ref: f894f24bcd63dc8b2a0604a9b659dd95aebbb384
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 "i_swap.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 0x0004 /* 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 voices[2];
} 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;
// Pitch bend value:
int bend;
} 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 voice number in the instrument to use.
// This is normally set to zero; if this is a double voice
// instrument, it may be one.
unsigned int current_instr_voice;
// The channel currently using this voice.
opl_channel_data_t *channel;
// The midi key that this voice is playing.
unsigned int key;
// The note being played. This is normally the same as
// the key, but if the instrument is a fixed pitch
// instrument, it is different.
unsigned int note;
// The frequency value being used.
unsigned int freq;
// The volume of the note being played on this channel.
unsigned int note_volume;
// The current volume (register value) that has been set for this channel.
unsigned int reg_volume;
// Next in linked list; a voice is always either in the
// free list or the allocated list.
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 short frequency_curve[] = {
0x133, 0x133, 0x134, 0x134, 0x135, 0x136, 0x136, 0x137, // -1
0x137, 0x138, 0x138, 0x139, 0x139, 0x13a, 0x13b, 0x13b,
0x13c, 0x13c, 0x13d, 0x13d, 0x13e, 0x13f, 0x13f, 0x140,
0x140, 0x141, 0x142, 0x142, 0x143, 0x143, 0x144, 0x144,
0x145, 0x146, 0x146, 0x147, 0x147, 0x148, 0x149, 0x149, // -2
0x14a, 0x14a, 0x14b, 0x14c, 0x14c, 0x14d, 0x14d, 0x14e,
0x14f, 0x14f, 0x150, 0x150, 0x151, 0x152, 0x152, 0x153,
0x153, 0x154, 0x155, 0x155, 0x156, 0x157, 0x157, 0x158,
// These are used for the first seven MIDI note values:
0x158, 0x159, 0x15a, 0x15a, 0x15b, 0x15b, 0x15c, 0x15d, // 0
0x15d, 0x15e, 0x15f, 0x15f, 0x160, 0x161, 0x161, 0x162,
0x162, 0x163, 0x164, 0x164, 0x165, 0x166, 0x166, 0x167,
0x168, 0x168, 0x169, 0x16a, 0x16a, 0x16b, 0x16c, 0x16c,
0x16d, 0x16e, 0x16e, 0x16f, 0x170, 0x170, 0x171, 0x172, // 1
0x172, 0x173, 0x174, 0x174, 0x175, 0x176, 0x176, 0x177,
0x178, 0x178, 0x179, 0x17a, 0x17a, 0x17b, 0x17c, 0x17c,
0x17d, 0x17e, 0x17e, 0x17f, 0x180, 0x181, 0x181, 0x182,
0x183, 0x183, 0x184, 0x185, 0x185, 0x186, 0x187, 0x188, // 2
0x188, 0x189, 0x18a, 0x18a, 0x18b, 0x18c, 0x18d, 0x18d,
0x18e, 0x18f, 0x18f, 0x190, 0x191, 0x192, 0x192, 0x193,
0x194, 0x194, 0x195, 0x196, 0x197, 0x197, 0x198, 0x199,
0x19a, 0x19a, 0x19b, 0x19c, 0x19d, 0x19d, 0x19e, 0x19f, // 3
0x1a0, 0x1a0, 0x1a1, 0x1a2, 0x1a3, 0x1a3, 0x1a4, 0x1a5,
0x1a6, 0x1a6, 0x1a7, 0x1a8, 0x1a9, 0x1a9, 0x1aa, 0x1ab,
0x1ac, 0x1ad, 0x1ad, 0x1ae, 0x1af, 0x1b0, 0x1b0, 0x1b1,
0x1b2, 0x1b3, 0x1b4, 0x1b4, 0x1b5, 0x1b6, 0x1b7, 0x1b8, // 4
0x1b8, 0x1b9, 0x1ba, 0x1bb, 0x1bc, 0x1bc, 0x1bd, 0x1be,
0x1bf, 0x1c0, 0x1c0, 0x1c1, 0x1c2, 0x1c3, 0x1c4, 0x1c4,
0x1c5, 0x1c6, 0x1c7, 0x1c8, 0x1c9, 0x1c9, 0x1ca, 0x1cb,
0x1cc, 0x1cd, 0x1ce, 0x1ce, 0x1cf, 0x1d0, 0x1d1, 0x1d2, // 5
0x1d3, 0x1d3, 0x1d4, 0x1d5, 0x1d6, 0x1d7, 0x1d8, 0x1d8,
0x1d9, 0x1da, 0x1db, 0x1dc, 0x1dd, 0x1de, 0x1de, 0x1df,
0x1e0, 0x1e1, 0x1e2, 0x1e3, 0x1e4, 0x1e5, 0x1e5, 0x1e6,
0x1e7, 0x1e8, 0x1e9, 0x1ea, 0x1eb, 0x1ec, 0x1ed, 0x1ed, // 6
0x1ee, 0x1ef, 0x1f0, 0x1f1, 0x1f2, 0x1f3, 0x1f4, 0x1f5,
0x1f6, 0x1f6, 0x1f7, 0x1f8, 0x1f9, 0x1fa, 0x1fb, 0x1fc,
0x1fd, 0x1fe, 0x1ff, 0x200, 0x201, 0x201, 0x202, 0x203,
// First note of looped range used for all octaves:
0x204, 0x205, 0x206, 0x207, 0x208, 0x209, 0x20a, 0x20b, // 7
0x20c, 0x20d, 0x20e, 0x20f, 0x210, 0x210, 0x211, 0x212,
0x213, 0x214, 0x215, 0x216, 0x217, 0x218, 0x219, 0x21a,
0x21b, 0x21c, 0x21d, 0x21e, 0x21f, 0x220, 0x221, 0x222,
0x223, 0x224, 0x225, 0x226, 0x227, 0x228, 0x229, 0x22a, // 8
0x22b, 0x22c, 0x22d, 0x22e, 0x22f, 0x230, 0x231, 0x232,
0x233, 0x234, 0x235, 0x236, 0x237, 0x238, 0x239, 0x23a,
0x23b, 0x23c, 0x23d, 0x23e, 0x23f, 0x240, 0x241, 0x242,
0x244, 0x245, 0x246, 0x247, 0x248, 0x249, 0x24a, 0x24b, // 9
0x24c, 0x24d, 0x24e, 0x24f, 0x250, 0x251, 0x252, 0x253,
0x254, 0x256, 0x257, 0x258, 0x259, 0x25a, 0x25b, 0x25c,
0x25d, 0x25e, 0x25f, 0x260, 0x262, 0x263, 0x264, 0x265,
0x266, 0x267, 0x268, 0x269, 0x26a, 0x26c, 0x26d, 0x26e, // 10
0x26f, 0x270, 0x271, 0x272, 0x273, 0x275, 0x276, 0x277,
0x278, 0x279, 0x27a, 0x27b, 0x27d, 0x27e, 0x27f, 0x280,
0x281, 0x282, 0x284, 0x285, 0x286, 0x287, 0x288, 0x289,
0x28b, 0x28c, 0x28d, 0x28e, 0x28f, 0x290, 0x292, 0x293, // 11
0x294, 0x295, 0x296, 0x298, 0x299, 0x29a, 0x29b, 0x29c,
0x29e, 0x29f, 0x2a0, 0x2a1, 0x2a2, 0x2a4, 0x2a5, 0x2a6,
0x2a7, 0x2a9, 0x2aa, 0x2ab, 0x2ac, 0x2ae, 0x2af, 0x2b0,
0x2b1, 0x2b2, 0x2b4, 0x2b5, 0x2b6, 0x2b7, 0x2b9, 0x2ba, // 12
0x2bb, 0x2bd, 0x2be, 0x2bf, 0x2c0, 0x2c2, 0x2c3, 0x2c4,
0x2c5, 0x2c7, 0x2c8, 0x2c9, 0x2cb, 0x2cc, 0x2cd, 0x2ce,
0x2d0, 0x2d1, 0x2d2, 0x2d4, 0x2d5, 0x2d6, 0x2d8, 0x2d9,
0x2da, 0x2dc, 0x2dd, 0x2de, 0x2e0, 0x2e1, 0x2e2, 0x2e4, // 13
0x2e5, 0x2e6, 0x2e8, 0x2e9, 0x2ea, 0x2ec, 0x2ed, 0x2ee,
0x2f0, 0x2f1, 0x2f2, 0x2f4, 0x2f5, 0x2f6, 0x2f8, 0x2f9,
0x2fb, 0x2fc, 0x2fd, 0x2ff, 0x300, 0x302, 0x303, 0x304,
0x306, 0x307, 0x309, 0x30a, 0x30b, 0x30d, 0x30e, 0x310, // 14
0x311, 0x312, 0x314, 0x315, 0x317, 0x318, 0x31a, 0x31b,
0x31c, 0x31e, 0x31f, 0x321, 0x322, 0x324, 0x325, 0x327,
0x328, 0x329, 0x32b, 0x32c, 0x32e, 0x32f, 0x331, 0x332,
0x334, 0x335, 0x337, 0x338, 0x33a, 0x33b, 0x33d, 0x33e, // 15
0x340, 0x341, 0x343, 0x344, 0x346, 0x347, 0x349, 0x34a,
0x34c, 0x34d, 0x34f, 0x350, 0x352, 0x353, 0x355, 0x357,
0x358, 0x35a, 0x35b, 0x35d, 0x35e, 0x360, 0x361, 0x363,
0x365, 0x366, 0x368, 0x369, 0x36b, 0x36c, 0x36e, 0x370, // 16
0x371, 0x373, 0x374, 0x376, 0x378, 0x379, 0x37b, 0x37c,
0x37e, 0x380, 0x381, 0x383, 0x384, 0x386, 0x388, 0x389,
0x38b, 0x38d, 0x38e, 0x390, 0x392, 0x393, 0x395, 0x397,
0x398, 0x39a, 0x39c, 0x39d, 0x39f, 0x3a1, 0x3a2, 0x3a4, // 17
0x3a6, 0x3a7, 0x3a9, 0x3ab, 0x3ac, 0x3ae, 0x3b0, 0x3b1,
0x3b3, 0x3b5, 0x3b7, 0x3b8, 0x3ba, 0x3bc, 0x3bd, 0x3bf,
0x3c1, 0x3c3, 0x3c4, 0x3c6, 0x3c8, 0x3ca, 0x3cb, 0x3cd,
// The last note has an incomplete range, and loops round back to
// the start. Note that the last value is actually a buffer overrun
// and does not fit with the other values.
0x3cf, 0x3d1, 0x3d2, 0x3d4, 0x3d6, 0x3d8, 0x3da, 0x3db, // 18
0x3dd, 0x3df, 0x3e1, 0x3e3, 0x3e4, 0x3e6, 0x3e8, 0x3ea,
0x3ec, 0x3ed, 0x3ef, 0x3f1, 0x3f3, 0x3f5, 0x3f6, 0x3f8,
0x3fa, 0x3fc, 0x3fe, 0x36c,
};
// Mapping from MIDI volume level to OPL level value.
static const unsigned int volume_mapping_table[] = {
0, 1, 3, 5, 6, 8, 10, 11,
13, 14, 16, 17, 19, 20, 22, 23,
25, 26, 27, 29, 30, 32, 33, 34,
36, 37, 39, 41, 43, 45, 47, 49,
50, 52, 54, 55, 57, 59, 60, 61,
63, 64, 66, 67, 68, 69, 71, 72,
73, 74, 75, 76, 77, 79, 80, 81,
82, 83, 84, 84, 85, 86, 87, 88,
89, 90, 91, 92, 92, 93, 94, 95,
96, 96, 97, 98, 99, 99, 100, 101,
101, 102, 103, 103, 104, 105, 105, 106,
107, 107, 108, 109, 109, 110, 110, 111,
112, 112, 113, 113, 114, 114, 115, 115,
116, 117, 117, 118, 118, 119, 119, 120,
120, 121, 121, 122, 122, 123, 123, 123,
124, 124, 125, 125, 126, 126, 127, 127
};
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;
static opl_voice_t *voice_alloced_list;
// Track data for playing tracks:
static opl_track_data_t *tracks;
static unsigned int num_tracks;
static unsigned int running_tracks = 0;
static boolean song_looping;
// 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;
}
// Remove from free list
result = voice_free_list;
voice_free_list = voice_free_list->next;
// Add to allocated list
result->next = voice_alloced_list;
voice_alloced_list = result;
return result;
}
// Remove a voice from the allocated voices list.
static void RemoveVoiceFromAllocedList(opl_voice_t *voice)
{
opl_voice_t **rover;
rover = &voice_alloced_list;
// Search the list until we find the voice, then remove it.
while (*rover != NULL)
{
if (*rover == voice)
{
*rover = voice->next;
voice->next = NULL;
break;
}
rover = &(*rover)->next;
}
}
// Release a voice back to the freelist.
static void ReleaseVoice(opl_voice_t *voice)
{
opl_voice_t **rover;
voice->channel = NULL;
voice->note = 0;
// Remove from alloced list.
RemoveVoiceFromAllocedList(voice);
// 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_instr_t *instr,
unsigned int instr_voice)
{
genmidi_voice_t *data;
unsigned int modulating;
// Instrument already set for this channel?
if (voice->current_instr == instr
&& voice->current_instr_voice == instr_voice)
{
return;
}
voice->current_instr = instr;
voice->current_instr_voice = instr_voice;
data = &instr->voices[instr_voice];
// Are we usind modulated feedback mode?
modulating = (data->feedback & 0x01) == 0;
// Doom loads the second operator first, then the first.
// The carrier is set to minimum volume until the voice volume
// is set in SetVoiceVolume (below). If we are not using
// modulating mode, we must set both to minimum volume.
LoadOperatorData(voice->op2, &data->carrier, true);
LoadOperatorData(voice->op1, &data->modulator, !modulating);
// 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);
// Hack to force a volume update.
voice->reg_volume = 999;
}
static void SetVoiceVolume(opl_voice_t *voice, unsigned int volume)
{
genmidi_voice_t *opl_voice;
unsigned int full_volume;
unsigned int op_volume;
unsigned int reg_volume;
voice->note_volume = volume;
opl_voice = &voice->current_instr->voices[voice->current_instr_voice];
// Multiply note volume and channel volume to get the actual volume.
full_volume = (volume_mapping_table[voice->note_volume]
* volume_mapping_table[voice->channel->volume]) / 127;
// The volume of each instrument can be controlled via GENMIDI:
op_volume = 0x3f - opl_voice->carrier.level;
// The volume value to use in the register:
reg_volume = (op_volume * full_volume) / 128;
reg_volume = (0x3f - reg_volume) | opl_voice->carrier.scale;
// Update the volume register(s) if necessary.
if (reg_volume != voice->reg_volume)
{
voice->reg_volume = reg_volume;
WriteRegister(OPL_REGS_LEVEL + voice->op2, reg_volume);
// If we are using non-modulated feedback mode, we must set the
// volume for both voices.
// Note that the same register volume value is written for
// both voices, always calculated from the carrier's level
// value.
if ((opl_voice->feedback & 0x01) != 0)
{
WriteRegister(OPL_REGS_LEVEL + voice->op1, reg_volume);
}
}
}
// 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], 0);
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 void VoiceKeyOff(opl_voice_t *voice)
{
WriteRegister(OPL_REGS_FREQ_2 + voice->index, voice->freq >> 8);
}
// Get the frequency that we should be using for a voice.
static void KeyOffEvent(opl_track_data_t *track, midi_event_t *event)
{
opl_channel_data_t *channel;
unsigned int key;
unsigned int i;
/*
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];
key = event->data.channel.param1;
// Turn off voices being used to play this key.
// If it is a double voice instrument there will be two.
for (i=0; i<OPL_NUM_VOICES; ++i)
{
if (voices[i].channel == channel && voices[i].key == key)
{
VoiceKeyOff(&voices[i]);
// Finished with this voice now.
ReleaseVoice(&voices[i]);
}
}
}
// When all voices are in use, we must discard an existing voice to
// play a new note. Find and free an existing voice. The channel
// passed to the function is the channel for the new note to be
// played.
static opl_voice_t *ReplaceExistingVoice(opl_channel_data_t *channel)
{
opl_voice_t *rover;
opl_voice_t *result;
// Check the allocated voices, if we find an instrument that is
// of a lower priority to the new instrument, discard it.
// Priority is determined by MIDI instrument number; old
result = NULL;
for (rover = voice_alloced_list; rover != NULL; rover = rover->next)
{
if (rover->current_instr > channel->instrument)
{
result = rover;
break;
}
}
// If we didn't find a voice, find an existing voice being used to
// play a note on the same channel, and use that.
if (result == NULL)
{
for (rover = voice_alloced_list; rover != NULL; rover = rover->next)
{
if (rover->channel == channel)
{
result = rover;
break;
}
}
}
// Still nothing found? Give up and just use the first voice in
// the list.
if (result == NULL)
{
result = voice_alloced_list;
}
// Stop playing this voice playing and release it back to the free
// list.
VoiceKeyOff(result);
ReleaseVoice(result);
// Re-allocate the voice again and return it.
return GetFreeVoice();
}
static unsigned int FrequencyForVoice(opl_voice_t *voice)
{
genmidi_voice_t *gm_voice;
unsigned int freq_index;
unsigned int octave;
unsigned int sub_index;
unsigned int note;
note = voice->note;
// Apply note offset:
gm_voice = &voice->current_instr->voices[voice->current_instr_voice];
note += (signed short) SHORT(gm_voice->base_note_offset);
// Avoid possible overflow due to base note offset:
if (note > 0x7f)
{
note = voice->note;
}
freq_index = 64 + 32 * note + voice->channel->bend;
// If this is the second voice of a double voice instrument, the
// frequency index can be adjusted by the fine tuning field.
if (voice->current_instr_voice != 0)
{
freq_index += (voice->current_instr->fine_tuning / 2) - 64;
}
// The first 7 notes use the start of the table, while
// consecutive notes loop around the latter part.
if (freq_index < 284)
{
return frequency_curve[freq_index];
}
sub_index = (freq_index - 284) % (12 * 32);
octave = (freq_index - 284) / (12 * 32);
// Calculate the resulting register value to use for the frequency.
return frequency_curve[sub_index + 284] | (octave << 10);
}
// Update the frequency that a voice is programmed to use.
static void UpdateVoiceFrequency(opl_voice_t *voice)
{
unsigned int freq;
// Calculate the frequency to use for this voice and update it
// if neccessary.
freq = FrequencyForVoice(voice);
if (voice->freq != freq)
{
WriteRegister(OPL_REGS_FREQ_1 + voice->index, freq & 0xff);
WriteRegister(OPL_REGS_FREQ_2 + voice->index, (freq >> 8) | 0x20);
voice->freq = freq;
}
}
// Program a single voice for an instrument. For a double voice
// instrument (GENMIDI_FLAG_2VOICE), this is called twice for each
// key on event.
static void VoiceKeyOn(opl_channel_data_t *channel,
genmidi_instr_t *instrument,
unsigned int instrument_voice,
unsigned int key,
unsigned int volume)
{
opl_voice_t *voice;
// Find a voice to use for this new note.
voice = GetFreeVoice();
// If there are no more voices left, we must decide what to do.
// If this is the first voice of the instrument, free an existing
// voice and use that. Otherwise, if this is the second voice,
// it isn't as important; just discard it.
if (voice == NULL)
{
if (instrument_voice == 0)
{
voice = ReplaceExistingVoice(channel);
}
else
{
return;
}
}
voice->channel = channel;
voice->key = key;
// Work out the note to use. This is normally the same as
// the key, unless it is a fixed pitch instrument.
if ((instrument->flags & GENMIDI_FLAG_FIXED) != 0)
{
voice->note = instrument->fixed_note;
}
else
{
voice->note = key;
}
// Program the voice with the instrument data:
SetVoiceInstrument(voice, instrument, instrument_voice);
// Set the volume level.
SetVoiceVolume(voice, volume);
// Write the frequency value to turn the note on.
voice->freq = 0;
UpdateVoiceFrequency(voice);
}
static void KeyOnEvent(opl_track_data_t *track, midi_event_t *event)
{
genmidi_instr_t *instrument;
opl_channel_data_t *channel;
unsigned int key;
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];
key = event->data.channel.param1;
volume = event->data.channel.param2;
// Percussion channel (10) is treated differently.
if (event->data.channel.channel == 9)
{
if (key < 35 || key > 81)
{
return;
}
instrument = &percussion_instrs[key - 35];
}
else
{
instrument = channel->instrument;
}
// Find and program a voice for this instrument. If this
// is a double voice instrument, we must do this twice.
VoiceKeyOn(channel, instrument, 0, key, volume);
if ((instrument->flags & GENMIDI_FLAG_2VOICE) != 0)
{
VoiceKeyOn(channel, instrument, 1, key, volume);
}
}
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 SetChannelVolume(opl_channel_data_t *channel, unsigned int volume)
{
unsigned int i;
channel->volume = volume;
// Update all voices that this channel is using.
for (i=0; i<OPL_NUM_VOICES; ++i)
{
if (voices[i].channel == channel)
{
SetVoiceVolume(&voices[i], voices[i].note_volume);
}
}
}
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:
SetChannelVolume(channel, param);
break;
default:
fprintf(stderr, "Unknown MIDI controller type: %i\n", controller);
break;
}
}
// Process a pitch bend event.
static void PitchBendEvent(opl_track_data_t *track, midi_event_t *event)
{
opl_channel_data_t *channel;
unsigned int i;
// Update the channel bend value. Only the MSB of the pitch bend
// value is considered: this is what Doom does.
channel = &track->channels[event->data.channel.channel];
channel->bend = event->data.channel.param2 - 64;
// Update all voices for this channel.
for (i=0; i<OPL_NUM_VOICES; ++i)
{
if (voices[i].channel == channel)
{
UpdateVoiceFrequency(&voices[i]);
}
}
}
// Process a meta event.
static void MetaEvent(opl_track_data_t *track, midi_event_t *event)
{
switch (event->data.meta.type)
{
// Things we can just ignore.
case MIDI_META_SEQUENCE_NUMBER:
case MIDI_META_TEXT:
case MIDI_META_COPYRIGHT:
case MIDI_META_TRACK_NAME:
case MIDI_META_INSTR_NAME:
case MIDI_META_LYRICS:
case MIDI_META_MARKER:
case MIDI_META_CUE_POINT:
case MIDI_META_SEQUENCER_SPECIFIC:
break;
// End of track - actually handled when we run out of events
// in the track, see below.
case MIDI_META_END_OF_TRACK:
break;
default:
fprintf(stderr, "Unknown MIDI meta event type: %i\n",
event->data.meta.type);
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:
KeyOffEvent(track, event);
break;
case MIDI_EVENT_NOTE_ON:
KeyOnEvent(track, event);
break;
case MIDI_EVENT_CONTROLLER:
ControllerEvent(track, event);
break;
case MIDI_EVENT_PROGRAM_CHANGE:
ProgramChangeEvent(track, event);
break;
case MIDI_EVENT_PITCH_BEND:
PitchBendEvent(track, event);
break;
case MIDI_EVENT_META:
MetaEvent(track, event);
break;
// SysEx events can be ignored.
case MIDI_EVENT_SYSEX:
case MIDI_EVENT_SYSEX_SPLIT:
break;
default:
fprintf(stderr, "Unknown MIDI event type %i\n", event->event_type);
break;
}
}
static void ScheduleTrack(opl_track_data_t *track);
// Restart a song from the beginning.
static void RestartSong(void)
{
unsigned int i;
running_tracks = num_tracks;
for (i=0; i<num_tracks; ++i)
{
MIDI_RestartIterator(tracks[i].iter);
ScheduleTrack(&tracks[i]);
}
}
// 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);
// End of track?
if (event->event_type == MIDI_EVENT_META
&& event->data.meta.type == MIDI_META_END_OF_TRACK)
{
--running_tracks;
// When all tracks have finished, restart the song.
if (running_tracks <= 0 && song_looping)
{
RestartSong();
}
return;
}
// 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;
channel->bend = 0;
}
// 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));
num_tracks = MIDI_NumTracks(file);
running_tracks = num_tracks;
song_looping = looping;
for (i=0; i<num_tracks; ++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)
{
VoiceKeyOff(&voices[i]);
ReleaseVoice(&voices[i]);
}
}
// Free all track data.
for (i=0; i<num_tracks; ++i)
{
MIDI_FreeIterator(tracks[i].iter);
}
free(tracks);
}
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,
};