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/* ScummVM - Scumm Interpreter
* Copyright (C) 2001/2002 The ScummVM project
*
* 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.
*
* $Header$
*
*/
// #include "stdafx.h"
#include "midistreamer.h"
#include "common/util.h"
MidiStreamer::MidiStreamer (MidiDriver *target) :
_target (target),
_stream_proc (0),
_stream_param (0),
_isOpen (false),
_paused (false),
_event_count (0),
_event_index (0),
_tempo (500000), // 120 BPM = 500,000 microseconds between each beat
_ticks_per_beat (96),
_delay (0)
{ }
void MidiStreamer::set_stream_callback (void *param, StreamCallback *sc)
{
_stream_param = param;
_stream_proc = sc;
if (_isOpen) {
_event_count = _stream_proc (_stream_param, _events, ARRAYSIZE (_events));
_event_index = 0;
}
}
void MidiStreamer::timer_thread (void *param) {
((MidiStreamer *) param)->on_timer();
}
void MidiStreamer::on_timer()
{
if (_paused || !_stream_proc)
return;
_delay += _driver_tempo;
while (true) {
if (_event_index >= _event_count) {
_event_count = _stream_proc (_stream_param, _events, ARRAYSIZE (_events));
_event_index = 0;
}
if (!_event_count)
return;
MidiEvent *ev = &_events [_event_index];
if (_delay < _tempo * (long) ev->delta / (long) _ticks_per_beat)
return;
_delay -= _tempo * ev->delta / _ticks_per_beat;
if ((ev->event >> 24) != ME_TEMPO) {
_target->send (ev->event);
} else {
_tempo = ev->event & 0xFFFFFF;
}
++_event_index;
} // end while
}
int MidiStreamer::open()
{
if (_isOpen)
close();
int res = _target->open();
if (res && res != MERR_ALREADY_OPEN)
return res;
_event_index = _event_count = _delay = 0;
_isOpen = true;
_paused = false;
_driver_tempo = _target->getBaseTempo() / 500;
_target->setTimerCallback (this, &timer_thread);
return 0;
}
void MidiStreamer::close()
{
if (!_isOpen)
return;
_target->setTimerCallback (NULL, NULL);
// Turn off all notes on all channels,
// just to catch anything still playing.
int i;
for (i = 0; i < 16; ++i)
_target->send ((0x7B << 8) | 0xB0 | i);
_isOpen = false;
_paused = true;
}
uint32 MidiStreamer::property (int prop, uint32 param)
{
switch (prop) {
// 16-bit time division according to standard midi specification
case PROP_TIMEDIV:
_ticks_per_beat = (uint16)param;
return 1;
}
return 0;
}
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