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 2009,2010,2011,2012 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 "DspCosine.h"
#include "PdGraph.h"

// initialise the static class variables
float *DspCosine::cos_table = NULL;
int DspCosine::refCount = 0;

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

DspCosine::DspCosine(pd::Message *init_message, PdGraph *graph) : DspObject(0, 1, 0, 1, graph) {
  this->sample_rate = graph->get_sample_rate();
  process_function = &procesSignal;
  #if !__APPLE__ // only create the lookup table if it is really needed
  refCount++;
  if (cos_table == NULL) {
    int sample_rateInt = (int) sample_rate;
    cos_table = (float *) malloc((sample_rateInt + 1) * sizeof(float));
    for (int i = 0; i < sample_rateInt; i++) {
      cos_table[i] = cosf(2.0f * M_PI * ((float) i) / sample_rate);
    }
    cos_table[sample_rateInt] = cos_table[0];
  }
  #endif
}

DspCosine::~DspCosine() {
  #if !__APPLE__
  if (--refCount == 0) {
    free(cos_table);
    cos_table = NULL;
  }
  #endif
}

void DspCosine::procesSignal(DspObject *dspObject, int fromIndex, int toIndex) {
  DspCosine *d = reinterpret_cast<DspCosine *>(dspObject);
  // as no messages are received and there is only one inlet, processDsp does not need much of the
  // infrastructure provided by DspObject
  
  #if __APPLE__
  static float twoPi = 2.0f*M_PI;
  vDSP_vsmul(d->dspBufferAtInlet[0], 1, &twoPi, d->dspBufferAtOutlet[0], 1, toIndex);
  vvcosf(d->dspBufferAtOutlet[0], d->dspBufferAtOutlet[0], &toIndex);
  #else
  for (int i = fromIndex; i < toIndex; ++i) {
    // works because cosine is symmetric about zero
    float f = fabsf(d->dspBufferAtInlet[0][i]);
    f -= floorf(f);
    d->dspBufferAtOutlet[0][i] = cos_table[(int) (f * d->sample_rate)];
  }
  #endif
}