Mercurial > sdl-ios-xcode
diff src/audio/dummy/SDL_dummyaudio.c @ 1532:30f189cdd82b
Implemented dummy audio driver.
Fixes Bugzilla #161.
author | Ryan C. Gordon <icculus@icculus.org> |
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date | Tue, 14 Mar 2006 08:53:33 +0000 |
parents | |
children | 38c1eb6b0083 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/audio/dummy/SDL_dummyaudio.c Tue Mar 14 08:53:33 2006 +0000 @@ -0,0 +1,154 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997-2006 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 hacked^H^H^H^H^H^Hwritten by Ryan C. Gordon + (icculus@icculus.org) +*/ +#include "SDL_config.h" + +/* Output raw audio data to a file. */ + +#if HAVE_STDIO_H +#include <stdio.h> +#endif + +#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" + +/* environment variables and defaults. */ +#define DUMMYENVR_WRITEDELAY "SDL_DUMMYAUDIODELAY" +#define DUMMYDEFAULT_WRITEDELAY 150 + +/* 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; + const char *envr; + + /* 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)); + + envr = SDL_getenv(DUMMYENVR_WRITEDELAY); + this->hidden->write_delay = (envr) ? SDL_atoi(envr) : DUMMYDEFAULT_WRITEDELAY; + + /* 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) +{ + 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) +{ +#if HAVE_STDIO_H + fprintf(stderr, "\nWARNING: You are using the SDL dummy audio driver!" + " No sound will be output!\n\n"); +#endif + + /* 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); + + /* We're ready to rock and roll. :-) */ + return(0); +} +