AGI: Implement FR #1913900.

FR #1913900: "AGI: MIDI support".
Currently it gets selected when Adlib is chosen. Finding a better
way to do it is a todo.

Also default instrument mapping is plain.

Based on original code by Jens. Christian Restemeier.

svn-id: r49751

1 files changed, 340 insertions, 0 deletions

diff --git a/engines/agi/sound_midi.cpp b/engines/agi/sound_midi.cpp
new file mode 100755
index 0000000000..b31a4228fb
--- /dev/null
+++ b/engines/agi/sound_midi.cpp
@@ -0,0 +1,340 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+// Code is based on:
+//
+// A very simple program, that converts an AGI-song into a MIDI-song.
+// Feel free to use it for anything.
+//
+// The default instrument is "piano" for all the channels, what gives
+// good results on most games. But I found, that some songs are interesting
+// with other instruments. If you want to experiment, modify the "instr"
+// array.
+//
+// Timing is not perfect, yet. It plays correct, when I use the
+// Gravis-Midiplayer, but the songs are too fast when I use playmidi on
+// Linux.
+// 
+// Original program developed by Jens. Christian Restemeier
+//
+
+// MIDI and digital music class
+
+#include "sound/audiostream.h"
+#include "sound/mididrv.h"
+#include "sound/midiparser.h"
+#include "common/config-manager.h"
+#include "common/file.h"
+#include "common/stream.h"
+
+#include "agi/agi.h"
+
+#include "agi/sound.h"
+#include "agi/sound_midi.h"
+
+#define SPEED_FACTOR 6
+
+namespace Agi {
+
+static uint32 convertSND2MIDI(byte *snddata, byte **data);
+
+MIDISound::MIDISound(uint8 *data, uint32 len, int resnum, SoundMgr &manager) : AgiSound(manager) {
+	_data = data; // Save the resource pointer
+	_len  = len;  // Save the resource's length
+	_type = READ_LE_UINT16(data); // Read sound resource's type
+	_isValid = (_type == AGI_SOUND_4CHN) && (_data != NULL) && (_len >= 2);
+
+	if (!_isValid) // Check for errors
+		warning("Error creating MIDI sound from resource %d (Type %d, length %d)", resnum, _type, len);
+}
+
+MusicPlayer::MusicPlayer(MidiDriver *driver, SoundMgr *manager) : _parser(0), _driver(driver), _isPlaying(false), _passThrough(false), _isGM(false), _manager(manager) {
+	memset(_channel, 0, sizeof(_channel));
+	memset(_channelVolume, 255, sizeof(_channelVolume));
+	_masterVolume = 0;
+	this->open();
+	_smfParser = MidiParser::createParser_SMF();
+	_midiMusicData = NULL;
+}
+
+MusicPlayer::~MusicPlayer() {
+	_driver->setTimerCallback(NULL, NULL);
+	stop();
+	this->close();
+	_smfParser->setMidiDriver(NULL);
+	delete _smfParser;
+	delete[] _midiMusicData;
+}
+
+void MusicPlayer::setChannelVolume(int channel) {
+	int newVolume = _channelVolume[channel] * _masterVolume / 255;
+	_channel[channel]->volume(newVolume);
+}
+
+void MusicPlayer::setVolume(int volume) {
+	Common::StackLock lock(_mutex);
+
+	volume = CLIP(volume, 0, 255);
+	if (_masterVolume == volume)
+		return;
+	_masterVolume = volume;
+
+	for (int i = 0; i < 16; ++i) {
+		if (_channel[i]) {
+			setChannelVolume(i);
+		}
+	}
+}
+
+int MusicPlayer::open() {
+	// Don't ever call open without first setting the output driver!
+	if (!_driver)
+		return 255;
+
+	int ret = _driver->open();
+	if (ret)
+		return ret;
+
+	_driver->setTimerCallback(this, &onTimer);
+	return 0;
+}
+
+void MusicPlayer::close() {
+	stop();
+	if (_driver)
+		_driver->close();
+	_driver = 0;
+}
+
+void MusicPlayer::send(uint32 b) {
+	if (_passThrough) {
+		_driver->send(b);
+		return;
+	}
+
+	byte channel = (byte)(b & 0x0F);
+	if ((b & 0xFFF0) == 0x07B0) {
+		// Adjust volume changes by master volume
+		byte volume = (byte)((b >> 16) & 0x7F);
+		_channelVolume[channel] = volume;
+		volume = volume * _masterVolume / 255;
+		b = (b & 0xFF00FFFF) | (volume << 16);
+	} else if ((b & 0xF0) == 0xC0 && !_isGM && !_nativeMT32) {
+		b = (b & 0xFFFF00FF) | MidiDriver::_mt32ToGm[(b >> 8) & 0xFF] << 8;
+	}
+	else if ((b & 0xFFF0) == 0x007BB0) {
+		//Only respond to All Notes Off if this channel
+		//has currently been allocated
+		if (_channel[b & 0x0F])
+			return;
+	}
+
+	if (!_channel[channel]) {
+		_channel[channel] = (channel == 9) ? _driver->getPercussionChannel() : _driver->allocateChannel();
+		// If a new channel is allocated during the playback, make sure
+		// its volume is correctly initialized.
+		if (_channel[channel])
+			setChannelVolume(channel);
+	}
+
+	if (_channel[channel])
+		_channel[channel]->send(b);
+}
+
+void MusicPlayer::metaEvent(byte type, byte *data, uint16 length) {
+
+	switch (type) {
+	case 0x2F:	// End of Track
+		stop();
+		break;
+	default:
+		//warning("Unhandled meta event: %02x", type);
+		break;
+	}
+}
+
+void MusicPlayer::onTimer(void *refCon) {
+	MusicPlayer *music = (MusicPlayer *)refCon;
+	Common::StackLock lock(music->_mutex);
+
+	if (music->_parser)
+		music->_parser->onTimer();
+}
+
+void MusicPlayer::playMIDI(MIDISound *track) {
+	stop();
+
+	_isGM = true;
+
+	// Convert AGI Sound data to MIDI
+	int midiMusicSize = convertSND2MIDI(track->_data, &_midiMusicData);
+
+	if (_smfParser->loadMusic(_midiMusicData, midiMusicSize)) {
+		MidiParser *parser = _smfParser;
+		parser->setTrack(0);
+		parser->setMidiDriver(this);
+		parser->setTimerRate(getBaseTempo());
+		parser->property(MidiParser::mpCenterPitchWheelOnUnload, 1);
+
+		_parser = parser;
+
+		syncVolume();
+
+		_isPlaying = true;
+	}
+}
+
+void MusicPlayer::stop() {
+	Common::StackLock lock(_mutex);
+
+	if (!_isPlaying)
+		return;
+
+	_isPlaying = false;
+	if (_parser) {
+		_parser->unloadMusic();
+		_parser = NULL;
+	}
+
+	if (_manager->_endflag != -1)
+		_manager->_vm->setflag(_manager->_endflag, true);
+}
+
+void MusicPlayer::pause() {
+	setVolume(-1);
+	_isPlaying = false;
+}
+
+void MusicPlayer::resume() {
+	syncVolume();
+	_isPlaying = true;
+}
+
+void MusicPlayer::syncVolume() {
+	int volume = ConfMan.getInt("music_volume");
+	if (ConfMan.getBool("mute")) {
+		volume = -1;
+	}
+	setVolume(volume);
+}
+
+/* channel / intrument setup: */
+
+/* most songs are good with this: */
+unsigned char instr[] = {0, 0, 0};
+
+/* cool for sq2:
+unsigned char instr[] = {50, 51, 19};
+*/
+
+static void writeDelta(Common::MemoryWriteStreamDynamic *st, int32 delta) {
+	int32 i;
+
+	i = delta >> 21; if (i > 0) st->writeByte((i & 127) | 128); 
+	i = delta >> 14; if (i > 0) st->writeByte((i & 127) | 128);
+	i = delta >> 7;  if (i > 0) st->writeByte((i & 127) | 128);
+	st->writeByte(delta & 127);
+}
+
+static uint32 convertSND2MIDI(byte *snddata, byte **data) {
+	int32 lp, ep;
+	int n;
+	double ll;
+
+	Common::MemoryWriteStreamDynamic st;
+
+	ll = log10(pow(2.0, 1.0 / 12.0));
+
+	/* Header */
+	st.write("MThd", 4);
+	st.writeUint32BE(6);
+	st.writeUint16BE(1);    /* mode */
+	st.writeUint16BE(3);    /* number of tracks */
+	st.writeUint16BE(192);  /* ticks / quarter */
+
+	for (n = 0; n < 3; n++) {
+		uint16 start, end, pos;
+        
+		st.write("MTrk", 4);
+		lp = st.pos();
+		st.writeUint32BE(0);        /* chunklength */
+		writeDelta(&st, 0);       /* set instrument */
+		st.writeByte(0xc0 + n);
+		st.writeByte(instr[n]);
+		start = snddata[n * 2 + 0] | (snddata[n * 2 + 1] << 8);
+		end = ((snddata[n * 2 + 2] | (snddata[n * 2 + 3] << 8))) - 5;
+
+		for (pos = start; pos < end; pos += 5) {
+			uint16 freq,  dur;
+			dur = (snddata[pos + 0] | (snddata[pos + 1] << 8)) * SPEED_FACTOR;
+			freq = ((snddata[pos + 2] & 0x3F)  <<  4)  +  (snddata[pos + 3] & 0x0F);
+			if (snddata[pos + 2] > 0) {
+				double fr;
+				int note;
+				/* I don't know,  what frequency equals midi note 0 ... */
+				/* This moves the song 4 octaves down: */
+				fr = (log10(111860.0 / (double)freq) / ll) - 48; 
+				note = (int)floor(fr + 0.5);
+				if (note < 0) note = 0;
+				if (note > 127) note = 127;
+				/* note on */
+				writeDelta(&st, 0);
+				st.writeByte(144 + n);
+				st.writeByte(note);
+				st.writeByte(100);
+				/* note off */
+				writeDelta(&st, dur);
+				st.writeByte(128 + n);
+				st.writeByte(note);
+				st.writeByte(0);
+			} else {
+				/* note on */
+				writeDelta(&st, 0);
+				st.writeByte(144 + n);
+				st.writeByte(0);
+				st.writeByte(0);
+				/* note off */
+				writeDelta(&st, dur);
+				st.writeByte(128 + n);
+				st.writeByte(0);
+				st.writeByte(0);
+			}
+		}       
+		writeDelta(&st, 0);
+		st.writeByte(0xff);
+		st.writeByte(0x2f);
+		st.writeByte(0x0);
+		ep = st.pos();
+		st.seek(lp, SEEK_SET);
+		st.writeUint32BE((ep - lp) - 4);
+		st.seek(ep, SEEK_SET);
+	}
+
+	*data = st.getData();
+
+	return st.pos();
+}
+
+} // End of namespace Agi