purezen 0.0.2

Runtime for the Pure Data (Pd) audio programming language, implemented as an extensible audio library allowing full control over signal processing, message passing, and graph manipulation. Pure Data is a graph-based programming language environment creating interactive music and multimedia works.
Documentation
/*
 *  Copyright 2010 Reality Jockey, Ltd.
 *                 info@rjdj.me
 *                 http://rjdj.me/
 *
 *  This file is part of ZenGarden.
 *
 *  ZenGarden is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  ZenGarden 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with ZenGarden.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "ArrayArithmetic.h"
#include "BufferPool.h"
#include "DspRfft.h"
#include "PdGraph.h"

message::Object *DspRfft::new_object(pd::Message *init_message, PdGraph *graph) {
  return new DspRfft(init_message, graph);
}

DspRfft::DspRfft(pd::Message *init_message, PdGraph *graph) : DspObject(0, 1, 0, 2, graph) {
  #if __APPLE__
  log2n = lrintf(log2f((float) block_sizeInt));
  fftSetup = vDSP_create_fftsetup(log2n, kFFTRadix2);
  zeroBuffer = graph->get_buffer_pool()->get_zero_buffer(); // cache the local zero buffer
  #else
  graph->print_err("[rfft~] is not supported on this platform. It is only supported on Apple OS X and iOS platforms.");
  #endif // __APPLE__
  
  process_function = &processSignal;
}

DspRfft::~DspRfft() {
  #if __APPLE__
  vDSP_destroy_fftsetup(fftSetup);
  #endif // __APPLE__
}

void DspRfft::processSignal(DspObject *dspObject, int fromIndex, int toIndex) {
  DspRfft *d = reinterpret_cast<DspRfft *>(dspObject);
  
  #if __APPLE__
  DSPSplitComplex inputVector;
  inputVector.realp = d->dspBufferAtInlet[0];
  inputVector.imagp = d->zeroBuffer;
  DSPSplitComplex outputVector;
  outputVector.realp = d->dspBufferAtOutlet[0];
  outputVector.imagp = d->dspBufferAtOutlet[1];
  vDSP_fft_zop(d->fftSetup, &inputVector, 1, &outputVector, 1, d->log2n, kFFTDirection_Forward);
  
  // NOTE(mhroth): vDSP_fft_zop outputs the entire series of symmetric coefficients.
  // Pd only returns the unique values. The below code makes this object output values in the same
  // way that Pd does. But since the Apple fft and ifft functions require the symmetric values,
  // we leave it like this for now.
  
  //int halfBlockSize = block_sizeInt >> 1;
  //memset(dspBufferAtOutlet0+halfBlockSize+1, 0, (halfBlockSize-1) * sizeof(float));
  //memset(dspBufferAtOutlet[1]+halfBlockSize, 0, halfBlockSize * sizeof(float));
  #endif // __APPLE__
}