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.
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/*
 *  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 "DspOsc.h"
#include "PdGraph.h"

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

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

DspOsc::DspOsc(pd::Message *init_message, PdGraph *graph) : DspObject(2, 2, 0, 1, graph) {
  frequency = init_message->is_float(0) ? init_message->get_float(0) : 0.0f;
  sampleStep = frequency * 65536.0f / graph->get_sample_rate();
  #if __SSE3__
  short step = (short) roundf(sampleStep);
  inc = _mm_set_epi16(8*step, 8*step, 8*step, 8*step, 8*step, 8*step, 8*step, 8*step);
  indicies = _mm_set_epi16(7*step, 6*step, 5*step, 4*step, 3*step, 2*step, step, 0);
  #endif
  
  phase = 0.0f;
  refCount++;
  if (cos_table == NULL) {
    cos_table = ALLOC_ALIGNED_BUFFER(65536 * sizeof(float));
    for (int i = 0; i < 65536; i++) {
      cos_table[i] = cosf(2.0f * M_PI * ((float) i) / 65536.0f);
    }
  }
  
  process_function = &processScalar;
  process_functionNoMessage = &processScalar;
}

DspOsc::~DspOsc() {
  if (--refCount == 0) {
    FREE_ALIGNED_BUFFER(cos_table);
    cos_table = NULL;
  }
}

void DspOsc::onInletConnectionUpdate(unsigned int inlet_index) {
  // TODO(mhroth): support this with processSignal
}

string DspOsc::toString() {
  char str[snprintf(NULL, 0, "%s %g", get_object_label(), frequency)+1];
  snprintf(str, sizeof(str), "%s %g", get_object_label(), frequency);
  return string(str);
}

void DspOsc::process_message(int inlet_index, pd::Message *message) {
  switch (inlet_index) {
    case 0: { // update the frequency
      if (message->is_float(0)) {
        frequency = fabsf(message->get_float(0));
        sampleStep = frequency * 65536.0f / graph->get_sample_rate();
        
        #if __SSE3__
        short step = (short) roundf(sampleStep);
        inc = _mm_set_epi16(8*step, 8*step, 8*step, 8*step, 8*step, 8*step, 8*step, 8*step);
        unsigned short currentIndex = _mm_extract_epi16(indicies,0);
        indicies = _mm_set_epi16(7*step+currentIndex, 6*step+currentIndex, 5*step+currentIndex,
            4*step+currentIndex, 3*step+currentIndex, 2*step+currentIndex, step+currentIndex, currentIndex);
        #endif
      }
      break;
    }
    case 1: { // update the phase
      // TODO(mhroth)
      break;
    }
    default: break;
  }
}

void DspOsc::processScalar(DspObject *dspObject, int fromIndex, int toIndex) {
  DspOsc *d = reinterpret_cast<DspOsc *>(dspObject);
  #if __SSE3__
  /*
   * Creates an array of unsigned short indicies (since the length of the cosine lookup table is
   * of length 2^16. These indicies are incremented by a step size based on the desired frequency.
   * As the indicies overflow during addition, they loop back around to zero.
   */
  float *output = d->dspBufferAtOutlet[0]+fromIndex;
  __m128i inc = d->inc;
  __m128i indicies = d->indicies;
  int n = toIndex - fromIndex;
  
  unsigned short currentIndex = _mm_extract_epi16(indicies,0);
  short step = _mm_extract_epi16(inc,0)/8;
  
  switch (fromIndex & 0x7) {
    case 0: default: break;
    case 1: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step; --n; // allow fallthrough
    case 2: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step; --n;
    case 3: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step; --n;
    case 4: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step; --n;
    case 5: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step; --n;
    case 6: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step; --n;
    case 7: {
      *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step; --n;
      
      d->indicies = _mm_set_epi16(7*step+currentIndex, 6*step+currentIndex, 5*step+currentIndex,
          4*step+currentIndex, 3*step+currentIndex, 2*step+currentIndex, step+currentIndex, currentIndex);
    }
  }
  
  int n4 = n & 0xFFFFFFF8; // we can process 8 indicies at a time
  while (n4) {
    __m128 values = _mm_set_ps(DspOsc::cos_table[(unsigned short) _mm_extract_epi16(indicies,3)],
                               DspOsc::cos_table[(unsigned short) _mm_extract_epi16(indicies,2)],
                               DspOsc::cos_table[(unsigned short) _mm_extract_epi16(indicies,1)],
                               DspOsc::cos_table[(unsigned short) _mm_extract_epi16(indicies,0)]);
    _mm_store_ps(output, values);
    output += 4;
    values = _mm_set_ps(DspOsc::cos_table[(unsigned short) _mm_extract_epi16(indicies,7)],
                        DspOsc::cos_table[(unsigned short) _mm_extract_epi16(indicies,6)],
                        DspOsc::cos_table[(unsigned short) _mm_extract_epi16(indicies,5)],
                        DspOsc::cos_table[(unsigned short) _mm_extract_epi16(indicies,4)]);
    _mm_store_ps(output, values);
    indicies = _mm_add_epi16(indicies, inc);
    output += 4;
    n4 -= 8;
  }
  
  currentIndex = _mm_extract_epi16(indicies,0);
  switch (n & 0x7) {
    case 7: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step; // allow fallthrough
    case 6: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step;
    case 5: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step;
    case 4: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step;
    case 3: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step;
    case 2: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step;
    case 1: *output++ = DspOsc::cos_table[currentIndex]; currentIndex += step;
    default: {
      // set the current index to the correct location, given that the step size is actually
      // a real number, not an integer
      // NOTE(mhroth): but doing this will cause clicks :-/ Osc will thus go out of phase over time
      // Will anyone complain?
//      d->currentIndex = currentIndex + ((short) ((d->sampleStep - floorf(d->sampleStep)) * n));
      
      if ((n & 0x7) == 0) {
        d->indicies = indicies;
      } else {
        d->indicies = _mm_set_epi16(7*step+currentIndex, 6*step+currentIndex, 5*step+currentIndex,
            4*step+currentIndex, 3*step+currentIndex, 2*step+currentIndex, step+currentIndex, currentIndex);        
      }
      break;
    }
  }
  #else
  // TODO(mhroth):!!!
  #endif
}