andrewm@0: /*
andrewm@0:   TouchKeys: multi-touch musical keyboard control software
andrewm@0:   Copyright (c) 2013 Andrew McPherson
andrewm@0: 
andrewm@0:   This program is free software: you can redistribute it and/or modify
andrewm@0:   it under the terms of the GNU General Public License as published by
andrewm@0:   the Free Software Foundation, either version 3 of the License, or
andrewm@0:   (at your option) any later version.
andrewm@0:  
andrewm@0:   This program is distributed in the hope that it will be useful,
andrewm@0:   but WITHOUT ANY WARRANTY; without even the implied warranty of
andrewm@0:   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
andrewm@0:   GNU General Public License for more details.
andrewm@0: 
andrewm@0:   You should have received a copy of the GNU General Public License
andrewm@0:   along with this program.  If not, see <http://www.gnu.org/licenses/>.
andrewm@0:  
andrewm@0:   =====================================================================
andrewm@0: 
andrewm@0:   TimerNode.cpp: creates a Node object which runs its own thread to generate
andrewm@0:   timestamps.
andrewm@0: */
andrewm@0: 
andrewm@0: #include "TimerNode.h"
andrewm@0: 
andrewm@0: using std::cout;
andrewm@0: using std::endl;
andrewm@0: 
andrewm@0: // Start the timer, if it isn't already running.  The update rate is set elsewhere.
andrewm@0: void TimerNode::start(timestamp_type where) {
andrewm@0: 	if(isRunning_)
andrewm@0: 		return;
andrewm@0:     startingTimestamp_ = where;
andrewm@0:     startThread();
andrewm@0: 	isRunning_ = true;
andrewm@0: }
andrewm@0: 
andrewm@0: // Stop the timer if it is currently running.  This kills the associated thread.
andrewm@0: void TimerNode::stop() {
andrewm@0: 	if(!isRunning_)
andrewm@0: 		return;
andrewm@0:     signalThreadShouldExit();
andrewm@0:     notify();
andrewm@0:     stopThread(-1); // Ask the thread to stop; no timeout
andrewm@0: 	isRunning_ = false;
andrewm@0: }
andrewm@0: 
andrewm@0: // This function runs in its own thread, as managed by the Juce Thread parent class.  It produces
andrewm@0: // data points approximately separated in time by intervalMicros_.  The resolution of the system
andrewm@0: // timer affects how precise the spacing will be.  Though the ticks may jitter, there shouldn't
andrewm@0: // be any systematic drift unless intervalMicros_ is smaller than the execution time of the loop.
andrewm@0: // (For example, 1000 will be fine; 1 is too short)
andrewm@0: 
andrewm@0: void TimerNode::run() {
andrewm@0: 	unsigned long long targetMicros = 0;
andrewm@0: 	
andrewm@0: 	// Find the start time, against which our offsets will be measured.
andrewm@0:     double startTime = Time::getMillisecondCounterHiRes();
andrewm@0:     double nextTime;
andrewm@0:     
andrewm@0: 	while(!threadShouldExit()) {
andrewm@0: 		// Get the current time relative to when we started, using it as the "official" timestamp 
andrewm@0: 		// for the data source.
andrewm@0: 		insert(startingTimestamp_ + microseconds_to_timestamp(targetMicros), milliseconds_to_timestamp(Time::getMillisecondCounterHiRes() - startTime));
andrewm@0: 		targetMicros += intervalMicros_;
andrewm@0:         
andrewm@0:         // Next millisecond time according to Juce timer
andrewm@0:         nextTime = startTime + (double)targetMicros/1000.0;
andrewm@0: 		
andrewm@0: 		// Sleep until we get to the next tick.
andrewm@0: 		// thread_.sleep(startTime + microseconds(target_micros));
andrewm@0:         wait((int)(nextTime - Time::getMillisecondCounterHiRes()));
andrewm@0: 	}
andrewm@0: }