Initial commit

engines/sky/music/gmchannel.cpp

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+/* 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "gmchannel.h"
+#include "common/util.h"
+#include "common/textconsole.h"
+#include "audio/mididrv.h"
+
+namespace Sky {
+
+GmChannel::GmChannel(uint8 *pMusicData, uint16 startOfData, MidiDriver *pMidiDrv, const byte *pInstMap, const byte *veloTab) {
+	_musicData = pMusicData;
+	_midiDrv = pMidiDrv;
+	_channelData.midiChannelNumber = 0;
+	_channelData.loopPoint = startOfData;
+	_channelData.eventDataPtr = startOfData;
+	_channelData.channelActive = true;
+	_channelData.nextEventTime = getNextEventTime();
+	_instMap = pInstMap;
+	_veloTab = veloTab;
+
+	_musicVolume = 0x7F;
+	_currentChannelVolume = 0x7F;
+}
+
+GmChannel::~GmChannel() {
+	stopNote();
+}
+
+bool GmChannel::isActive() {
+	return _channelData.channelActive;
+}
+
+void GmChannel::updateVolume(uint16 pVolume) {
+	_musicVolume = pVolume;
+	if (_musicVolume > 0)
+		_musicVolume = (_musicVolume * 2) / 3 + 43;
+
+	uint8 newVol = (_currentChannelVolume * _musicVolume) >> 7;
+	_midiDrv->send((0xB0 | _channelData.midiChannelNumber) | 0x700 | (newVol << 16));
+}
+
+void GmChannel::stopNote() {
+	// All Notes Off
+	_midiDrv->send((0xB0 | _channelData.midiChannelNumber) | 0x7B00 | 0 | 0x79000000);
+	// Reset the Pitch Wheel. See bug #1742.
+	_midiDrv->send((0xE0 | _channelData.midiChannelNumber) | 0x400000);
+}
+
+int32 GmChannel::getNextEventTime() {
+	int32 retV = 0;
+	uint8 cnt, lVal = 0;
+	for (cnt = 0; cnt < 4; cnt++) {
+		lVal = _musicData[_channelData.eventDataPtr];
+		_channelData.eventDataPtr++;
+		retV = (retV << 7) | (lVal & 0x7F);
+		if (!(lVal & 0x80))
+			break;
+	}
+	if (lVal & 0x80) { // should never happen
+		return -1;
+	} else
+		return retV;
+}
+
+uint8 GmChannel::process(uint16 aktTime) {
+	if (!_channelData.channelActive)
+		return 0;
+
+	uint8 returnVal = 0;
+
+	_channelData.nextEventTime -= aktTime;
+	uint8 opcode;
+
+	while ((_channelData.nextEventTime < 0) && (_channelData.channelActive)) {
+		opcode = _musicData[_channelData.eventDataPtr];
+		_channelData.eventDataPtr++;
+		if (opcode&0x80) {
+			if (opcode == 0xFF) {
+				// dummy opcode
+			} else if (opcode >= 0x90) {
+				switch (opcode&0xF) {
+				case 0: com90_caseNoteOff(); break;
+				case 1: com90_stopChannel(); break;
+				case 2: com90_setupInstrument(); break;
+				case 3:
+					returnVal = com90_updateTempo();
+					break;
+				case 5: com90_getPitch(); break;
+				case 6: com90_getChannelVolume(); break;
+				case 8: com90_loopMusic(); break;
+				case 9: com90_keyOff(); break;
+				case 11: com90_getChannelPanValue(); break;
+				case 12: com90_setLoopPoint(); break;
+				case 13: com90_getChannelControl(); break;
+
+				default:
+					error("GmChannel: Unknown music opcode 0x%02X", opcode);
+					break;
+				}
+			} else {
+				// new midi channel assignment
+				_channelData.midiChannelNumber = opcode&0xF;
+			}
+		} else {
+			_channelData.note = opcode;
+			byte velocity = _musicData[_channelData.eventDataPtr];
+			if (_veloTab)
+				velocity = _veloTab[velocity];
+			_channelData.eventDataPtr++;
+			_midiDrv->send((0x90 | _channelData.midiChannelNumber) | (opcode << 8) | (velocity << 16));
+		}
+		if (_channelData.channelActive)
+			_channelData.nextEventTime += getNextEventTime();
+	}
+	return returnVal;
+}
+
+//- command 90h routines
+
+void GmChannel::com90_caseNoteOff() {
+	_midiDrv->send((0x90 | _channelData.midiChannelNumber) | (_musicData[_channelData.eventDataPtr] << 8));
+	_channelData.eventDataPtr++;
+}
+
+void GmChannel::com90_stopChannel() {
+	stopNote();
+	_channelData.channelActive = false;
+}
+
+void GmChannel::com90_setupInstrument() {
+	byte instrument = _musicData[_channelData.eventDataPtr];
+	if (_instMap)
+		instrument = _instMap[instrument];
+	_midiDrv->send((0xC0 | _channelData.midiChannelNumber) | (instrument << 8));
+	_channelData.eventDataPtr++;
+}
+
+uint8 GmChannel::com90_updateTempo() {
+	return _musicData[_channelData.eventDataPtr++];
+}
+
+void GmChannel::com90_getPitch() {
+	_midiDrv->send((0xE0 | _channelData.midiChannelNumber) | 0 | (_musicData[_channelData.eventDataPtr] << 16));
+	_channelData.eventDataPtr++;
+}
+
+void GmChannel::com90_getChannelVolume() {
+	_currentChannelVolume = _musicData[_channelData.eventDataPtr++];
+	uint8 newVol = (uint8)((_currentChannelVolume * _musicVolume) >> 7);
+	_midiDrv->send((0xB0 | _channelData.midiChannelNumber) | 0x700 | (newVol << 16));
+}
+
+void GmChannel::com90_loopMusic() {
+	_channelData.eventDataPtr = _channelData.loopPoint;
+}
+
+void GmChannel::com90_keyOff() {
+	_midiDrv->send((0x90 | _channelData.midiChannelNumber) | (_channelData.note << 8) | 0);
+}
+
+void GmChannel::com90_setLoopPoint() {
+	_channelData.loopPoint = _channelData.eventDataPtr;
+}
+
+void GmChannel::com90_getChannelPanValue() {
+	_midiDrv->send((0xB0 | _channelData.midiChannelNumber) | 0x0A00 | (_musicData[_channelData.eventDataPtr] << 16));
+	_channelData.eventDataPtr++;
+}
+
+void GmChannel::com90_getChannelControl() {
+	uint8 conNum = _musicData[_channelData.eventDataPtr++];
+	uint8 conDat = _musicData[_channelData.eventDataPtr++];
+	_midiDrv->send((0xB0 | _channelData.midiChannelNumber) | (conNum << 8) | (conDat << 16));
+}
+
+} // End of namespace Sky