UnixSeqMidiDriver.cpp

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/*
Copyright (C) 2004-2005  The Pentagram Team

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.
*/

/*
  Unix MIDI sequencer
  Adapted from ScummVM's backends/midi/seq.cpp
*/

#include "pent_include.h"
#include "UnixSeqMidiDriver.h"

#ifdef USE_UNIX_SEQ_MIDI

#include <fcntl.h>
#include <unistd.h>
#include <cerrno>

const MidiDriver::MidiDriverDesc UnixSeqMidiDriver::desc =
                MidiDriver::MidiDriverDesc ("UnixSeqDevice", createInstance);

#define SEQ_MIDIPUTC 5
#define SEQ_DEVICE "/dev/sequencer"

UnixSeqMidiDriver::UnixSeqMidiDriver()
        : isOpen(false), device(0), deviceNum(0)
{
        // see if the config file specifies an alternate midi device
        devname = getConfigSetting("unixseqdevice", SEQ_DEVICE);
}

int UnixSeqMidiDriver::open()
{
        if (isOpen) return 1;
        isOpen = true;
        device = 0;

        pout << "UnixSeqDevice: opening device: " << devname << std::endl;

        device = ::open(devname.c_str(), O_RDWR, 0);
        if (device < 0) {
                perr << "UnixSeqDevice: failed: " << strerror(errno);
                perr << std::endl;
                return device;
        }

        return 0;
}

void UnixSeqMidiDriver::close()
{
	::close(device);
        isOpen = false;
}

void UnixSeqMidiDriver::send(uint32 b) {
        unsigned char buf[256];
        int position = 0;

        switch (b & 0xF0) {
        case 0x80:
        case 0x90:
        case 0xA0:
        case 0xB0:
        case 0xE0:
                buf[position++] = SEQ_MIDIPUTC;
                buf[position++] = (unsigned char)b;
                buf[position++] = deviceNum;
                buf[position++] = 0;
                buf[position++] = SEQ_MIDIPUTC;
                buf[position++] = (unsigned char)((b >> 8) & 0x7F);
                buf[position++] = deviceNum;
                buf[position++] = 0;
                buf[position++] = SEQ_MIDIPUTC;
                buf[position++] = (unsigned char)((b >> 16) & 0x7F);
                buf[position++] = deviceNum;
                buf[position++] = 0;
                break;
        case 0xC0:
        case 0xD0:
                buf[position++] = SEQ_MIDIPUTC;
                buf[position++] = (unsigned char)b;
                buf[position++] = deviceNum;
                buf[position++] = 0;
                buf[position++] = SEQ_MIDIPUTC;
                buf[position++] = (unsigned char)((b >> 8) & 0x7F);
                buf[position++] = deviceNum;
                buf[position++] = 0;
                break;
        default:
                perr << "UnixSeqMidiDriver: Unknown Command: "
                         << std::hex << (int)b << std::dec << std::endl;
                break;
        }

        ::write(device, buf, position);
}

void UnixSeqMidiDriver::send_sysex(uint8 status,const uint8 *msg,uint16 length)
{
        if (length > 511) {
                perr << "UnixSeqMidiDriver: "
                         << "Cannot send SysEx block - data too large" << std::endl;
                return;
        }

        unsigned char buf [2048];
        int position = 0;
        const uint8 *chr = msg;

        buf[position++] = SEQ_MIDIPUTC;
        buf[position++] = status;
        buf[position++] = deviceNum;
        buf[position++] = 0;

        for (; length; --length) {
                buf[position++] = SEQ_MIDIPUTC;
                buf[position++] = *chr++;
                buf[position++] = deviceNum;
                buf[position++] = 0;
        }

        ::write (device, buf, position);
}

#endif

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