triggerbox.h

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/*
 * Copyright (C) 2021 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 <pthread.h>
 
#include <atomic>
#include <map>
#include <memory>
#include <vector>
#include <string>
#include <exception>
 
#include <glibmm/threads.h>
 
#include "pbd/crossthread.h"
#include "pbd/pcg_rand.h"
#include "pbd/pool.h"
#include "pbd/properties.h"
#include "pbd/ringbuffer.h"
#include "pbd/stateful.h"
 
#include "midi++/types.h"
 
#include "temporal/beats.h"
#include "temporal/bbt_time.h"
#include "temporal/tempo.h"
 
#include "evoral/PatchChange.h"
#include "evoral/SMF.h"
 
#include "ardour/event_ring_buffer.h"
#include "ardour/midi_model.h"
#include "ardour/midi_state_tracker.h"
#include "ardour/processor.h"
#include "ardour/rt_midibuffer.h"
#include "ardour/segment_descriptor.h"
#include "ardour/types.h"
#include "ardour/types_convert.h"
 
#include "ardour/libardour_visibility.h"
 
class XMLNode;
 
namespace RubberBand {
        class RubberBandStretcher;
}
 
namespace MIDI {
        class Parser;
}
 
namespace ARDOUR {
 
class Session;
class AudioRegion;
class MidiRegion;
class TriggerBox;
struct SlotArmInfo;
class SideChain;
class MidiPort;
 
typedef uint32_t color_t;
 
LIBARDOUR_API std::string cue_marker_name (int32_t);
 
class Trigger;
 
typedef std::shared_ptr<Trigger> TriggerPtr;
typedef RTMidiBufferBase<Temporal::Beats,Temporal::Beats> RTMidiBufferBeats;
 
class LIBARDOUR_API Trigger : public PBD::Stateful {
  public:
        enum State {
                /* This is the initial state for a Trigger, and means that it is not
                 * doing anything at all
                 */
                Stopped,
                /* A Trigger in this state has been chosen by its parent TriggerBox
                 * (e.g. because of a bang() call that put it in the queue), a Trigger in
                 * this state is waiting for the next occurence of its quantization to
                 * occur before transitioning to Running
                 */
                WaitingToStart,
                /* a Trigger in this state is going to deliver data during calls
                 * to its ::run() method.
                 */
                Running,
                /* a Trigger in this state was running, has been re-triggered e.g. by a
                 * ::bang() call with LaunchStyle set to Repeat, and is waiting for the
                 * next occurence of its quantization to occur before transitioning
                 * back to Running.
                 */
                WaitingForRetrigger,
                /* a Trigger in this state is delivering data during calls to ::run(), but
                 * is waiting for the next occurence of its quantization to occur when it will
                 * transition to Stopping and then Stopped.
                 */
                WaitingToStop,
                /* a Trigger in this state is delivering data during calls to ::run(), but
                 * is waiting for the next occurence of another Trigger's quantization to occur when it will
                 * transition to Stopping and then Stopped (and be followed by
                 * the other Trigger.
                 */
                WaitingToSwitch,
                /* a Trigger in this state was Running but noticed that it should stop
                 * during the current call to ::run(). By the end of that call, it will
                 * have transitioned to Stopped.
                 */
                Stopping,
        };
 
        enum LaunchStyle {
                OneShot,  /* mouse down/NoteOn starts; mouse up/NoteOff ignored */
                ReTrigger, /* mouse down/NoteOn starts or retriggers; mouse up/NoteOff */
                Gate,     /* runs till mouse up/note off then to next quantization */
                Toggle,   /* runs till next mouse down/NoteOn */
                Repeat,   /* plays only quantization extent until mouse up/note off */
        };
 
        enum StretchMode { /* currently mapped to the matching RubberBand::RubberBandStretcher::Option  */
                Crisp,
                Mixed,
                Smooth,
        };
 
        Trigger (uint32_t index, TriggerBox&);
        virtual ~Trigger() {}
 
        static void make_property_quarks ();
 
  protected:
        /* properties controllable by the user */
 
        PBD::Property<LaunchStyle>          _launch_style;
        PBD::Property<FollowAction>         _follow_action0;
        PBD::Property<FollowAction>         _follow_action1;
        PBD::Property<int>                  _follow_action_probability; /* 1 .. 100 */
        PBD::Property<uint32_t>             _follow_count;
        PBD::Property<Temporal::BBT_Offset> _quantization;
        PBD::Property<Temporal::BBT_Offset> _follow_length;
        PBD::Property<Temporal::BBT_Offset> _capture_duration;
        PBD::Property<bool>                 _use_follow_length;
        PBD::Property<bool>                 _legato;
        PBD::Property<gain_t>               _gain;
        PBD::Property<float>                _velocity_effect;
        PBD::Property<bool>                 _stretchable;
        PBD::Property<bool>                 _cue_isolated;
        PBD::Property<bool>                 _allow_patch_changes;
        PBD::Property<StretchMode>          _stretch_mode;
 
        /* Properties that are not CAS-updated at retrigger */
 
        PBD::Property<std::string>          _name;
        PBD::Property<color_t>              _color;
 
  public:
        /* this is positioned here so that we can easily keep it in sync
           with the properties list above.
        */
        struct UIState {
                std::atomic<unsigned int> generation; /* used for CAS */
 
                LaunchStyle launch_style = OneShot;
                FollowAction follow_action0 = FollowAction (FollowAction::Again);
                FollowAction follow_action1 = FollowAction (FollowAction::Stop);
                int follow_action_probability = 0;
                uint32_t follow_count = 1;
                Temporal::BBT_Offset quantization = Temporal::BBT_Offset (1, 0, 0);
                Temporal::BBT_Offset follow_length = Temporal::BBT_Offset (1, 0, 0);
                Temporal::BBT_Offset capture_duration = Temporal::BBT_Offset (1, 0, 0);
                bool use_follow_length = false;
                bool legato = false;
                gain_t gain = 1.0;
                float velocity_effect = 0;
                bool stretchable = true;
                bool cue_isolated = false;
                bool allow_patch_changes = true;
                StretchMode stretch_mode = Trigger::Crisp;
 
                Evoral::SMF::UsedChannels used_channels = Evoral::SMF::UsedChannels();
                Evoral::PatchChange<MidiBuffer::TimeType> patch_change[16];
 
                std::string  name = "";
                color_t      color = 0xBEBEBEFF;
                double       tempo = 0;  //unset
 
                UIState() : generation (0) {}
 
                UIState& operator= (UIState const & other) {
 
                        /* we do not copy generation */
 
                        generation = 0;
 
                        launch_style = other.launch_style;
                        follow_action0 = other.follow_action0;
                        follow_action1 = other.follow_action1;
                        follow_action_probability = other.follow_action_probability;
                        follow_count = other.follow_count;
                        quantization = other.quantization;
                        follow_length = other.follow_length;
                        capture_duration = other.capture_duration;
                        use_follow_length = other.use_follow_length;
                        legato = other.legato;
                        gain = other.gain;
                        velocity_effect = other.velocity_effect;
                        stretchable = other.stretchable;
                        cue_isolated = other.cue_isolated;
                        allow_patch_changes = other.allow_patch_changes;
                        stretch_mode = other.stretch_mode;
                        used_channels = other.used_channels;
 
                        for (int i = 0; i<16; i++) {
                                if (other.patch_change[i].is_set()) {
                                        patch_change[i] = other.patch_change[i];
                                }
                        }
 
                        name = other.name;
                        color = other.color;
                        tempo = other.tempo;
 
                        return *this;
                }
        };
 
#define TRIGGERBOX_PROPERTY_DECL(name,type) void set_ ## name (type); type name () const;
#define TRIGGERBOX_PROPERTY_DECL_CONST_REF(name,type) void set_ ## name (type const &); type name () const
 
        TRIGGERBOX_PROPERTY_DECL (launch_style, LaunchStyle);
        TRIGGERBOX_PROPERTY_DECL_CONST_REF (follow_action0, FollowAction);
        TRIGGERBOX_PROPERTY_DECL_CONST_REF (follow_action1, FollowAction);
        TRIGGERBOX_PROPERTY_DECL (follow_action_probability, int);
        TRIGGERBOX_PROPERTY_DECL (follow_count, uint32_t);
        TRIGGERBOX_PROPERTY_DECL_CONST_REF (quantization, Temporal::BBT_Offset);
        TRIGGERBOX_PROPERTY_DECL_CONST_REF (follow_length, Temporal::BBT_Offset);
        TRIGGERBOX_PROPERTY_DECL_CONST_REF (capture_duration, Temporal::BBT_Offset);
        TRIGGERBOX_PROPERTY_DECL (use_follow_length, bool);
        TRIGGERBOX_PROPERTY_DECL (legato, bool);
        TRIGGERBOX_PROPERTY_DECL (velocity_effect, float);
        TRIGGERBOX_PROPERTY_DECL (stretchable, bool);
        TRIGGERBOX_PROPERTY_DECL (cue_isolated, bool);
        TRIGGERBOX_PROPERTY_DECL (allow_patch_changes, bool);
        TRIGGERBOX_PROPERTY_DECL (gain, gain_t);
        TRIGGERBOX_PROPERTY_DECL (stretch_mode, StretchMode);
        TRIGGERBOX_PROPERTY_DECL (color, color_t);
        TRIGGERBOX_PROPERTY_DECL_CONST_REF (name, std::string);
 
#undef TRIGGERBOX_PROPERTY_DECL
#undef TRIGGERBOX_PROPERTY_DECL_CONST_REF
 
        /* Calling ::bang() will cause this Trigger to be placed in its owning
           TriggerBox's queue.
        */
        void bang (float velocity = 1.0f);
 
        /* Calling ::unbang() is equivalent to a mouse-up or note-off
            ... it MIGHT cause a clip to stop, but more likely has no effect, depending on the slot's launch-style.
        */
        void unbang ();
 
        /* Calling ::request_stop() to stop a Trigger at the earliest possible
         * opportunity, rather than at the next quantization point.
         */
        void request_stop ();
 
        /* Call ::stop_quantized() to stop a Trigger at the next quantization point.
         */
        void stop_quantized ();
 
        virtual void tempo_map_changed() {}
 
        virtual pframes_t run (BufferSet&, samplepos_t start_sample, samplepos_t end_sample,
                               Temporal::Beats const & start, Temporal::Beats const & end,
                               pframes_t nframes, pframes_t offset, double bpm, pframes_t& quantize_offset) = 0;
        virtual void io_change () {}
        virtual void set_legato_offset (timepos_t const & offset) = 0;
 
        timepos_t current_pos() const;
        double position_as_fraction() const;
 
        virtual void captured (SlotArmInfo&) {}
        void arm (Temporal::BBT_Offset duration = Temporal::BBT_Offset()) {
                _arm (duration);
        }
        virtual void disarm ();
        bool armed() const { return _armed; }
        PBD::Signal<void()> ArmChanged;
        static PBD::Signal<void(Trigger const *)> TriggerArmChanged;
 
 
        Temporal::BBT_Argument compute_start (Temporal::TempoMap::SharedPtr const &, samplepos_t start, samplepos_t end, Temporal::BBT_Offset const & q, samplepos_t& start_samples, bool& will_start);
        virtual timepos_t compute_end (Temporal::TempoMap::SharedPtr const &, Temporal::BBT_Time const &, samplepos_t, Temporal::Beats &) = 0;
        virtual void start_and_roll_to (samplepos_t start, samplepos_t position, uint32_t cnt) = 0;
 
        /* because follow actions involve probability is it easier to code the will-not-follow case */
 
        bool will_not_follow() const;
        bool will_follow() const { return !will_not_follow(); }
 
        /* assumes that this is currently playing but does not enforce it */
        bool cue_launched() const { return _cue_launched; }
 
        virtual bool probably_oneshot () const = 0;
 
        void process_state_requests (BufferSet& bufs, pframes_t dest_offset);
 
        bool active() const { return _state >= Running; }
        State state() const { return _state; }
 
        void set_region (std::shared_ptr<Region>, bool use_thread = true);
        void clear_region ();
        virtual int set_region_in_worker_thread (std::shared_ptr<Region>) = 0;
        virtual int set_region_in_worker_thread_from_capture (std::shared_ptr<Region>) = 0;
        std::shared_ptr<Region> the_region() const { return _region; }
        virtual bool playable() const = 0;
 
        uint32_t index() const { return _index; }
 
        /* Managed by TriggerBox, these record the time that the trigger is
         * scheduled to start or stop at. Computed in
         * Trigger::maybe_compute_next_transition().
         */
        samplepos_t transition_samples;
        Temporal::Beats transition_beats;
        Temporal::BBT_Time _transition_bbt;
 
        XMLNode& get_state () const;
        int set_state (const XMLNode&, int version);
 
        void maybe_compute_next_transition (samplepos_t start_sample, Temporal::Beats const & start, Temporal::Beats const & end, pframes_t& nframes, pframes_t& dest_offset);
 
 
        bool compute_quantized_transition (samplepos_t start_sample, Temporal::Beats const & start, Temporal::Beats const & end,
                                           Temporal::BBT_Argument& t_bbt, Temporal::Beats& t_beats, samplepos_t& t_samples,
                                           Temporal::TempoMap::SharedPtr const & tmap, Temporal::BBT_Offset const & q);
 
        pframes_t compute_next_transition (samplepos_t start_sample, Temporal::Beats const & start, Temporal::Beats const & end, pframes_t nframes,
                                           Temporal::BBT_Argument& t_bbt, Temporal::Beats& t_beats, samplepos_t& t_samples,
                                           Temporal::TempoMap::SharedPtr const & tmap);
 
 
        template<typename TriggerType>
                void start_and_roll_to (samplepos_t start_pos, samplepos_t end_position, TriggerType& trigger,
                                        pframes_t (TriggerType::*run_method) (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample,
                                                                              Temporal::Beats const & start_beats, Temporal::Beats const & end_beats,
                                                                              pframes_t nframes, pframes_t dest_offset, double bpm, pframes_t&), uint32_t cnt);
        void set_next_trigger (int n);
        int next_trigger() const { return _next_trigger; }
 
        /* any non-zero value will work for the default argument, and means
           "use your own launch quantization". BBT_Offset (0, 0, 0) means what
           it says: start immediately
        */
        void startup (BufferSet&, pframes_t dest_offset, Temporal::BBT_Offset const & start_quantization = Temporal::BBT_Offset (9, 3,0));
        void startup_from_ffwd (BufferSet&, uint32_t loop_cnt);
        void shutdown_from_fwd ();
        virtual void shutdown (BufferSet& bufs, pframes_t dest_offset);
        virtual void jump_start ();
        virtual void jump_stop (BufferSet& bufs, pframes_t dest_offset);
        void begin_stop (bool explicit_stop = false);
        void begin_switch (TriggerPtr);
 
        bool explicitly_stopped() const { return _explicitly_stopped; }
        void set_scene_switch (bool yn);
 
        uint32_t loop_count() const { return _loop_cnt; }
 
        void set_ui (void*);
        void* ui () const { return _ui; }
 
        TriggerBox& box() const { return _box; }
        std::shared_ptr<TriggerBox> boxptr() const;
 
        double estimated_tempo() const { return _estimated_tempo; }
 
        /* the following functions deal with audio- or midi-specific SegmentDescriptor properties, provided as virtuals so we don't have to do lots of dynamic_casting  */
        /* segment_tempo is currently a no-op for MIDI, but may be implemented later  */
        virtual double segment_tempo() const = 0;
        virtual void set_segment_tempo (double t) = 0;
 
        /* used_channels is a no-op for audio  */
        virtual Evoral::SMF::UsedChannels used_channels() const { return Evoral::SMF::UsedChannels(); }
        virtual void set_used_channels (Evoral::SMF::UsedChannels) {}
 
        /* patch changes are a no-op for audio */
        virtual void set_patch_change (Evoral::PatchChange<MidiBuffer::TimeType> const &) {}
        virtual Evoral::PatchChange<MidiBuffer::TimeType> const patch_change (uint8_t) const { return Evoral::PatchChange<MidiBuffer::TimeType>(); }
        virtual void unset_patch_change (uint8_t channel) {}
        virtual void unset_all_patch_changes () {}
        virtual bool patch_change_set (uint8_t channel) const { return false; }
 
        virtual void setup_stretcher () = 0;
 
        Temporal::Meter meter() const { return _meter; }
 
        void set_velocity_gain (gain_t g) {_pending_velocity_gain=g;}
 
        void set_pending (Trigger*);
        Trigger* swap_pending (Trigger*);
 
        void update_properties ();
 
        static Trigger * const MagicClearPointerValue;
 
        virtual SegmentDescriptor get_segment_descriptor () const = 0;
 
        static void request_trigger_delete (Trigger* t);
 
        /* these operations are provided to get/set all the "user visible" trigger properties at once */
        /* examples: drag+dropping from slot to slot, or "Range->Bounce to Slot", where a single operation sets many  */
        void get_ui_state (UIState &state) const;
        void set_ui_state (UIState &state);
 
        virtual void check_edit_swap (timepos_t const & time, bool playing, BufferSet& bufs) = 0;
 
        static PBD::Signal<void(PBD::PropertyChange,Trigger*)> TriggerPropertyChange;
 
        void region_property_change (PBD::PropertyChange const &);
        virtual void bounds_changed (Temporal::timepos_t const & start, Temporal::timepos_t const & end, Temporal::timecnt_t const & len);
 
  protected:
        struct UIRequests {
                std::atomic<bool> stop;
                UIRequests() : stop (false) {}
        };
 
        std::shared_ptr<Region> _region;
        samplecnt_t                process_index;
        samplepos_t                final_process_index;  /* where we stop playing, in process time, compare with process_index */
        UIState                    ui_state;
        TriggerBox&               _box;
        UIRequests                _requests;
        State                     _state;
        bool                      _playout;
        std::atomic<int>          _bang;
        std::atomic<int>          _unbang;
        uint32_t                  _index;
        int                       _next_trigger;
        uint32_t                  _loop_cnt; /* how many times in a row has this played */
        void*                     _ui;
        bool                      _explicitly_stopped;
        bool                      _scene_switch;
        gain_t                    _pending_velocity_gain;
        gain_t                    _velocity_gain;
        bool                      _cue_launched;
        bool                      _armed;
 
        /* these are only used by midi triggers but the ui_state API needs them */
        Evoral::SMF::UsedChannels _used_channels;
        Evoral::PatchChange<MidiBuffer::TimeType> _patch_change[16];
        std::vector<int> _channel_map;
 
        void copy_to_ui_state ();
 
 
        /* computed from data */
 
        double                    _estimated_tempo;  //TODO:  this should come from the MIDI file
        double                    _segment_tempo;  //TODO: this will likely get stored in the SegmentDescriptor for audio triggers
 
        /* basic process is :
           1) when a file is loaded, we infer its bpm either by minibpm's estimate, a flag in the filename, metadata (TBD) or other means
           2) we assume the clip must have an integer number of beats in it  (simplest case is a one-bar loop with 4 beats in it)
           3) ...so we round to the nearest beat length, and set the tempo to *exactly* fit the sample-length into the assumed beat-length
           4) the user may recognize a problem:  "this was a 3/4 beat, which was rounded to 4 beats but it should have been 3"
           5) if the user changes the beat-length, then the tempo is recalculated for use during stretching
           6) someday, we will also allow the sample start and length to be adjusted in a trimmer, and that will also adjust the tempo
           7) in all cases the user should be in final control; but our "internal" value for stretching are just sample-start and BPM, end of story
        */
        double                    _beatcnt;
        Temporal::Meter           _meter;
 
        samplepos_t                expected_end_sample;
        Temporal::BBT_Offset      _start_quantization;
        Temporal::BBT_Offset      _nxt_quantization;
        std::atomic<Trigger*>     _pending;
        std::atomic<unsigned int>  last_property_generation;
        PBD::ScopedConnection      region_connection;
 
        void when_stopped_during_run (BufferSet& bufs, pframes_t dest_offset);
        void set_region_internal (std::shared_ptr<Region>);
        virtual void retrigger();
        virtual void _startup (BufferSet&, pframes_t dest_offset, Temporal::BBT_Offset const &);
 
        bool internal_use_follow_length() const;
        void send_property_change (PBD::PropertyChange pc);
 
        virtual void _arm (Temporal::BBT_Offset const &);
 
        struct PendingSwap {
                timepos_t play_start;
                timepos_t play_end;
                timepos_t loop_start;
                timepos_t loop_end;
                timecnt_t length;
 
                virtual ~PendingSwap() {}
        };
 
        std::atomic<PendingSwap*> pending_swap;
        std::atomic<PendingSwap*> old_pending_swap;
 
        virtual int load_pending_data (PendingSwap&) = 0;
        virtual PendingSwap* pending_factory() const = 0;
};
 
class LIBARDOUR_API AudioTrigger : public Trigger {
  public:
        AudioTrigger (uint32_t index, TriggerBox&);
        ~AudioTrigger ();
 
        template<bool actually_run>  pframes_t audio_run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample,
                                                          Temporal::Beats const & start, Temporal::Beats const & end,
                                                          pframes_t nframes, pframes_t dest_offset, double bpm, pframes_t& quantize_offset);
 
        pframes_t run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, Temporal::Beats const & start, Temporal::Beats const & end, pframes_t nframes, pframes_t dest_offset, double bpm, pframes_t& quantize_offset) {
                return audio_run<true> (bufs, start_sample, end_sample, start, end, nframes, dest_offset, bpm, quantize_offset);
        }
 
        bool playable() const { return data.length || _region; }
 
        StretchMode stretch_mode() const { return _stretch_mode; }
        void set_stretch_mode (StretchMode);
 
        double segment_tempo() const { return _segment_tempo; }
        void set_segment_tempo (double t);
 
        double segment_beatcnt () { return _beatcnt; }
        void set_segment_beatcnt (double count);
 
        void set_legato_offset (timepos_t const &);
        void set_length (timecnt_t const &);
        void io_change ();
        bool probably_oneshot () const;
 
        void captured (SlotArmInfo&);
 
        int set_region_in_worker_thread (std::shared_ptr<Region>);
        int set_region_in_worker_thread_from_capture (std::shared_ptr<Region>);
        void jump_start ();
        void jump_stop (BufferSet& bufs, pframes_t dest_offset);
 
        XMLNode& get_state () const;
        int set_state (const XMLNode&, int version);
 
        RubberBand::RubberBandStretcher* stretcher() { return (_stretcher); }
 
        SegmentDescriptor get_segment_descriptor () const;
        timepos_t compute_end (Temporal::TempoMap::SharedPtr const &, Temporal::BBT_Time const &, samplepos_t, Temporal::Beats &);
        void start_and_roll_to (samplepos_t start, samplepos_t position, uint32_t cnt);
 
        bool stretching () const;
        uint32_t channels () const { return data.size(); }
 
        RubberBand::RubberBandStretcher* alloc_stretcher () const;
 
        struct AudioData : std::vector<Sample*> {
                samplecnt_t length;
                samplecnt_t capacity;
 
                AudioData () : length (0), capacity (0) {}
                ~AudioData ();
                AudioData& operator= (AudioData& other); /* really move semantics */
 
                samplecnt_t append (Sample const * src, samplecnt_t cnt, uint32_t chan);
                void alloc (samplecnt_t cnt, uint32_t nchans);
                void reset () { length = 0; }
                void drop ();
        };
 
 
        Sample const * audio_data (size_t n) const;
        size_t data_length() const { return data.length; }
 
        struct AudioPendingSwap : public PendingSwap {
                AudioData audio_data;
 
                AudioPendingSwap() {}
                ~AudioPendingSwap() {}
        };
 
        void check_edit_swap (timepos_t const &, bool playing, BufferSet&);
 
  protected:
        void retrigger ();
        PendingSwap* pending_factory() const;
        int load_pending_data (PendingSwap&);
 
  private:
        AudioData         data;
        RubberBand::RubberBandStretcher*  _stretcher;
 
        /* computed during run */
 
        samplecnt_t read_index;
        samplepos_t last_readable_sample;   /* where the data runs out, relative to the start of the data, compare with read_index */
        samplepos_t _legato_offset;
        samplecnt_t retrieved;
        samplecnt_t got_stretcher_padding;
        samplecnt_t to_pad;
        samplecnt_t to_drop;
 
        virtual void setup_stretcher ();
 
        void drop_data (AudioData&);
        int load_data (std::shared_ptr<AudioRegion>, AudioData&);
        void estimate_tempo ();
        void reset_stretcher ();
        void _startup (BufferSet&, pframes_t dest_offset, Temporal::BBT_Offset const &);
        int set_region_in_worker_thread_internal (std::shared_ptr<Region> r, bool from_capture);
};
 
 
class LIBARDOUR_API MIDITrigger : public Trigger {
  public:
        MIDITrigger (uint32_t index, TriggerBox&);
        ~MIDITrigger ();
 
        bool playable() const { return rt_midibuffer.load() || _region; }
 
        void captured (SlotArmInfo&);
        void disarm ();
 
        template<bool actually_run> pframes_t midi_run (BufferSet&, samplepos_t start_sample, samplepos_t end_sample,
                                                        Temporal::Beats const & start_beats, Temporal::Beats const & end_beats, pframes_t nframes, pframes_t offset, double bpm, pframes_t& quantize_offset);
 
        pframes_t run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, Temporal::Beats const & start, Temporal::Beats const & end, pframes_t nframes, pframes_t dest_offset, double bpm, pframes_t& quantize_offset) {
                return midi_run<true> (bufs, start_sample, end_sample, start, end, nframes, dest_offset, bpm, quantize_offset);
        }
 
        void set_start (timepos_t const &);
        void set_end (timepos_t const &);
        void set_legato_offset (timepos_t const &);
        void set_length (timecnt_t const &);
        timepos_t start_offset () const;
        timepos_t end() const;            /* offset from start of data */
        bool probably_oneshot () const;
 
        void tempo_map_changed();
        void estimate_midi_patches ();
 
        int set_region_in_worker_thread (std::shared_ptr<Region>);
        int set_region_in_worker_thread_from_capture (std::shared_ptr<Region>);
        void jump_start ();
        void shutdown (BufferSet& bufs, pframes_t dest_offset);
        void jump_stop (BufferSet& bufs, pframes_t dest_offset);
 
        XMLNode& get_state () const;
        int set_state (const XMLNode&, int version);
 
        SegmentDescriptor get_segment_descriptor () const;
        timepos_t compute_end (Temporal::TempoMap::SharedPtr const &, Temporal::BBT_Time const &, samplepos_t, Temporal::Beats &);
        void start_and_roll_to (samplepos_t start, samplepos_t position, uint32_t cnt);
 
        void set_patch_change (Evoral::PatchChange<MidiBuffer::TimeType> const &);
        Evoral::PatchChange<MidiBuffer::TimeType> const patch_change (uint8_t) const;
        void unset_patch_change (uint8_t channel);
        void unset_all_patch_changes ();
        bool patch_change_set (uint8_t channel) const;
 
        /* It's possible that a portion of a midi file would use a subset of the total channels used, so store that info in the segment descriptor */
        Evoral::SMF::UsedChannels used_channels() const { return ui_state.used_channels; }
        void set_used_channels (Evoral::SMF::UsedChannels);
 
        /* theoretically, MIDI files can have a dedicated tempo outside the session tempo map (*un-stretched*) but this is currently unimplemented */
        /* boilerplate tempo functions are provided here so we don't have to do constant dynamic_cast checks to use the tempo+stretch APIs */
        virtual double segment_tempo() const {return 120.0;}
        virtual void set_segment_tempo (double t) {}
        virtual void setup_stretcher () {}
 
        void set_channel_map (int channel, int target);
        void unset_channel_map (int channel);
        int channel_map (int channel);
        std::vector<int> const & channel_map() const { return _channel_map; }
 
        void check_edit_swap (timepos_t const &, bool playing, BufferSet&);
        PendingSwap* pending_factory() const;
 
        RTMidiBufferBeats const & rt_midi_buffer() const { return *rt_midibuffer.load(); }
 
        Temporal::Beats play_start() const { return _play_start; }
        Temporal::Beats play_end() const { return _play_end; }
        Temporal::Beats loop_start() const { return _loop_start; }
        Temporal::Beats loop_end() const { return _loop_end; }
 
  protected:
        void retrigger ();
        void _arm (Temporal::BBT_Offset const &);
        void adjust_bounds (Temporal::timepos_t const & start, Temporal::timepos_t const & end, Temporal::timecnt_t const & length, bool from_region);
        int load_pending_data (PendingSwap&);
 
  private:
        PBD::ID data_source;
 
        Temporal::Beats final_beat;
 
        Temporal::DoubleableBeats data_length;   /* using timestamps from data */
        Temporal::DoubleableBeats last_event_beats;
        samplepos_t last_event_samples;
 
        Temporal::BBT_Offset _start_offset;
        Temporal::BBT_Offset _legato_offset;
 
        std::shared_ptr<MidiModel> _model;
        PBD::ScopedConnection content_connection;
        void model_contents_changed();
 
        Temporal::Beats _play_start;
        Temporal::Beats _play_end;
        Temporal::Beats _loop_start;
        Temporal::Beats _loop_end;
        uint32_t first_event_index;
        uint32_t last_event_index;
 
        std::atomic<RTMidiBufferBeats*> rt_midibuffer;
        uint32_t iter; /* index into the above RTMidiBufferBeats for current playback */
 
        struct MIDIPendingSwap : public PendingSwap {
                RTMidiBufferBeats* rt_midibuffer;
 
                MIDIPendingSwap();
                ~MIDIPendingSwap() { delete rt_midibuffer; }
        };
 
        bool         map_change;
 
        int load_data (std::shared_ptr<MidiRegion>);
        void compute_and_set_length ();
        void _startup (BufferSet&, pframes_t dest_offset, Temporal::BBT_Offset const &);
        void setup_event_indices ();
};
 
class LIBARDOUR_API TriggerBoxThread
{
  public:
        TriggerBoxThread ();
        ~TriggerBoxThread();
 
        static void init_request_pool() { Request::init_pool(); }
 
        void set_region (TriggerBox&, uint32_t slot, std::shared_ptr<Region>);
        void request_delete_trigger (Trigger* t);
        void request_build_source (Trigger* t, Temporal::timecnt_t const & duration, Temporal::timepos_t const &);
 
        void summon();
        void stop();
        void wait_until_finished();
 
  private:
        static void* _thread_work(void *arg);
        void*         thread_work();
 
        enum RequestType {
                Quit,
                SetRegion,
                DeleteTrigger,
                BuildSourceAndRegion
        };
 
        struct Request {
 
                Request (RequestType t) : type (t) {}
 
                RequestType type;
                /* for set region */
                TriggerBox* box;
                uint32_t slot;
                std::shared_ptr<Region> region;
                /* for DeleteTrigger and BuildSourceAndRegion */
                Trigger* trigger;
                Temporal::timecnt_t duration;
                Temporal::timepos_t position;
 
                void* operator new (size_t);
                void  operator delete (void* ptr, size_t);
 
                static PBD::MultiAllocSingleReleasePool* pool;
                static void init_pool ();
        };
 
        pthread_t thread;
        PBD::RingBuffer<Request*>  requests;
 
        CrossThreadChannel _xthread;
        void queue_request (Request*);
        void delete_trigger (Trigger*);
        void build_source (Trigger*, Temporal::timecnt_t const & duration, Temporal::timepos_t const &);
        void build_midi_source (MIDITrigger*, Temporal::timecnt_t const &, Temporal::timepos_t const &);
        void build_audio_source (AudioTrigger*, Temporal::timecnt_t const &, Temporal::timepos_t const &);
};
 
struct CueRecord {
        int32_t cue_number;
        samplepos_t when;
 
        CueRecord (int32_t cn, samplepos_t t): cue_number (cn), when (t) {}
        CueRecord () : cue_number (0), when (0) {}
 
        static const int32_t stop_all = INT32_MAX;
};
 
typedef PBD::RingBuffer<CueRecord> CueRecords;
 
struct SlotArmInfo {
        SlotArmInfo ();
        ~SlotArmInfo();
 
        void reset (Trigger&);
 
        Trigger* slot;
        Temporal::Beats start_beats;
        samplepos_t start_samples;
        Temporal::Beats end_beats;
        samplepos_t end_samples;
        samplecnt_t captured;
        MidiNoteTracker tracker;
        RTMidiBufferBeats* midi_buf;
        AudioTrigger::AudioData audio_buf;
        RubberBand::RubberBandStretcher* stretcher;
};
 
class LIBARDOUR_API TriggerBox : public Processor, public std::enable_shared_from_this<TriggerBox>
{
  public:
 
#ifdef MIXBUS
        static const int32_t default_triggers_per_box = 8;
#else
        static const int32_t default_triggers_per_box = 16;
#endif
 
        TriggerBox (Session&, DataType dt);
        ~TriggerBox ();
 
        static CueRecords cue_records;
        static bool cue_recording () { return _cue_recording; }
        static void set_cue_recording (bool yn);
        static PBD::Signal<void()> CueRecordingChanged;
 
        void set_record_enabled (bool yn);
        RecordState record_enabled() const { return _record_state; }
        PBD::Signal<void()> RecEnableChanged;
        PBD::Signal<void(Trigger const *)> ReCountIn;
        static PBD::Signal<void()> TriggerRecEnableChanged;
        static PBD::Signal<void(Trigger const *)> RegionCaptured;
 
        void arm_from_another_thread (Trigger& slot, samplepos_t, uint32_t chans, Temporal::BBT_Offset const &);
        void setup_arm_info_bounds (SlotArmInfo& ai, samplepos_t, Trigger& slot, Temporal::BBT_Offset const & duration);
        void disarm();
        void disarm_all();
        bool armed() const { return (bool) _arm_info.load(); }
        PBD::Signal<void()> ArmedChanged;
 
        void run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, double speed, pframes_t nframes, bool result_required);
        void run_cycle (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, double speed, pframes_t nframes);
        bool can_support_io_configuration (const ChanCount& in, ChanCount& out);
        bool configure_io (ChanCount in, ChanCount out);
 
        bool empty() const { return _active_slots == 0; }
        PBD::Signal<void()> EmptyStatusChanged;
 
        int32_t order() const { return _order; }
        void set_order(int32_t n);
 
        typedef std::vector<TriggerPtr> Triggers;
 
        TriggerPtr trigger (Triggers::size_type);
 
        void bang_trigger_at (Triggers::size_type row, float velocity = 1.0f);
        void unbang_trigger_at (Triggers::size_type row);
 
        void add_trigger (TriggerPtr);
 
        void fast_forward (CueEvents const &, samplepos_t transport_position);
        bool fast_forwarding() const { return _fast_forwarding; }
 
        void set_pending (uint32_t slot, Trigger*);
 
        XMLNode& get_state () const;
        int set_state (const XMLNode&, int version);
 
        void deep_sources (std::set<std::shared_ptr<Source>>&);
        void used_regions (std::set<std::shared_ptr<Region>>&);
 
        void set_from_path (uint32_t slot, std::string const & path);
        void set_from_selection (uint32_t slot, std::shared_ptr<Region>);
 
        DataType data_type() const { return _data_type; }
 
        void stop_all_immediately ();
        void stop_all_quantized ();
 
        TriggerPtr currently_playing() const { return _currently_playing; }
 
        TriggerPtr trigger_by_id (PBD::ID);
 
        void clear_all_triggers ();
        void clear_cue (int cue);
        void set_all_follow_action (ARDOUR::FollowAction const &, uint32_t n=0);
        void set_all_launch_style (ARDOUR::Trigger::LaunchStyle);
        void set_all_quantization (Temporal::BBT_Offset const&);
        void set_all_probability (int zero_to_a_hundred);
 
        /* Returns a negative value is there is no active Trigger, or a value between 0
         * and 1.0 if there is, corresponding to the value of position_as_fraction() for
         *  the active Trigger.
         */
        double position_as_fraction() const;
 
        void queue_explict (uint32_t);
        TriggerPtr get_next_trigger ();
        TriggerPtr peek_next_trigger ();
 
        void set_region (uint32_t slot, std::shared_ptr<Region> region);
 
        void non_realtime_transport_stop (samplepos_t now, bool flush);
        void non_realtime_locate (samplepos_t now);
        void realtime_handle_transport_stopped ();
 
        void enqueue_trigger_state_for_region (std::shared_ptr<Region>, std::shared_ptr<Trigger::UIState>);
 
        void tempo_map_changed ();
 
        /* valid only within the ::run() call tree */
        int32_t active_scene() const { return _active_scene; }
 
        PBD::Signal<void(uint32_t)> TriggerSwapped;
 
        enum TriggerMidiMapMode {
                AbletonPush,
                SequentialNote,
                ByMidiChannel,
                Custom,
        };
 
        /* This is null for TriggerBoxen constructed with DataType::AUDIO */
        MidiStateTracker* tracker;
 
        static bool lookup_custom_midi_binding (std::vector<uint8_t> const &, int& x, int& y);
        static void add_custom_midi_binding (std::vector<uint8_t> const &, int x, int y);
        static void remove_custom_midi_binding (int x, int y);
        static void clear_custom_midi_bindings ();
        static int  save_custom_midi_bindings (std::string const & path);
        static int  load_custom_midi_bindings (XMLNode const &);
        static XMLNode* get_custom_midi_binding_state ();
 
        void begin_midi_learn (int index);
        void midi_unlearn (int index);
        void stop_midi_learn ();
 
        static Temporal::BBT_Offset assumed_trigger_duration () { return _assumed_trigger_duration; }
        static void set_assumed_trigger_duration (Temporal::BBT_Offset const &);
 
        static TriggerMidiMapMode midi_map_mode () { return _midi_map_mode; }
        static void set_midi_map_mode (TriggerMidiMapMode m);
 
        static int first_midi_note() { return _first_midi_note; }
        static void set_first_midi_note (int n);
 
        static void init ();
        static void static_init (Session&);
        static void begin_process_cycle ();
 
        static TriggerBoxThread* worker;
 
        static void start_transport_stop (Session&);
 
        static PBD::PropertyChange all_trigger_props();
 
        void send_property_change (PBD::PropertyChange pc);
        static PBD::Signal<void(PBD::PropertyChange,int)> TriggerBoxPropertyChange;
 
        std::shared_ptr<MidiBuffer> get_gui_feed_buffer () const;
 
        void dump (std::ostream &) const;
 
        PBD::Signal<void(samplecnt_t)> Captured;
 
        /* return start time for capture; only valid if is_set is true upon return */
        Temporal::Beats start_time (bool& is_set) const;
 
        void finish_recording ();
 
  private:
        struct Requests {
                std::atomic<bool> stop_all;
 
                Requests () : stop_all (false) {}
        };
 
        static Temporal::BBT_Offset _assumed_trigger_duration;
 
        DataType _data_type;
        int32_t _order;
        mutable Glib::Threads::RWLock trigger_lock; /* protects all_triggers */
        Triggers all_triggers;
 
        typedef std::vector<Trigger*> PendingTriggers;
        PendingTriggers pending;
 
        PBD::RingBuffer<uint32_t> explicit_queue; /* user queued triggers */
        TriggerPtr               _currently_playing;
        Requests                 _requests;
        bool                     _stop_all;
        int32_t                  _active_scene;
        int32_t                  _active_slots;
        bool                     _locate_armed;
        bool                     _cancel_locate_armed;
        bool                     _fast_forwarding;
        RecordState              _record_state;
 
        PBD::PCGRand _pcg;
 
        void maybe_capture (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, double speed, pframes_t nframes);
        void set_armed (SlotArmInfo*);
 
        /* These four are accessed (read/write) only from process() context */
 
        void drop_triggers ();
        void process_ui_trigger_requests ();
        void process_midi_trigger_requests (BufferSet&);
        int determine_next_trigger (uint32_t n);
        void stop_all ();
 
        void maybe_swap_pending (uint32_t);
 
        void parameter_changed (std::string const &);
        static void static_parameter_changed (std::string const &);
 
        static int _first_midi_note;
        static TriggerMidiMapMode _midi_map_mode;
 
        struct Request {
                enum Type {
                        Use,
                };
 
                Type type;
 
                /* cannot use a union here because we need Request to have a
                 * "trivial" constructor.
                 */
 
                TriggerPtr trigger;
                void* ptr;
                int32_t slot;
 
                Request (Type t) : type (t) {}
 
                static PBD::MultiAllocSingleReleasePool* pool;
                static void init_pool();
 
                void* operator new (size_t);
                void  operator delete (void* ptr, size_t);
        };
 
        typedef PBD::RingBuffer<Request*> RequestBuffer;
        RequestBuffer requests;
 
        void process_requests (BufferSet&);
        void process_request (BufferSet&, Request*);
 
        void cancel_locate_armed ();
        void fast_forward_nothing_to_do ();
        int handle_stopped_trigger (BufferSet& bufs, pframes_t dest_offset);
 
        PBD::ScopedConnection stop_all_connection;
        std::atomic<SlotArmInfo*> _arm_info;
        SlotArmInfo _the_arm_info;
 
        mutable EventRingBuffer<samplepos_t> _gui_feed_fifo;
        mutable Glib::Threads::Mutex         _gui_feed_reset_mutex;
 
        typedef  std::map<std::vector<uint8_t>,std::pair<int,int> > CustomMidiMap;
        static CustomMidiMap _custom_midi_map;
 
        static void midi_input_handler (MIDI::Parser&, MIDI::byte*, size_t, samplecnt_t);
        static std::shared_ptr<MIDI::Parser> input_parser;
        static PBD::ScopedConnection midi_input_connection;
        static void input_port_check ();
        static PBD::ScopedConnectionList static_connections;
        static std::shared_ptr<MidiPort> current_input;
 
        static bool _learning;
        static std::pair<int,int> learning_for;
        static PBD::Signal<void()> TriggerMIDILearned;
 
        static void init_pool();
 
        static std::atomic<int> active_trigger_boxes;
        static std::atomic<bool> _cue_recording;
        static bool roll_requested;
        static void maybe_request_roll (Session&);
};
 
class TriggerReference
{
 public:
        TriggerReference () : _slot (0) {}
        TriggerReference (std::shared_ptr<ARDOUR::TriggerBox> b, uint32_t s) : weak_box (b), _slot (s) {}
 
        std::shared_ptr<ARDOUR::Trigger> trigger() const { std::shared_ptr<ARDOUR::TriggerBox> box (weak_box.lock()); return box ? box->trigger (_slot) : std::shared_ptr<ARDOUR::Trigger>(); }
        void set (std::shared_ptr<ARDOUR::TriggerBox> b, uint32_t s) { weak_box = b; _slot = s; }
        uint32_t slot() const { return _slot; }
        std::shared_ptr<ARDOUR::TriggerBox> box() const { return weak_box.lock(); }
 
        bool operator== (TriggerReference const & other) {
                return _slot == other._slot && box() == other.box();
        }
 
 private:
        std::weak_ptr<ARDOUR::TriggerBox> weak_box;
        uint32_t              _slot;
};
 
namespace Properties {
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> running;
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> legato;
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> use_follow_length;
        LIBARDOUR_API extern PBD::PropertyDescriptor<Temporal::BBT_Offset> quantization;
        LIBARDOUR_API extern PBD::PropertyDescriptor<Temporal::BBT_Offset> follow_length;
        LIBARDOUR_API extern PBD::PropertyDescriptor<Temporal::BBT_Offset> capture_duration;
        LIBARDOUR_API extern PBD::PropertyDescriptor<Trigger::LaunchStyle> launch_style;
        LIBARDOUR_API extern PBD::PropertyDescriptor<FollowAction> follow_action0;
        LIBARDOUR_API extern PBD::PropertyDescriptor<FollowAction> follow_action1;
        LIBARDOUR_API extern PBD::PropertyDescriptor<Trigger::StretchMode> stretch_mode;
        LIBARDOUR_API extern PBD::PropertyDescriptor<uint32_t> follow_count;
        LIBARDOUR_API extern PBD::PropertyDescriptor<int> follow_action_probability;
        LIBARDOUR_API extern PBD::PropertyDescriptor<float> velocity_effect;
        LIBARDOUR_API extern PBD::PropertyDescriptor<gain_t> gain;
        LIBARDOUR_API extern PBD::PropertyDescriptor<uint32_t> currently_playing;
        LIBARDOUR_API extern PBD::PropertyDescriptor<uint32_t> queued;
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> stretchable;
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> cue_isolated;
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> allow_patch_changes;
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> patch_change; /* type not important */
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> channel_map; /* type not important */
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> used_channels; /* type not important */
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> region; /* type not important */
 
        LIBARDOUR_API extern PBD::PropertyDescriptor<bool> tempo_meter; /* only used to transmit changes, not storage */
}
 
 
} // namespace ARDOUR
 
namespace PBD {
DEFINE_ENUM_CONVERT(ARDOUR::FollowAction::Type);
DEFINE_ENUM_CONVERT(ARDOUR::Trigger::LaunchStyle);
DEFINE_ENUM_CONVERT(ARDOUR::Trigger::StretchMode);
} /* namespace PBD */