quakeforge/libs/audio/renderer/snd_mix.c
Bill Currie 79f3f651a4 [sound] Bring QF into the atomic age
Nuclear powered audio ;)

More seriously, use _Atomic on a few fields that very obviously need it.
That is, channel's buffer pointer (used to signal to the mixer that the
channel is ready for use) and "flow control" flags (stop, done and
pause), and head and tail in the buffer itself. Since QF has been
working without _Atomic (admittedly, thanks to luck and x86's strong
memory model), this should do until proven otherwise. I imagine getting
stream reading out of the RT thread will highlight any issues.
2022-06-06 12:39:54 +09:00

473 lines
11 KiB
C

/*
snd_mix.c
portable code to mix sounds for snd_dma.c
Copyright (C) 1996-1997 Id Software, Inc.
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:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include "winquake.h"
#include "QF/cvar.h"
#include "QF/sound.h"
#include "QF/sys.h"
#include "compat.h"
#include "snd_internal.h"
#define VOLSCALE 0.5 // so mixing is less likely to overflow
portable_samplepair_t snd_paintbuffer[PAINTBUFFER_SIZE * 2];
static int max_overpaint; // number of extra samples painted
// due to phase shift
/* CHANNEL MIXING */
static inline int
check_channel_end (channel_t *ch, sfxbuffer_t *sb, int count, unsigned ltime)
{
if (count <= 0 || ltime >= ch->end) {
if (ch->loopstart != (unsigned) -1) {
ch->pos = ch->loopstart;
ch->end = ltime + sb->sfx_length - ch->pos;
} else { // channel just stopped
ch->done = 1;
return 1;
}
}
return 0;
}
static inline void
snd_paint_channel (channel_t *ch, sfxbuffer_t *sb, int count)
{
unsigned pos;
int offs = 0;
float *samps;
if ((int) ch->pos < 0) {
ch->pos += count;
if ((int) ch->pos <= 0)
return;
offs = count - ch->pos;
count -= offs;
ch->pos = 0;
}
if (ch->pos < sb->pos || ch->pos - sb->pos >= sb->size)
sb->setpos (sb, ch->pos);
pos = (ch->pos - sb->pos + sb->tail) % sb->size;
samps = sb->data + pos * sb->channels;
if (pos + count > sb->size) {
unsigned sub = sb->size - pos;
sb->paint (offs, ch, samps, sub);
sb->paint (offs + sub, ch, sb->data, count - sub);
} else {
sb->paint (offs, ch, samps, count);
}
ch->pos += count;
}
void
SND_PaintChannels (snd_t *snd, unsigned endtime)
{
unsigned end, ltime;
int i, count;
channel_t *ch;
sfxbuffer_t *sb;
// clear the paint buffer
for (i = 0; i < PAINTBUFFER_SIZE * 2; i++) {
snd_paintbuffer[i].left = 0;
snd_paintbuffer[i].right = 0;
}
while (snd->paintedtime < endtime) {
// if snd_paintbuffer is smaller than DMA buffer
end = endtime;
if (end - snd->paintedtime > PAINTBUFFER_SIZE)
end = snd->paintedtime + PAINTBUFFER_SIZE;
max_overpaint = 0;
// paint in the channels.
ch = snd_channels;
for (i = 0; i < snd_total_channels; i++, ch++) {
if (!(sb = ch->buffer) || ch->done) {
// channel is inactive
continue;
}
if (ch->stop) {
ch->done = 1; // acknowledge stopped signal
continue;
}
if (ch->pause)
continue;
if (!ch->end)
ch->end = snd->paintedtime + sb->sfx_length - ch->pos;
ltime = snd->paintedtime;
while (ltime < end) { // paint up to end
count = ((ch->end < end) ? ch->end : end) - ltime;
if (count > 0) {
if (ch->leftvol || ch->rightvol) {
snd_paint_channel (ch, sb, count);
if (sb->advance) {
if (!sb->advance (sb, count)) {
// this channel can no longer be used as its
// source has died.
ch->done = 1;
break;
}
}
}
ltime += count;
}
if (check_channel_end (ch, sb, count, ltime))
break;
}
}
// transfer out according to DMA format
snd->xfer (snd, snd_paintbuffer, end - snd->paintedtime,
snd_volume);
memmove (snd_paintbuffer, snd_paintbuffer + end - snd->paintedtime,
max_overpaint * sizeof (snd_paintbuffer[0]));
memset (snd_paintbuffer + max_overpaint, 0, sizeof (snd_paintbuffer)
- max_overpaint * sizeof (snd_paintbuffer[0]));
snd->paintedtime = end;
}
}
static inline void
snd_mix_single (portable_samplepair_t *pair, float **samp,
float lvol, float rvol)
{
float single = *(*samp)++;
pair->left += single * lvol;
pair->right += single * rvol;
}
static inline void
snd_mix_pair (portable_samplepair_t *pair, float **samp,
float lvol, float rvol)
{
float left = *(*samp)++;
float right = *(*samp)++;
pair->left += left * lvol;
pair->right += right * rvol;
}
static inline void
snd_mix_triple (portable_samplepair_t *pair, float **samp,
float lvol, float rvol)
{
float left = *(*samp)++;
float center = *(*samp)++;
float right = *(*samp)++;
pair->left += left * lvol;
pair->left += center * lvol;
pair->right += center * rvol;
pair->right += right * rvol;
}
/* mono
center
Spacializes the sound.
*/
static void
snd_paint_mono (int offs, channel_t *ch, float *sfx, unsigned count)
{
float leftvol, rightvol;
unsigned left_phase, right_phase; // Never allowed < 0 anyway
unsigned i = 0;
portable_samplepair_t *pair;
leftvol = ch->leftvol * VOLSCALE;
rightvol = ch->rightvol * VOLSCALE;
max_overpaint = max (abs (ch->phase),
max (abs (ch->oldphase), max_overpaint));
pair = snd_paintbuffer + offs;
if (ch->phase >= 0) {
left_phase = ch->phase;
right_phase = 0;
} else {
left_phase = 0;
right_phase = -ch->phase;
}
if (ch->oldphase != ch->phase) {
unsigned old_phase_left, old_phase_right;
unsigned new_phase_left, new_phase_right;
unsigned count_left, count_right, c;
if (ch->oldphase >= 0) {
old_phase_left = ch->oldphase;
old_phase_right = 0;
} else {
old_phase_left = 0;
old_phase_right = -ch->oldphase;
}
new_phase_left = left_phase;
new_phase_right = right_phase;
if (new_phase_left > old_phase_left)
count_left = 2 * (new_phase_left - old_phase_left);
else
count_left = old_phase_left - new_phase_left;
if (new_phase_right > old_phase_right)
count_right = 2 * (new_phase_right - old_phase_right);
else
count_right = old_phase_right - new_phase_right;
c = min (count, max (count_right, count_left));
count -= c;
while (c) {
float left = sfx[i] * leftvol;
float right = sfx[i] * rightvol;
if (new_phase_left < old_phase_left) {
if (!(count_left & 1)) {
pair[i + old_phase_left].left += left;
old_phase_left--;
}
count_left--;
} else {
if (new_phase_left > old_phase_left) {
pair[i + old_phase_left].left += left;
old_phase_left++;
}
pair[i + old_phase_left].left += left;
}
if (new_phase_right < old_phase_right) {
if (!(count_right & 1)) {
pair[i + old_phase_right].right += right;
old_phase_right--;
}
count_right--;
} else {
if (new_phase_right > old_phase_right) {
pair[i + old_phase_right].right += right;
old_phase_right++;
}
pair[i + old_phase_right].right += right;
}
c--;
i++;
}
}
for (i = 0; i < count; i++) {
pair[i + left_phase].left += sfx[i] * leftvol;
pair[i + right_phase].right += sfx[i] * rightvol;
}
}
/* stereo
left, right
Does not spacialize the sound.
*/
static void
snd_paint_stereo (int offs, channel_t *ch, float *samp, unsigned count)
{
portable_samplepair_t *pair;
float leftvol = ch->leftvol * VOLSCALE;
float rightvol = ch->rightvol * VOLSCALE;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
snd_mix_pair (pair, &samp, leftvol, rightvol);
pair++;
}
}
/* 1d surround
left, center, right
Does not spacialize the sound.
*/
static void
snd_paint_3 (int offs, channel_t *ch, float *samp, unsigned count)
{
portable_samplepair_t *pair;
float leftvol = ch->leftvol * VOLSCALE;
float rightvol = ch->rightvol * VOLSCALE;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
snd_mix_triple (pair, &samp, leftvol, rightvol);
pair++;
}
}
/* quadraphonic surround
front (left, right),
rear (left, right)
Does not spacialize the sound.
*/
static void
snd_paint_4 (int offs, channel_t *ch, float *samp, unsigned count)
{
portable_samplepair_t *pair;
float leftvol = ch->leftvol * VOLSCALE;
float rightvol = ch->rightvol * VOLSCALE;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
snd_mix_pair (pair, &samp, leftvol, rightvol);
snd_mix_pair (pair, &samp, leftvol, rightvol);
pair++;
}
}
/* five-channel surround
front (left, center, right),
rear (left, right)
Does not spacialize the sound.
*/
static void
snd_paint_5 (int offs, channel_t *ch, float *samp, unsigned count)
{
portable_samplepair_t *pair;
float leftvol = ch->leftvol * VOLSCALE;
float rightvol = ch->rightvol * VOLSCALE;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
snd_mix_triple (pair, &samp, leftvol, rightvol);
snd_mix_pair (pair, &samp, leftvol, rightvol);
pair++;
}
}
/* 5.1 surround
front (left, center, right),
rear (left, right),
lfe
Does not spacialize the sound.
*/
static void
snd_paint_6 (int offs, channel_t *ch, float *samp, unsigned count)
{
portable_samplepair_t *pair;
float leftvol = ch->leftvol * VOLSCALE;
float rightvol = ch->rightvol * VOLSCALE;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
snd_mix_triple (pair, &samp, leftvol, rightvol);
snd_mix_pair (pair, &samp, leftvol, rightvol);
snd_mix_single (pair, &samp, leftvol, rightvol);
pair++;
}
}
/* 6.1 surround
front (left, center, right),
side (left, right),
rear (center),
lfe
Does not spacialize the sound.
*/
static void
snd_paint_7 (int offs, channel_t *ch, float *samp, unsigned count)
{
portable_samplepair_t *pair;
float leftvol = ch->leftvol * VOLSCALE;
float rightvol = ch->rightvol * VOLSCALE;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
snd_mix_triple (pair, &samp, leftvol, rightvol);
snd_mix_pair (pair, &samp, leftvol, rightvol);
snd_mix_single (pair, &samp, leftvol, rightvol);
snd_mix_single (pair, &samp, leftvol, rightvol);
pair++;
}
}
/* 7.1 surround
front (left, center, right),
side (left, right),
rear (left, right),
lfe
Does not spacialize the sound.
*/
static void
snd_paint_8 (int offs, channel_t *ch, float *samp, unsigned count)
{
portable_samplepair_t *pair;
float leftvol = ch->leftvol * VOLSCALE;
float rightvol = ch->rightvol * VOLSCALE;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
snd_mix_triple (pair, &samp, leftvol, rightvol);
snd_mix_pair (pair, &samp, leftvol, rightvol);
snd_mix_pair (pair, &samp, leftvol, rightvol);
snd_mix_single (pair, &samp, leftvol, rightvol);
pair++;
}
}
void
SND_SetPaint (sfxbuffer_t *sb)
{
static sfxpaint_t *painters[] = {
0,
snd_paint_mono,
snd_paint_stereo,
snd_paint_3,
snd_paint_4,
snd_paint_5,
snd_paint_6,
snd_paint_7,
snd_paint_8,
};
if (sb->channels > 8 || !sb->channels)
Sys_Error ("invaliid channel count %d", sb->channels);
sb->paint = painters[sb->channels];
}