ref: c887c9804b07ffc2d56fc4ab31ed1aa1486fd5c4
dir: /src/i_oplmusic.c/
// Emacs style mode select -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005 Simon Howard
//
// 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.
//
// DESCRIPTION:
// System interface for music.
//
//-----------------------------------------------------------------------------
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "doomdef.h"
#include "memio.h"
#include "mus2mid.h"
#include "deh_main.h"
#include "m_misc.h"
#include "s_sound.h"
#include "w_wad.h"
#include "z_zone.h"
#include "opl.h"
#include "midifile.h"
//#define TEST
#define MAXMIDLENGTH (96 * 1024)
#define GENMIDI_NUM_INSTRS 128
#define GENMIDI_HEADER "#OPL_II#"
#define GENMIDI_FLAG_FIXED 0x0001 /* fixed pitch */
#define GENMIDI_FLAG_2VOICE 0x0002 /* double voice (OPL3) */
typedef struct
{
byte tremolo;
byte attack;
byte sustain;
byte waveform;
byte scale;
byte level;
} PACKEDATTR genmidi_op_t;
typedef struct
{
genmidi_op_t modulator;
byte feedback;
genmidi_op_t carrier;
byte unused;
short base_note_offset;
} PACKEDATTR genmidi_voice_t;
typedef struct
{
unsigned short flags;
byte fine_tuning;
byte fixed_note;
genmidi_voice_t opl2_voice;
genmidi_voice_t opl3_voice;
} PACKEDATTR genmidi_instr_t;
// Data associated with a channel of a track that is currently playing.
typedef struct
{
// The instrument currently used for this track.
genmidi_instr_t *instrument;
// Volume level
int volume;
} opl_channel_data_t;
// Data associated with a track that is currently playing.
typedef struct
{
// Data for each channel.
opl_channel_data_t channels[MIDI_CHANNELS_PER_TRACK];
// Track iterator used to read new events.
midi_track_iter_t *iter;
// Tempo control variables
unsigned int ticks_per_beat;
unsigned int ms_per_beat;
} opl_track_data_t;
typedef struct opl_voice_s opl_voice_t;
struct opl_voice_s
{
// Index of this voice:
int index;
// The operators used by this voice:
int op1, op2;
// Currently-loaded instrument data
genmidi_instr_t *current_instr;
// The channel currently using this voice.
opl_channel_data_t *channel;
// The note that this voice is playing.
unsigned int note;
// The frequency value being used.
unsigned int freq;
// Next in freelist
opl_voice_t *next;
};
// Operators used by the different voices.
static const int voice_operators[2][OPL_NUM_VOICES] = {
{ 0x00, 0x01, 0x02, 0x08, 0x09, 0x0a, 0x10, 0x11, 0x12 },
{ 0x03, 0x04, 0x05, 0x0b, 0x0c, 0x0d, 0x13, 0x14, 0x15 }
};
// Frequency values to use for each note.
static const unsigned int note_frequencies[] = {
// These frequencies are only used for the first seven
// MIDI note values:
0x158, 0x16d, 0x183, 0x19a, 0x1b2, 0x1cc, 0x1e7,
// These frequencies are used repeatedly, cycling around
// for each octave:
0x204, 0x223, 0x244, 0x266, 0x28b, 0x2b1,
0x2da, 0x306, 0x334, 0x365, 0x398, 0x3cf,
};
// Mapping from MIDI volume level to OPL level value.
static const unsigned int volume_mapping_table[] = {
0x3f, 0x3f, 0x3e, 0x3d, 0x3c, 0x3b, 0x3a, 0x3a,
0x39, 0x38, 0x37, 0x37, 0x36, 0x35, 0x34, 0x34,
0x33, 0x32, 0x32, 0x31, 0x30, 0x2f, 0x2f, 0x2e,
0x2d, 0x2d, 0x2c, 0x2b, 0x2a, 0x29, 0x28, 0x27,
0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x22, 0x21,
0x20, 0x20, 0x1f, 0x1e, 0x1e, 0x1d, 0x1c, 0x1c,
0x1b, 0x1b, 0x1a, 0x1a, 0x19, 0x18, 0x18, 0x17,
0x17, 0x16, 0x16, 0x16, 0x16, 0x15, 0x15, 0x14,
0x14, 0x13, 0x13, 0x12, 0x12, 0x12, 0x11, 0x11,
0x10, 0x10, 0x10, 0x0f, 0x0f, 0x0f, 0x0e, 0x0e,
0x0e, 0x0d, 0x0d, 0x0d, 0x0c, 0x0c, 0x0c, 0x0b,
0x0b, 0x0b, 0x0a, 0x0a, 0x0a, 0x09, 0x09, 0x09,
0x08, 0x08, 0x08, 0x08, 0x07, 0x07, 0x07, 0x07,
0x06, 0x06, 0x06, 0x05, 0x05, 0x05, 0x05, 0x04,
0x04, 0x04, 0x04, 0x03, 0x03, 0x03, 0x03, 0x03,
0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
};
static boolean music_initialised = false;
//static boolean musicpaused = false;
static int current_music_volume;
// GENMIDI lump instrument data:
static genmidi_instr_t *main_instrs;
static genmidi_instr_t *percussion_instrs;
// Voices:
static opl_voice_t voices[OPL_NUM_VOICES];
static opl_voice_t *voice_free_list;
// Track data for playing tracks:
static opl_track_data_t *tracks;
// In the initialisation stage, register writes are spaced by reading
// from the register port (0). After initialisation, spacing is
// peformed by reading from the data port instead. I have no idea
// why.
static boolean init_stage_reg_writes = false;
// Configuration file variable, containing the port number for the
// adlib chip.
int snd_mport = 0x388;
static unsigned int GetStatus(void)
{
return OPL_ReadPort(OPL_REGISTER_PORT);
}
// Write an OPL register value
static void WriteRegister(int reg, int value)
{
int i;
OPL_WritePort(OPL_REGISTER_PORT, reg);
// For timing, read the register port six times after writing the
// register number to cause the appropriate delay
for (i=0; i<6; ++i)
{
// An oddity of the Doom OPL code: at startup initialisation,
// the spacing here is performed by reading from the register
// port; after initialisation, the data port is read, instead.
if (init_stage_reg_writes)
{
OPL_ReadPort(OPL_REGISTER_PORT);
}
else
{
OPL_ReadPort(OPL_DATA_PORT);
}
}
OPL_WritePort(OPL_DATA_PORT, value);
// Read the register port 25 times after writing the value to
// cause the appropriate delay
for (i=0; i<24; ++i)
{
GetStatus();
}
}
// Detect the presence of an OPL chip
static boolean DetectOPL(void)
{
int result1, result2;
int i;
// Reset both timers:
WriteRegister(OPL_REG_TIMER_CTRL, 0x60);
// Enable interrupts:
WriteRegister(OPL_REG_TIMER_CTRL, 0x80);
// Read status
result1 = GetStatus();
// Set timer:
WriteRegister(OPL_REG_TIMER1, 0xff);
// Start timer 1:
WriteRegister(OPL_REG_TIMER_CTRL, 0x21);
// Wait for 80 microseconds
// This is how Doom does it:
for (i=0; i<200; ++i)
{
GetStatus();
}
OPL_Delay(1);
// Read status
result2 = GetStatus();
// Reset both timers:
WriteRegister(OPL_REG_TIMER_CTRL, 0x60);
// Enable interrupts:
WriteRegister(OPL_REG_TIMER_CTRL, 0x80);
return (result1 & 0xe0) == 0x00
&& (result2 & 0xe0) == 0xc0;
}
// Initialise registers on startup
static void InitRegisters(void)
{
int r;
// Initialise level registers
for (r=OPL_REGS_LEVEL; r <= OPL_REGS_LEVEL + OPL_NUM_OPERATORS; ++r)
{
WriteRegister(r, 0x3f);
}
// Initialise other registers
// These two loops write to registers that actually don't exist,
// but this is what Doom does ...
// Similarly, the <= is also intenational.
for (r=OPL_REGS_ATTACK; r <= OPL_REGS_WAVEFORM + OPL_NUM_OPERATORS; ++r)
{
WriteRegister(r, 0x00);
}
// More registers ...
for (r=1; r < OPL_REGS_LEVEL; ++r)
{
WriteRegister(r, 0x00);
}
// Re-initialise the low registers:
// Reset both timers and enable interrupts:
WriteRegister(OPL_REG_TIMER_CTRL, 0x60);
WriteRegister(OPL_REG_TIMER_CTRL, 0x80);
// "Allow FM chips to control the waveform of each operator":
WriteRegister(OPL_REG_WAVEFORM_ENABLE, 0x20);
// Keyboard split point on (?)
WriteRegister(OPL_REG_FM_MODE, 0x40);
}
// Load instrument table from GENMIDI lump:
static boolean LoadInstrumentTable(void)
{
byte *lump;
lump = W_CacheLumpName("GENMIDI", PU_STATIC);
// Check header
if (strncmp((char *) lump, GENMIDI_HEADER, strlen(GENMIDI_HEADER)) != 0)
{
W_ReleaseLumpName("GENMIDI");
return false;
}
main_instrs = (genmidi_instr_t *) (lump + strlen(GENMIDI_HEADER));
percussion_instrs = main_instrs + GENMIDI_NUM_INSTRS;
return true;
}
// Get the next available voice from the freelist.
static opl_voice_t *GetFreeVoice(void)
{
opl_voice_t *result;
// None available?
if (voice_free_list == NULL)
{
return NULL;
}
result = voice_free_list;
voice_free_list = voice_free_list->next;
return result;
}
// Release a voice back to the freelist.
static void ReleaseVoice(opl_voice_t *voice)
{
opl_voice_t **rover;
voice->channel = NULL;
voice->note = 0;
// Search to the end of the freelist (This is how Doom behaves!)
rover = &voice_free_list;
while (*rover != NULL)
{
rover = &(*rover)->next;
}
*rover = voice;
voice->next = NULL;
}
// Load data to the specified operator
static void LoadOperatorData(int operator, genmidi_op_t *data,
boolean max_level)
{
int level;
// The scale and level fields must be combined for the level register.
// For the carrier wave we always set the maximum level.
level = (data->scale & 0xc0) | (data->level & 0x3f);
if (max_level)
{
level |= 0x3f;
}
WriteRegister(OPL_REGS_LEVEL + operator, level);
WriteRegister(OPL_REGS_TREMOLO + operator, data->tremolo);
WriteRegister(OPL_REGS_ATTACK + operator, data->attack);
WriteRegister(OPL_REGS_SUSTAIN + operator, data->sustain);
WriteRegister(OPL_REGS_WAVEFORM + operator, data->waveform);
}
// Set the instrument for a particular voice.
static void SetVoiceInstrument(opl_voice_t *voice, genmidi_voice_t *data)
{
// Doom loads the second operator first, then the first.
LoadOperatorData(voice->op2, &data->carrier, true);
LoadOperatorData(voice->op1, &data->modulator, false);
// Set feedback register that control the connection between the
// two operators. Turn on bits in the upper nybble; I think this
// is for OPL3, where it turns on channel A/B.
WriteRegister(OPL_REGS_FEEDBACK + voice->index,
data->feedback | 0x30);
}
// Initialise the voice table and freelist
static void InitVoices(void)
{
int i;
// Start with an empty free list.
voice_free_list = NULL;
// Initialise each voice.
for (i=0; i<OPL_NUM_VOICES; ++i)
{
voices[i].index = i;
voices[i].op1 = voice_operators[0][i];
voices[i].op2 = voice_operators[1][i];
voices[i].current_instr = NULL;
// Add this voice to the freelist.
ReleaseVoice(&voices[i]);
}
}
// Shutdown music
static void I_OPL_ShutdownMusic(void)
{
if (music_initialised)
{
#ifdef TEST
InitRegisters();
#endif
OPL_Shutdown();
// Release GENMIDI lump
W_ReleaseLumpName("GENMIDI");
music_initialised = false;
}
}
#ifdef TEST
static void TestCallback(void *arg)
{
opl_voice_t *voice = arg;
int note;
int wait_time;
// Set level:
WriteRegister(OPL_REGS_LEVEL + voice->op2, 0);
// Note off:
WriteRegister(OPL_REGS_FREQ_2 + voice->index, 0x00);
// Note on:
note = (rand() % (0x2ae - 0x16b)) + 0x16b;
WriteRegister(OPL_REGS_FREQ_1 + voice->index, note & 0xff);
WriteRegister(OPL_REGS_FREQ_2 + voice->index, 0x30 + (note >> 8));
wait_time = (rand() % 700) + 50;
OPL_SetCallback(wait_time, TestCallback, arg);
}
#endif
// Initialise music subsystem
static boolean I_OPL_InitMusic(void)
{
if (!OPL_Init(snd_mport))
{
return false;
}
init_stage_reg_writes = true;
// Doom does the detection sequence twice, for some reason:
if (!DetectOPL() || !DetectOPL())
{
printf("Dude. The Adlib isn't responding.\n");
OPL_Shutdown();
return false;
}
// Load instruments from GENMIDI lump:
if (!LoadInstrumentTable())
{
OPL_Shutdown();
return false;
}
InitRegisters();
InitVoices();
// Now that initialisation has finished, switch the
// register writing mode:
init_stage_reg_writes = false;
#ifdef TEST
{
int i;
opl_voice_t *voice;
int instr_num;
for (i=0; i<3; ++i)
{
voice = GetFreeVoice();
instr_num = rand() % 100;
SetVoiceInstrument(voice, &main_instrs[instr_num].opl2_voice);
OPL_SetCallback(0, TestCallback, voice);
}
}
#endif
music_initialised = true;
return true;
}
// Set music volume (0 - 127)
static void I_OPL_SetMusicVolume(int volume)
{
// Internal state variable.
current_music_volume = volume;
}
static opl_voice_t *FindVoiceForNote(opl_channel_data_t *channel, int note)
{
unsigned int i;
for (i=0; i<OPL_NUM_VOICES; ++i)
{
if (voices[i].channel == channel && voices[i].note == note)
{
return &voices[i];
}
}
return NULL;
}
static void VoiceNoteOff(opl_voice_t *voice)
{
WriteRegister(OPL_REGS_FREQ_2 + voice->index, voice->freq >> 8);
}
static void NoteOffEvent(opl_track_data_t *track, midi_event_t *event)
{
opl_voice_t *voice;
opl_channel_data_t *channel;
printf("note off: channel %i, %i, %i\n",
event->data.channel.channel,
event->data.channel.param1,
event->data.channel.param2);
channel = &track->channels[event->data.channel.channel];
// Find the voice being used to play the note.
voice = FindVoiceForNote(channel, event->data.channel.param1);
if (voice == NULL)
{
return;
}
VoiceNoteOff(voice);
// Finished with this voice now.
ReleaseVoice(voice);
}
// Given a MIDI note number, get the corresponding OPL
// frequency value to use.
static unsigned int FrequencyForNote(unsigned int note)
{
unsigned int octave;
unsigned int key_num;
// The first seven frequencies in the frequencies array are used
// only for the first seven MIDI notes. After this, the frequency
// value loops around the same twelve notes, increasing the
// octave.
if (note < 7)
{
return note_frequencies[note];
}
else
{
octave = (note - 7) / 12;
key_num = (note - 7) % 12;
return note_frequencies[key_num + 7] | (octave << 10);
}
}
static void NoteOnEvent(opl_track_data_t *track, midi_event_t *event)
{
genmidi_instr_t *instrument;
opl_voice_t *voice;
opl_channel_data_t *channel;
unsigned int note;
unsigned int volume;
printf("note on: channel %i, %i, %i\n",
event->data.channel.channel,
event->data.channel.param1,
event->data.channel.param2);
// The channel.
channel = &track->channels[event->data.channel.channel];
note = event->data.channel.param1;
volume = event->data.channel.param2;
// Percussion channel (10) is treated differently to normal notes.
if (event->data.channel.channel == 9)
{
if (note < 35 || note > 81)
{
return;
}
instrument = &percussion_instrs[note - 35];
}
else
{
instrument = channel->instrument;
}
// Find a voice to use for this new note.
voice = GetFreeVoice();
if (voice == NULL)
{
return;
}
voice->channel = channel;
voice->note = note;
// Program the voice with the instrument data:
SetVoiceInstrument(voice, &instrument->opl2_voice);
// TODO: Set the volume level.
WriteRegister(OPL_REGS_LEVEL + voice->op2,
volume_mapping_table[volume]);
// Fixed pitch?
if ((instrument->flags & GENMIDI_FLAG_FIXED) != 0)
{
note = instrument->fixed_note;
}
// Write the frequency value to turn the note on.
voice->freq = FrequencyForNote(note);
WriteRegister(OPL_REGS_FREQ_1 + voice->index, voice->freq & 0xff);
WriteRegister(OPL_REGS_FREQ_2 + voice->index, (voice->freq >> 8) | 0x20);
}
static void ProgramChangeEvent(opl_track_data_t *track, midi_event_t *event)
{
int channel;
int instrument;
// Set the instrument used on this channel.
channel = event->data.channel.channel;
instrument = event->data.channel.param1;
track->channels[channel].instrument = &main_instrs[instrument];
// TODO: Look through existing voices that are turned on on this
// channel, and change the instrument.
}
static void ControllerEvent(opl_track_data_t *track, midi_event_t *event)
{
unsigned int controller;
unsigned int param;
opl_channel_data_t *channel;
printf("change controller: channel %i, %i, %i\n",
event->data.channel.channel,
event->data.channel.param1,
event->data.channel.param2);
channel = &track->channels[event->data.channel.channel];
controller = event->data.channel.param1;
param = event->data.channel.param2;
switch (controller)
{
case MIDI_CONTROLLER_MAIN_VOLUME:
channel->volume = param;
break;
case MIDI_CONTROLLER_PAN:
break;
default:
fprintf(stderr, "Unknown MIDI controller type: %i\n", controller);
break;
}
}
// Process a MIDI event from a track.
static void ProcessEvent(opl_track_data_t *track, midi_event_t *event)
{
switch (event->event_type)
{
case MIDI_EVENT_NOTE_OFF:
NoteOffEvent(track, event);
break;
case MIDI_EVENT_NOTE_ON:
NoteOnEvent(track, event);
break;
case MIDI_EVENT_CONTROLLER:
ControllerEvent(track, event);
break;
case MIDI_EVENT_PROGRAM_CHANGE:
ProgramChangeEvent(track, event);
break;
default:
fprintf(stderr, "Unknown MIDI event type %i\n", event->event_type);
break;
}
}
static void ScheduleTrack(opl_track_data_t *track);
// Callback function invoked when another event needs to be read from
// a track.
static void TrackTimerCallback(void *arg)
{
opl_track_data_t *track = arg;
midi_event_t *event;
// Get the next event and process it.
if (!MIDI_GetNextEvent(track->iter, &event))
{
return;
}
ProcessEvent(track, event);
// Reschedule the callback for the next event in the track.
ScheduleTrack(track);
}
static void ScheduleTrack(opl_track_data_t *track)
{
unsigned int nticks;
unsigned int ms;
static int total = 0;
// Get the number of milliseconds until the next event.
nticks = MIDI_GetDeltaTime(track->iter);
ms = (nticks * track->ms_per_beat) / track->ticks_per_beat;
total += ms;
// Set a timer to be invoked when the next event is
// ready to play.
OPL_SetCallback(ms, TrackTimerCallback, track);
}
// Initialise a channel.
static void InitChannel(opl_track_data_t *track, opl_channel_data_t *channel)
{
// TODO: Work out sensible defaults?
channel->instrument = &main_instrs[0];
channel->volume = 127;
}
// Start a MIDI track playing:
static void StartTrack(midi_file_t *file, unsigned int track_num)
{
opl_track_data_t *track;
unsigned int i;
track = &tracks[track_num];
track->iter = MIDI_IterateTrack(file, track_num);
track->ticks_per_beat = MIDI_GetFileTimeDivision(file);
// Default is 120 bpm.
// TODO: this is wrong
track->ms_per_beat = 500 * 260;
for (i=0; i<MIDI_CHANNELS_PER_TRACK; ++i)
{
InitChannel(track, &track->channels[i]);
}
// Schedule the first event.
ScheduleTrack(track);
}
// Start playing a mid
static void I_OPL_PlaySong(void *handle, int looping)
{
midi_file_t *file;
unsigned int i;
if (!music_initialised || handle == NULL)
{
return;
}
file = handle;
// Allocate track data.
tracks = malloc(MIDI_NumTracks(file) * sizeof(opl_track_data_t));
for (i=0; i<MIDI_NumTracks(file); ++i)
{
StartTrack(file, i);
}
}
static void I_OPL_PauseSong(void)
{
if (!music_initialised)
{
return;
}
}
static void I_OPL_ResumeSong(void)
{
if (!music_initialised)
{
return;
}
}
static void I_OPL_StopSong(void)
{
unsigned int i;
if (!music_initialised)
{
return;
}
// Stop all playback.
OPL_ClearCallbacks();
// Free all voices.
for (i=0; i<OPL_NUM_VOICES; ++i)
{
if (voices[i].channel != NULL)
{
VoiceNoteOff(&voices[i]);
ReleaseVoice(&voices[i]);
}
}
}
static void I_OPL_UnRegisterSong(void *handle)
{
if (!music_initialised)
{
return;
}
if (handle != NULL)
{
MIDI_FreeFile(handle);
}
}
// Determine whether memory block is a .mid file
static boolean IsMid(byte *mem, int len)
{
return len > 4 && !memcmp(mem, "MThd", 4);
}
static boolean ConvertMus(byte *musdata, int len, char *filename)
{
MEMFILE *instream;
MEMFILE *outstream;
void *outbuf;
size_t outbuf_len;
int result;
instream = mem_fopen_read(musdata, len);
outstream = mem_fopen_write();
result = mus2mid(instream, outstream);
if (result == 0)
{
mem_get_buf(outstream, &outbuf, &outbuf_len);
M_WriteFile(filename, outbuf, outbuf_len);
}
mem_fclose(instream);
mem_fclose(outstream);
return result;
}
static void *I_OPL_RegisterSong(void *data, int len)
{
midi_file_t *result;
char *filename;
if (!music_initialised)
{
return NULL;
}
// MUS files begin with "MUS"
// Reject anything which doesnt have this signature
filename = M_TempFile("doom.mid");
if (IsMid(data, len) && len < MAXMIDLENGTH)
{
M_WriteFile(filename, data, len);
}
else
{
// Assume a MUS file and try to convert
ConvertMus(data, len, filename);
}
result = MIDI_LoadFile(filename);
if (result == NULL)
{
fprintf(stderr, "I_OPL_RegisterSong: Failed to load MID.\n");
}
// remove file now
remove(filename);
Z_Free(filename);
return result;
}
// Is the song playing?
static boolean I_OPL_MusicIsPlaying(void)
{
if (!music_initialised)
{
return false;
}
return false;
}
static snddevice_t music_opl_devices[] =
{
SNDDEVICE_ADLIB,
SNDDEVICE_SB,
};
music_module_t music_opl_module =
{
music_opl_devices,
arrlen(music_opl_devices),
I_OPL_InitMusic,
I_OPL_ShutdownMusic,
I_OPL_SetMusicVolume,
I_OPL_PauseSong,
I_OPL_ResumeSong,
I_OPL_RegisterSong,
I_OPL_UnRegisterSong,
I_OPL_PlaySong,
I_OPL_StopSong,
I_OPL_MusicIsPlaying,
};