soundSource) {
            Panner * inPan = (Panner *) mPanners[i];
            mDryMix.removeInput(*inPan);
            mFiltMix.removeInput(*inPan);
            mRevMix.removeInput(*inPan);
            
            mSources.erase(mSources.begin() + i);
            mPanners.erase(mPanners.begin() + i);
            delete inPan;
            return;
        }
    }
}

// fill the buffer with the next buffer of values
    
void SimplePanner::nextBuffer(Buffer &outputBuffer) throw (CException) {
    float az, pos;
    float half = 1.0f/2.0f;
    if (mSources.size() == 0)
        return;
                                        // set all the panner values
    for (unsigned i = 0; i < mSources.size(); i++) {
        az = ((SpatialSource *) mSources[i])->azimuth() / CSL_TWOPI;    // range 0 - 1 = 0 - 2 pi
        while (az < 0.0f)   az += 1.0f; // clip to range 0 - 1
        while (az > 1.0f)   az -= 1.0f;
        pos = az;
        if (pos > half)     pos = 1.0f - pos;
        pos *= 4.0f;                    // range 0 - 2
        pos -= 1.0f;                    // range -1 - +1
        ((Panner *) mPanners[i])->setPosition(pos); // set stereo position
        
                                        // set reverb feed from distance
        float distScale = 1.0f / sqrt(((SpatialSource *) mSources[i])->distance());
//      float distScale = 1.0f / ((SpatialSource *) mSources[i]->distance());   // this brings up the reverb closer
        mRevMix.scaleInput(*mPanners[i], 1.0f - distScale);
        
                                        // set filter/dry ratio from front/back angle
        if (az < half) {                // front half
            mFiltMix.scaleInput(*mPanners[i], 0.0f);
            mDryMix.scaleInput(*mPanners[i], distScale);
        } else {                        // rear half
            float ratio = fabs(0.75f - az) * 4.0f;      // scale 0 - 1
            mFiltMix.scaleInput(*mPanners[i], (1.5f - ratio) * distScale);
            mDryMix.scaleInput(*mPanners[i], ratio * distScale);
        }
    }
    mOutMix.nextBuffer(outputBuffer);   // now call the out mixer to run the graph
}

} // namespace