/////////////////////////////////////////////////////////////////////////////
// Sets new song position (new_song_pos resolution: 16th notes)
/////////////////////////////////////////////////////////////////////////////
static s32 SEQ_SongPos(u16 new_song_pos)
{
u16 new_tick = new_song_pos * (SEQ_BPM_PPQN_Get() / 4);
// set new tick value
SEQ_BPM_TickSet(new_tick);
#if DEBUG_VERBOSE_LEVEL >= 2
DEBUG_MSG("[SEQ] Setting new song position %u (-> %u ticks)\n", new_song_pos, new_tick);
#endif
// since timebase has been changed, ensure that Off-Events are played
// (otherwise they will be played much later...)
SEQ_PlayOffEvents();
// restart song
MID_PARSER_RestartSong();
// release pause
seq_pause = 0;
if( new_song_pos > 1 ) {
// (silently) fast forward to requested position
ffwd_silent_mode = 1;
MID_PARSER_FetchEvents(0, new_tick-1);
ffwd_silent_mode = 0;
}
// when do we expect the next prefetch:
next_prefetch = new_tick;
prefetch_offset = new_tick;
return 0; // no error
}
/////////////////////////////////////////////////////////////////////////////
// Resets song position of sequencer
/////////////////////////////////////////////////////////////////////////////
s32 SEQ_Reset(u8 play_off_events)
{
// since timebase has been changed, ensure that Off-Events are played
// (otherwise they will be played much later...)
if( play_off_events )
SEQ_PlayOffEvents();
// release pause and FFWD mode
seq_pause = 0;
ffwd_silent_mode = 0;
next_prefetch = 0;
prefetch_offset = 0;
// restart song
MID_PARSER_RestartSong();
// set initial BPM (according to MIDI file spec)
SEQ_BPM_PPQN_Set(384); // not specified
SEQ_BPM_Set(120.0);
// reset BPM tick
SEQ_BPM_TickSet(0);
return 0; // no error
}
/////////////////////////////////////////////////////////////////////////////
// this sequencer handler is called periodically to check for new requests
// from BPM generator
/////////////////////////////////////////////////////////////////////////////
s32 SEQ_Handler(void)
{
// handle requests
u8 num_loops = 0;
u8 again = 0;
do {
++num_loops;
// note: don't remove any request check - clocks won't be propagated
// so long any Stop/Cont/Start/SongPos event hasn't been flagged to the sequencer
if( SEQ_BPM_ChkReqStop() ) {
SEQ_PlayOffEvents();
}
if( SEQ_BPM_ChkReqCont() ) {
// release pause mode
seq_pause = 0;
}
if( SEQ_BPM_ChkReqStart() ) {
SEQ_Reset();
}
u16 new_song_pos;
if( SEQ_BPM_ChkReqSongPos(&new_song_pos) ) {
SEQ_PlayOffEvents();
}
u32 bpm_tick;
if( SEQ_BPM_ChkReqClk(&bpm_tick) > 0 ) {
again = 1; // check all requests again after execution of this part
SEQ_Tick(bpm_tick);
}
} while( again && num_loops < 10 );
return 0; // no error
}
/////////////////////////////////////////////////////////////////////////////
// Resets song position of sequencer
/////////////////////////////////////////////////////////////////////////////
s32 SEQ_Reset(void)
{
// since timebase has been changed, ensure that Off-Events are played
// (otherwise they will be played much later...)
SEQ_PlayOffEvents();
// release pause mode
seq_pause = 0;
// reset BPM tick
SEQ_BPM_TickSet(0);
return 0; // no error
}
/////////////////////////////////////////////////////////////////////////////
// Plays the first .mid file if next == 0, the next file if next != 0
/////////////////////////////////////////////////////////////////////////////
static s32 SEQ_PlayFile(u32 next)
{
// play off events before loading new file
SEQ_PlayOffEvents();
char next_file[13];
if( MID_FILE_FindNext(next ? MID_FILE_UI_NameGet() : NULL, next_file) == 1 ||
MID_FILE_FindNext(NULL, next_file) == 1 ) { // if next file not found, try first file
#if DEBUG_VERBOSE_LEVEL >= 1
DEBUG_MSG("[SEQ] next file found '%s'\n", next_file);
#endif
SEQ_BPM_Stop(); // stop BPM generator
if( MID_FILE_open(next_file) ) { // try to open next file
#if DEBUG_VERBOSE_LEVEL >= 1
DEBUG_MSG("[SEQ] file %s cannot be opened (wrong directory?)\n", next_file);
#endif
return -1; // file cannot be opened
}
if( MID_PARSER_Read() < 0 ) { // read file, stop on failure
#if DEBUG_VERBOSE_LEVEL >= 1
DEBUG_MSG("[SEQ] file %s is invalid!\n", next_file);
#endif
return -2; // file is invalid
}
SEQ_BPM_Start(); // start BPM generator
} else {
SEQ_BPM_Stop(); // stop BPM generator
#if DEBUG_VERBOSE_LEVEL >= 1
DEBUG_MSG("[SEQ] no file found\n");
#endif
return -1; // file not found
}
return 0; // no error
}
