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 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 "MessageDelay.h"
#include "PdGraph.h"

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

MessageDelay::MessageDelay(pd::Message *init_message, PdGraph *graph) : message::Object(2, 1, graph) {
  delayMs = init_message->is_float(0) ? (double) init_message->get_float(0) : 0.0;
  scheduledMessage = NULL;
}

MessageDelay::~MessageDelay() {
  // nothing to do
}

void MessageDelay::cancelScheduledMessageIfExists() {
  if (scheduledMessage != NULL) {
    graph->cancel_message(this, 0, scheduledMessage);
    scheduledMessage = NULL;
  }
}

void MessageDelay::process_message(int inlet_index, pd::Message *message) {
  switch (inlet_index) {
    case 0: {
      switch (message->get_type(0)) {
        case SYMBOL: {
          if (message->is_symbol_str(0, "stop")) {
            cancelScheduledMessageIfExists();
            break;
          }
          // allow fall-through
        }
        case FLOAT:
        case BANG: {
          cancelScheduledMessageIfExists();
          scheduledMessage = PD_MESSAGE_ON_STACK(1);
          scheduledMessage->from_timestamp_and_bang(message->get_timestamp() + delayMs);
          scheduledMessage = graph->schedule_message(this, 0, scheduledMessage);
          break;
        }
        default: {
          break;
        }
      }
      break;
    }
    case 1: {
      if (message->is_float(0)) {
        // if an outstanding message exists when the delay is reset, the message is cancelled
        cancelScheduledMessageIfExists();
        delayMs = (double) message->get_float(0);
      }
      break;
    }
    default: {
      break;
    }
  }
}

void MessageDelay::send_message(int outlet_index, pd::Message *message) {
  if (message == scheduledMessage) {
    // now that we know that this message is being sent, we don't have to worry about it anymore
    scheduledMessage = NULL;
  }
  message::Object::send_message(outlet_index, message);
}