view Source/Utility/TimerNode.cpp @ 20:dfff66c07936

Lots of minor changes to support building on Visual Studio. A few MSVC-specific #ifdefs to eliminate things Visual Studio doesn't like. This version now compiles on Windows (provided liblo, Juce and pthread are present) but the TouchKeys device support is not yet enabled. Also, the code now needs to be re-checked on Mac and Linux.

/*
  TouchKeys: multi-touch musical keyboard control software
  Copyright (c) 2013 Andrew McPherson

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
 
  This program 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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
  =====================================================================

  TimerNode.cpp: creates a Node object which runs its own thread to generate
  timestamps.
*/

#include "TimerNode.h"

using std::cout;
using std::endl;

// Start the timer, if it isn't already running.  The update rate is set elsewhere.
void TimerNode::start(timestamp_type where) {
	if(isRunning_)
		return;
    startingTimestamp_ = where;
    startThread();
	isRunning_ = true;
}

// Stop the timer if it is currently running.  This kills the associated thread.
void TimerNode::stop() {
	if(!isRunning_)
		return;
    signalThreadShouldExit();
    notify();
    stopThread(-1); // Ask the thread to stop; no timeout
	isRunning_ = false;
}

// This function runs in its own thread, as managed by the Juce Thread parent class.  It produces
// data points approximately separated in time by intervalMicros_.  The resolution of the system
// timer affects how precise the spacing will be.  Though the ticks may jitter, there shouldn't
// be any systematic drift unless intervalMicros_ is smaller than the execution time of the loop.
// (For example, 1000 will be fine; 1 is too short)

void TimerNode::run() {
	unsigned long long targetMicros = 0;
	
	// Find the start time, against which our offsets will be measured.
    double startTime = Time::getMillisecondCounterHiRes();
    double nextTime;
    
	while(!threadShouldExit()) {
		// Get the current time relative to when we started, using it as the "official" timestamp 
		// for the data source.
		insert(startingTimestamp_ + microseconds_to_timestamp(targetMicros), milliseconds_to_timestamp(Time::getMillisecondCounterHiRes() - startTime));
		targetMicros += intervalMicros_;
        
        // Next millisecond time according to Juce timer
        nextTime = startTime + (double)targetMicros/1000.0;
		
		// Sleep until we get to the next tick.
		// thread_.sleep(startTime + microseconds(target_micros));
        wait((int)(nextTime - Time::getMillisecondCounterHiRes()));
	}
}