ref: bff9e7cab76d907ea4666c76a61bb9f547f11b1e
dir: /Game/src/audiolib/midi.c/
/* Copyright (C) 1994-1995 Apogee Software, Ltd. 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. */ /********************************************************************** module: MIDI.C author: James R. Dose date: May 25, 1994 Midi song file playback routines. (c) Copyright 1994 James R. Dose. All Rights Reserved. **********************************************************************/ #include <stdlib.h> #include <time.h> #include <dos.h> #include <string.h> #include "sndcards.h" #include "interrup.h" #include "dpmi.h" #include "standard.h" #include "task_man.h" #include "ll_man.h" #include "usrhooks.h" #include "music.h" #include "_midi.h" #include "midi.h" #include "debugio.h" extern int MUSIC_SoundDevice; static const int _MIDI_CommandLengths[ NUM_MIDI_CHANNELS ] = { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 1, 1, 2, 0 }; static int cdecl ( *_MIDI_RerouteFunctions[ NUM_MIDI_CHANNELS ] ) ( int event, int c1, int c2 ) = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; static track *_MIDI_TrackPtr = NULL; static int _MIDI_TrackMemSize; static int _MIDI_NumTracks; static int _MIDI_SongActive = FALSE; static int _MIDI_SongLoaded = FALSE; static int _MIDI_Loop = FALSE; static task *_MIDI_PlayRoutine = NULL; static int _MIDI_Division; static int _MIDI_Tick = 0; static int _MIDI_Beat = 1; static int _MIDI_Measure = 1; static unsigned _MIDI_Time; static int _MIDI_BeatsPerMeasure; static int _MIDI_TicksPerBeat; static int _MIDI_TimeBase; static long _MIDI_FPSecondsPerTick; static unsigned _MIDI_TotalTime; static int _MIDI_TotalTicks; static int _MIDI_TotalBeats; static int _MIDI_TotalMeasures; static unsigned long _MIDI_PositionInTicks; static int _MIDI_Context; static int _MIDI_ActiveTracks; static int _MIDI_TotalVolume = MIDI_MaxVolume; static int _MIDI_ChannelVolume[ NUM_MIDI_CHANNELS ]; static int _MIDI_UserChannelVolume[ NUM_MIDI_CHANNELS ] = { 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256 }; static midifuncs *_MIDI_Funcs = NULL; static int Reset = FALSE; int MIDI_Tempo = 120; char MIDI_PatchMap[ 128 ]; /********************************************************************** Memory locked functions: **********************************************************************/ #define MIDI_LockStart _MIDI_ReadNumber /*--------------------------------------------------------------------- Function: _MIDI_ReadNumber Reads a variable length number from a MIDI track. ---------------------------------------------------------------------*/ static long _MIDI_ReadNumber ( void *from, size_t size ) { unsigned char *FromPtr; long value; if ( size > 4 ) { size = 4; } FromPtr = ( unsigned char * )from; value = 0; while( size-- ) { value <<= 8; value += *FromPtr++; } return( value ); } /*--------------------------------------------------------------------- Function: _MIDI_ReadDelta Reads a variable length encoded delta delay time from the MIDI data. ---------------------------------------------------------------------*/ static long _MIDI_ReadDelta ( track *ptr ) { long value; unsigned char c; GET_NEXT_EVENT( ptr, value ); if ( value & 0x80 ) { value &= 0x7f; do { GET_NEXT_EVENT( ptr, c ); value = ( value << 7 ) + ( c & 0x7f ); } while ( c & 0x80 ); } return( value ); } /*--------------------------------------------------------------------- Function: _MIDI_ResetTracks Sets the track pointers to the beginning of the song. ---------------------------------------------------------------------*/ static void _MIDI_ResetTracks ( void ) { int i; track *ptr; _MIDI_Tick = 0; _MIDI_Beat = 1; _MIDI_Measure = 1; _MIDI_Time = 0; _MIDI_BeatsPerMeasure = 4; _MIDI_TicksPerBeat = _MIDI_Division; _MIDI_TimeBase = 4; _MIDI_PositionInTicks = 0; _MIDI_ActiveTracks = 0; _MIDI_Context = 0; ptr = _MIDI_TrackPtr; for( i = 0; i < _MIDI_NumTracks; i++ ) { ptr->pos = ptr->start; ptr->delay = _MIDI_ReadDelta( ptr ); ptr->active = ptr->EMIDI_IncludeTrack; ptr->RunningStatus = 0; ptr->currentcontext = 0; ptr->context[ 0 ].loopstart = ptr->start; ptr->context[ 0 ].loopcount = 0; if ( ptr->active ) { _MIDI_ActiveTracks++; } ptr++; } } /*--------------------------------------------------------------------- Function: _MIDI_AdvanceTick Increment tick counters. ---------------------------------------------------------------------*/ static void _MIDI_AdvanceTick ( void ) { _MIDI_PositionInTicks++; _MIDI_Time += _MIDI_FPSecondsPerTick; _MIDI_Tick++; while( _MIDI_Tick > _MIDI_TicksPerBeat ) { _MIDI_Tick -= _MIDI_TicksPerBeat; _MIDI_Beat++; } while( _MIDI_Beat > _MIDI_BeatsPerMeasure ) { _MIDI_Beat -= _MIDI_BeatsPerMeasure; _MIDI_Measure++; } } /*--------------------------------------------------------------------- Function: _MIDI_SysEx Interpret SysEx Event. ---------------------------------------------------------------------*/ static void _MIDI_SysEx ( track *Track ) { int length; length = _MIDI_ReadDelta( Track ); Track->pos += length; } /*--------------------------------------------------------------------- Function: _MIDI_MetaEvent Interpret Meta Event. ---------------------------------------------------------------------*/ static void _MIDI_MetaEvent ( track *Track ) { int command; int length; int denominator; long tempo; GET_NEXT_EVENT( Track, command ); GET_NEXT_EVENT( Track, length ); switch( command ) { case MIDI_END_OF_TRACK : Track->active = FALSE; _MIDI_ActiveTracks--; break; case MIDI_TEMPO_CHANGE : tempo = 60000000L / _MIDI_ReadNumber( Track->pos, 3 ); MIDI_SetTempo( tempo ); break; case MIDI_TIME_SIGNATURE : if ( ( _MIDI_Tick > 0 ) || ( _MIDI_Beat > 1 ) ) { _MIDI_Measure++; } _MIDI_Tick = 0; _MIDI_Beat = 1; _MIDI_BeatsPerMeasure = (int)*Track->pos; denominator = (int)*( Track->pos + 1 ); _MIDI_TimeBase = 1; while( denominator > 0 ) { _MIDI_TimeBase += _MIDI_TimeBase; denominator--; } _MIDI_TicksPerBeat = ( _MIDI_Division * 4 ) / _MIDI_TimeBase; break; } Track->pos += length; } /*--------------------------------------------------------------------- Function: _MIDI_InterpretControllerInfo Interprets the MIDI controller info. ---------------------------------------------------------------------*/ static int _MIDI_InterpretControllerInfo ( track *Track, int TimeSet, int channel, int c1, int c2 ) { track *trackptr; int tracknum; int loopcount; switch( c1 ) { case MIDI_MONO_MODE_ON : Track->pos++; break; case MIDI_VOLUME : if ( !Track->EMIDI_VolumeChange ) { _MIDI_SetChannelVolume( channel, c2 ); } break; case EMIDI_INCLUDE_TRACK : case EMIDI_EXCLUDE_TRACK : break; case EMIDI_PROGRAM_CHANGE : if ( Track->EMIDI_ProgramChange ) { _MIDI_Funcs->ProgramChange( channel, MIDI_PatchMap[ c2 & 0x7f ] ); } break; case EMIDI_VOLUME_CHANGE : if ( Track->EMIDI_VolumeChange ) { _MIDI_SetChannelVolume( channel, c2 ); } break; case EMIDI_CONTEXT_START : break; case EMIDI_CONTEXT_END : if ( ( Track->currentcontext == _MIDI_Context ) || ( _MIDI_Context < 0 ) || ( Track->context[ _MIDI_Context ].pos == NULL ) ) { break; } Track->currentcontext = _MIDI_Context; Track->context[ 0 ].loopstart = Track->context[ _MIDI_Context ].loopstart; Track->context[ 0 ].loopcount = Track->context[ _MIDI_Context ].loopcount; Track->pos = Track->context[ _MIDI_Context ].pos; Track->RunningStatus = Track->context[ _MIDI_Context ].RunningStatus; if ( TimeSet ) { break; } _MIDI_Time = Track->context[ _MIDI_Context ].time; _MIDI_FPSecondsPerTick = Track->context[ _MIDI_Context ].FPSecondsPerTick; _MIDI_Tick = Track->context[ _MIDI_Context ].tick; _MIDI_Beat = Track->context[ _MIDI_Context ].beat; _MIDI_Measure = Track->context[ _MIDI_Context ].measure; _MIDI_BeatsPerMeasure = Track->context[ _MIDI_Context ].BeatsPerMeasure; _MIDI_TicksPerBeat = Track->context[ _MIDI_Context ].TicksPerBeat; _MIDI_TimeBase = Track->context[ _MIDI_Context ].TimeBase; TimeSet = TRUE; break; case EMIDI_LOOP_START : case EMIDI_SONG_LOOP_START : if ( c2 == 0 ) { loopcount = EMIDI_INFINITE; } else { loopcount = c2; } if ( c1 == EMIDI_SONG_LOOP_START ) { trackptr = _MIDI_TrackPtr; tracknum = _MIDI_NumTracks; } else { trackptr = Track; tracknum = 1; } while( tracknum > 0 ) { trackptr->context[ 0 ].loopcount = loopcount; trackptr->context[ 0 ].pos = trackptr->pos; trackptr->context[ 0 ].loopstart = trackptr->pos; trackptr->context[ 0 ].RunningStatus = trackptr->RunningStatus; trackptr->context[ 0 ].active = trackptr->active; trackptr->context[ 0 ].delay = trackptr->delay; trackptr->context[ 0 ].time = _MIDI_Time; trackptr->context[ 0 ].FPSecondsPerTick = _MIDI_FPSecondsPerTick; trackptr->context[ 0 ].tick = _MIDI_Tick; trackptr->context[ 0 ].beat = _MIDI_Beat; trackptr->context[ 0 ].measure = _MIDI_Measure; trackptr->context[ 0 ].BeatsPerMeasure = _MIDI_BeatsPerMeasure; trackptr->context[ 0 ].TicksPerBeat = _MIDI_TicksPerBeat; trackptr->context[ 0 ].TimeBase = _MIDI_TimeBase; trackptr++; tracknum--; } break; case EMIDI_LOOP_END : case EMIDI_SONG_LOOP_END : if ( ( c2 != EMIDI_END_LOOP_VALUE ) || ( Track->context[ 0 ].loopstart == NULL ) || ( Track->context[ 0 ].loopcount == 0 ) ) { break; } if ( c1 == EMIDI_SONG_LOOP_END ) { trackptr = _MIDI_TrackPtr; tracknum = _MIDI_NumTracks; _MIDI_ActiveTracks = 0; } else { trackptr = Track; tracknum = 1; _MIDI_ActiveTracks--; } while( tracknum > 0 ) { if ( trackptr->context[ 0 ].loopcount != EMIDI_INFINITE ) { trackptr->context[ 0 ].loopcount--; } trackptr->pos = trackptr->context[ 0 ].loopstart; trackptr->RunningStatus = trackptr->context[ 0 ].RunningStatus; trackptr->delay = trackptr->context[ 0 ].delay; trackptr->active = trackptr->context[ 0 ].active; if ( trackptr->active ) { _MIDI_ActiveTracks++; } if ( !TimeSet ) { _MIDI_Time = trackptr->context[ 0 ].time; _MIDI_FPSecondsPerTick = trackptr->context[ 0 ].FPSecondsPerTick; _MIDI_Tick = trackptr->context[ 0 ].tick; _MIDI_Beat = trackptr->context[ 0 ].beat; _MIDI_Measure = trackptr->context[ 0 ].measure; _MIDI_BeatsPerMeasure = trackptr->context[ 0 ].BeatsPerMeasure; _MIDI_TicksPerBeat = trackptr->context[ 0 ].TicksPerBeat; _MIDI_TimeBase = trackptr->context[ 0 ].TimeBase; TimeSet = TRUE; } trackptr++; tracknum--; } break; default : if ( _MIDI_Funcs->ControlChange ) { _MIDI_Funcs->ControlChange( channel, c1, c2 ); } } return TimeSet; } /*--------------------------------------------------------------------- Function: _MIDI_ServiceRoutine Task that interperates the MIDI data. ---------------------------------------------------------------------*/ // NOTE: We have to use a stack frame here because of a strange bug // that occurs with Watcom. This means that we cannot access Task! //Turned off to test if it works with Watcom 10a //#pragma aux _MIDI_ServiceRoutine frame; /* static void test ( task *Task ) { _MIDI_ServiceRoutine( Task ); _MIDI_ServiceRoutine( Task ); _MIDI_ServiceRoutine( Task ); _MIDI_ServiceRoutine( Task ); } */ static void _MIDI_ServiceRoutine ( task *Task ) { int event; int channel; int command; track *Track; int tracknum; int status; int c1; int c2; int TimeSet = FALSE; if ( !_MIDI_SongActive ) { return; } 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(); } /*--------------------------------------------------------------------- Function: _MIDI_SendControlChange Sends a control change to the proper device ---------------------------------------------------------------------*/ static int _MIDI_SendControlChange ( int channel, int c1, int c2 ) { int 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 ( int channel, int cdecl ( *function )( int event, int c1, int c2 ) ) { if ( ( channel >= 1 ) && ( channel <= 16 ) ) { _MIDI_RerouteFunctions[ channel - 1 ] = function; } } /*--------------------------------------------------------------------- Function: MIDI_AllNotesOff Sends all notes off commands on all midi channels. ---------------------------------------------------------------------*/ int MIDI_AllNotesOff ( void ) { int 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 ( int channel, int volume ) { int status; int 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 ( int channel, int 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 ) { int 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 ) { int 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. ---------------------------------------------------------------------*/ int MIDI_Reset ( void ) { int channel; long time; unsigned flags; MIDI_AllNotesOff(); flags = DisableInterrupts(); _enable(); time = clock() + CLOCKS_PER_SEC/24; while(clock() < time) ; RestoreInterrupts( flags ); 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. ---------------------------------------------------------------------*/ int MIDI_SetVolume ( int volume ) { int 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. ---------------------------------------------------------------------*/ int MIDI_GetVolume ( void ) { int 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 ( int context ) { if ( ( context > 0 ) && ( context < EMIDI_NUM_CONTEXTS ) ) { _MIDI_Context = context; } } /*--------------------------------------------------------------------- Function: MIDI_GetContext Returns the current song context. ---------------------------------------------------------------------*/ int MIDI_GetContext ( void ) { return _MIDI_Context; } /*--------------------------------------------------------------------- Function: MIDI_SetLoopFlag Sets whether the song should loop when finished or not. ---------------------------------------------------------------------*/ void MIDI_SetLoopFlag ( int loopflag ) { _MIDI_Loop = loopflag; } /*--------------------------------------------------------------------- Function: MIDI_ContinueSong Continues playback of a paused song. ---------------------------------------------------------------------*/ void MIDI_ContinueSong ( void ) { if ( _MIDI_SongLoaded ) { _MIDI_SongActive = TRUE; } } /*--------------------------------------------------------------------- Function: MIDI_PauseSong Pauses playback of the current song. ---------------------------------------------------------------------*/ void MIDI_PauseSong ( void ) { if ( _MIDI_SongLoaded ) { _MIDI_SongActive = FALSE; MIDI_AllNotesOff(); } } /*--------------------------------------------------------------------- Function: MIDI_SongPlaying Returns whether a song is playing or not. ---------------------------------------------------------------------*/ int MIDI_SongPlaying ( void ) { return( _MIDI_SongActive ); } /*--------------------------------------------------------------------- Function: MIDI_SetMidiFuncs Selects the routines that send the MIDI data to the music device. ---------------------------------------------------------------------*/ void MIDI_SetMidiFuncs ( midifuncs *funcs ) { _MIDI_Funcs = funcs; } /*--------------------------------------------------------------------- Function: MIDI_StopSong Stops playback of the currently playing song. ---------------------------------------------------------------------*/ void MIDI_StopSong ( void ) { if ( _MIDI_SongLoaded ) { TS_Terminate( _MIDI_PlayRoutine ); _MIDI_PlayRoutine = NULL; _MIDI_SongActive = FALSE; _MIDI_SongLoaded = FALSE; MIDI_Reset(); _MIDI_ResetTracks(); if ( _MIDI_Funcs->ReleasePatches ) { _MIDI_Funcs->ReleasePatches(); } DPMI_UnlockMemory( _MIDI_TrackPtr, _MIDI_TrackMemSize ); USRHOOKS_FreeMem( _MIDI_TrackPtr ); _MIDI_TrackPtr = NULL; _MIDI_NumTracks = 0; _MIDI_TrackMemSize = 0; _MIDI_TotalTime = 0; _MIDI_TotalTicks = 0; _MIDI_TotalBeats = 0; _MIDI_TotalMeasures = 0; } } /*--------------------------------------------------------------------- Function: MIDI_PlaySong Begins playback of a MIDI song. ---------------------------------------------------------------------*/ int MIDI_PlaySong ( unsigned char *song, int loopflag ) { int numtracks; int format; long headersize; long tracklength; track *CurrentTrack; unsigned char *ptr; int status; if ( _MIDI_SongLoaded ) { MIDI_StopSong(); } _MIDI_Loop = loopflag; if ( _MIDI_Funcs == NULL ) { return( MIDI_NullMidiModule ); } if ( *( unsigned long * )song != MIDI_HEADER_SIGNATURE ) { return( MIDI_InvalidMidiFile ); } song += 4; headersize = _MIDI_ReadNumber( song, 4 ); song += 4; format = _MIDI_ReadNumber( song, 2 ); _MIDI_NumTracks = _MIDI_ReadNumber( song + 2, 2 ); _MIDI_Division = _MIDI_ReadNumber( song + 4, 2 ); if ( _MIDI_Division < 0 ) { // If a SMPTE time division is given, just set to 96 so no errors occur _MIDI_Division = 96; } if ( format > MAX_FORMAT ) { return( MIDI_UnknownMidiFormat ); } ptr = song + headersize; if ( _MIDI_NumTracks == 0 ) { return( MIDI_NoTracks ); } _MIDI_TrackMemSize = _MIDI_NumTracks * sizeof( track ); status = USRHOOKS_GetMem( &_MIDI_TrackPtr, _MIDI_TrackMemSize ); if ( status != USRHOOKS_Ok ) { return( MIDI_NoMemory ); } status = DPMI_LockMemory( _MIDI_TrackPtr, _MIDI_TrackMemSize ); if ( status != DPMI_Ok ) { USRHOOKS_FreeMem( _MIDI_TrackPtr ); _MIDI_TrackPtr = NULL; _MIDI_TrackMemSize = 0; _MIDI_NumTracks = 0; // MIDI_SetErrorCode( MIDI_DPMI_Error ); return( MIDI_Error ); } CurrentTrack = _MIDI_TrackPtr; numtracks = _MIDI_NumTracks; while( numtracks-- ) { if ( *( unsigned long * )ptr != MIDI_TRACK_SIGNATURE ) { DPMI_UnlockMemory( _MIDI_TrackPtr, _MIDI_TrackMemSize ); USRHOOKS_FreeMem( _MIDI_TrackPtr ); _MIDI_TrackPtr = NULL; _MIDI_TrackMemSize = 0; return( MIDI_InvalidTrack ); } tracklength = _MIDI_ReadNumber( ptr + 4, 4 ); ptr += 8; CurrentTrack->start = ptr; ptr += tracklength; CurrentTrack++; } if ( _MIDI_Funcs->GetVolume != NULL ) { _MIDI_TotalVolume = _MIDI_Funcs->GetVolume(); } _MIDI_InitEMIDI(); if ( _MIDI_Funcs->LoadPatch ) { MIDI_LoadTimbres(); } _MIDI_ResetTracks(); if ( !Reset ) { MIDI_Reset(); } Reset = FALSE; _MIDI_PlayRoutine = TS_ScheduleTask( _MIDI_ServiceRoutine, 100, 1, NULL ); // _MIDI_PlayRoutine = TS_ScheduleTask( test, 100, 1, NULL ); MIDI_SetTempo( 120 ); TS_Dispatch(); _MIDI_SongLoaded = TRUE; _MIDI_SongActive = TRUE; return( MIDI_Ok ); } /*--------------------------------------------------------------------- Function: MIDI_SetTempo Sets the song tempo. ---------------------------------------------------------------------*/ void MIDI_SetTempo ( int tempo ) { long tickspersecond; MIDI_Tempo = tempo; tickspersecond = ( tempo * _MIDI_Division ) / 60; if ( _MIDI_PlayRoutine != NULL ) { TS_SetTaskRate( _MIDI_PlayRoutine, tickspersecond ); // TS_SetTaskRate( _MIDI_PlayRoutine, tickspersecond / 4 ); } _MIDI_FPSecondsPerTick = ( 1 << TIME_PRECISION ) / tickspersecond; } /*--------------------------------------------------------------------- Function: MIDI_GetTempo Returns the song tempo. ---------------------------------------------------------------------*/ int MIDI_GetTempo ( void ) { return( MIDI_Tempo ); } /*--------------------------------------------------------------------- Function: _MIDI_ProcessNextTick Sets the position of the song pointer. ---------------------------------------------------------------------*/ static int _MIDI_ProcessNextTick ( void ) { int event; int channel; int command; track *Track; int tracknum; int status; int c1; int c2; int TimeSet = FALSE; Track = _MIDI_TrackPtr; tracknum = 0; while( ( tracknum < _MIDI_NumTracks ) && ( Track != NULL ) ) { 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 : break; case MIDI_NOTE_ON : 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, c1 ); } 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 ) { break; } } _MIDI_AdvanceTick(); return( TimeSet ); } /*--------------------------------------------------------------------- Function: MIDI_SetSongTick Sets the position of the song pointer. ---------------------------------------------------------------------*/ void MIDI_SetSongTick ( unsigned long PositionInTicks ) { if ( !_MIDI_SongLoaded ) { return; } MIDI_PauseSong(); if ( PositionInTicks < _MIDI_PositionInTicks ) { _MIDI_ResetTracks(); MIDI_Reset(); } while( _MIDI_PositionInTicks < PositionInTicks ) { if ( _MIDI_ProcessNextTick() ) { break; } if ( _MIDI_ActiveTracks == 0 ) { _MIDI_ResetTracks(); if ( !_MIDI_Loop ) { return; } break; } } MIDI_SetVolume( _MIDI_TotalVolume ); MIDI_ContinueSong(); } /*--------------------------------------------------------------------- Function: MIDI_SetSongTime Sets the position of the song pointer. ---------------------------------------------------------------------*/ void MIDI_SetSongTime ( unsigned long milliseconds ) { unsigned long mil; unsigned long sec; unsigned long newtime; if ( !_MIDI_SongLoaded ) { return; } MIDI_PauseSong(); mil = ( ( milliseconds % 1000 ) << TIME_PRECISION ) / 1000; sec = ( milliseconds / 1000 ) << TIME_PRECISION; newtime = sec + mil; if ( newtime < _MIDI_Time ) { _MIDI_ResetTracks(); MIDI_Reset(); } while( _MIDI_Time < newtime ) { if ( _MIDI_ProcessNextTick() ) { break; } if ( _MIDI_ActiveTracks == 0 ) { _MIDI_ResetTracks(); if ( !_MIDI_Loop ) { return; } break; } } MIDI_SetVolume( _MIDI_TotalVolume ); MIDI_ContinueSong(); } /*--------------------------------------------------------------------- Function: MIDI_SetSongPosition Sets the position of the song pointer. ---------------------------------------------------------------------*/ void MIDI_SetSongPosition ( int measure, int beat, int tick ) { unsigned long pos; if ( !_MIDI_SongLoaded ) { return; } MIDI_PauseSong(); pos = RELATIVE_BEAT( measure, beat, tick ); if ( pos < RELATIVE_BEAT( _MIDI_Measure, _MIDI_Beat, _MIDI_Tick ) ) { _MIDI_ResetTracks(); MIDI_Reset(); } while( RELATIVE_BEAT( _MIDI_Measure, _MIDI_Beat, _MIDI_Tick ) < pos ) { if ( _MIDI_ProcessNextTick() ) { break; } if ( _MIDI_ActiveTracks == 0 ) { _MIDI_ResetTracks(); if ( !_MIDI_Loop ) { return; } break; } } MIDI_SetVolume( _MIDI_TotalVolume ); MIDI_ContinueSong(); } /*--------------------------------------------------------------------- Function: MIDI_GetSongPosition Returns the position of the song pointer in Measures, beats, ticks. ---------------------------------------------------------------------*/ void MIDI_GetSongPosition ( songposition *pos ) { unsigned long mil; unsigned long sec; mil = ( _MIDI_Time & ( ( 1 << TIME_PRECISION ) - 1 ) ) * 1000; sec = _MIDI_Time >> TIME_PRECISION; pos->milliseconds = ( mil >> TIME_PRECISION ) + ( sec * 1000 ); pos->tickposition = _MIDI_PositionInTicks; pos->measure = _MIDI_Measure; pos->beat = _MIDI_Beat; pos->tick = _MIDI_Tick; } /*--------------------------------------------------------------------- Function: MIDI_GetSongLength Returns the length of the song. ---------------------------------------------------------------------*/ void MIDI_GetSongLength ( songposition *pos ) { unsigned long mil; unsigned long sec; mil = ( _MIDI_TotalTime & ( ( 1 << TIME_PRECISION ) - 1 ) ) * 1000; sec = _MIDI_TotalTime >> TIME_PRECISION; pos->milliseconds = ( mil >> TIME_PRECISION ) + ( sec * 1000 ); pos->measure = _MIDI_TotalMeasures; pos->beat = _MIDI_TotalBeats; pos->tick = _MIDI_TotalTicks; pos->tickposition = 0; } /*--------------------------------------------------------------------- Function: MIDI_InitEMIDI Sets up the EMIDI ---------------------------------------------------------------------*/ static void _MIDI_InitEMIDI ( void ) { int event; int command; int channel; int length; int IncludeFound; track *Track; int tracknum; int type; int c1; int c2; type = EMIDI_GeneralMIDI; switch( MUSIC_SoundDevice ) { case SoundBlaster : type = EMIDI_SoundBlaster; break; case ProAudioSpectrum : type = EMIDI_ProAudio; break; case SoundMan16 : type = EMIDI_SoundMan16; break; case Adlib : type = EMIDI_Adlib; break; case GenMidi : type = EMIDI_GeneralMIDI; break; case SoundCanvas : type = EMIDI_SoundCanvas; break; case Awe32 : type = EMIDI_AWE32; break; case WaveBlaster : type = EMIDI_WaveBlaster; break; case SoundScape : type = EMIDI_Soundscape; break; case UltraSound : type = EMIDI_Ultrasound; break; } _MIDI_ResetTracks(); _MIDI_TotalTime = 0; _MIDI_TotalTicks = 0; _MIDI_TotalBeats = 0; _MIDI_TotalMeasures = 0; Track = _MIDI_TrackPtr; tracknum = 0; while( ( tracknum < _MIDI_NumTracks ) && ( Track != NULL ) ) { _MIDI_Tick = 0; _MIDI_Beat = 1; _MIDI_Measure = 1; _MIDI_Time = 0; _MIDI_BeatsPerMeasure = 4; _MIDI_TicksPerBeat = _MIDI_Division; _MIDI_TimeBase = 4; _MIDI_PositionInTicks = 0; _MIDI_ActiveTracks = 0; _MIDI_Context = -1; Track->RunningStatus = 0; Track->active = TRUE; Track->EMIDI_ProgramChange = FALSE; Track->EMIDI_VolumeChange = FALSE; Track->EMIDI_IncludeTrack = TRUE; memset( Track->context, 0, sizeof( Track->context ) ); while( Track->delay > 0 ) { _MIDI_AdvanceTick(); Track->delay--; } IncludeFound = FALSE; while ( Track->active ) { 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 ); while( Track->delay > 0 ) { _MIDI_AdvanceTick(); Track->delay--; } } 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 ); length = _MIDI_CommandLengths[ command ]; if ( command == MIDI_CONTROL_CHANGE ) { if ( *Track->pos == MIDI_MONO_MODE_ON ) { length++; } GET_NEXT_EVENT( Track, c1 ); GET_NEXT_EVENT( Track, c2 ); length -= 2; switch( c1 ) { case EMIDI_LOOP_START : case EMIDI_SONG_LOOP_START : if ( c2 == 0 ) { Track->context[ 0 ].loopcount = EMIDI_INFINITE; } else { Track->context[ 0 ].loopcount = c2; } Track->context[ 0 ].pos = Track->pos; Track->context[ 0 ].loopstart = Track->pos; Track->context[ 0 ].RunningStatus = Track->RunningStatus; Track->context[ 0 ].time = _MIDI_Time; Track->context[ 0 ].FPSecondsPerTick = _MIDI_FPSecondsPerTick; Track->context[ 0 ].tick = _MIDI_Tick; Track->context[ 0 ].beat = _MIDI_Beat; Track->context[ 0 ].measure = _MIDI_Measure; Track->context[ 0 ].BeatsPerMeasure = _MIDI_BeatsPerMeasure; Track->context[ 0 ].TicksPerBeat = _MIDI_TicksPerBeat; Track->context[ 0 ].TimeBase = _MIDI_TimeBase; break; case EMIDI_LOOP_END : case EMIDI_SONG_LOOP_END : if ( c2 == EMIDI_END_LOOP_VALUE ) { Track->context[ 0 ].loopstart = NULL; Track->context[ 0 ].loopcount = 0; } break; case EMIDI_INCLUDE_TRACK : if ( EMIDI_AffectsCurrentCard( c2, type ) ) { //printf( "Include track %d on card %d\n", tracknum, c2 ); IncludeFound = TRUE; Track->EMIDI_IncludeTrack = TRUE; } else if ( !IncludeFound ) { //printf( "Track excluded %d on card %d\n", tracknum, c2 ); IncludeFound = TRUE; Track->EMIDI_IncludeTrack = FALSE; } break; case EMIDI_EXCLUDE_TRACK : if ( EMIDI_AffectsCurrentCard( c2, type ) ) { //printf( "Exclude track %d on card %d\n", tracknum, c2 ); Track->EMIDI_IncludeTrack = FALSE; } break; case EMIDI_PROGRAM_CHANGE : if ( !Track->EMIDI_ProgramChange ) //printf( "Program change on track %d\n", tracknum ); Track->EMIDI_ProgramChange = TRUE; break; case EMIDI_VOLUME_CHANGE : if ( !Track->EMIDI_VolumeChange ) //printf( "Volume change on track %d\n", tracknum ); Track->EMIDI_VolumeChange = TRUE; break; case EMIDI_CONTEXT_START : if ( ( c2 > 0 ) && ( c2 < EMIDI_NUM_CONTEXTS ) ) { Track->context[ c2 ].pos = Track->pos; Track->context[ c2 ].loopstart = Track->context[ 0 ].loopstart; Track->context[ c2 ].loopcount = Track->context[ 0 ].loopcount; Track->context[ c2 ].RunningStatus = Track->RunningStatus; Track->context[ c2 ].time = _MIDI_Time; Track->context[ c2 ].FPSecondsPerTick = _MIDI_FPSecondsPerTick; Track->context[ c2 ].tick = _MIDI_Tick; Track->context[ c2 ].beat = _MIDI_Beat; Track->context[ c2 ].measure = _MIDI_Measure; Track->context[ c2 ].BeatsPerMeasure = _MIDI_BeatsPerMeasure; Track->context[ c2 ].TicksPerBeat = _MIDI_TicksPerBeat; Track->context[ c2 ].TimeBase = _MIDI_TimeBase; } break; case EMIDI_CONTEXT_END : break; } } Track->pos += length; Track->delay = _MIDI_ReadDelta( Track ); while( Track->delay > 0 ) { _MIDI_AdvanceTick(); Track->delay--; } } _MIDI_TotalTime = max( _MIDI_TotalTime, _MIDI_Time ); if ( RELATIVE_BEAT( _MIDI_Measure, _MIDI_Beat, _MIDI_Tick ) > RELATIVE_BEAT( _MIDI_TotalMeasures, _MIDI_TotalBeats, _MIDI_TotalTicks ) ) { _MIDI_TotalTicks = _MIDI_Tick; _MIDI_TotalBeats = _MIDI_Beat; _MIDI_TotalMeasures = _MIDI_Measure; } Track++; tracknum++; } _MIDI_ResetTracks(); } /*--------------------------------------------------------------------- Function: MIDI_LoadTimbres Preloads the timbres on cards that use patch-caching. ---------------------------------------------------------------------*/ void MIDI_LoadTimbres ( void ) { int event; int command; int channel; int length; int Finished; track *Track; int tracknum; Track = _MIDI_TrackPtr; tracknum = 0; while( ( tracknum < _MIDI_NumTracks ) && ( Track != NULL ) ) { Finished = FALSE; while ( !Finished ) { GET_NEXT_EVENT( Track, event ); if ( GET_MIDI_COMMAND( event ) == MIDI_SPECIAL ) { switch( event ) { case MIDI_SYSEX : case MIDI_SYSEX_CONTINUE : length = _MIDI_ReadDelta( Track ); Track->pos += length; break; case MIDI_META_EVENT : GET_NEXT_EVENT( Track, command ); GET_NEXT_EVENT( Track, length ); if ( command == MIDI_END_OF_TRACK ) { Finished = TRUE; } Track->pos += length; break; } if ( !Finished ) { _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 ); length = _MIDI_CommandLengths[ command ]; if ( command == MIDI_CONTROL_CHANGE ) { if ( *Track->pos == MIDI_MONO_MODE_ON ) { length++; } if ( *Track->pos == EMIDI_PROGRAM_CHANGE ) { _MIDI_Funcs->LoadPatch( *( Track->pos + 1 ) ); } } if ( channel == MIDI_RHYTHM_CHANNEL ) { if ( command == MIDI_NOTE_ON ) { _MIDI_Funcs->LoadPatch( 128 + *Track->pos ); } } else { if ( command == MIDI_PROGRAM_CHANGE ) { _MIDI_Funcs->LoadPatch( *Track->pos ); } } Track->pos += length; _MIDI_ReadDelta( Track ); } Track++; tracknum++; } _MIDI_ResetTracks(); } /*--------------------------------------------------------------------- Function: MIDI_LockEnd Used for determining the length of the functions to lock in memory. ---------------------------------------------------------------------*/ static void MIDI_LockEnd ( void ) { } /*--------------------------------------------------------------------- Function: MIDI_UnlockMemory Unlocks all neccessary data. ---------------------------------------------------------------------*/ void MIDI_UnlockMemory ( void ) { DPMI_UnlockMemoryRegion( MIDI_LockStart, MIDI_LockEnd ); DPMI_UnlockMemory( ( void * )&_MIDI_CommandLengths[ 0 ], sizeof( _MIDI_CommandLengths ) ); DPMI_Unlock( _MIDI_TrackPtr ); DPMI_Unlock( _MIDI_NumTracks ); DPMI_Unlock( _MIDI_SongActive ); DPMI_Unlock( _MIDI_SongLoaded ); DPMI_Unlock( _MIDI_Loop ); DPMI_Unlock( _MIDI_PlayRoutine ); DPMI_Unlock( _MIDI_Division ); DPMI_Unlock( _MIDI_ActiveTracks ); DPMI_Unlock( _MIDI_TotalVolume ); DPMI_Unlock( _MIDI_ChannelVolume ); DPMI_Unlock( _MIDI_Funcs ); DPMI_Unlock( _MIDI_PositionInTicks ); DPMI_Unlock( _MIDI_Division ); DPMI_Unlock( _MIDI_Tick ); DPMI_Unlock( _MIDI_Beat ); DPMI_Unlock( _MIDI_Measure ); DPMI_Unlock( _MIDI_Time ); DPMI_Unlock( _MIDI_BeatsPerMeasure ); DPMI_Unlock( _MIDI_TicksPerBeat ); DPMI_Unlock( _MIDI_TimeBase ); DPMI_Unlock( _MIDI_FPSecondsPerTick ); DPMI_Unlock( _MIDI_Context ); DPMI_Unlock( _MIDI_TotalTime ); DPMI_Unlock( _MIDI_TotalTicks ); DPMI_Unlock( _MIDI_TotalBeats ); DPMI_Unlock( _MIDI_TotalMeasures ); DPMI_Unlock( MIDI_Tempo ); } /*--------------------------------------------------------------------- Function: MIDI_LockMemory Locks all neccessary data. ---------------------------------------------------------------------*/ int MIDI_LockMemory ( void ) { int status; status = DPMI_LockMemoryRegion( MIDI_LockStart, MIDI_LockEnd ); status |= DPMI_LockMemory( ( void * )&_MIDI_CommandLengths[ 0 ], sizeof( _MIDI_CommandLengths ) ); status |= DPMI_Lock( _MIDI_TrackPtr ); status |= DPMI_Lock( _MIDI_NumTracks ); status |= DPMI_Lock( _MIDI_SongActive ); status |= DPMI_Lock( _MIDI_SongLoaded ); status |= DPMI_Lock( _MIDI_Loop ); status |= DPMI_Lock( _MIDI_PlayRoutine ); status |= DPMI_Lock( _MIDI_Division ); status |= DPMI_Lock( _MIDI_ActiveTracks ); status |= DPMI_Lock( _MIDI_TotalVolume ); status |= DPMI_Lock( _MIDI_ChannelVolume ); status |= DPMI_Lock( _MIDI_Funcs ); status |= DPMI_Lock( _MIDI_PositionInTicks ); status |= DPMI_Lock( _MIDI_Division ); status |= DPMI_Lock( _MIDI_Tick ); status |= DPMI_Lock( _MIDI_Beat ); status |= DPMI_Lock( _MIDI_Measure ); status |= DPMI_Lock( _MIDI_Time ); status |= DPMI_Lock( _MIDI_BeatsPerMeasure ); status |= DPMI_Lock( _MIDI_TicksPerBeat ); status |= DPMI_Lock( _MIDI_TimeBase ); status |= DPMI_Lock( _MIDI_FPSecondsPerTick ); status |= DPMI_Lock( _MIDI_Context ); status |= DPMI_Lock( _MIDI_TotalTime ); status |= DPMI_Lock( _MIDI_TotalTicks ); status |= DPMI_Lock( _MIDI_TotalBeats ); status |= DPMI_Lock( _MIDI_TotalMeasures ); status |= DPMI_Lock( MIDI_Tempo ); if ( status != DPMI_Ok ) { MIDI_UnlockMemory(); // MIDI_SetErrorCode( MIDI_DPMI_Error ); return( MIDI_Error ); } return( MIDI_Ok ); }