ref: 7d800ed67c0d2a6480a046f9816278a30c62cf16
dir: /src/i_oplmusic.c/
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 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.
//
// DESCRIPTION:
// System interface for music.
//
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "memio.h"
#include "mus2mid.h"
#include "deh_main.h"
#include "i_sound.h"
#include "i_swap.h"
#include "m_misc.h"
#include "w_wad.h"
#include "z_zone.h"
#include "opl.h"
#include "midifile.h"
// #define OPL_MIDI_DEBUG
#define MAXMIDLENGTH (96 * 1024)
#define GENMIDI_NUM_INSTRS 128
#define GENMIDI_NUM_PERCUSSION 47
#define GENMIDI_HEADER "#OPL_II#"
#define GENMIDI_FLAG_FIXED 0x0001 /* fixed pitch */
#define GENMIDI_FLAG_2VOICE 0x0004 /* double voice (OPL3) */
#define PERCUSSION_LOG_LEN 16
typedef PACKED_STRUCT (
{
byte tremolo;
byte attack;
byte sustain;
byte waveform;
byte scale;
byte level;
}) genmidi_op_t;
typedef PACKED_STRUCT (
{
genmidi_op_t modulator;
byte feedback;
genmidi_op_t carrier;
byte unused;
short base_note_offset;
}) genmidi_voice_t;
typedef PACKED_STRUCT (
{
unsigned short flags;
byte fine_tuning;
byte fixed_note;
genmidi_voice_t voices[2];
}) 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;
int volume_base;
// Pan
int pan;
// Pitch bend value:
int bend;
} opl_channel_data_t;
// Data associated with a track that is currently playing.
typedef struct
{
// Track iterator used to read new events.
midi_track_iter_t *iter;
} 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;
// Array used by voice:
int array;
// 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 car_volume;
unsigned int mod_volume;
// Pan.
unsigned int reg_pan;
// Priority.
unsigned int priority;
};
// 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 opl_driver_ver_t opl_drv_ver = opl_doom_1_9;
static boolean music_initialized = false;
//static boolean musicpaused = false;
static int start_music_volume;
static int current_music_volume;
// GENMIDI lump instrument data:
static genmidi_instr_t *main_instrs;
static genmidi_instr_t *percussion_instrs;
static char (*main_instr_names)[32];
static char (*percussion_names)[32];
// Voices:
static opl_voice_t voices[OPL_NUM_VOICES * 2];
static opl_voice_t *voice_free_list[OPL_NUM_VOICES * 2];
static opl_voice_t *voice_alloced_list[OPL_NUM_VOICES * 2];
static int voice_free_num;
static int voice_alloced_num;
static int opl_opl3mode;
static int num_opl_voices;
// Data for each channel.
static opl_channel_data_t channels[MIDI_CHANNELS_PER_TRACK];
// Track data for playing tracks:
static opl_track_data_t *tracks;
static unsigned int num_tracks = 0;
static unsigned int running_tracks = 0;
static boolean song_looping;
// Tempo control variables
static unsigned int ticks_per_beat;
static unsigned int us_per_beat;
// Mini-log of recently played percussion instruments:
static uint8_t last_perc[PERCUSSION_LOG_LEN];
static unsigned int last_perc_count;
// Configuration file variable, containing the port number for the
// adlib chip.
char *snd_dmxoption = "";
int opl_io_port = 0x388;
// If true, OPL sound channels are reversed to their correct arrangement
// (as intended by the MIDI standard) rather than the backwards one
// used by DMX due to a bug.
static boolean opl_stereo_correct = false;
// Load instrument table from GENMIDI lump:
static boolean LoadInstrumentTable(void)
{
byte *lump;
lump = W_CacheLumpName(DEH_String("genmidi"), PU_STATIC);
// DMX does not check header
main_instrs = (genmidi_instr_t *) (lump + strlen(GENMIDI_HEADER));
percussion_instrs = main_instrs + GENMIDI_NUM_INSTRS;
main_instr_names =
(char (*)[32]) (percussion_instrs + GENMIDI_NUM_PERCUSSION);
percussion_names = main_instr_names + GENMIDI_NUM_INSTRS;
return true;
}
// Get the next available voice from the freelist.
static opl_voice_t *GetFreeVoice(void)
{
opl_voice_t *result;
int i;
// None available?
if (voice_free_num == 0)
{
return NULL;
}
// Remove from free list
result = voice_free_list[0];
voice_free_num--;
for (i = 0; i < voice_free_num; i++)
{
voice_free_list[i] = voice_free_list[i + 1];
}
// Add to allocated list
voice_alloced_list[voice_alloced_num++] = result;
return result;
}
// Release a voice back to the freelist.
static void VoiceKeyOff(opl_voice_t *voice);
static void ReleaseVoice(int index)
{
opl_voice_t *voice;
boolean double_voice;
int i;
// Doom 2 1.666 OPL crash emulation.
if (index >= voice_alloced_num)
{
voice_alloced_num = 0;
voice_free_num = 0;
return;
}
voice = voice_alloced_list[index];
VoiceKeyOff(voice);
voice->channel = NULL;
voice->note = 0;
double_voice = voice->current_instr_voice != 0;
// Remove from alloced list.
voice_alloced_num--;
for (i = index; i < voice_alloced_num; i++)
{
voice_alloced_list[i] = voice_alloced_list[i + 1];
}
// Search to the end of the freelist (This is how Doom behaves!)
voice_free_list[voice_free_num++] = voice;
if (double_voice && opl_drv_ver < opl_doom_1_9)
{
ReleaseVoice(index);
}
}
// Load data to the specified operator
static void LoadOperatorData(int operator, genmidi_op_t *data,
boolean max_level, unsigned int *volume)
{
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;
if (max_level)
{
level |= 0x3f;
}
else
{
level |= data->level;
}
*volume = level;
OPL_WriteRegister(OPL_REGS_LEVEL + operator, level);
OPL_WriteRegister(OPL_REGS_TREMOLO + operator, data->tremolo);
OPL_WriteRegister(OPL_REGS_ATTACK + operator, data->attack);
OPL_WriteRegister(OPL_REGS_SUSTAIN + operator, data->sustain);
OPL_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 | voice->array, &data->carrier, true,
&voice->car_volume);
LoadOperatorData(voice->op1 | voice->array, &data->modulator, !modulating,
&voice->mod_volume);
// 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.
OPL_WriteRegister((OPL_REGS_FEEDBACK + voice->index) | voice->array,
data->feedback | voice->reg_pan);
// Calculate voice priority.
voice->priority = 0x0f - (data->carrier.attack >> 4)
+ 0x0f - (data->carrier.sustain & 0x0f);
}
static void SetVoiceVolume(opl_voice_t *voice, unsigned int volume)
{
genmidi_voice_t *opl_voice;
unsigned int midi_volume;
unsigned int full_volume;
unsigned int car_volume;
unsigned int mod_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.
midi_volume = 2 * (volume_mapping_table[voice->channel->volume] + 1);
full_volume = (volume_mapping_table[voice->note_volume] * midi_volume)
>> 9;
// The volume value to use in the register:
car_volume = 0x3f - full_volume;
// Update the volume register(s) if necessary.
if (car_volume != (voice->car_volume & 0x3f))
{
voice->car_volume = car_volume | (voice->car_volume & 0xc0);
OPL_WriteRegister((OPL_REGS_LEVEL + voice->op2) | voice->array,
voice->car_volume);
// If we are using non-modulated feedback mode, we must set the
// volume for both voices.
if ((opl_voice->feedback & 0x01) != 0
&& opl_voice->modulator.level != 0x3f)
{
mod_volume = opl_voice->modulator.level;
if (mod_volume < car_volume)
{
mod_volume = car_volume;
}
mod_volume |= voice->mod_volume & 0xc0;
if(mod_volume != voice->mod_volume)
{
voice->mod_volume = mod_volume;
OPL_WriteRegister((OPL_REGS_LEVEL + voice->op1) | voice->array,
mod_volume |
(opl_voice->modulator.scale & 0xc0));
}
}
}
}
static void SetVoicePan(opl_voice_t *voice, unsigned int pan)
{
genmidi_voice_t *opl_voice;
voice->reg_pan = pan;
opl_voice = &voice->current_instr->voices[voice->current_instr_voice];;
OPL_WriteRegister((OPL_REGS_FEEDBACK + voice->index) | voice->array,
opl_voice->feedback | pan);
}
// Initialize the voice table and freelist
static void InitVoices(void)
{
int i;
// Start with an empty free list.
voice_free_num = num_opl_voices;
voice_alloced_num = 0;
// Initialize each voice.
for (i = 0; i < num_opl_voices; ++i)
{
voices[i].index = i % OPL_NUM_VOICES;
voices[i].op1 = voice_operators[0][i % OPL_NUM_VOICES];
voices[i].op2 = voice_operators[1][i % OPL_NUM_VOICES];
voices[i].array = (i / OPL_NUM_VOICES) << 8;
voices[i].current_instr = NULL;
// Add this voice to the freelist.
voice_free_list[i] = &voices[i];
}
}
static void SetChannelVolume(opl_channel_data_t *channel, unsigned int volume,
boolean clip_start);
// Set music volume (0 - 127)
static void I_OPL_SetMusicVolume(int volume)
{
unsigned int i;
if (current_music_volume == volume)
{
return;
}
// Internal state variable.
current_music_volume = volume;
// Update the volume of all voices.
for (i = 0; i < MIDI_CHANNELS_PER_TRACK; ++i)
{
if (i == 15)
{
SetChannelVolume(&channels[i], volume, false);
}
else
{
SetChannelVolume(&channels[i], channels[i].volume_base, false);
}
}
}
static void VoiceKeyOff(opl_voice_t *voice)
{
OPL_WriteRegister((OPL_REGS_FREQ_2 + voice->index) | voice->array,
voice->freq >> 8);
}
static opl_channel_data_t *TrackChannelForEvent(opl_track_data_t *track,
midi_event_t *event)
{
unsigned int channel_num = event->data.channel.channel;
// MIDI uses track #9 for percussion, but for MUS it's track #15
// instead. Because DMX works on MUS data internally, we need to
// swap back to the MUS version of the channel number.
if (channel_num == 9)
{
channel_num = 15;
}
else if (channel_num == 15)
{
channel_num = 9;
}
return &channels[channel_num];
}
// 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;
int i;
unsigned int key;
/*
printf("note off: channel %i, %i, %i\n",
event->data.channel.channel,
event->data.channel.param1,
event->data.channel.param2);
*/
channel = TrackChannelForEvent(track, event);
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 < voice_alloced_num; i++)
{
if (voice_alloced_list[i]->channel == channel
&& voice_alloced_list[i]->key == key)
{
// Finished with this voice now.
ReleaseVoice(i);
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 void ReplaceExistingVoice(void)
{
int i;
int result;
// Check the allocated voices, if we find an instrument that is
// of a lower priority to the new instrument, discard it.
// If a voice is being used to play the second voice of an instrument,
// use that, as second voices are non-essential.
// Lower numbered MIDI channels implicitly have a higher priority
// than higher-numbered channels, eg. MIDI channel 1 is never
// discarded for MIDI channel 2.
result = 0;
for (i = 0; i < voice_alloced_num; i++)
{
if (voice_alloced_list[i]->current_instr_voice != 0
|| voice_alloced_list[i]->channel
>= voice_alloced_list[result]->channel)
{
result = i;
}
}
ReleaseVoice(result);
}
// Alternate versions of ReplaceExistingVoice() used when emulating old
// versions of the DMX library used in Doom 1.666, Heretic and Hexen.
static void ReplaceExistingVoiceDoom1(void)
{
int i;
int result;
result = 0;
for (i = 0; i < voice_alloced_num; i++)
{
if (voice_alloced_list[i]->channel
> voice_alloced_list[result]->channel)
{
result = i;
}
}
ReleaseVoice(result);
}
static void ReplaceExistingVoiceDoom2(opl_channel_data_t *channel)
{
int i;
int result;
int priority;
result = 0;
priority = 0x8000;
for (i = 0; i < voice_alloced_num - 3; i++)
{
if (voice_alloced_list[i]->priority < priority
&& voice_alloced_list[i]->channel >= channel)
{
priority = voice_alloced_list[i]->priority;
result = i;
}
}
ReleaseVoice(result);
}
static unsigned int FrequencyForVoice(opl_voice_t *voice)
{
genmidi_voice_t *gm_voice;
signed int freq_index;
unsigned int octave;
unsigned int sub_index;
signed int note;
note = voice->note;
// Apply note offset.
// Don't apply offset if the instrument is a fixed note instrument.
gm_voice = &voice->current_instr->voices[voice->current_instr_voice];
if ((SHORT(voice->current_instr->flags) & GENMIDI_FLAG_FIXED) == 0)
{
note += (signed short) SHORT(gm_voice->base_note_offset);
}
// Avoid possible overflow due to base note offset:
while (note < 0)
{
note += 12;
}
while (note > 95)
{
note -= 12;
}
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;
}
if (freq_index < 0)
{
freq_index = 0;
}
// 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);
// Once the seventh octave is reached, things break down.
// We can only go up to octave 7 as a maximum anyway (the OPL
// register only has three bits for octave number), but for the
// notes in octave 7, the first five bits have octave=7, the
// following notes have octave=6. This 7/6 pattern repeats in
// following octaves (which are technically impossible to
// represent anyway).
if (octave >= 7)
{
octave = 7;
}
// 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)
{
OPL_WriteRegister((OPL_REGS_FREQ_1 + voice->index) | voice->array,
freq & 0xff);
OPL_WriteRegister((OPL_REGS_FREQ_2 + voice->index) | voice->array,
(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 note,
unsigned int key,
unsigned int volume)
{
opl_voice_t *voice;
if (!opl_opl3mode && opl_drv_ver == opl_doom1_1_666)
{
instrument_voice = 0;
}
// Find a voice to use for this new note.
voice = GetFreeVoice();
if (voice == NULL)
{
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 ((SHORT(instrument->flags) & GENMIDI_FLAG_FIXED) != 0)
{
voice->note = instrument->fixed_note;
}
else
{
voice->note = note;
}
voice->reg_pan = channel->pan;
// 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 note, key, volume, voicenum;
boolean double_voice;
/*
printf("note on: channel %i, %i, %i\n",
event->data.channel.channel,
event->data.channel.param1,
event->data.channel.param2);
*/
note = event->data.channel.param1;
key = event->data.channel.param1;
volume = event->data.channel.param2;
// A volume of zero means key off. Some MIDI tracks, eg. the ones
// in AV.wad, use a second key on with a volume of zero to mean
// key off.
if (volume <= 0)
{
KeyOffEvent(track, event);
return;
}
// The channel.
channel = TrackChannelForEvent(track, event);
// Percussion channel is treated differently.
if (event->data.channel.channel == 9)
{
if (key < 35 || key > 81)
{
return;
}
instrument = &percussion_instrs[key - 35];
last_perc[last_perc_count] = key;
last_perc_count = (last_perc_count + 1) % PERCUSSION_LOG_LEN;
note = 60;
}
else
{
instrument = channel->instrument;
}
double_voice = (SHORT(instrument->flags) & GENMIDI_FLAG_2VOICE) != 0;
switch (opl_drv_ver)
{
case opl_doom1_1_666:
voicenum = double_voice + 1;
if (!opl_opl3mode)
{
voicenum = 1;
}
while (voice_alloced_num > num_opl_voices - voicenum)
{
ReplaceExistingVoiceDoom1();
}
// Find and program a voice for this instrument. If this
// is a double voice instrument, we must do this twice.
if (double_voice)
{
VoiceKeyOn(channel, instrument, 1, note, key, volume);
}
VoiceKeyOn(channel, instrument, 0, note, key, volume);
break;
case opl_doom2_1_666:
if (voice_alloced_num == num_opl_voices)
{
ReplaceExistingVoiceDoom2(channel);
}
if (voice_alloced_num == num_opl_voices - 1 && double_voice)
{
ReplaceExistingVoiceDoom2(channel);
}
// Find and program a voice for this instrument. If this
// is a double voice instrument, we must do this twice.
if (double_voice)
{
VoiceKeyOn(channel, instrument, 1, note, key, volume);
}
VoiceKeyOn(channel, instrument, 0, note, key, volume);
break;
default:
case opl_doom_1_9:
if (voice_free_num == 0)
{
ReplaceExistingVoice();
}
// Find and program a voice for this instrument. If this
// is a double voice instrument, we must do this twice.
VoiceKeyOn(channel, instrument, 0, note, key, volume);
if (double_voice)
{
VoiceKeyOn(channel, instrument, 1, note, key, volume);
}
break;
}
}
static void ProgramChangeEvent(opl_track_data_t *track, midi_event_t *event)
{
opl_channel_data_t *channel;
int instrument;
// Set the instrument used on this channel.
channel = TrackChannelForEvent(track, event);
instrument = event->data.channel.param1;
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,
boolean clip_start)
{
unsigned int i;
channel->volume_base = volume;
if (volume > current_music_volume)
{
volume = current_music_volume;
}
if (clip_start && volume > start_music_volume)
{
volume = start_music_volume;
}
channel->volume = volume;
// Update all voices that this channel is using.
for (i = 0; i < num_opl_voices; ++i)
{
if (voices[i].channel == channel)
{
SetVoiceVolume(&voices[i], voices[i].note_volume);
}
}
}
static void SetChannelPan(opl_channel_data_t *channel, unsigned int pan)
{
unsigned int reg_pan;
unsigned int i;
// The DMX library has the stereo channels backwards, maybe because
// Paul Radek had a Soundblaster card with the channels reversed, or
// perhaps it was just a bug in the OPL3 support that was never
// finished. By default we preserve this bug, but we also provide a
// secret DMXOPTION to fix it.
if (opl_stereo_correct)
{
pan = 144 - pan;
}
if (opl_opl3mode)
{
if (pan >= 96)
{
reg_pan = 0x10;
}
else if (pan <= 48)
{
reg_pan = 0x20;
}
else
{
reg_pan = 0x30;
}
if (channel->pan != reg_pan)
{
channel->pan = reg_pan;
for (i = 0; i < num_opl_voices; i++)
{
if (voices[i].channel == channel)
{
SetVoicePan(&voices[i], reg_pan);
}
}
}
}
}
// Handler for the MIDI_CONTROLLER_ALL_NOTES_OFF channel event.
static void AllNotesOff(opl_channel_data_t *channel, unsigned int param)
{
int i;
for (i = 0; i < voice_alloced_num; i++)
{
if (voice_alloced_list[i]->channel == channel)
{
// Finished with this voice now.
ReleaseVoice(i);
i--;
}
}
}
static void ControllerEvent(opl_track_data_t *track, midi_event_t *event)
{
opl_channel_data_t *channel;
unsigned int controller;
unsigned int param;
/*
printf("change controller: channel %i, %i, %i\n",
event->data.channel.channel,
event->data.channel.param1,
event->data.channel.param2);
*/
channel = TrackChannelForEvent(track, event);
controller = event->data.channel.param1;
param = event->data.channel.param2;
switch (controller)
{
case MIDI_CONTROLLER_MAIN_VOLUME:
SetChannelVolume(channel, param, true);
break;
case MIDI_CONTROLLER_PAN:
SetChannelPan(channel, param);
break;
case MIDI_CONTROLLER_ALL_NOTES_OFF:
AllNotesOff(channel, param);
break;
default:
#ifdef OPL_MIDI_DEBUG
fprintf(stderr, "Unknown MIDI controller type: %i\n", controller);
#endif
break;
}
}
// Process a pitch bend event.
static void PitchBendEvent(opl_track_data_t *track, midi_event_t *event)
{
opl_channel_data_t *channel;
int i;
opl_voice_t *voice_updated_list[OPL_NUM_VOICES * 2];
unsigned int voice_updated_num = 0;
opl_voice_t *voice_not_updated_list[OPL_NUM_VOICES * 2];
unsigned int voice_not_updated_num = 0;
// Update the channel bend value. Only the MSB of the pitch bend
// value is considered: this is what Doom does.
channel = TrackChannelForEvent(track, event);
channel->bend = event->data.channel.param2 - 64;
// Update all voices for this channel.
for (i = 0; i < voice_alloced_num; ++i)
{
if (voice_alloced_list[i]->channel == channel)
{
UpdateVoiceFrequency(voice_alloced_list[i]);
voice_updated_list[voice_updated_num++] = voice_alloced_list[i];
}
else
{
voice_not_updated_list[voice_not_updated_num++] =
voice_alloced_list[i];
}
}
for (i = 0; i < voice_not_updated_num; i++)
{
voice_alloced_list[i] = voice_not_updated_list[i];
}
for (i = 0; i < voice_updated_num; i++)
{
voice_alloced_list[i + voice_not_updated_num] = voice_updated_list[i];
}
}
static void MetaSetTempo(unsigned int tempo)
{
OPL_AdjustCallbacks((float) us_per_beat / tempo);
us_per_beat = tempo;
}
// Process a meta event.
static void MetaEvent(opl_track_data_t *track, midi_event_t *event)
{
byte *data = event->data.meta.data;
unsigned int data_len = event->data.meta.length;
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;
case MIDI_META_SET_TEMPO:
if (data_len == 3)
{
MetaSetTempo((data[0] << 16) | (data[1] << 8) | data[2]);
}
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:
#ifdef OPL_MIDI_DEBUG
fprintf(stderr, "Unknown MIDI meta event type: %i\n",
event->data.meta.type);
#endif
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:
#ifdef OPL_MIDI_DEBUG
fprintf(stderr, "Unknown MIDI event type %i\n", event->event_type);
#endif
break;
}
}
static void ScheduleTrack(opl_track_data_t *track);
static void InitChannel(opl_channel_data_t *channel);
// Restart a song from the beginning.
static void RestartSong(void *unused)
{
unsigned int i;
running_tracks = num_tracks;
start_music_volume = current_music_volume;
for (i = 0; i < num_tracks; ++i)
{
MIDI_RestartIterator(tracks[i].iter);
ScheduleTrack(&tracks[i]);
}
for (i = 0; i < MIDI_CHANNELS_PER_TRACK; ++i)
{
InitChannel(&channels[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.
// Don't restart the song immediately, but wait for 5ms
// before triggering a restart. Otherwise it is possible
// to construct an empty MIDI file that causes the game
// to lock up in an infinite loop. (5ms should be short
// enough not to be noticeable by the listener).
if (running_tracks <= 0 && song_looping)
{
OPL_SetCallback(5000, RestartSong, NULL);
}
return;
}
// Reschedule the callback for the next event in the track.
ScheduleTrack(track);
}
static void ScheduleTrack(opl_track_data_t *track)
{
unsigned int nticks;
uint64_t us;
// Get the number of microseconds until the next event.
nticks = MIDI_GetDeltaTime(track->iter);
us = ((uint64_t) nticks * us_per_beat) / ticks_per_beat;
// Set a timer to be invoked when the next event is
// ready to play.
OPL_SetCallback(us, TrackTimerCallback, track);
}
// Initialize a channel.
static void InitChannel(opl_channel_data_t *channel)
{
// TODO: Work out sensible defaults?
channel->instrument = &main_instrs[0];
channel->volume = current_music_volume;
channel->volume_base = 100;
if (channel->volume > channel->volume_base)
{
channel->volume = channel->volume_base;
}
channel->pan = 0x30;
channel->bend = 0;
}
// Start a MIDI track playing:
static void StartTrack(midi_file_t *file, unsigned int track_num)
{
opl_track_data_t *track;
track = &tracks[track_num];
track->iter = MIDI_IterateTrack(file, track_num);
// Schedule the first event.
ScheduleTrack(track);
}
// Start playing a mid
static void I_OPL_PlaySong(void *handle, boolean looping)
{
midi_file_t *file;
unsigned int i;
if (!music_initialized || 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;
ticks_per_beat = MIDI_GetFileTimeDivision(file);
// Default is 120 bpm.
// TODO: this is wrong
us_per_beat = 500 * 1000;
start_music_volume = current_music_volume;
for (i = 0; i < num_tracks; ++i)
{
StartTrack(file, i);
}
for (i = 0; i < MIDI_CHANNELS_PER_TRACK; ++i)
{
InitChannel(&channels[i]);
}
}
static void I_OPL_PauseSong(void)
{
unsigned int i;
if (!music_initialized)
{
return;
}
// Pause OPL callbacks.
OPL_SetPaused(1);
// Turn off all main instrument voices (not percussion).
// This is what Vanilla does.
for (i = 0; i < num_opl_voices; ++i)
{
if (voices[i].channel != NULL
&& voices[i].current_instr < percussion_instrs)
{
VoiceKeyOff(&voices[i]);
}
}
}
static void I_OPL_ResumeSong(void)
{
if (!music_initialized)
{
return;
}
OPL_SetPaused(0);
}
static void I_OPL_StopSong(void)
{
unsigned int i;
if (!music_initialized)
{
return;
}
OPL_Lock();
// Stop all playback.
OPL_ClearCallbacks();
// Free all voices.
for (i = 0; i < MIDI_CHANNELS_PER_TRACK; ++i)
{
AllNotesOff(&channels[i], 0);
}
// Free all track data.
for (i = 0; i < num_tracks; ++i)
{
MIDI_FreeIterator(tracks[i].iter);
}
free(tracks);
tracks = NULL;
num_tracks = 0;
OPL_Unlock();
}
static void I_OPL_UnRegisterSong(void *handle)
{
if (!music_initialized)
{
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_initialized)
{
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);
free(filename);
return result;
}
// Is the song playing?
static boolean I_OPL_MusicIsPlaying(void)
{
if (!music_initialized)
{
return false;
}
return num_tracks > 0;
}
// Shutdown music
static void I_OPL_ShutdownMusic(void)
{
if (music_initialized)
{
// Stop currently-playing track, if there is one:
I_OPL_StopSong();
OPL_Shutdown();
// Release GENMIDI lump
W_ReleaseLumpName(DEH_String("genmidi"));
music_initialized = false;
}
}
// Initialize music subsystem
static boolean I_OPL_InitMusic(void)
{
char *dmxoption;
opl_init_result_t chip_type;
OPL_SetSampleRate(snd_samplerate);
chip_type = OPL_Init(opl_io_port);
if (chip_type == OPL_INIT_NONE)
{
printf("Dude. The Adlib isn't responding.\n");
return false;
}
// The DMXOPTION variable must be set to enable OPL3 support.
// As an extension, we also allow it to be set from the config file.
dmxoption = getenv("DMXOPTION");
if (dmxoption == NULL)
{
dmxoption = snd_dmxoption != NULL ? snd_dmxoption : "";
}
if (chip_type == OPL_INIT_OPL3 && strstr(dmxoption, "-opl3") != NULL)
{
opl_opl3mode = 1;
num_opl_voices = OPL_NUM_VOICES * 2;
}
else
{
opl_opl3mode = 0;
num_opl_voices = OPL_NUM_VOICES;
}
// Secret, undocumented DMXOPTION that reverses the stereo channels
// into their correct orientation.
opl_stereo_correct = strstr(dmxoption, "-reverse") != NULL;
// Initialize all registers.
OPL_InitRegisters(opl_opl3mode);
// Load instruments from GENMIDI lump:
if (!LoadInstrumentTable())
{
OPL_Shutdown();
return false;
}
InitVoices();
tracks = NULL;
num_tracks = 0;
music_initialized = true;
return true;
}
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,
NULL, // Poll
};
void I_SetOPLDriverVer(opl_driver_ver_t ver)
{
opl_drv_ver = ver;
}
//----------------------------------------------------------------------
//
// Development / debug message generation, to help developing GENMIDI
// lumps.
//
//----------------------------------------------------------------------
static int NumActiveChannels(void)
{
int i;
for (i = MIDI_CHANNELS_PER_TRACK - 1; i >= 0; --i)
{
if (channels[i].instrument != &main_instrs[0])
{
return i + 1;
}
}
return 0;
}
static int ChannelInUse(opl_channel_data_t *channel)
{
int i;
for (i = 0; i < voice_alloced_num; i++)
{
if (voice_alloced_list[i]->channel == channel)
{
return 1;
}
}
return 0;
}
void I_OPL_DevMessages(char *result, size_t result_len)
{
char tmp[80];
int instr_num;
int lines;
int i;
if (num_tracks == 0)
{
M_snprintf(result, result_len, "No OPL track!");
return;
}
M_snprintf(result, result_len, "Tracks:\n");
lines = 1;
for (i = 0; i < NumActiveChannels(); ++i)
{
if (channels[i].instrument == NULL)
{
continue;
}
instr_num = channels[i].instrument - main_instrs;
M_snprintf(tmp, sizeof(tmp),
"chan %i: %c i#%i (%s)\n",
i,
ChannelInUse(&channels[i]) ? '\'' : ' ',
instr_num + 1,
main_instr_names[instr_num]);
M_StringConcat(result, tmp, result_len);
++lines;
}
M_snprintf(tmp, sizeof(tmp), "\nLast percussion:\n");
M_StringConcat(result, tmp, result_len);
lines += 2;
i = (last_perc_count + PERCUSSION_LOG_LEN - 1) % PERCUSSION_LOG_LEN;
do {
if (last_perc[i] == 0)
{
break;
}
M_snprintf(tmp, sizeof(tmp),
"%cp#%i (%s)\n",
i == 0 ? '\'' : ' ',
last_perc[i],
percussion_names[last_perc[i] - 35]);
M_StringConcat(result, tmp, result_len);
++lines;
i = (i + PERCUSSION_LOG_LEN - 1) % PERCUSSION_LOG_LEN;
} while (lines < 25 && i != last_perc_count);
}