midi.c

来自「An interactive water fountain. A realis」· C语言 代码 · 共 2,070 行 · 第 1/4 页

    default :
        if (_MIDI_Funcs->ControlChange)
        {
            _MIDI_Funcs->ControlChange(channel, c1, c2);
        }
    }

    return TimeSet;
}


/*---------------------------------------------------------------------
   Function: _MIDI_ServiceRoutine

   Task that interperates the MIDI data.
---------------------------------------------------------------------*/

static int32_t _MIDI_ServiceRoutine(void)
{
    int32_t   event;
    int32_t   channel;
    int32_t   command;
    track *Track;
    int32_t   tracknum;
    int32_t   status;
    int32_t   c1 = 0;
    int32_t   c2 = 0;
    int32_t   TimeSet = FALSE;

    if (_MIDI_SongActive)
    {
        Track = _MIDI_TrackPtr;
        tracknum = 0;
        while (tracknum < _MIDI_NumTracks)
        {
            while ((Track->active) && (Track->delay == 0))
            {
                GET_NEXT_EVENT(Track, event);

                if (GET_MIDI_COMMAND(event) == MIDI_SPECIAL)
                {
                    switch (event)
                    {
                    case MIDI_SYSEX :
                    case MIDI_SYSEX_CONTINUE :
                        _MIDI_SysEx(Track);
                        break;

                    case MIDI_META_EVENT :
                        _MIDI_MetaEvent(Track);
                        break;
                    }

                    if (Track->active)
                    {
                        Track->delay = _MIDI_ReadDelta(Track);
                    }
                    continue;
                }

                if (event & MIDI_RUNNING_STATUS)
                {
                    Track->RunningStatus = event;
                }
                else
                {
                    event = Track->RunningStatus;
                    Track->pos--;
                }

                channel = GET_MIDI_CHANNEL(event);
                command = GET_MIDI_COMMAND(event);

                if (_MIDI_CommandLengths[ command ] > 0)
                {
                    GET_NEXT_EVENT(Track, c1);
                    if (_MIDI_CommandLengths[ command ] > 1)
                    {
                        GET_NEXT_EVENT(Track, c2);
                    }
                }

                if (_MIDI_RerouteFunctions[ channel ] != NULL)
                {
                    status = _MIDI_RerouteFunctions[ channel ](event, c1, c2);

                    if (status == MIDI_DONT_PLAY)
                    {
                        Track->delay = _MIDI_ReadDelta(Track);
                        continue;
                    }
                }

                switch (command)
                {
                case MIDI_NOTE_OFF :
                    if (_MIDI_Funcs->NoteOff)
                    {
                        _MIDI_Funcs->NoteOff(channel, c1, c2);
                    }
                    break;

                case MIDI_NOTE_ON :
                    if (_MIDI_Funcs->NoteOn)
                    {
                        _MIDI_Funcs->NoteOn(channel, c1, c2);
                    }
                    break;

                case MIDI_POLY_AFTER_TCH :
                    if (_MIDI_Funcs->PolyAftertouch)
                    {
                        _MIDI_Funcs->PolyAftertouch(channel, c1, c2);
                    }
                    break;

                case MIDI_CONTROL_CHANGE :
                    TimeSet = _MIDI_InterpretControllerInfo(Track, TimeSet, channel, c1, c2);
                    break;

                case MIDI_PROGRAM_CHANGE :
                    if ((_MIDI_Funcs->ProgramChange) && (!Track->EMIDI_ProgramChange))
                    {
                        _MIDI_Funcs->ProgramChange(channel, MIDI_PatchMap[ c1 & 0x7f ]);
                    }
                    break;

                case MIDI_AFTER_TOUCH :
                    if (_MIDI_Funcs->ChannelAftertouch)
                    {
                        _MIDI_Funcs->ChannelAftertouch(channel, c1);
                    }
                    break;

                case MIDI_PITCH_BEND :
                    if (_MIDI_Funcs->PitchBend)
                    {
                        _MIDI_Funcs->PitchBend(channel, c1, c2);
                    }
                    break;

                default :
                    break;
                }

                Track->delay = _MIDI_ReadDelta(Track);
            }

            Track->delay--;
            Track++;
            tracknum++;

            if (_MIDI_ActiveTracks == 0)
            {
                _MIDI_ResetTracks();
                if (_MIDI_Loop)
                {
                    tracknum = 0;
                    Track = _MIDI_TrackPtr;
                }
                else
                {
                    _MIDI_SongActive = FALSE;
                    break;
                }
            }
        }

        _MIDI_AdvanceTick();
        _MIDI_GlobalPositionInTicks++;
    }
    return 0;
}


/*---------------------------------------------------------------------
   Function: _MIDI_SendControlChange

   Sends a control change to the proper device
---------------------------------------------------------------------*/

static int32_t _MIDI_SendControlChange
(
    int32_t channel,
    int32_t c1,
    int32_t c2
)

{
    int32_t status;

    if (_MIDI_RerouteFunctions[ channel ] != NULL)
    {
        status = _MIDI_RerouteFunctions[ channel ](0xB0 + channel,
                 c1, c2);
        if (status == MIDI_DONT_PLAY)
        {
            return(MIDI_Ok);
        }
    }

    if (_MIDI_Funcs == NULL)
    {
        return(MIDI_Error);
    }

    if (_MIDI_Funcs->ControlChange == NULL)
    {
        return(MIDI_Error);
    }

    _MIDI_Funcs->ControlChange(channel, c1, c2);

    return(MIDI_Ok);
}


/*---------------------------------------------------------------------
   Function: MIDI_RerouteMidiChannel

   Sets callback function to reroute MIDI commands from specified
   function.
---------------------------------------------------------------------*/

void MIDI_RerouteMidiChannel
(
    int32_t channel,
    int32_t(*function)(int32_t event, int32_t c1, int32_t c2)
)

{
    if ((channel >= 1) && (channel <= 16))
    {
        _MIDI_RerouteFunctions[ channel - 1 ] = function;
    }
}


/*---------------------------------------------------------------------
   Function: MIDI_AllNotesOff

   Sends all notes off commands on all midi channels.
---------------------------------------------------------------------*/

int32_t MIDI_AllNotesOff
(
    void
)

{
    int32_t channel;

    for (channel = 0; channel < NUM_MIDI_CHANNELS; channel++)
    {
        _MIDI_SendControlChange(channel, 0x40, 0);
        _MIDI_SendControlChange(channel, MIDI_ALL_NOTES_OFF, 0);
        _MIDI_SendControlChange(channel, 0x78, 0);
    }

    return(MIDI_Ok);
}


/*---------------------------------------------------------------------
   Function: _MIDI_SetChannelVolume

   Sets the volume of the specified midi channel.
---------------------------------------------------------------------*/

static void _MIDI_SetChannelVolume
(
    int32_t channel,
    int32_t volume
)

{
    int32_t status;
    int32_t remotevolume;

    _MIDI_ChannelVolume[ channel ] = volume;

    if (_MIDI_RerouteFunctions[ channel ] != NULL)
    {
        remotevolume = volume * _MIDI_TotalVolume;
        remotevolume *= _MIDI_UserChannelVolume[ channel ];
        remotevolume /= MIDI_MaxVolume;
        remotevolume >>= 8;

        status = _MIDI_RerouteFunctions[ channel ](0xB0 + channel,
                 MIDI_VOLUME, remotevolume);
        if (status == MIDI_DONT_PLAY)
        {
            return;
        }
    }

    if (_MIDI_Funcs == NULL)
    {
        return;
    }

    if (_MIDI_Funcs->ControlChange == NULL)
    {
        return;
    }

    // For user volume
    volume *= _MIDI_UserChannelVolume[ channel ];

    if (_MIDI_Funcs->SetVolume == NULL)
    {
        volume *= _MIDI_TotalVolume;
        volume /= MIDI_MaxVolume;
    }

    // For user volume
    volume >>= 8;

    _MIDI_Funcs->ControlChange(channel, MIDI_VOLUME, volume);
}


/*---------------------------------------------------------------------
   Function: MIDI_SetUserChannelVolume

   Sets the volume of the specified midi channel.
---------------------------------------------------------------------*/

void MIDI_SetUserChannelVolume
(
    int32_t channel,
    int32_t volume
)

{
    // Convert channel from 1-16 to 0-15
    channel--;

    volume = max(0, volume);
    volume = min(volume, 256);

    if ((channel >= 0) && (channel < NUM_MIDI_CHANNELS))
    {
        _MIDI_UserChannelVolume[ channel ] = volume;
        _MIDI_SetChannelVolume(channel, _MIDI_ChannelVolume[ channel ]);
    }
}


/*---------------------------------------------------------------------
   Function: MIDI_ResetUserChannelVolume

   Sets the volume of the specified midi channel.
---------------------------------------------------------------------*/

void MIDI_ResetUserChannelVolume
(
    void
)

{
    int32_t channel;

    for (channel = 0; channel < NUM_MIDI_CHANNELS; channel++)
    {
        _MIDI_UserChannelVolume[ channel ] = 256;
    }

    _MIDI_SendChannelVolumes();
}


/*---------------------------------------------------------------------
   Function: _MIDI_SendChannelVolumes

   Sets the volume on all the midi channels.
---------------------------------------------------------------------*/

static void _MIDI_SendChannelVolumes
(
    void
)

{
    int32_t channel;

    for (channel = 0; channel < NUM_MIDI_CHANNELS; channel++)
    {
        _MIDI_SetChannelVolume(channel, _MIDI_ChannelVolume[ channel ]);
    }
}


/*---------------------------------------------------------------------
   Function: MIDI_Reset

   Resets the MIDI device to General Midi defaults.
---------------------------------------------------------------------*/

int32_t MIDI_Reset
(
    void
)

{
    int32_t channel;

    MIDI_AllNotesOff();

    for (channel = 0; channel < NUM_MIDI_CHANNELS; channel++)
    {
        _MIDI_SendControlChange(channel, MIDI_RESET_ALL_CONTROLLERS, 0);
        _MIDI_SendControlChange(channel, MIDI_RPN_MSB, MIDI_PITCHBEND_MSB);
        _MIDI_SendControlChange(channel, MIDI_RPN_LSB, MIDI_PITCHBEND_LSB);
        _MIDI_SendControlChange(channel, MIDI_DATAENTRY_MSB, 2); /* Pitch Bend Sensitivity MSB */
        _MIDI_SendControlChange(channel, MIDI_DATAENTRY_LSB, 0); /* Pitch Bend Sensitivity LSB */
        _MIDI_ChannelVolume[ channel ] = GENMIDI_DefaultVolume;
    }

    _MIDI_SendChannelVolumes();

    Reset = TRUE;

    return(MIDI_Ok);
}


/*---------------------------------------------------------------------
   Function: MIDI_SetVolume

   Sets the total volume of the music.
---------------------------------------------------------------------*/

int32_t MIDI_SetVolume
(
    int32_t volume
)

{
    int32_t i;

    if (_MIDI_Funcs == NULL)
    {
        return(MIDI_NullMidiModule);
    }

    volume = min(MIDI_MaxVolume, volume);
    volume = max(0, volume);

    _MIDI_TotalVolume = volume;

    if (_MIDI_Funcs->SetVolume)
    {
        _MIDI_Funcs->SetVolume(volume);

        for (i = 0; i < NUM_MIDI_CHANNELS; i++)
        {
            if (_MIDI_RerouteFunctions[ i ] != NULL)
            {
                _MIDI_SetChannelVolume(i, _MIDI_ChannelVolume[ i ]);
            }
        }
    }
    else
    {
        _MIDI_SendChannelVolumes();
    }

    return(MIDI_Ok);
}


/*---------------------------------------------------------------------
   Function: MIDI_GetVolume

   Returns the total volume of the music.
---------------------------------------------------------------------*/

int32_t MIDI_GetVolume
(
    void
)

{
    int32_t volume;

    if (_MIDI_Funcs == NULL)
    {
        return(MIDI_NullMidiModule);
    }

    if (_MIDI_Funcs->GetVolume)
    {
        volume = _MIDI_Funcs->GetVolume();
    }
    else
    {
        volume = _MIDI_TotalVolume;
    }

    return(volume);
}


/*---------------------------------------------------------------------
   Function: MIDI_SetContext

   Sets the song context.
---------------------------------------------------------------------*/

void MIDI_SetContext
(
    int32_t context
)

{
    if ((context > 0) && (context < EMIDI_NUM_CONTEXTS))
    {