-Added SDL sound support (still needs a bit debugging, though).

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@4271 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/snd_sdl.c b/snd_sdl.c
new file mode 100644 (file)
index 0000000..45b359a
--- /dev/null
+++ b/snd_sdl.c
@@ -0,0 +1,205 @@
+/*
+Copyright (C) 2004 Andreas Kirsch
+
+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.
+*/
+#include "quakedef.h"
+#include <SDL.h>
+
+/*
+Info:
+One SDL sample consists of x channel samples
+The mixer supposes that the driver has one channel entry/sample though it has x channels/sample
+like the SDL
+*/
+
+#define AUDIO_SDL_SAMPLES              4096
+#define AUDIO_LOCALFACTOR              4
+
+typedef struct AudioState_s
+{
+       int             width;
+    int                size;
+       int             pos;
+       void    *buffer;
+} AudioState;
+
+
+extern mempool_t *snd_mempool;
+static AudioState       as;
+
+static void Buffer_Callback(void *userdata, Uint8 *stream, int len);
+
+/*
+==================
+S_BlockSound
+==================
+*/
+void S_BlockSound( void )
+{
+       snd_blocked++;
+
+       if( snd_blocked == 1 )
+               SDL_PauseAudio( true );
+}
+
+
+/*
+==================
+S_UnblockSound
+==================
+*/
+void S_UnblockSound( void )
+{
+       snd_blocked--;
+       if( snd_blocked == 0 )
+               SDL_PauseAudio( false );
+}
+
+
+/*
+==================
+SNDDMA_Init
+
+Try to find a sound device to mix for.
+Returns false if nothing is found.
+==================
+*/
+
+qboolean SNDDMA_Init(void)
+{
+       SDL_AudioSpec spec;
+       int i;
+
+       // Init the SDL Audio subsystem
+       if( SDL_InitSubSystem( SDL_INIT_AUDIO ) ) {
+               Con_SafePrint( "Initializing the SDL Audio subsystem failed!\n" );
+               return false;
+       }
+
+       // Init the shm structure
+       memset( (void*) shm, 0, sizeof(*shm) );
+       
+       shm->format.channels = 2; //stereo
+       shm->format.width = 2;
+
+       i = COM_CheckParm( "-sndspeed" );
+       if( i && i != ( com_argc - 1 ) )
+               shm->format.speed = atoi( com_argv[ i+1 ] );
+       else
+               shm->format.speed = 44100;
+
+       shm->samplepos = 0;
+       shm->samples = AUDIO_SDL_SAMPLES * AUDIO_LOCALFACTOR;
+       shm->bufferlength = shm->samples * shm->format.width;
+       shm->buffer = Mem_Alloc( snd_mempool, shm->bufferlength );
+
+       // Init the as structure
+       as.buffer = shm->buffer;
+       as.width = shm->format.width;
+       as.pos = 0;
+       as.size = shm->bufferlength;
+
+       // Init the SDL Audio subsystem
+       spec.callback = Buffer_Callback;
+       spec.channels = shm->format.channels;
+       spec.format = AUDIO_S16LSB;
+       spec.freq = shm->format.speed;
+       spec.userdata = NULL;
+       spec.samples = AUDIO_SDL_SAMPLES; 
+       
+       if( SDL_OpenAudio( &spec, NULL ) ) {
+               Con_SafePrint( "Failed to open the audio device!\n" );
+               Con_DPrintf( 
+                       "Audio Specification:\n"
+                       "\tChannels  : %i\n"
+                       "\tFormat    : %x\n"
+                       "\tFrequency : %i\n"
+                       "\tBuffersize: %i Bytes(%i Samples)\n", 
+                       spec.channels, spec.format, spec.freq, shm->bufferlength , spec.samples );
+               Mem_Free( shm->buffer ); 
+               return false;
+       }
+
+       SDL_PauseAudio( false );
+
+       return true;
+}
+
+/*
+==============
+SNDDMA_GetDMAPos
+
+return the current sample position (in mono samples read)
+inside the recirculating dma buffer, so the mixing code will know
+how many sample are required to fill it up.
+===============
+*/
+int SNDDMA_GetDMAPos(void)
+{
+       shm->samplepos = (as.pos / as.width) % shm->samples;
+       return shm->samplepos;
+}
+
+/*
+==============
+SNDDMA_Submit
+
+Send sound to device if buffer isn't really the dma buffer
+===============
+*/
+void SNDDMA_Submit(void)
+{
+
+}
+
+/*
+==============
+SNDDMA_Shutdown
+
+Reset the sound device for exiting
+===============
+*/
+void SNDDMA_Shutdown(void)
+{
+       SDL_CloseAudio();
+       Mem_Free( as.buffer );
+}
+
+void *S_LockBuffer(void)
+{
+       SDL_LockAudio();
+       return shm->buffer;
+}
+
+void S_UnlockBuffer(void)
+{
+       SDL_UnlockAudio();
+}
+
+static void Buffer_Callback(void *userdata, Uint8 *stream, int len)
+{
+       if( len > as.size )
+               len = as.size;
+       if( len > as.size - as.pos ) {
+               memcpy( stream, (Uint8*) as.buffer + as.pos, as.size - as.pos );
+               len -= as.size - as.pos;
+               as.pos = 0;
+       }
+       memcpy( stream, (Uint8*) as.buffer + as.pos, len );
+       as.pos = (as.pos + len) % as.size;
+}
+