transport_master_manager.h

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/*
 * Copyright (C) 2018-2019 Paul Davis <paul@linuxaudiosystems.com>
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#pragma once
 
#include <string>
 
#include "ardour/transport_master.h"
#include "ardour/types.h"
 
namespace ARDOUR {
 
class UI_TransportMaster;
 
class LIBARDOUR_API TransportMasterManager
{
  public:
        static TransportMasterManager& create ();
        TransportMasterManager (const TransportMasterManager&) = delete;
        TransportMasterManager& operator= (const TransportMasterManager&) = delete;
        ~TransportMasterManager ();
 
        int set_default_configuration ();
        void restart ();
        void engine_stopped ();
 
        static TransportMasterManager& instance();
        static void destroy();
        /* this method is not thread-safe and is intended to be used only
         * very early in application-lifetime to check if the TMM has
         * been created yet. Do not use in other code.
         */
        static bool exists() { return _instance != 0; }
 
        typedef std::list<std::shared_ptr<TransportMaster> > TransportMasters;
 
        int add (SyncSource type, std::string const & name, bool removeable = true);
        int remove (std::string const & name);
        void clear (bool emit = true);
 
        PBD::Signal<void(std::shared_ptr<TransportMaster> )> Added;
        PBD::Signal<void(std::shared_ptr<TransportMaster> )> Removed; // null argument means "clear"
 
        double pre_process_transport_masters (pframes_t, samplepos_t session_transport_position);
 
        double get_current_speed_in_process_context() const { return _master_speed; }
        samplepos_t get_current_position_in_process_context() const { return _master_position; }
 
        std::shared_ptr<TransportMaster> current() const { return _current_master; }
        int set_current (std::shared_ptr<TransportMaster>);
        int set_current (SyncSource);
        int set_current (std::string const &);
 
        PBD::Signal<void(std::shared_ptr<TransportMaster>, std::shared_ptr<TransportMaster> )> CurrentChanged;
 
        int set_state (XMLNode const &, int);
        XMLNode& get_state() const;
 
        void set_session (Session*);
        Session* session() const { return _session; }
 
        bool master_invalid_this_cycle() const { return _master_invalid_this_cycle; }
 
        std::shared_ptr<TransportMaster> master_by_type (SyncSource src) const;
        std::shared_ptr<TransportMaster> master_by_name (std::string const &) const;
        std::shared_ptr<TransportMaster> master_by_port (std::shared_ptr<Port> const &p) const;
 
        TransportMasters const & transport_masters() const { return _transport_masters; }
 
        static const std::string state_node_name;
 
        void block_disk_output ();
        void unblock_disk_output ();
        void reinit (double speed, samplepos_t pos);
 
  private:
        TransportMasterManager();
 
        TransportMasters      _transport_masters;
        mutable Glib::Threads::RWLock  lock;
        double                _master_speed;
        samplepos_t           _master_position;
 
        std::shared_ptr<TransportMaster> _current_master;
        Session* _session;
 
        bool _master_invalid_this_cycle;
        bool disk_output_blocked;
 
        /* a DLL to chase the transport master, calculate playback speed
         * by matching Ardour's current playhead position against
         * the position of the transport-master */
        double t0; // PH position at the beginning of this cycle
        double t1; // expected PH position if next cycle
        double e2; // second order loop error
        double bandwidth; // DLL filter bandwidth
        double b, c, omega; // DLL filter coefficients
 
        void init_transport_master_dll (double speed, samplepos_t pos);
        int master_dll_initstate; // play-direction -1, +1, or 0: not initialized
 
        static TransportMasterManager* _instance;
 
        /* original TC format in case the slave changed it */
        std::optional<Timecode::TimecodeFormat> _session_tc_format;
        void maybe_restore_tc_format ();
        void maybe_set_tc_format ();
 
        int add_locked (std::shared_ptr<TransportMaster>);
        double compute_matching_master_speed (pframes_t nframes, samplepos_t, bool& locate_required);
        int set_current_locked (std::shared_ptr<TransportMaster>);
 
        PBD::ScopedConnection config_connection;
        void parameter_changed (std::string const & what);
};
 
} // namespace ARDOUR