automation_watch.cc

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/*
    Copyright (C) 2012 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.

*/

#include <iostream>

#include <glibmm/timer.h>

#include "pbd/compose.h"

#include "ardour/automation_control.h"
#include "ardour/automation_watch.h"
#include "ardour/debug.h"
#include "ardour/session.h"

using namespace ARDOUR;
using namespace PBD;

AutomationWatch* AutomationWatch::_instance = 0;

AutomationWatch&
AutomationWatch::instance ()
{
        if (_instance == 0) {
                _instance = new AutomationWatch;
        }
        return *_instance;
}

AutomationWatch::AutomationWatch ()
        : _thread (0)
        , _last_time (0)
        , _run_thread (false)
{
        
}

AutomationWatch::~AutomationWatch ()
{
        if (_thread) {
                _run_thread = false;
                _thread->join ();
                _thread = 0;
        }

        Glib::Threads::Mutex::Lock lm (automation_watch_lock);
        automation_watches.clear ();
}

void
AutomationWatch::add_automation_watch (boost::shared_ptr<AutomationControl> ac)
{
        Glib::Threads::Mutex::Lock lm (automation_watch_lock);
        DEBUG_TRACE (DEBUG::Automation, string_compose ("now watching control %1 for automation, astate = %2\n", ac->name(), enum_2_string (ac->automation_state())));
        automation_watches.insert (ac);

        /* if an automation control is added here while the transport is
         * rolling, make sure that it knows that there is a write pass going
         * on, rather than waiting for the transport to start.
         */

        if (_session && _session->transport_rolling() && ac->alist()->automation_write()) {
                DEBUG_TRACE (DEBUG::Automation, string_compose ("\ttransport is rolling @ %1, audible = %2so enter write pass\n", 
                                                                _session->transport_speed(), _session->audible_frame()));
                /* add a guard point since we are already moving */
                ac->list()->set_in_write_pass (true, true, _session->audible_frame());
        }

        /* we can't store shared_ptr<Destructible> in connections because it
         * creates reference cycles. we don't need to make the weak_ptr<>
         * explicit here, but it helps to remind us what is going on.
         */
        
        boost::weak_ptr<AutomationControl> wac (ac);
        ac->DropReferences.connect_same_thread (*this, boost::bind (&AutomationWatch::remove_weak_automation_watch, this, wac));
}

void
AutomationWatch::remove_weak_automation_watch (boost::weak_ptr<AutomationControl> wac)
{
        boost::shared_ptr<AutomationControl> ac = wac.lock();

        if (!ac) {
                return;
        }

        remove_automation_watch (ac);
}

void
AutomationWatch::remove_automation_watch (boost::shared_ptr<AutomationControl> ac)
{
        Glib::Threads::Mutex::Lock lm (automation_watch_lock);
        DEBUG_TRACE (DEBUG::Automation, string_compose ("remove control %1 from automation watch\n", ac->name()));
        automation_watches.erase (ac);
        ac->list()->set_in_write_pass (false);
}

gint
AutomationWatch::timer ()
{
        if (!_session || !_session->transport_rolling()) {
                return TRUE;
        }

        {
                Glib::Threads::Mutex::Lock lm (automation_watch_lock);

                framepos_t time = _session->audible_frame ();
                if (time > _last_time) {  //we only write automation in the forward direction; this fixes automation-recording in a loop
                        for (AutomationWatches::iterator aw = automation_watches.begin(); aw != automation_watches.end(); ++aw) {
                                if ((*aw)->alist()->automation_write()) {
                                        (*aw)->list()->add (time, (*aw)->user_double(), true);
                                }
                        }
                } else {  //transport stopped or reversed.  stop the automation pass and start a new one (for bonus points, someday store the previous pass in an undo record)
                        for (AutomationWatches::iterator aw = automation_watches.begin(); aw != automation_watches.end(); ++aw) {
                                DEBUG_TRACE (DEBUG::Automation, string_compose ("%1: transport in rewind, speed %2, in write pass ? %3 writing ? %4\n", 
                                                                                (*aw)->name(), _session->transport_speed(), _session->transport_rolling(),
                                                                                (*aw)->alist()->automation_write()));
                                (*aw)->list()->set_in_write_pass (false);
                                if ( (*aw)->alist()->automation_write() ) {
                                        (*aw)->list()->set_in_write_pass (true);
                                }
                        }
                }
                
                _last_time = time;
        }

        return TRUE;
}

void
AutomationWatch::thread ()
{
        while (_run_thread) {
                Glib::usleep ((gulong) floor (Config->get_automation_interval_msecs() * 1000));
                timer ();
        }
}

void
AutomationWatch::set_session (Session* s)
{
        transport_connection.disconnect ();

        if (_thread) {
                _run_thread = false;
                _thread->join ();
                _thread = 0;
        }

        SessionHandlePtr::set_session (s);

        if (_session) {
                _run_thread = true;
                _thread = Glib::Threads::Thread::create (boost::bind (&AutomationWatch::thread, this));
                
                _session->TransportStateChange.connect_same_thread (transport_connection, boost::bind (&AutomationWatch::transport_state_change, this));
        }
}

void
AutomationWatch::transport_state_change ()
{
        if (!_session) {
                return;
        }

        bool rolling = _session->transport_rolling();
        
        _last_time = _session->audible_frame ();

        {
                Glib::Threads::Mutex::Lock lm (automation_watch_lock);

                for (AutomationWatches::iterator aw = automation_watches.begin(); aw != automation_watches.end(); ++aw) {
                        DEBUG_TRACE (DEBUG::Automation, string_compose ("%1: transport state changed, speed %2, in write pass ? %3 writing ? %4\n", 
                                                                        (*aw)->name(), _session->transport_speed(), rolling,
                                                                        (*aw)->alist()->automation_write()));
                        if (rolling && (*aw)->alist()->automation_write()) {
                                (*aw)->list()->set_in_write_pass (true);
                        } else {
                                (*aw)->list()->set_in_write_pass (false);
                        }
                }
        }
}