Files
2026-02-02 04:50:13 +01:00

99 lines
3.2 KiB
C++

/* 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/>.
*
*/
#ifndef AGOS_DRIVERS_ACCOLADE_CMS_H
#define AGOS_DRIVERS_ACCOLADE_CMS_H
#include "audio/mididrv.h"
#include "audio/cms.h"
namespace AGOS {
// MIDI driver for the Creative Music System / Gameblaster.
// This driver uses only 6 of the available 12 channels and does not support
// stereo. It only supports note on and off and program change; the selected
// instrument only affects the note volume.
class MidiDriver_Accolade_Cms : public MidiDriver {
protected:
static const byte REGISTER_BASE_AMPLITUDE = 0x00;
static const byte REGISTER_BASE_FREQUENCY = 0x08;
static const byte REGISTER_BASE_OCTAVE = 0x10;
static const byte REGISTER_FREQUENCY_ENABLE = 0x14;
static const byte REGISTER_RESET_SOUND_ENABLE = 0x1C;
// Frequency register values for octave notes.
static const byte CMS_NOTE_FREQUENCIES[12];
// Volume adjustments for all instruments.
static const byte CMS_VOLUME_ADJUSTMENTS[128];
public:
MidiDriver_Accolade_Cms();
~MidiDriver_Accolade_Cms() override;
int open() override;
void close() override;
bool isOpen() const override;
uint32 getBaseTempo() override;
// This driver does not support MidiChannel objects.
MidiChannel *allocateChannel() override;
// This driver does not support MidiChannel objects.
MidiChannel *getPercussionChannel() override;
using MidiDriver::send;
void send(uint32 b) override;
void setTimerCallback(void *timer_param, Common::TimerManager::TimerProc timer_proc) override;
void onTimer();
protected:
void cmsInit();
void noteOff(uint8 channel, uint8 note);
void noteOn(uint8 channel, uint8 note, uint8 velocity);
void programChange(uint8 channel, uint8 instrument);
void controlChange(uint8 channel, uint8 controller, uint8 value);
// Returns the value for the frequency enable register of the first CMS
// chip based on the _activeNotes array (if a note is active, the bit for
// the corresponding channel is set).
byte determineFrequencyEnableRegisterValue();
void writeRegister(uint16 reg, uint8 value);
CMS::CMS *_cms;
bool _isOpen;
// The selected instrument on each MIDI channel.
byte _instruments[16];
// The active note on each CMS channel (0xFF if no note is active).
byte _activeNotes[12];
// The current values of the CMS octave registers (0x10 - 0x12).
byte _octaveRegisterValues[6];
// External timer callback
void *_timer_param;
Common::TimerManager::TimerProc _timer_proc;
};
} // End of namespace AGOS
#endif