diff options
Diffstat (limited to 'distrib/sdl-1.2.15/src/audio/dummy')
| -rw-r--r-- | distrib/sdl-1.2.15/src/audio/dummy/SDL_dummyaudio.c | 156 | ||||
| -rw-r--r-- | distrib/sdl-1.2.15/src/audio/dummy/SDL_dummyaudio.h | 40 |
2 files changed, 196 insertions, 0 deletions
diff --git a/distrib/sdl-1.2.15/src/audio/dummy/SDL_dummyaudio.c b/distrib/sdl-1.2.15/src/audio/dummy/SDL_dummyaudio.c new file mode 100644 index 0000000..484b50d --- /dev/null +++ b/distrib/sdl-1.2.15/src/audio/dummy/SDL_dummyaudio.c @@ -0,0 +1,156 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997-2012 Sam Lantinga + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + This library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + + Sam Lantinga + slouken@libsdl.org + + This file written by Ryan C. Gordon (icculus@icculus.org) +*/ +#include "SDL_config.h" + +/* Output audio to nowhere... */ + +#include "SDL_rwops.h" +#include "SDL_timer.h" +#include "SDL_audio.h" +#include "../SDL_audiomem.h" +#include "../SDL_audio_c.h" +#include "../SDL_audiodev_c.h" +#include "SDL_dummyaudio.h" + +/* The tag name used by DUMMY audio */ +#define DUMMYAUD_DRIVER_NAME "dummy" + +/* Audio driver functions */ +static int DUMMYAUD_OpenAudio(_THIS, SDL_AudioSpec *spec); +static void DUMMYAUD_WaitAudio(_THIS); +static void DUMMYAUD_PlayAudio(_THIS); +static Uint8 *DUMMYAUD_GetAudioBuf(_THIS); +static void DUMMYAUD_CloseAudio(_THIS); + +/* Audio driver bootstrap functions */ +static int DUMMYAUD_Available(void) +{ + const char *envr = SDL_getenv("SDL_AUDIODRIVER"); + if (envr && (SDL_strcmp(envr, DUMMYAUD_DRIVER_NAME) == 0)) { + return(1); + } + return(0); +} + +static void DUMMYAUD_DeleteDevice(SDL_AudioDevice *device) +{ + SDL_free(device->hidden); + SDL_free(device); +} + +static SDL_AudioDevice *DUMMYAUD_CreateDevice(int devindex) +{ + SDL_AudioDevice *this; + + /* Initialize all variables that we clean on shutdown */ + this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); + if ( this ) { + SDL_memset(this, 0, (sizeof *this)); + this->hidden = (struct SDL_PrivateAudioData *) + SDL_malloc((sizeof *this->hidden)); + } + if ( (this == NULL) || (this->hidden == NULL) ) { + SDL_OutOfMemory(); + if ( this ) { + SDL_free(this); + } + return(0); + } + SDL_memset(this->hidden, 0, (sizeof *this->hidden)); + + /* Set the function pointers */ + this->OpenAudio = DUMMYAUD_OpenAudio; + this->WaitAudio = DUMMYAUD_WaitAudio; + this->PlayAudio = DUMMYAUD_PlayAudio; + this->GetAudioBuf = DUMMYAUD_GetAudioBuf; + this->CloseAudio = DUMMYAUD_CloseAudio; + + this->free = DUMMYAUD_DeleteDevice; + + return this; +} + +AudioBootStrap DUMMYAUD_bootstrap = { + DUMMYAUD_DRIVER_NAME, "SDL dummy audio driver", + DUMMYAUD_Available, DUMMYAUD_CreateDevice +}; + +/* This function waits until it is possible to write a full sound buffer */ +static void DUMMYAUD_WaitAudio(_THIS) +{ + /* Don't block on first calls to simulate initial fragment filling. */ + if (this->hidden->initial_calls) + this->hidden->initial_calls--; + else + SDL_Delay(this->hidden->write_delay); +} + +static void DUMMYAUD_PlayAudio(_THIS) +{ + /* no-op...this is a null driver. */ +} + +static Uint8 *DUMMYAUD_GetAudioBuf(_THIS) +{ + return(this->hidden->mixbuf); +} + +static void DUMMYAUD_CloseAudio(_THIS) +{ + if ( this->hidden->mixbuf != NULL ) { + SDL_FreeAudioMem(this->hidden->mixbuf); + this->hidden->mixbuf = NULL; + } +} + +static int DUMMYAUD_OpenAudio(_THIS, SDL_AudioSpec *spec) +{ + float bytes_per_sec = 0.0f; + + /* Allocate mixing buffer */ + this->hidden->mixlen = spec->size; + this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen); + if ( this->hidden->mixbuf == NULL ) { + return(-1); + } + SDL_memset(this->hidden->mixbuf, spec->silence, spec->size); + + bytes_per_sec = (float) (((spec->format & 0xFF) / 8) * + spec->channels * spec->freq); + + /* + * We try to make this request more audio at the correct rate for + * a given audio spec, so timing stays fairly faithful. + * Also, we have it not block at all for the first two calls, so + * it seems like we're filling two audio fragments right out of the + * gate, like other SDL drivers tend to do. + */ + this->hidden->initial_calls = 2; + this->hidden->write_delay = + (Uint32) ((((float) spec->size) / bytes_per_sec) * 1000.0f); + + /* We're ready to rock and roll. :-) */ + return(0); +} + diff --git a/distrib/sdl-1.2.15/src/audio/dummy/SDL_dummyaudio.h b/distrib/sdl-1.2.15/src/audio/dummy/SDL_dummyaudio.h new file mode 100644 index 0000000..74a69ca --- /dev/null +++ b/distrib/sdl-1.2.15/src/audio/dummy/SDL_dummyaudio.h @@ -0,0 +1,40 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997-2012 Sam Lantinga + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + This library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + + Sam Lantinga + slouken@libsdl.org +*/ +#include "SDL_config.h" + +#ifndef _SDL_dummyaudio_h +#define _SDL_dummyaudio_h + +#include "../SDL_sysaudio.h" + +/* Hidden "this" pointer for the video functions */ +#define _THIS SDL_AudioDevice *this + +struct SDL_PrivateAudioData { + /* The file descriptor for the audio device */ + Uint8 *mixbuf; + Uint32 mixlen; + Uint32 write_delay; + Uint32 initial_calls; +}; + +#endif /* _SDL_dummyaudio_h */ |