diff options
Diffstat (limited to 'Alc/backends/null.c')
-rw-r--r-- | Alc/backends/null.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/Alc/backends/null.c b/Alc/backends/null.c new file mode 100644 index 00000000..dd1ac216 --- /dev/null +++ b/Alc/backends/null.c @@ -0,0 +1,164 @@ +/** + * OpenAL cross platform audio library + * Copyright (C) 2010 by Chris Robinson + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 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 + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * Or go to http://www.gnu.org/copyleft/lgpl.html + */ + +#include "config.h" + +#include <stdlib.h> +#include "alMain.h" +#include "AL/al.h" +#include "AL/alc.h" + + +typedef struct { + volatile int killNow; + ALvoid *thread; +} null_data; + + +static const ALCchar nullDevice[] = "No Output"; + +static ALuint NullProc(ALvoid *ptr) +{ + ALCdevice *Device = (ALCdevice*)ptr; + null_data *data = (null_data*)Device->ExtraData; + ALuint now, start; + ALuint64 avail, done; + const ALuint restTime = (ALuint64)Device->UpdateSize * 1000 / + Device->Frequency / 2; + + done = 0; + start = timeGetTime(); + while(!data->killNow && Device->Connected) + { + now = timeGetTime(); + + avail = (ALuint64)(now-start) * Device->Frequency / 1000; + if(avail < done) + { + /* Timer wrapped. Add the remainder of the cycle to the available + * count and reset the number of samples done */ + avail += (ALuint64)0xFFFFFFFFu*Device->Frequency/1000 - done; + done = 0; + } + if(avail-done < Device->UpdateSize) + { + Sleep(restTime); + continue; + } + + while(avail-done >= Device->UpdateSize) + { + aluMixData(Device, NULL, Device->UpdateSize); + done += Device->UpdateSize; + } + } + + return 0; +} + +static ALCboolean null_open_playback(ALCdevice *device, const ALCchar *deviceName) +{ + null_data *data; + + if(!deviceName) + deviceName = nullDevice; + else if(strcmp(deviceName, nullDevice) != 0) + return ALC_FALSE; + + data = (null_data*)calloc(1, sizeof(*data)); + + device->szDeviceName = strdup(deviceName); + device->ExtraData = data; + return ALC_TRUE; +} + +static void null_close_playback(ALCdevice *device) +{ + null_data *data = (null_data*)device->ExtraData; + + free(data); + device->ExtraData = NULL; +} + +static ALCboolean null_reset_playback(ALCdevice *device) +{ + null_data *data = (null_data*)device->ExtraData; + + SetDefaultWFXChannelOrder(device); + + data->thread = StartThread(NullProc, device); + if(data->thread == NULL) + return ALC_FALSE; + + return ALC_TRUE; +} + +static void null_stop_playback(ALCdevice *device) +{ + null_data *data = (null_data*)device->ExtraData; + + if(!data->thread) + return; + + data->killNow = 1; + StopThread(data->thread); + data->thread = NULL; + + data->killNow = 0; +} + + +static const BackendFuncs null_funcs = { + null_open_playback, + null_close_playback, + null_reset_playback, + null_stop_playback, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL +}; + +ALCboolean alc_null_init(BackendFuncs *func_list) +{ + *func_list = null_funcs; + return ALC_TRUE; +} + +void alc_null_deinit(void) +{ +} + +void alc_null_probe(enum DevProbe type) +{ + switch(type) + { + case DEVICE_PROBE: + AppendDeviceList(nullDevice); + break; + case ALL_DEVICE_PROBE: + AppendAllDeviceList(nullDevice); + break; + case CAPTURE_DEVICE_PROBE: + break; + } +} |