Files
MontaukOS/programs/src/doom/i_sound_montauk.c
T

363 lines
11 KiB
C

/*
* i_sound_montauk.c
* DOOM sound effects and music modules for MontaukOS
* Implements software mixing of 16 SFX channels into the HDA audio device.
* Copyright (c) 2026 Daniel Hammer
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "deh_str.h"
#include "i_sound.h"
#include "i_system.h"
#include "i_swap.h"
#include "m_argv.h"
#include "m_misc.h"
#include "w_wad.h"
#include "z_zone.h"
#include "doomtype.h"
/* ========================================================================
Raw syscall interface for audio
======================================================================== */
static inline long _snd_syscall1(long nr, long a1) {
long ret;
__asm__ volatile(
"mov %[a1], %%rdi\n\t"
"syscall"
: "=a"(ret)
: "a"(nr), [a1] "r"(a1)
: "rcx", "r11", "rdi", "rsi", "rdx", "r8", "r9", "r10", "memory");
return ret;
}
static inline long _snd_syscall3(long nr, long a1, long a2, long a3) {
long ret;
__asm__ volatile(
"mov %[a1], %%rdi\n\t"
"mov %[a2], %%rsi\n\t"
"mov %[a3], %%rdx\n\t"
"syscall"
: "=a"(ret)
: "a"(nr), [a1] "r"(a1), [a2] "r"(a2), [a3] "r"(a3)
: "rcx", "r11", "rdi", "rsi", "rdx", "r8", "r9", "r10", "memory");
return ret;
}
#define SYS_AUDIOOPEN 80
#define SYS_AUDIOCLOSE 81
#define SYS_AUDIOWRITE 82
/* ========================================================================
Audio mixing engine
======================================================================== */
/* Required by i_sound.c config binding */
int use_libsamplerate = 0;
float libsamplerate_scale = 0.65f;
#define NUM_CHANNELS 16
#define MIX_RATE 44100
#define MIX_CHANNELS 2
#define MIX_BITS 16
/* Samples per mix frame (~35 fps, slightly oversized for timing jitter) */
#define MIX_SAMPLES 1260
#define MIX_BUF_BYTES (MIX_SAMPLES * MIX_CHANNELS * (MIX_BITS / 8))
/* Channel state */
struct snd_channel {
const uint8_t *data; /* 8-bit unsigned PCM samples */
uint32_t length; /* number of samples */
uint32_t pos; /* playback position (16.16 fixed-point) */
uint32_t step; /* step per output sample (16.16 fixed-point) */
int vol_left; /* left volume (0-127) */
int vol_right; /* right volume (0-127) */
sfxinfo_t *sfxinfo; /* NULL = inactive */
};
static struct snd_channel channels[NUM_CHANNELS];
static int audio_handle = -1;
static boolean sound_initialized = false;
static boolean use_sfx_prefix;
/* Static mix buffer (stereo interleaved int16_t) */
static int16_t mix_buf[MIX_SAMPLES * MIX_CHANNELS];
/* ========================================================================
Sound effect loading (DMX format from WAD lumps)
======================================================================== */
static void GetSfxLumpName(sfxinfo_t *sfx, char *buf, size_t buf_len) {
if (sfx->link != NULL)
sfx = sfx->link;
if (use_sfx_prefix)
M_snprintf(buf, buf_len, "ds%s", DEH_String(sfx->name));
else
M_StringCopy(buf, DEH_String(sfx->name), buf_len);
}
/* Parse a DMX sound lump. Returns the raw 8-bit PCM data and fills in
samplerate and length. Returns NULL on failure. */
static const uint8_t *ParseDmxSound(int lumpnum, int *out_rate, uint32_t *out_len) {
unsigned int lumplen = W_LumpLength(lumpnum);
const uint8_t *data = W_CacheLumpNum(lumpnum, PU_STATIC);
if (lumplen < 8 || data[0] != 0x03 || data[1] != 0x00)
return NULL;
int samplerate = (data[3] << 8) | data[2];
uint32_t length = (data[7] << 24) | (data[6] << 16) | (data[5] << 8) | data[4];
if (length > lumplen - 8 || length <= 48)
return NULL;
/* DMX skips first 16 and last 16 bytes of sample data */
*out_rate = samplerate;
*out_len = length - 32;
return data + 16;
}
/* ========================================================================
Volume/separation helpers
======================================================================== */
static void SetChannelVolSep(int ch, int vol, int sep) {
/* vol: 0-127, sep: 0-254 (0=full left, 127=center, 254=full right) */
channels[ch].vol_left = ((254 - sep) * vol) / 127;
channels[ch].vol_right = (sep * vol) / 127;
}
/* ========================================================================
Software mixer - mix all active channels into mix_buf
======================================================================== */
static void MixChannels(int num_samples) {
/* Clear mix buffer */
memset(mix_buf, 0, (size_t)(num_samples * MIX_CHANNELS) * sizeof(int16_t));
for (int ch = 0; ch < NUM_CHANNELS; ch++) {
struct snd_channel *c = &channels[ch];
if (c->sfxinfo == NULL)
continue;
int16_t *out = mix_buf;
for (int i = 0; i < num_samples; i++) {
uint32_t ipos = c->pos >> 16;
if (ipos >= c->length) {
/* Sound finished */
c->sfxinfo = NULL;
break;
}
/* Convert 8-bit unsigned (0-255, 128=silence) to signed (-128..127)
then scale to 16-bit range */
int sample = ((int)c->data[ipos] - 128) << 8;
/* Apply volume and accumulate (additive mixing) */
int left = out[i * 2 + 0] + ((sample * c->vol_left) >> 7);
int right = out[i * 2 + 1] + ((sample * c->vol_right) >> 7);
/* Clamp to int16_t range */
if (left > 32767) left = 32767;
else if (left < -32768) left = -32768;
if (right > 32767) right = 32767;
else if (right < -32768) right = -32768;
out[i * 2 + 0] = (int16_t)left;
out[i * 2 + 1] = (int16_t)right;
c->pos += c->step;
}
}
}
/* ========================================================================
sound_module_t implementation
======================================================================== */
static boolean I_Montauk_InitSound(boolean _use_sfx_prefix) {
use_sfx_prefix = _use_sfx_prefix;
for (int i = 0; i < NUM_CHANNELS; i++) {
memset(&channels[i], 0, sizeof(channels[i]));
}
audio_handle = (int)_snd_syscall3(SYS_AUDIOOPEN,
(long)MIX_RATE, (long)MIX_CHANNELS, (long)MIX_BITS);
if (audio_handle < 0) {
return false;
}
sound_initialized = true;
return true;
}
static void I_Montauk_ShutdownSound(void) {
if (!sound_initialized)
return;
for (int i = 0; i < NUM_CHANNELS; i++)
channels[i].sfxinfo = NULL;
if (audio_handle >= 0) {
_snd_syscall1(SYS_AUDIOCLOSE, (long)audio_handle);
audio_handle = -1;
}
sound_initialized = false;
}
static int I_Montauk_GetSfxLumpNum(sfxinfo_t *sfx) {
char namebuf[9];
GetSfxLumpName(sfx, namebuf, sizeof(namebuf));
return W_GetNumForName(namebuf);
}
static void I_Montauk_UpdateSound(void) {
if (!sound_initialized || audio_handle < 0)
return;
/* Mix one frame of audio and submit to the device */
MixChannels(MIX_SAMPLES);
const uint8_t *ptr = (const uint8_t *)mix_buf;
int remaining = MIX_BUF_BYTES;
/* Write as much as the device accepts (non-blocking) */
while (remaining > 0) {
int written = (int)_snd_syscall3(SYS_AUDIOWRITE,
(long)audio_handle, (long)ptr, (long)remaining);
if (written <= 0)
break;
ptr += written;
remaining -= written;
}
}
static void I_Montauk_UpdateSoundParams(int channel, int vol, int sep) {
if (!sound_initialized || channel < 0 || channel >= NUM_CHANNELS)
return;
if (channels[channel].sfxinfo == NULL)
return;
SetChannelVolSep(channel, vol, sep);
}
static int I_Montauk_StartSound(sfxinfo_t *sfxinfo, int channel, int vol, int sep) {
if (!sound_initialized || channel < 0 || channel >= NUM_CHANNELS)
return -1;
/* Stop any sound already on this channel */
channels[channel].sfxinfo = NULL;
/* Load and parse the sound lump */
if (sfxinfo->lumpnum == -1)
return -1;
int samplerate;
uint32_t length;
const uint8_t *data = ParseDmxSound(sfxinfo->lumpnum, &samplerate, &length);
if (data == NULL)
return -1;
/* Set up the channel */
channels[channel].data = data;
channels[channel].length = length;
channels[channel].pos = 0;
/* Resampling step: source_rate / MIX_RATE in 16.16 fixed-point */
channels[channel].step = ((uint32_t)samplerate << 16) / MIX_RATE;
SetChannelVolSep(channel, vol, sep);
channels[channel].sfxinfo = sfxinfo;
return channel;
}
static void I_Montauk_StopSound(int channel) {
if (!sound_initialized || channel < 0 || channel >= NUM_CHANNELS)
return;
channels[channel].sfxinfo = NULL;
}
static boolean I_Montauk_SoundIsPlaying(int channel) {
if (!sound_initialized || channel < 0 || channel >= NUM_CHANNELS)
return false;
return channels[channel].sfxinfo != NULL;
}
static void I_Montauk_PrecacheSounds(sfxinfo_t *sounds, int num_sounds) {
/* No-op: we load on demand */
(void)sounds;
(void)num_sounds;
}
static snddevice_t sound_montauk_devices[] = {
SNDDEVICE_SB,
SNDDEVICE_PAS,
SNDDEVICE_GUS,
SNDDEVICE_WAVEBLASTER,
SNDDEVICE_SOUNDCANVAS,
SNDDEVICE_AWE32,
};
sound_module_t DG_sound_module = {
sound_montauk_devices,
arrlen(sound_montauk_devices),
I_Montauk_InitSound,
I_Montauk_ShutdownSound,
I_Montauk_GetSfxLumpNum,
I_Montauk_UpdateSound,
I_Montauk_UpdateSoundParams,
I_Montauk_StartSound,
I_Montauk_StopSound,
I_Montauk_SoundIsPlaying,
I_Montauk_PrecacheSounds,
};
/* ========================================================================
music_module_t implementation (stub - no MIDI synthesis)
======================================================================== */
static boolean I_Montauk_InitMusic(void) { return true; }
static void I_Montauk_ShutdownMusic(void) {}
static void I_Montauk_SetMusicVolume(int vol) { (void)vol; }
static void I_Montauk_PauseMusic(void) {}
static void I_Montauk_ResumeMusic(void) {}
static void *I_Montauk_RegisterSong(void *data, int len) { (void)data; (void)len; return (void *)1; }
static void I_Montauk_UnRegisterSong(void *h) { (void)h; }
static void I_Montauk_PlaySong(void *h, boolean loop) { (void)h; (void)loop; }
static void I_Montauk_StopSong(void) {}
static boolean I_Montauk_MusicIsPlaying(void) { return false; }
static void I_Montauk_PollMusic(void) {}
static snddevice_t music_montauk_devices[] = {
SNDDEVICE_SB,
SNDDEVICE_ADLIB,
SNDDEVICE_GUS,
};
music_module_t DG_music_module = {
music_montauk_devices,
arrlen(music_montauk_devices),
I_Montauk_InitMusic,
I_Montauk_ShutdownMusic,
I_Montauk_SetMusicVolume,
I_Montauk_PauseMusic,
I_Montauk_ResumeMusic,
I_Montauk_RegisterSong,
I_Montauk_UnRegisterSong,
I_Montauk_PlaySong,
I_Montauk_StopSong,
I_Montauk_MusicIsPlaying,
I_Montauk_PollMusic,
};