tdelibs/libtdemid/deviceman.h

/*  deviceman.h  - The device manager, that hides the use of midiOut
    This file is part of LibKMid 0.9.5
    Copyright (C) 1997,98,99,2000  Antonio Larrosa Jimenez
    LibKMid's homepage : http://www.arrakis.es/~rlarrosa/libtdemid.html
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.

    Send comments and bug fixes to Antonio Larrosa <larrosa@kde.org>

***************************************************************************/
#ifndef DEVICEMAN_H
#define DEVICEMAN_H

#include <libtdemid/dattypes.h>
#include <tdelibs_export.h>

class MidiOut;
class MidiMapper;

/**
 * MIDI Device Manager class . This class is the one you should use to
 * send MIDI events to any device, as it creates and manages the *Out classes.
 *
 * This class is usually used by creating a DeviceManager object, then call
 * openDev() and initDev() . Then, use numberOfMidiPorts(),
 * numberOfSynthDevices(), name() and type() to choose which
 * device to play MIDI events to and then use defaultDevice() to set the
 * MIDI device to play.
 *
 * @short Manages all MIDI devices and redirects MIDI events to each one as
 * configured.
 * @version 0.9.5 17/01/2000
 * @author Antonio Larrosa Jimenez <larrosa@kde.org>
 */
class KMID_EXPORT DeviceManager
{
  protected:

    /**
     * @internal
     * The midi devices objects
     */
    MidiOut **device;

    /**
     * @internal
     * Midi info
     */
    struct midi_info *midiinfo;

    /**
     * @internal
     * Synth info
     */
    struct synth_info *synthinfo;

    /**
     * @internal
     * Stores the device thru which a channel will be sent
     */
    int chn2dev[16];

    /**
     * @internal
     * Number of synths devices
     */
    int n_synths;

    /**
     * @internal
     * Number of midi ports
     */
    int n_midi;

    /**
     * @internal
     * n_midi + n_synths
     */
    int n_total;

    /**
     * @internal
     * rate
     */
    int m_rate;

    /**
     * @internal
     * A "constant" used to convert from milliseconds to the computer rate.
     */
    double convertrate;

    /**
     * @internal
     * Newest kernels don't want me to stop a timer that hasn't been started :-)
     */
    int timerstarted;

    /**
     * @internal
     * Last time waited for in wait(double)
     */
    double lastwaittime;

    /**
     * @internal
     * Keeps a pointer to the mapper so that if devices weren't initialized when
     * first called setMidiMap then, when they get initialized, they use the
     * proper mapper
     */
    MidiMapper *mapper_tmp;

    int initialized;

    /**
     * @internal
     * The real file handler for /dev/sequencer, that is opened and closed.
     */
    int seqfd;

    /**
     * @internal
     * The device to which timer events will be sent
     */
    int default_dev;

    /**
     * @internal
     */
    int _ok;

    /**
     * @internal
     * True if the user is running ALSA. False if (s)he's using OSS
     */
    bool alsa;

    /**
     * @internal
     */
    void seqbuf_dump (void);

    /**
     * @internal
     */
    void seqbuf_clean (void);

    /**
     * @internal
     */
    void checkAlsa (void);
  public:
    /**
     * Constructor. It just initializes internal variables, before playing any
     * music, you should call initManager(), setMidiMap()
     * (optional), openDev(), initDev(), setPatchesToUse()
     * (not required, unless you're playing to a GUS device, which must load
     * the patches), tmrStart(), and finally, play the music.
     */
    DeviceManager(int def=-1);

    /**
     * Destructor. It closes the device (calling closeDev() ) if it wasn't
     * closed before.
     */
    ~DeviceManager(void);

    /**
     * Initializes the MIDI Device Manager object.
     *
     * The /dev/sequencer and/or /dev/snd/seq files are opened, available
     * devices are analyzed and *Out objects are created. Then, the
     * device files are closed.
     *
     * @return 0 if everything was OK, or -1 if there was an error and it
     * couldn't be initialized (for example, because it couldn't open the
     * /dev/sequencer file)
     */
    int initManager(void);

    /**
     * Checks if the device manager has been initialized (with @p initManager),
     * and in case it wasn't, initializes it.
     *
     * @return 0 if it was (or has just been) correctly initialized, and -1 if
     * there was an error.
     */
    int checkInit(void);

    /**
     * \obsolete Please use deviceForChannel() instead.
     *
     */
    MidiOut *chntodev(int chn)
		{ return deviceForChannel(chn); }

    /**
     * It's possible to send different MIDI channels to different MIDI devices,
     * so that you can for example send channel 1 to an external synthesizer,
     * channel 2 to a FM device and channel 10 to an AWE synth.
     *
     * @return the device to which MIDI events goind to channel @p chn should
     * be sent.
     */
    MidiOut *deviceForChannel(int chn)
		{ return (device!=0L) ? device[chn2dev[chn]] : 0L ; }

    /**
     * Returns the device number associated with a given channel.
     */
    int deviceNumberForChannel(int chn) { return chn2dev[chn]; }

    /**
     * Sets the device number associated with a given channel.
     */
    void setDeviceNumberForChannel(int chn, int dev);

    /**
     * @return 0 if there was a problem and 1 if everything was OK. Note that the
     * return value is changed after you check it, so you can only check it once.
     */
    int ok(void);

    /**
     * Returns true if it's running ALSA and false if OSS is being run
     */
    int usingAlsa(void) { return alsa; }

    // The following function are here to emulate a midi, so that the
    // DeviceManager sends the events to the appropriate devices.

    /**
     * Open the devices. It first initializes the manager it that wasn't done
     * yet (you should do it yourself, to be able to choose the MIDI output
     * device, as it will be set to an external synth by default, if available).
     *
     * Then /dev/sequencer is opened and the MIDI devices are opened
     * (calling MidiOut::openDev() ).
     * @see ok() to check if there was any problem
     * @see closeDev()
     * @see initDev()
     */
    void openDev        (void);

    /**
     * Closes the devices, and /dev/sequencer.
     *
     * @see openDev()
     */
    void closeDev       (void);

    /**
     * Calls MidiOut::initDev() in turn in each of the available devices.
     *
     * @see MidiOut::initDev()
     */
    void initDev        (void);

    /**
     * Sends a Note On MIDI event.
     *
     * @param chn the MIDI channel (0 to 15) to play the note on.
     * @param note the key of the note to play (0 to 127).
     * @param vel the velocity of the note (0 to 127).
     *
     * @see noteOff()
     */
    void noteOn         ( uchar chn, uchar note, uchar vel );

    /**
     * Sends a Note Off MIDI event. This is equivalent to send a Note On event
     * with a vel value of 0.
     *
     * @param chn the MIDI channel (0 to 15) to play the note on.
     * @param note the key of the note to play (0 to 127).
     * @param vel the velocity of the note (0 to 127).
     *
     * @see noteOn()
     */
    void noteOff        ( uchar chn, uchar note, uchar vel );

    /**
     * Sends a Key Pressure (or Aftertouch) MIDI event.
     * This event changes the pressure over a key after this key has been played.
     *
     * @param chn the MIDI channel (0 to 15) where the note is being played.
     * @param note the key of the note (0 to 127).
     * @param vel the new velocity (or pressure) of the note (0 to 127).
     */
    void keyPressure    ( uchar chn, uchar note, uchar vel );

    /**
     * Changes the patch (instrument) on a MIDI channel.
     *
     * @see setPatchesToUse()
     *
     * @param chn the MIDI channel (0 to 15) .
     * @param patch the General Midi patch (0 to 127) to use on the channel chn.
     */
    void chnPatchChange ( uchar chn, uchar patch );

    /**
     * Changes the Pressure (Aftertouch) on a MIDI channel. Keep in mind that
     * some synthesizers don't like this events, and it's better not to send it.
     *
     * @param chn the MIDI channel (0 to 15) to change.
     * @param vel the velocity (0 to 127) to use on the channel chn.
     */
    void chnPressure    ( uchar chn, uchar vel );

    /**
     * Changes the Pitch Bender value on a MIDI channel. This bends the tone of
     * each note played on this channel.
     *
     * @param chn the MIDI channel (0 to 15) to use.
     * @param lsb and @p msb the less significant byte and the most significant
     * byte (0 to 127 each) of the number by which notes will be bend. a 0x4000
     * value means not to bend.
     * @param msb the most significant byte
     */
    void chnPitchBender ( uchar chn, uchar lsb,  uchar msb );

    /**
     * Sends a Controller event to a MIDI channel. This can be used for example
     * to change the volume, set a XG patch, etc. Look for any General Midi
     * resource page on the net for more information about the available
     * controller events.
     *
     * For example, to set the tremolo value to a maximum on the MIDI channel
     * number one, you should pass 1 to @p chn, 1 to @p ctl and 127 to @p v.
     *
     * @param chn the MIDI channel (0 to 15) to send the event to.
     * @param ctl the controller (0 to 15) to send.
     * @param v the value (data) of the controller.
     */
    void chnController  ( uchar chn, uchar ctl , uchar v );

    /**
     * Sends a SYStem EXclusive message to the default MIDI device (usually,
     * external MIDI synths, as most internal synths do not support sysex
     * messages)
     *
     * @param data the array of bytes that comform the system exclusive message.
     * Without the initial 0xF0 char, and including the final 0xF7 char (end of
     * exclusive message)
     * @param size the size in bytes of the data to send
     *
     * @see setDefaultDevice()
     */
    void sysEx          ( uchar *data,ulong size);

    /**
     * Sets the number of milliseconds at which the next event will be sent.
     * This way, you can schedule notes and events to send to the MIDI device.
     * @see tmrStart()
     */
    void wait (double ms);

    /**
     * Sets the tempo which will be used to convert between ticks and
     * milliseconds.
     */
     void tmrSetTempo(int v);

    /**
     * Starts the timer. You must call tmrStart before using wait()
     */
    void tmrStart(long int tpcn);

    /**
     * Stops the timer. This will be called by closeDev() before closing
     * the device
     */
    void tmrStop(void);

    /**
     * Continue the stopped timer . It is the same than starting a new timer, but
     * without resetting it.
     */
    void tmrContinue(void);

    /**
     * Sends an all notes off event
     */
    void allNotesOff(void);

    /**
     * Synchronizes with the MIDI buffer. Midi events are put into a buffer,
     * along with timer delays (see wait() ). sync returns when the buffer
     * is empty.
     *
     * @param f if false, it syncronizes by waiting for the buffer to be sent.
     * If true, it forces the synchronization by clearing the buffer
     * inmediately. The "force" method is, of course, not recommended, except
     * in rare situations.
     */
    void sync(bool f=0);

    /**
     * Changes the "master" volume of the played events by altering next volume
     * controller events. The parameter @p i should be in the range of 0
     * (nothing is heard) to 150 (music is played at a 150% of the original
     * volume).
     *
     * Keep in mind that as most MIDI files already play music at near the
     * maximum volume, an @p i value greater than 100 is very probably ignored
     * most of the times.
     */
    void setVolumePercentage(int i);

    /**
     * Returns the device to which the MIDI events will be sent.
     * Returns -1 if there's no available device.
     *
     * @see setDefaultDevice()
     */
    int defaultDevice(void);

    /**
     * Sets the device to send the MIDI events to.
     *
     * By using midiPorts(), synthDevices(), name() and
     * type(), you should choose which device to use (note that they are
     * numbered with midi ports being first and synth devices next)
     *
     * @see defaultDevice()
     */
    void setDefaultDevice(int i);

    /**
     * Loads the patches you're going to use . This has effect only for GUS
     * cards, although, if you use this function when defaultDevice() is
     * not a GUS device, it will be ignored.
     *
     * The parameter is an int [256] array, which contain the following:
     *
     * The first 0..127 integers, are the number of times each General MIDI patch
     * will be used, and -1 when the corresponding patch won't be used.
     *
     * The 128..255 integers are the number of times each drum voice (each note
     * on the drum channel) will be used, and -1 when the corresponding
     * percussion won't be used.
     *
     * This is done this way so that if the user has very little memory on his
     * GUS card, and not all patches will be loaded, they are at least
     * reordered, so that it first loads the one you're going to use most.
     *
     * In case you don't worry about such users, or you don't know "a priori"
     * the number of notes you're going to play, you can just use 1 for each
     * patch you want to load and -1 in the rest.
     *
     * @see GUSOut::setPatchesToUse()
     * @see GUSOut::loadPatch()
     *
     * @return 0 if ok, and -1 if there wasn't enough memory to load the patches
     * in the card's memory.
     */
    int setPatchesToUse(int *patchesused);

    /**
     * Returns the filename where the Midi Mapper was loaded from, or "" if no
     * MIDI Mapper is in use.
     *
     * @see setMidiMap()
     */
    const char *midiMapFilename(void);

    /**
     * Sets a MidiMapper object to use. This object should already have
     * loaded the configuration. See the description of MidiMapper for
     * more information.
     *
     * @see MidiMapper::MidiMapper()
     * @see midiMapFilename()
     */
    void setMidiMap(MidiMapper *map);

    /**
     * Returns the SNDCTL_SEQ_CTRLRATE ioctl value
     */
    int rate(void) { return m_rate; }

    /**
     * Returns the number of MIDI ports available on the system. It's common that
     * users have MIDI ports available, but there are no external synthesizers
     * connected to these ports, so sending MIDI events to these ports will not
     * produce any music in this case.
     *
     * @see synthDevices()
     * @see setDefaultDevice()
     */
    int midiPorts(void) { return n_midi; }

    /**
     * Returns the number of internal synthesizers available on the system. Some
     * of these devices will need special configuration, for example, to load
     * sound patches.
     *
     * @see midiPorts()
     * @see setDefaultDevice()
     * @see setPatchesToUse()
     */
    int synthDevices(void) { return n_synths; }

    /**
     * Returns the name of the @p i-th device . In case the DeviceManager wasn't
     * yet initialized ( see checkInit() ), the return value is NULL, and
     * in case the parameter has a value out of the valid range ( 0 to
     * midiPorts() + synthDevices() ) it returns an empty string.
     */
    const char *name(int i);

    /**
     * Returns the type of device the @p i-th device is , in a user-friendly
     * string . For example, "External Midi Port" for midi ports, "FM" for FM
     * synthesizers, "GUS" for Gravis Ultrasound devices, etc.
     */
    const char *type(int i);

  private:
    class DeviceManagerPrivate;
    DeviceManagerPrivate *d;
};

#endif