livetrax/libs/surfaces/generic_midi/generic_midi_control_protocol.cc

/*
    Copyright (C) 2006 Paul Davis
 
    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 2 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, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    $Id$
*/

#include <algorithm>

#include <midi++/port.h>
#include <midi++/manager.h>
#include <midi++/port_request.h>

#include <ardour/route.h>
#include <ardour/session.h>

#include "generic_midi_control_protocol.h"
#include "midicontrollable.h"

using namespace ARDOUR;
using namespace PBD;

#include "i18n.h"

GenericMidiControlProtocol::GenericMidiControlProtocol (Session& s)
	: ControlProtocol  (s, _("GenericMIDI"))
{
	MIDI::Manager* mm = MIDI::Manager::instance();
	MIDI::PortRequest pr ("ardour:MIDI control", "ardour:MIDI control", "duplex", "alsa/seq");
	
	_port = mm->add_port (pr);

	_feedback_interval = 10000; // microseconds
	last_feedback_time = 0;

	Controllable::StartLearning.connect (mem_fun (*this, &GenericMidiControlProtocol::start_learning));
	Controllable::StopLearning.connect (mem_fun (*this, &GenericMidiControlProtocol::stop_learning));
	Session::SendFeedback.connect (mem_fun (*this, &GenericMidiControlProtocol::send_feedback));
}

GenericMidiControlProtocol::~GenericMidiControlProtocol ()
{
}

int
GenericMidiControlProtocol::set_active (bool yn)
{
	/* start/stop delivery/outbound thread */
	return 0;
}

void
GenericMidiControlProtocol::set_feedback_interval (microseconds_t ms)
{
	_feedback_interval = ms;
}

void 
GenericMidiControlProtocol::send_feedback ()
{
	microseconds_t now = get_microseconds ();

	if (last_feedback_time != 0) {
		if ((now - last_feedback_time) < _feedback_interval) {
			return;
		}
	}

	_send_feedback ();
	
	last_feedback_time = now;
}

void 
GenericMidiControlProtocol::_send_feedback ()
{
	const int32_t bufsize = 16 * 1024;
	MIDI::byte buf[bufsize];
	int32_t bsize = bufsize;
	MIDI::byte* end = buf;
	
	for (MIDIControllables::iterator r = controllables.begin(); r != controllables.end(); ++r) {
		end = (*r)->write_feedback (end, bsize);
	}
	
	if (end == buf) {
		return;
	} 
	
	_port->write (buf, (int32_t) (end - buf));
}

bool
GenericMidiControlProtocol::start_learning (Controllable* c)
{
	if (c == 0) {
		return false;
	}

	MIDIControllable* mc = new MIDIControllable (*_port, *c);
	

	{
		Glib::Mutex::Lock lm (pending_lock);
		pending_controllables.push_back (mc);
		mc->learning_stopped.connect (bind (mem_fun (*this, &GenericMidiControlProtocol::learning_stopped), mc));
	}

	mc->learn_about_external_control ();
	return true;
}

void
GenericMidiControlProtocol::learning_stopped (MIDIControllable* mc)
{
	Glib::Mutex::Lock lm (pending_lock);
	Glib::Mutex::Lock lm2 (controllables_lock);
	
	MIDIControllables::iterator i = find (pending_controllables.begin(), pending_controllables.end(), mc);

	if (i != pending_controllables.end()) {
		pending_controllables.erase (i);
	}

	controllables.push_back (mc);
}

void
GenericMidiControlProtocol::stop_learning (Controllable* c)
{
	Glib::Mutex::Lock lm (pending_lock);

	/* learning timed out, and we've been told to consider this attempt to learn to be cancelled. find the
	   relevant MIDIControllable and remove it from the pending list.
	*/

	for (MIDIControllables::iterator i = pending_controllables.begin(); i != pending_controllables.end(); ++i) {
		if (&(*i)->get_controllable() == c) {
			(*i)->stop_learning ();
			delete (*i);
			pending_controllables.erase (i);
			break;
		}
	}
}