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 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 "DspTableRead4.h"
#include "PdGraph.h"

message::Object *DspTableRead4::new_object(pd::Message *init_message, PdGraph *graph) {
  return new DspTableRead4(init_message, graph);
}

DspTableRead4::DspTableRead4(pd::Message *init_message, PdGraph *graph) : DspObject(2, 1, 0, 1, graph) {
  name = init_message->is_symbol(0) ? utils::copy_string(init_message->get_symbol(0)) : NULL;
  table = NULL;
  offset = 0.0f;
}

DspTableRead4::~DspTableRead4() {
  free(name);
}

void DspTableRead4::set_table(MessageTable *aTable) {
  table = aTable;
}

void DspTableRead4::process_message(int inlet_index, pd::Message *message) {
  switch (inlet_index) {
    case 0: {
      if (message->is_symbol_str(0, "set") && message->is_symbol(1)) {
        // change the table from which this object reads
        free(name);
        name = utils::copy_string(message->get_symbol(1));
        table = graph->get_table(name);
      }
      break;
    }
    case 1: {
      if (message->is_float(0)) {
        offset = message->get_float(0); // set onset into table
      }
      break;
    }
    default: {
      break;
    }
  }
}

void DspTableRead4::processDspWithIndex(int fromIndex, int toIndex) {
  if (table != NULL) { // ensure that there is a table to read from!
    int bufferLength = 0;
    float *buffer = table->getBuffer(&bufferLength);
    #if __APPLE__
    //float zero = 0.0f;
    //float bufferLengthFloat = (float) (bufferLength-2);
    //vDSP_vclip(input_buffer+startSampleIndex, 1, &zero, &bufferLengthFloat,
    //    input_buffer+startSampleIndex, 1, endSampleIndex-startSampleIndex);
    // NOTE(mhroth): is isn't clear what the clipping behaviour of vDSP_vlint is, but I
    // *think* that it is doing the right thing (i.e., clipping OOB indicies)
    int duration = toIndex - fromIndex;
    vDSP_vsadd(dspBufferAtInlet[0]+fromIndex, 1, &offset, dspBufferAtOutlet[0]+fromIndex, 1, duration);
    vDSP_vlint(buffer, dspBufferAtOutlet[0]+fromIndex, 1, dspBufferAtOutlet[0]+fromIndex, 1,
        duration, bufferLength);
    #else
    float *input_buffer = dspBufferAtInlet[0];
    int maxIndex = bufferLength-1;
    for (int i = fromIndex; i < toIndex; i++) {
      float xf = input_buffer[i] + offset;
      int xi = (int) xf;
      if (xi <= 0) {
        dspBufferAtOutlet[0][i] = buffer[0];
      } else if (xi >= maxIndex) {
        dspBufferAtOutlet[0][i] = buffer[maxIndex];
      } else {
        // 2-point linear interpolation (basic and fast)
        float dx = xf - ((float) xi);
        float y0 = buffer[xi];
        float y1 = buffer[xi+1];
        float slope = (y1 - y0);
        dspBufferAtOutlet[0][i] = (slope * dx) + y0;
      }
    }
    #endif
  }
}