jdkmidi class library documentation
Copyright © 2004 J.D. Koftinoff Software, Ltd.
Released under the GNU General Public License (GPL)

---

src/jdkmidi_multitrack.cpp

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/*
 *  libjdkmidi-2004 C++ Class Library for MIDI
 *
 *  Copyright (C) 2004  J.D. Koftinoff Software, Ltd.
 *  www.jdkoftinoff.com
 *  jeffk@jdkoftinoff.com
 *
 *  *** RELEASED UNDER THE GNU GENERAL PUBLIC LICENSE (GPL) April 27, 2004 ***
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
/*
**  Copyright 1986 to 1998 By J.D. Koftinoff Software, Ltd.
**
**  All rights reserved.
**
**  No one may duplicate this source code in any form for any reason
**  without the written permission given by J.D. Koftinoff Software, Ltd.
**
*/



#include "jdkmidi/world.h"

#include "jdkmidi/multitrack.h"


#ifndef DEBUG_MDMLTTRK
# define DEBUG_MDMLTTRK 0
#endif

#if DEBUG_MDMLTTRK
# undef DBG
# define DBG(a) a
#endif

namespace jdkmidi
{
  
  
  MIDIMultiTrack::MIDIMultiTrack( int num_tracks_, bool deletable_ ) 
    :
    num_tracks( num_tracks_ ),
    deletable( deletable_ ) 
  {
    ENTER( "MIDIMultiTrack::MIDIMultiTrack()" );
    
    tracks = new MIDITrack * [num_tracks];
    if( tracks )
    {
      if( deletable )
      {     
        for( int i=0; i<num_tracks; ++i )
          tracks[i]=new MIDITrack;
      }
      else
      {
        for( int i=0; i<num_tracks; ++i )
          tracks[i]=0;
      }
    }     
  } 
  
  MIDIMultiTrack::~MIDIMultiTrack() 
  {
    ENTER( "MIDIMultiTrack::~MIDIMultiTrack()" );
    
    if( deletable )
    {
      for( int i=0; i<num_tracks; ++i )
        delete tracks[i];
    }
    
    delete [] tracks;
  } 
  
  void MIDIMultiTrack::Clear()
  {
    for( int i=0; i<num_tracks; ++i )
    {
      tracks[i]->Clear();
    }
  }
  
  void MIDIMultiTrack::SetTrack( int trk, MIDITrack *t ) 
  {
    tracks[trk]=t;
  } 
  
  
  MIDITrack *MIDIMultiTrack::GetTrack( int trk ) 
  {
    return tracks[trk];
  } 
  
  const MIDITrack *MIDIMultiTrack::GetTrack( int trk ) const 
  {
    return tracks[trk];
  } 
  
  
  
  
  
  
  MIDIMultiTrackIteratorState::MIDIMultiTrackIteratorState( int num_tracks_) 
  {
    num_tracks = num_tracks_;   
    
    cur_event_track=0;
    
    next_event_number = new int [num_tracks];
    next_event_time = new MIDIClockTime [num_tracks];
    
    Reset();
    
  } 
  
  MIDIMultiTrackIteratorState::MIDIMultiTrackIteratorState( const MIDIMultiTrackIteratorState &m ) 
  {
    num_tracks = m.num_tracks;
    cur_event_track = m.cur_event_track;
    next_event_number = new int [num_tracks];
    next_event_time = new MIDIClockTime [num_tracks];
    cur_time = m.cur_time;
    
    for( int i=0; i<num_tracks; ++i )
    {
      next_event_number[i] = m.next_event_number[i];    
      next_event_time[i] = m.next_event_time[i];
    }
    
  } 
  
  MIDIMultiTrackIteratorState::~MIDIMultiTrackIteratorState() 
  {
    delete [] next_event_number;
    delete [] next_event_time;
  } 
  
  const MIDIMultiTrackIteratorState & MIDIMultiTrackIteratorState::operator = ( const MIDIMultiTrackIteratorState &m ) 
  {
    if( num_tracks != m.num_tracks )
    {
      delete [] next_event_number;
      delete [] next_event_time;
      
      num_tracks = m.num_tracks;
      next_event_number = new int [num_tracks];
      next_event_time = new MIDIClockTime [num_tracks];
    }
    
    cur_time = m.cur_time;
    cur_event_track = m.cur_event_track;
    
    for( int i=0; i<num_tracks; ++i )
    {
      next_event_number[i] = m.next_event_number[i];
      next_event_time[i] = m.next_event_time[i];
    }   
    
    return *this;
  } 
  
  void MIDIMultiTrackIteratorState::Reset() 
  {
    cur_time = 0;
    cur_event_track = 0;
    for( int i=0; i<num_tracks; ++i )
    {
      next_event_number[i] = 0;
      next_event_time[i] = 0xffffffff;
    }     
  } 
  
  int MIDIMultiTrackIteratorState::FindTrackOfFirstEvent() 
  {
    MIDIClockTime minimum_time=0xffffffff;
    int minimum_time_track=-1;
    
    
    // go through all tracks and find the track with the smallest
    // event time. 
    
    for( int j=0; j<num_tracks; ++j )
    {
      int i=(j+cur_event_track+1) % num_tracks;
      
      // skip any tracks that have a current event number less than 0 - these are
      // finished already
      
      
      if( next_event_number[i]>=0 && next_event_time[i]<minimum_time )
      {
        minimum_time = next_event_time[i];
        minimum_time_track = i;
      }   
    } 
    
    // set cur_event_track to -1 if there are no more events left
    cur_event_track = minimum_time_track;
    cur_time = minimum_time;
    
    return cur_event_track;
  } 
  
  
  
  
  
  
  MIDIMultiTrackIterator::MIDIMultiTrackIterator( MIDIMultiTrack *mlt )
    : 
    multitrack(mlt), 
    state( mlt->GetNumTracks() )
    
  {
  } 
  
  MIDIMultiTrackIterator::~MIDIMultiTrackIterator() 
  { 
  } 
  
  void MIDIMultiTrackIterator::GoToTime( MIDIClockTime time ) 
  {
    // start at time 0
    
    state.Reset();
    
    // transfer info from the first events in each track in the
    // multitrack object to our current state.
    
    for( int i=0; i<multitrack->GetNumTracks(); ++i )
    {
      MIDITrack *track = multitrack->GetTrack(i);
      
      // default: set the next_event_number for this track to -1
      // to signify end of track
      
      state.next_event_number[ i ] = -1;
      
      // are there any events in this track?
      if( track && track->GetNumEvents()>0 )
      {
        // yes, extract the time of the first event     
        
        MIDITimedBigMessage *msg = track->GetEventAddress( 0 );
        
        if( msg )
        {
          // found the first message of the track. Keep track
          // of the event number and the event time.
          
          state.next_event_number[i]=0; 
          state.next_event_time[i]=msg->GetTime();
        }
      }   
    }
    
    
    // are there any events at all? find the track with the
    // earliest event
    
    if( state.FindTrackOfFirstEvent()!=-1 )
    {   
      // yes
      // iterate through all the events until we find a time >= the requested time
      
      while( state.GetCurrentTime()<time )
      {
        // did not get to the requested time yet.
        // go to the next chronological event on all tracks
        
        if( !GoToNextEvent() )
        {
          // there is no more events to go to
          
          break;
        }
        
      }
    }
    
  } 
  
  bool MIDIMultiTrackIterator::GetCurEventTime( MIDIClockTime *t) 
  {
    // if there is a next event, then set *t to the time of the event and return true
    
    if( state.GetCurEventTrack() != -1 )
    {   
      *t = state.GetCurrentTime();
      return true;    
    }
    else
    {
      return false; 
    }
    
  } 
  
  bool MIDIMultiTrackIterator::GetCurEvent( int *track, MIDITimedBigMessage **msg ) 
  { 
    int t = state.GetCurEventTrack();
    
    if( t != -1 )
    {
      if( track )
      {
        *track=t;
      }
      
      if( msg )
      {
        int num = state.next_event_number[t];
        
        if( num>=0 )
        {       
          *msg = multitrack->GetTrack(t)->GetEventAddress( state.next_event_number[t] );
        }
        else
        {
          *msg = 0;
        }
        
        // do we really have a message?
        if( ! *msg )
        {
          // no, return false then
          return false;
        }     
      }
      
      return true;
    }
    else
    {
      return false; 
    }
  } 
  
  bool MIDIMultiTrackIterator::GoToNextEvent() 
  {
    // find the next event in the multitrack list
    // and return it  
    // if there is no event left, return false
    
    if( state.cur_event_track==-1 )
    {
      // no tracks left - all tracks are at end
      return false;
    }
    
    // update the current event for the current track to the
    // next event on the same track.
    
    GoToNextEventOnTrack( state.cur_event_track );
    
    // now find out which track now has the earliest event
    
    if( state.FindTrackOfFirstEvent()==-1 )
    {
      // No tracks do. all tracks are at the end. return false.
      return false;
    }
    
    // ok, now state.cur_event_track has a valid track # of the next event
    
    return true;
  } 
  
  bool MIDIMultiTrackIterator::GoToNextEventOnTrack( int track_num ) 
  {
    // Get the track that we are dealing with
    MIDITrack *track = multitrack->GetTrack( track_num );
    
    // Get ptr to the current event number for this track
    int *event_num = &state.next_event_number[ track_num ];
    
    // skip this track if this event number is <0 - This track has hit end already.
    
    if( *event_num <0 )
    {   
      return false; // at end of track
    }
    
    // increment *event_num to next event on track
    
    (*event_num) += 1;
    
    // are we at end of track?
    if( *event_num >= track->GetNumEvents() )
    {
      // yes, set *event_num to -1
      *event_num=-1;
      return false; // at end of track
    }
    else
    {
      // not at end of track yet - get the time of the event
      MIDITimedBigMessage *msg;
      
      msg = track->GetEventAddress( *event_num );
      
      state.next_event_time[ track_num ] = msg->GetTime();
    }
    
    
    
    return true;
  } 
  
  
  
  
}