non/Timeline/Engine.C

152 lines
4.5 KiB
C

/*******************************************************************************/
/* Copyright (C) 2008 Jonathan Moore Liles */
/* */
/* 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; see the file COPYING. If not,write to the Free Software */
/* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/*******************************************************************************/
#include "Engine.H"
#include "Timeline.H" // for process()
#define APP_NAME "Non-DAW" // FIXME: wrong place for this!
/* This is the home of the JACK process callback (does this *really*
need to be a class?) */
Engine::Engine ( )
{
_client = NULL;
_buffers_dropped = 0;
}
/* static wrapper */
int
Engine::process ( nframes_t nframes, void *arg )
{
return ((Engine*)arg)->process( nframes );
}
/* static wrapper */
int
Engine::sync ( jack_transport_state_t state, jack_position_t *pos, void *arg )
{
return ((Engine*)arg)->sync( state, pos );
}
void
Engine::request_locate ( nframes_t frame )
{
if ( timeline )
timeline->seek( frame );
}
/* THREAD: RT */
/** This is the jack slow-sync callback. */
int
Engine::sync ( jack_transport_state_t state, jack_position_t *pos )
{
static bool seeking = false;
switch ( state )
{
case JackTransportStopped: /* new position requested */
/* JACK docs lie. This is only called when the transport
is *really* stopped, not when starting a slow-sync
cycle */
request_locate( pos->frame );
return 1;
case JackTransportStarting: /* this means JACK is polling slow-sync clients */
{
if ( ! seeking )
{
request_locate( pos->frame );
seeking = true;
}
int r = timeline->seek_pending();
if ( ! r )
seeking = false;
return ! seeking;
}
case JackTransportRolling: /* JACK's timeout has expired */
/* FIXME: what's the right thing to do here? */
// request_locate( pos->frame );
return 1;
// return transport.frame == pos->frame;
break;
default:
printf( "unknown transport state.\n" );
}
return 0;
}
/* THREAD: RT */
int
Engine::process ( nframes_t nframes )
{
jack_position_t pos;
jack_transport_state_t ts;
ts = jack_transport_query( _client, &pos );
if ( ts != JackTransportRolling )
return 0;
if ( ! trylock() )
{
/* the data structures we need to access here (tracks and
* their ports, but not track contents) may be in an
* inconsistent state at the moment. Just punt and drop this
* buffer. */
++_buffers_dropped;
return 0;
}
/* handle chicken/egg problem */
if ( timeline )
/* this will initiate the process() call graph for the various
* number and types of tracks, which will in turn send data out
* the appropriate ports. */
timeline->process( nframes );
unlock();
return 0;
}
int
Engine::init ( void )
{
if (( _client = jack_client_open ( APP_NAME, (jack_options_t)0, NULL )) == 0 )
return 0;
jack_set_process_callback( _client, &Engine::process, this );
/* FIXME: should we wait to register this until after the session
has been loaded (and we have disk threads running)? */
jack_set_sync_callback( _client, &Engine::sync, this );
jack_activate( _client );
/* we don't need to create any ports until tracks are created */
return 1;
}