yquake2remaster/src/backends/sdl/sound.c
2013-05-11 15:29:02 +02:00

1346 lines
24 KiB
C

/*
* Copyright (C) 1997-2001 Id Software, Inc.
* Copyright (C) 2010, 2013 Yamagi Burmeister
* Copyright (C) 2005 Ryan C. Gordon
*
* 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.
*
* =======================================================================
*
* SDL sound backend. Since SDL is just an API for sound playback, we
* must caculate everything in software: mixing, resampling, stereo
* spartializations, etc. Therefor this file is rather complex. :)
* Samples are read from the cache (see the upper layer of the sound
* system), manipulated and written into sound.buffer. sound.buffer is
* passed to SDL (in fact requested by SDL via the callback) and played
* with a platform dependend SDL driver. Parts of this file are based
* on ioQuake3s snd_sdl.c.
*
* =======================================================================
*/
/* SDL includes */
#ifdef _WIN32
#include <SDL/SDL.h>
#elif defined(__APPLE__)
#include <SDL/SDL.h>
#else
#include <SDL.h>
#endif
/* Local includes */
#include "../../client/header/client.h"
#include "../../client/sound/header/local.h"
/* Defines */
#define SDL_PAINTBUFFER_SIZE 2048
#define SDL_FULLVOLUME 80
#define SDL_LOOPATTENUATE 0.003
/* Globals */
cvar_t *s_sdldriver;
int *snd_p;
static sound_t *backend;
static portable_samplepair_t paintbuffer[SDL_PAINTBUFFER_SIZE];
static int beginofs;
static int playpos = 0;
static int samplesize = 0;
static int snd_inited = 0;
static int snd_scaletable[32][256];
static int snd_vol;
static int soundtime;
/* ------------------------------------------------------------------ */
/*
* Transfers a mixed "paint buffer" to
* the SDL output buffer and places it
* at the appropriate position.
*/
void
SDL_TransferPaintBuffer(int endtime)
{
int i;
int lpos;
int ls_paintedtime;
int out_idx;
int count;
int out_mask;
int *p;
int snd_linear_count;
int step;
int val;
short *snd_out;
unsigned char *pbuf;
pbuf = sound.buffer;
if (s_testsound->value)
{
int i;
int count;
/* write a fixed sine wave */
count = (endtime - paintedtime);
for (i = 0; i < count; i++)
{
paintbuffer[i].left = paintbuffer[i].right =
(int)((float)sin((paintedtime + i) * 0.1f) * 20000 * 256);
}
}
if ((sound.samplebits == 16) && (sound.channels == 2))
{
snd_p = (int *)paintbuffer;
ls_paintedtime = paintedtime;
while (ls_paintedtime < endtime)
{
lpos = ls_paintedtime & ((sound.samples >> 1) - 1);
snd_out = (short *)pbuf + (lpos << 1);
snd_linear_count = (sound.samples >> 1) - lpos;
if (ls_paintedtime + snd_linear_count > endtime)
{
snd_linear_count = endtime - ls_paintedtime;
}
snd_linear_count <<= 1;
for (i = 0; i < snd_linear_count; i += 2)
{
val = snd_p[i] >> 8;
if (val > 0x7fff)
{
snd_out[i] = 0x7fff;
}
else if (val < -32768)
{
snd_out[i] = -32768;
}
else
{
snd_out[i] = val;
}
val = snd_p[i + 1] >> 8;
if (val > 0x7fff)
{
snd_out[i + 1] = 0x7fff;
}
else if (val < -32768)
{
snd_out[i + 1] = -32768;
}
else
{
snd_out[i + 1] = val;
}
}
snd_p += snd_linear_count;
ls_paintedtime += (snd_linear_count >> 1);
}
}
else
{
p = (int *)paintbuffer;
count = (endtime - paintedtime) * sound.channels;
out_mask = sound.samples - 1;
out_idx = paintedtime * sound.channels & out_mask;
step = 3 - sound.channels;
if (sound.samplebits == 16)
{
short *out = (short *)pbuf;
while (count--)
{
val = *p >> 8;
p += step;
if (val > 0x7fff)
{
val = 0x7fff;
}
else if (val < -32768)
{
val = -32768;
}
out[out_idx] = val;
out_idx = (out_idx + 1) & out_mask;
}
}
else if (sound.samplebits == 8)
{
unsigned char *out = (unsigned char *)pbuf;
while (count--)
{
val = *p >> 8;
p += step;
if (val > 0x7fff)
{
val = 0x7fff;
}
else if (val < -32768)
{
val = -32768;
}
out[out_idx] = (val >> 8) + 128;
out_idx = (out_idx + 1) & out_mask;
}
}
}
}
/*
* Mixes an 8 bit sample into a channel.
*/
void
SDL_PaintChannelFrom8(channel_t *ch, sfxcache_t *sc, int count, int offset)
{
int data;
int *lscale, *rscale;
unsigned char *sfx;
int i;
portable_samplepair_t *samp;
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 = sc->data + ch->pos;
samp = &paintbuffer[offset];
for (i = 0; i < count; i++, samp++)
{
data = sfx[i];
samp->left += lscale[data];
samp->right += rscale[data];
}
ch->pos += count;
}
/*
* Mixes an 16 bit sample into a channel
*/
void
SDL_PaintChannelFrom16(channel_t *ch, sfxcache_t *sc, int count, int offset)
{
int data;
int left, right;
int leftvol, rightvol;
signed short *sfx;
int i;
portable_samplepair_t *samp;
leftvol = ch->leftvol * snd_vol;
rightvol = ch->rightvol * snd_vol;
sfx = (signed short *)sc->data + ch->pos;
samp = &paintbuffer[offset];
for (i = 0; i < count; i++, samp++)
{
data = sfx[i];
left = (data * leftvol) >> 8;
right = (data * rightvol) >> 8;
samp->left += left;
samp->right += right;
}
ch->pos += count;
}
/*
* Mixes all pending sounds into
* the available output channels.
*/
void
SDL_PaintChannels(int endtime)
{
int i;
int end;
channel_t *ch;
sfxcache_t *sc;
int ltime, count;
playsound_t *ps;
snd_vol = (int)(s_volume->value * 256);
while (paintedtime < endtime)
{
/* if paintbuffer is smaller than SDL buffer */
end = endtime;
if (endtime - paintedtime > SDL_PAINTBUFFER_SIZE)
{
end = paintedtime + SDL_PAINTBUFFER_SIZE;
}
/* start any playsounds */
for ( ; ; )
{
ps = s_pendingplays.next;
if (ps == NULL)
{
break;
}
if (ps == &s_pendingplays)
{
break; /* no more pending sounds */
}
if (ps->begin <= paintedtime)
{
S_IssuePlaysound(ps);
continue;
}
if (ps->begin < end)
{
end = ps->begin; /* stop here */
}
break;
}
/* clear the paint buffer */
if (s_rawend < paintedtime)
{
memset(paintbuffer, 0, (end - paintedtime)
* sizeof(portable_samplepair_t));
}
else
{
/* copy from the streaming sound source */
int s;
int stop;
stop = (end < s_rawend) ? end : s_rawend;
for (i = paintedtime; i < stop; i++)
{
s = i & (MAX_RAW_SAMPLES - 1);
paintbuffer[i - paintedtime] = s_rawsamples[s];
}
for ( ; i < end; i++)
{
memset(&paintbuffer[i - paintedtime], 0,
sizeof(paintbuffer[i - paintedtime]));
}
}
/* paint in the channels. */
ch = channels;
for (i = 0; i < s_numchannels; i++, ch++)
{
ltime = paintedtime;
while (ltime < end)
{
if (!ch->sfx || (!ch->leftvol && !ch->rightvol))
{
break;
}
/* max painting is to the end of the buffer */
count = end - ltime;
/* might be stopped by running out of data */
if (ch->end - ltime < count)
{
count = ch->end - ltime;
}
sc = S_LoadSound(ch->sfx);
if (!sc)
{
break;
}
if ((count > 0) && ch->sfx)
{
if (sc->width == 1)
{
SDL_PaintChannelFrom8(ch, sc, count, ltime - paintedtime);
}
else
{
SDL_PaintChannelFrom16(ch, sc, count, ltime - paintedtime);
}
ltime += count;
}
/* if at end of loop, restart */
if (ltime >= ch->end)
{
if (ch->autosound)
{
/* autolooping sounds always go back to start */
ch->pos = 0;
ch->end = ltime + sc->length;
}
else if (sc->loopstart >= 0)
{
ch->pos = sc->loopstart;
ch->end = ltime + sc->length - ch->pos;
}
else
{
/* channel just stopped */
ch->sfx = NULL;
}
}
}
}
/* transfer out according to SDL format */
SDL_TransferPaintBuffer(end);
paintedtime = end;
}
}
/* ------------------------------------------------------------------ */
/*
* Calculates when a sound
* must be started.
*/
int
SDL_DriftBeginofs(float timeofs)
{
int start = (int)(cl.frame.servertime * 0.001f * sound.speed + beginofs);
if (start < paintedtime)
{
start = paintedtime;
beginofs = (int)(start - (cl.frame.servertime * 0.001f * sound.speed));
}
else if (start > paintedtime + 0.3f * sound.speed)
{
start = (int)(paintedtime + 0.1f * sound.speed);
beginofs = (int)(start - (cl.frame.servertime * 0.001f * sound.speed));
}
else
{
beginofs -= 10;
}
return timeofs ? start + timeofs * sound.speed : paintedtime;
}
/*
* Spatialize a sound effect based on it's origin.
*/
void
SDL_SpatializeOrigin(vec3_t origin, float master_vol, float dist_mult,
int *left_vol, int *right_vol)
{
vec_t dot;
vec_t dist;
vec_t lscale, rscale, scale;
vec3_t source_vec;
if (cls.state != ca_active)
{
*left_vol = *right_vol = 255;
return;
}
/* Calculate stereo seperation and distance attenuation */
VectorSubtract(origin, listener_origin, source_vec);
dist = VectorNormalize(source_vec);
dist -= SDL_FULLVOLUME;
if (dist < 0)
{
dist = 0; /* Close enough to be at full volume */
}
dist *= dist_mult;
dot = DotProduct(listener_right, source_vec);
if ((sound.channels == 1) || !dist_mult)
{
rscale = 1.0f;
lscale = 1.0f;
}
else
{
rscale = 0.5f * (1.0f + dot);
lscale = 0.5f * (1.0f - dot);
}
/* Add in distance effect */
scale = (1.0f - dist) * rscale;
*right_vol = (int)(master_vol * scale);
if (*right_vol < 0)
{
*right_vol = 0;
}
scale = (1.0 - dist) * lscale;
*left_vol = (int)(master_vol * scale);
if (*left_vol < 0)
{
*left_vol = 0;
}
}
/*
* Spatializes a channel.
*/
void
SDL_Spatialize(channel_t *ch)
{
vec3_t origin;
/* Anything coming from the view entity
will always be full volume */
if (ch->entnum == cl.playernum + 1)
{
ch->leftvol = ch->master_vol;
ch->rightvol = ch->master_vol;
return;
}
if (ch->fixed_origin)
{
VectorCopy(ch->origin, origin);
}
else
{
CL_GetEntitySoundOrigin(ch->entnum, origin);
}
SDL_SpatializeOrigin(origin, (float)ch->master_vol, ch->dist_mult,
&ch->leftvol, &ch->rightvol);
}
/*
* Entities with a "sound" field will generated looped sounds
* that are automatically started, stopped, and merged together
* as the entities are sent to the client
*/
void
SDL_AddLoopSounds(void)
{
int i, j;
int sounds[MAX_EDICTS];
int left, right, left_total, right_total;
channel_t *ch;
sfx_t *sfx;
sfxcache_t *sc;
int num;
entity_state_t *ent;
vec3_t origin;
if (cl_paused->value)
{
return;
}
if (cls.state != ca_active)
{
return;
}
if (!cl.sound_prepped || !s_ambient->value)
{
return;
}
memset(&sounds, 0, sizeof(int) * MAX_EDICTS);
S_BuildSoundList(sounds);
for (i = 0; i < cl.frame.num_entities; i++)
{
if (!sounds[i])
{
continue;
}
sfx = cl.sound_precache[sounds[i]];
if (!sfx)
{
continue; /* bad sound effect */
}
sc = sfx->cache;
if (!sc)
{
continue;
}
num = (cl.frame.parse_entities + i) & (MAX_PARSE_ENTITIES - 1);
ent = &cl_parse_entities[num];
CL_GetEntitySoundOrigin(ent->number, origin);
/* find the total contribution of all sounds of this type */
SDL_SpatializeOrigin(ent->origin, 255.0f, SDL_LOOPATTENUATE,
&left_total, &right_total);
for (j = i + 1; j < cl.frame.num_entities; j++)
{
if (sounds[j] != sounds[i])
{
continue;
}
sounds[j] = 0; /* don't check this again later */
num = (cl.frame.parse_entities + j) & (MAX_PARSE_ENTITIES - 1);
ent = &cl_parse_entities[num];
SDL_SpatializeOrigin(ent->origin, 255.0f, SDL_LOOPATTENUATE, &left, &right);
left_total += left;
right_total += right;
}
if ((left_total == 0) && (right_total == 0))
{
continue; /* not audible */
}
/* allocate a channel */
ch = S_PickChannel(0, 0);
if (!ch)
{
return;
}
if (left_total > 255)
{
left_total = 255;
}
if (right_total > 255)
{
right_total = 255;
}
ch->leftvol = left_total;
ch->rightvol = right_total;
ch->autosound = true; /* remove next frame */
ch->sfx = sfx;
/* Sometimes, the sc->length argument can become 0,
and in that case we get a SIGFPE in the next
modulo operation. The workaround checks for this
situation and in that case, sets the pos and end
parameters to 0. */
if (sc->length == 0)
{
ch->pos = 0;
ch->end = 0;
}
else
{
ch->pos = paintedtime % sc->length;
ch->end = paintedtime + sc->length - ch->pos;
}
}
}
/*
* Clears the playback buffer so
* that all playback stops.
*/
void
SDL_ClearBuffer(void)
{
int clear;
int i;
unsigned char *ptr = sound.buffer;
if (!sound_started)
{
return;
}
s_rawend = 0;
if (sound.samplebits == 8)
{
clear = 0x80;
}
else
{
clear = 0;
}
SDL_LockAudio();
if (sound.buffer)
{
i = sound.samples * sound.samplebits / 8;
while (i--)
{
*ptr = clear;
ptr++;
}
}
SDL_UnlockAudio();
}
/*
* Calculates the absolute timecode
* of current playback.
*/
void
SDL_UpdateSoundtime(void)
{
static int buffers;
static int oldsamplepos;
int fullsamples;
fullsamples = sound.samples / sound.channels;
/* it is possible to miscount buffers if it has wrapped twice between
calls to S_Update. Oh well. This a hack around that. */
if (playpos < oldsamplepos)
{
buffers++; /* buffer wrapped */
if (paintedtime > 0x40000000)
{
/* time to chop things off to avoid 32 bit limits */
buffers = 0;
paintedtime = fullsamples;
S_StopAllSounds();
}
}
oldsamplepos = playpos;
soundtime = buffers * fullsamples + playpos / sound.channels;
}
/*
* Updates the volume scale table
* based on current volume setting.
*/
void
SDL_UpdateScaletable(void)
{
int i, j;
int scale;
if (s_volume->value > 2.0f)
{
Cvar_Set("s_volume", "2");
}
else if (s_volume->value < 0)
{
Cvar_Set("s_volume", "0");
}
s_volume->modified = false;
for (i = 0; i < 32; i++)
{
scale = (int)(i * 8 * 256 * s_volume->value);
for (j = 0; j < 256; j++)
{
snd_scaletable[i][j] = ((j < 128) ? j : j - 0xff) * scale;
}
}
}
/*
* Saves a sound sample into cache. If
* necessary endianess convertions are
* performed.
*/
qboolean
SDL_Cache(sfx_t *sfx, wavinfo_t *info, byte *data)
{
float stepscale;
int i;
int len;
int sample;
int srcsample;
sfxcache_t *sc;
unsigned int samplefrac = 0;
stepscale = (float)info->rate / sound.speed;
len = (int)(info->samples / stepscale);
if ((info->samples == 0) || (len == 0))
{
Com_Printf("WARNING: Zero length sound encountered: %s\n", sfx->name);
return false;
}
len = len * info->width * info->channels;
sc = sfx->cache = Z_Malloc(len + sizeof(sfxcache_t));
if (!sc)
{
return false;
}
sc->loopstart = info->loopstart;
sc->stereo = 0;
sc->length = (int)(info->samples / stepscale);
sc->speed = sound.speed;
if ((int)(info->samples / stepscale) == 0)
{
Com_Printf("ResampleSfx: Invalid sound file '%s' (zero length)\n", sfx->name);
Z_Free(sfx->cache);
sfx->cache = NULL;
return false;
}
if (sc->loopstart != -1)
{
sc->loopstart = (int)(sc->loopstart / stepscale);
}
if (s_loadas8bit->value)
{
sc->width = 1;
}
else
{
sc->width = info->width;
}
/* resample / decimate to the current source rate */
for (i = 0; i < (int)(info->samples / stepscale); i++)
{
srcsample = samplefrac >> 8;
samplefrac += (int)(stepscale * 256);
if (info->width == 2)
{
sample = LittleShort(((short *)data)[srcsample]);
}
else
{
sample = (int)((unsigned char)(data[srcsample]) - 128) << 8;
}
if (sc->width == 2)
{
((short *)sc->data)[i] = sample;
}
else
{
((signed char *)sc->data)[i] = sample >> 8;
}
}
return true;
}
/*
* Playback of "raw samples", e.g. samples
* without an origin entity. Used for music
* and cinematic playback.
*/
void
SDL_RawSamples(int samples, int rate, int width,
int channels, byte *data, float volume)
{
float scale;
int dst;
int i;
int src;
int intVolume;
scale = (float)rate / sound.speed;
intVolume = (int)(256 * volume);
if ((channels == 2) && (width == 2))
{
for (i = 0; ; i++)
{
src = (int)(i * scale);
if (src >= samples)
{
break;
}
dst = s_rawend & (MAX_RAW_SAMPLES - 1);
s_rawend++;
s_rawsamples[dst].left = ((short *)data)[src * 2] * intVolume;
s_rawsamples[dst].right = ((short *)data)[src * 2 + 1] * intVolume;
}
}
else if ((channels == 1) && (width == 2))
{
for (i = 0; ; i++)
{
src = (int)(i * scale);
if (src >= samples)
{
break;
}
dst = s_rawend & (MAX_RAW_SAMPLES - 1);
s_rawend++;
s_rawsamples[dst].left = ((short *)data)[src] * intVolume;
s_rawsamples[dst].right = ((short *)data)[src] * intVolume;
}
}
else if ((channels == 2) && (width == 1))
{
intVolume *= 256;
for (i = 0; ; i++)
{
src = (int)(i * scale);
if (src >= samples)
{
break;
}
dst = s_rawend & (MAX_RAW_SAMPLES - 1);
s_rawend++;
s_rawsamples[dst].left =
(((byte *)data)[src * 2] - 128) * intVolume;
s_rawsamples[dst].right =
(((byte *)data)[src * 2 + 1] - 128) * intVolume;
}
}
else if ((channels == 1) && (width == 1))
{
intVolume *= 256;
for (i = 0; ; i++)
{
src = (int)(i * scale);
if (src >= samples)
{
break;
}
dst = s_rawend & (MAX_RAW_SAMPLES - 1);
s_rawend++;
s_rawsamples[dst].left = (((byte *)data)[src] - 128) * intVolume;
s_rawsamples[dst].right = (((byte *)data)[src] - 128) * intVolume;
}
}
}
/*
* Runs every frame, handles all necessary
* sound calculations and fills the play-
* back buffer.
*/
void
SDL_Update(void)
{
channel_t *ch;
int i;
int samps;
int total;
unsigned int endtime;
/* if the loading plaque is up, clear everything
out to make sure we aren't looping a dirty
SDL buffer while loading */
if (cls.disable_screen)
{
SDL_ClearBuffer();
return;
}
/* rebuild scale tables if
volume is modified */
if (s_volume->modified)
{
SDL_UpdateScaletable();
}
/* update spatialization
for dynamic sounds */
ch = channels;
for (i = 0; i < s_numchannels; i++, ch++)
{
if (!ch->sfx)
{
continue;
}
if (ch->autosound)
{
/* autosounds are regenerated
fresh each frame */
memset(ch, 0, sizeof(*ch));
continue;
}
/* respatialize channel */
SDL_Spatialize(ch);
if (!ch->leftvol && !ch->rightvol)
{
memset(ch, 0, sizeof(*ch));
continue;
}
}
/* add loopsounds */
SDL_AddLoopSounds();
/* debugging output */
if (s_show->value)
{
total = 0;
ch = channels;
for (i = 0; i < s_numchannels; i++, ch++)
{
if (ch->sfx && (ch->leftvol || ch->rightvol))
{
Com_Printf("%3i %3i %s\n", ch->leftvol,
ch->rightvol, ch->sfx->name);
total++;
}
}
Com_Printf("----(%i)---- painted: %i\n", total, paintedtime);
}
#ifdef OGG
/* stream music */
OGG_Stream();
#endif
if (!sound.buffer)
{
return;
}
/* Mix the samples */
SDL_LockAudio();
/* Updates SDL time */
SDL_UpdateSoundtime();
if (!soundtime)
{
return;
}
/* check to make sure that we haven't overshot */
if (paintedtime < soundtime)
{
Com_DPrintf("S_Update_ : overflow\n");
paintedtime = soundtime;
}
/* mix ahead of current position */
endtime = (int)(soundtime + s_mixahead->value * sound.speed);
/* mix to an even submission block size */
endtime = (endtime + sound.submission_chunk - 1) & ~(sound.submission_chunk - 1);
samps = sound.samples >> (sound.channels - 1);
if (endtime - soundtime > samps)
{
endtime = soundtime + samps;
}
SDL_PaintChannels(endtime);
SDL_UnlockAudio();
}
/* ------------------------------------------------------------------ */
/*
* Gives information over user
* defineable variables
*/
void
SDL_SoundInfo(void)
{
Com_Printf("%5d stereo\n", sound.channels - 1);
Com_Printf("%5d samples\n", sound.samples);
Com_Printf("%5d samplepos\n", sound.samplepos);
Com_Printf("%5d samplebits\n", sound.samplebits);
Com_Printf("%5d submission_chunk\n", sound.submission_chunk);
Com_Printf("%5d speed\n", sound.speed);
Com_Printf("%p sound buffer\n", sound.buffer);
}
/*
* Callback funktion for SDL. Writes
* sound data to SDL when requested.
*/
static void
SDL_Callback(void *data, Uint8 *stream, int length)
{
int length1;
int length2;
int pos = (playpos * (backend->samplebits / 8));
if (pos >= samplesize)
{
playpos = pos = 0;
}
/* This can't happen! */
if (!snd_inited)
{
memset(stream, '\0', length);
return;
}
int tobufferend = samplesize - pos;
if (length > tobufferend)
{
length1 = tobufferend;
length2 = length - length1;
}
else
{
length1= length;
length2 = 0;
}
memcpy(stream, backend->buffer + pos, length1);
/* Set new position */
if (length2 <= 0)
{
playpos += (length1 / (backend->samplebits / 8));
}
else
{
memcpy(stream + length1, backend->buffer, length2);
playpos = (length2 / (backend->samplebits / 8));
}
if (playpos >= samplesize)
{
playpos = 0;
}
}
/*
* Initializes the SDL sound
* backend and sets up SDL.
*/
qboolean
SDL_BackendInit(void)
{
char drivername[128];
char reqdriver[128];
SDL_AudioSpec desired;
SDL_AudioSpec obtained;
int tmp, val;
/* This should never happen,
but this is Quake 2 ... */
if (snd_inited)
{
return 1;
}
int sndbits = (Cvar_Get("sndbits", "16", CVAR_ARCHIVE))->value;
int sndfreq = (Cvar_Get("s_khz", "44", CVAR_ARCHIVE))->value;
int sndchans = (Cvar_Get("sndchannels", "2", CVAR_ARCHIVE))->value;
#ifdef _WIN32
s_sdldriver = (Cvar_Get("s_sdldriver", "dsound", CVAR_ARCHIVE));
#elif __linux__
s_sdldriver = (Cvar_Get("s_sdldriver", "alsa", CVAR_ARCHIVE));
#elif __APPLE__
s_sdldriver = (Cvar_Get("s_sdldriver", "CoreAudio", CVAR_ARCHIVE));
#else
s_sdldriver = (Cvar_Get("s_sdldriver", "dsp", CVAR_ARCHIVE));
#endif
snprintf(reqdriver, sizeof(drivername), "%s=%s", "SDL_AUDIODRIVER", s_sdldriver->string);
putenv(reqdriver);
Com_Printf("Starting SDL audio callback.\n");
if (!SDL_WasInit(SDL_INIT_AUDIO))
{
if (SDL_Init(SDL_INIT_AUDIO) == -1)
{
Com_Printf ("Couldn't init SDL audio: %s.\n", SDL_GetError ());
return 0;
}
}
if (SDL_AudioDriverName(drivername, sizeof(drivername)) == NULL)
{
strcpy(drivername, "(UNKNOWN)");
}
Com_Printf("SDL audio driver is \"%s\".\n", drivername);
memset(&desired, '\0', sizeof(desired));
memset(&obtained, '\0', sizeof(obtained));
/* Users are stupid */
if ((sndbits != 16) && (sndbits != 8))
{
sndbits = 16;
}
if (sndfreq == 48)
{
desired.freq = 48000;
}
else if (sndfreq == 44)
{
desired.freq = 44100;
}
else if (sndfreq == 22)
{
desired.freq = 22050;
}
else if (sndfreq == 11)
{
desired.freq = 11025;
}
desired.format = ((sndbits == 16) ? AUDIO_S16SYS : AUDIO_U8);
if (desired.freq <= 11025)
{
desired.samples = 256;
}
else if (desired.freq <= 22050)
{
desired.samples = 512;
}
else if (desired.freq <= 44100)
{
desired.samples = 1024;
}
else
{
desired.samples = 2048;
}
desired.channels = sndchans;
desired.callback = SDL_Callback;
/* Okay, let's try our luck */
if (SDL_OpenAudio(&desired, &obtained) == -1)
{
Com_Printf("SDL_OpenAudio() failed: %s\n", SDL_GetError());
SDL_QuitSubSystem(SDL_INIT_AUDIO);
return 0;
}
/* This points to the frontend */
backend = &sound;
playpos = 0;
backend->samplebits = obtained.format & 0xFF;
backend->channels = obtained.channels;
tmp = (obtained.samples * obtained.channels) * 10;
if (tmp & (tmp - 1))
{ /* make it a power of two */
val = 1;
while (val < tmp)
val <<= 1;
tmp = val;
}
backend->samples = tmp;
backend->submission_chunk = 1;
backend->speed = obtained.freq;
samplesize = (backend->samples * (backend->samplebits / 8));
backend->buffer = calloc(1, samplesize);
s_numchannels = MAX_CHANNELS;
SDL_UpdateScaletable();
SDL_PauseAudio(0);
Com_Printf("SDL audio initialized.\n");
soundtime = 0;
snd_inited = 1;
return 1;
}
/*
* Shuts the SDL backend down.
*/
void
SDL_BackendShutdown(void)
{
Com_Printf("Closing SDL audio device...\n");
SDL_PauseAudio(1);
SDL_CloseAudio();
SDL_QuitSubSystem(SDL_INIT_AUDIO);
free(backend->buffer);
backend->buffer = NULL;
playpos = samplesize = 0;
snd_inited = 0;
Com_Printf("SDL audio device shut down.\n");
}