quakeforge/libs/audio/renderer/snd_mix.c
2007-03-17 07:05:24 +00:00

393 lines
8.9 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
static __attribute__ ((used)) const char rcsid[] =
"$Id$";
#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_render.h"
portable_samplepair_t snd_paintbuffer[PAINTBUFFER_SIZE * 2];
static int max_overpaint; // number of extra samples painted
// due to phase shift
static int snd_scaletable[32][256];
/* CHANNEL MIXING */
void
SND_PaintChannels (unsigned int endtime)
{
unsigned int end, ltime;
int i, count;
channel_t *ch;
sfxbuffer_t *sc;
while (snd_paintedtime < endtime) {
// if snd_paintbuffer is smaller than DMA buffer
end = endtime;
if (endtime - snd_paintedtime > PAINTBUFFER_SIZE)
end = snd_paintedtime + PAINTBUFFER_SIZE;
// clear the paint buffer
// memset (snd_paintbuffer, 0, (end - snd_paintedtime) *
// sizeof (portable_samplepair_t));
max_overpaint = 0;
// paint in the channels.
ch = snd_channels;
for (i = 0; i < snd_total_channels; i++, ch++) {
if (!ch->sfx)
continue;
if (!ch->leftvol && !ch->rightvol)
continue;
sc = ch->sfx->retain (ch->sfx);
if (!sc)
continue;
ltime = snd_paintedtime;
while (ltime < end) { // paint up to end
if (ch->end < end)
count = ch->end - ltime;
else
count = end - ltime;
if (count > 0) {
sc->paint (ch, sc, count);
if (sc->advance)
sc->advance (sc, count);
ltime += count;
}
// if at end of loop, restart
if (ltime >= ch->end) {
if (ch->sfx->loopstart != (unsigned int) -1) {
ch->pos = ch->sfx->loopstart;
ch->end = ltime + ch->sfx->length - ch->pos;
} else { // channel just stopped
ch->sfx->release (ch->sfx);
SND_ChannelStop (ch);
break;
}
}
}
if (ch->sfx)
ch->sfx->release (ch->sfx);
}
// transfer out according to DMA format
snd_shm->xfer (end);
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;
}
}
void
SND_InitScaletable (void)
{
int i, j;
for (i = 0; i < 32; i++)
for (j = 0; j < 256; j++)
snd_scaletable[i][j] = ((signed char) j) * i * 8;
}
static void
snd_paint_mono_8 (int offs, channel_t *ch, void *bytes, unsigned int count)
{
unsigned char *sfx;
int data;
unsigned int i;
int *lscale, *rscale;
portable_samplepair_t *pair;
if (ch->leftvol > 255)
ch->leftvol = 255;
if (ch->rightvol > 255)
ch->rightvol = 255;
lscale = snd_scaletable[ch->leftvol >> 3];
rscale = snd_scaletable[ch->rightvol >> 3];
sfx = (unsigned char *) bytes;
pair = snd_paintbuffer + offs;
for (i = 0; i < count; i++) {
data = sfx[i];
pair[i].left += lscale[data];
pair[i].right += rscale[data];
}
}
static void
snd_paint_mono_16 (int offs, channel_t *ch, void *bytes, unsigned int count)
{
int leftvol, rightvol;
unsigned int left_phase, right_phase; // Never allowed < 0 anyway
unsigned int i = 0;
signed short *sfx;
portable_samplepair_t *pair;
leftvol = ch->leftvol;
rightvol = ch->rightvol;
max_overpaint = max (abs (ch->phase),
max (abs (ch->oldphase), max_overpaint));
sfx = (signed short *) bytes;
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 int old_phase_left, old_phase_right;
unsigned int new_phase_left, new_phase_right;
unsigned int 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) {
int left = (sfx[i] * leftvol) >> 8;
int right = (sfx[i] * rightvol) >> 8;
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) >> 8;
pair[i + right_phase].right += (sfx[i] * rightvol) >> 8;
}
}
static void
snd_paint_stereo_8 (int offs, channel_t *ch, void *bytes, unsigned int count)
{
byte *samp;
portable_samplepair_t *pair;
int *lscale, *rscale;
if (ch->leftvol > 255)
ch->leftvol = 255;
if (ch->rightvol > 255)
ch->rightvol = 255;
lscale = snd_scaletable[ch->leftvol >> 3];
rscale = snd_scaletable[ch->rightvol >> 3];
samp = bytes;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
pair->left += lscale[*samp++];
pair->right += rscale[*samp++];
pair++;
}
}
static void
snd_paint_stereo_16 (int offs, channel_t *ch, void *bytes, unsigned int count)
{
short *samp;
portable_samplepair_t *pair;
int leftvol = ch->leftvol;
int rightvol = ch->rightvol;
samp = (short *) bytes;
pair = snd_paintbuffer + offs;
while (count-- > 0) {
pair->left += (*samp++ * leftvol) >> 8;
pair->right += (*samp++ * rightvol) >> 8;
pair++;
}
}
void
SND_PaintChannelFrom8 (channel_t *ch, sfxbuffer_t *sc, int count)
{
unsigned int pos;
byte *samps;
if (ch->pos < sc->pos)
sc->setpos (sc, ch->pos);
pos = (ch->pos - sc->pos + sc->tail) % sc->length;
samps = sc->data + pos;
if (pos + count > sc->length) {
int sub = sc->length - pos;
snd_paint_mono_8 (0, ch, samps, sub);
snd_paint_mono_8 (sub, ch, sc->data, count - sub);
} else {
snd_paint_mono_8 (0, ch, samps, count);
}
ch->pos += count;
}
void
SND_PaintChannelFrom16 (channel_t *ch, sfxbuffer_t *sc, int count)
{
unsigned int pos;
short *samps;
if (ch->pos < sc->pos)
sc->setpos (sc, ch->pos);
pos = (ch->pos - sc->pos + sc->tail) % sc->length;
samps = (short *) sc->data + pos;
if (pos + count > sc->length) {
unsigned int sub = sc->length - pos;
snd_paint_mono_16 (0, ch, samps, sub);
snd_paint_mono_16 (sub, ch, sc->data, count - sub);
} else {
snd_paint_mono_16 (0, ch, samps, count);
}
ch->pos += count;
}
void
SND_PaintChannelStereo8 (channel_t *ch, sfxbuffer_t *sc, int count)
{
unsigned int pos;
short *samps;
if (ch->pos < sc->pos)
sc->setpos (sc, ch->pos);
pos = (ch->pos - sc->pos + sc->tail) % sc->length;
samps = (short *) sc->data + pos;
if (pos + count > sc->length) {
unsigned int sub = sc->length - pos;
snd_paint_stereo_8 (0, ch, samps, sub);
snd_paint_stereo_8 (sub, ch, sc->data, count - sub);
} else {
snd_paint_stereo_8 (0, ch, samps, count);
}
ch->pos += count;
}
void
SND_PaintChannelStereo16 (channel_t *ch, sfxbuffer_t *sc, int count)
{
unsigned int pos;
int *samps;
if (ch->pos < sc->pos)
sc->setpos (sc, ch->pos);
pos = (ch->pos - sc->pos + sc->tail) % sc->length;
samps = (int *) sc->data + pos;
if (pos + count > sc->length) {
unsigned int sub = sc->length - pos;
snd_paint_stereo_16 (0, ch, samps, sub);
snd_paint_stereo_16 (sub, ch, sc->data, count - sub);
} else {
snd_paint_stereo_16 (0, ch, samps, count);
}
ch->pos += count;
}