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Diffstat (limited to 'Alc/backends/null.cpp')
| -rw-r--r-- | Alc/backends/null.cpp | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/Alc/backends/null.cpp b/Alc/backends/null.cpp new file mode 100644 index 00000000..2e1c6ac9 --- /dev/null +++ b/Alc/backends/null.cpp @@ -0,0 +1,232 @@ +/** + * 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * Or go to http://www.gnu.org/copyleft/lgpl.html + */ + +#include "config.h" + +#include <stdlib.h> +#ifdef HAVE_WINDOWS_H +#include <windows.h> +#endif + +#include "alMain.h" +#include "alu.h" +#include "threads.h" +#include "compat.h" + +#include "backends/base.h" + + +namespace { + +constexpr ALCchar nullDevice[] = "No Output"; + +} // namespace + +struct ALCnullBackend final : public ALCbackend { + ATOMIC(int) killNow; + althrd_t thread; +}; + +static int ALCnullBackend_mixerProc(void *ptr); + +static void ALCnullBackend_Construct(ALCnullBackend *self, ALCdevice *device); +static void ALCnullBackend_Destruct(ALCnullBackend *self); +static ALCenum ALCnullBackend_open(ALCnullBackend *self, const ALCchar *name); +static ALCboolean ALCnullBackend_reset(ALCnullBackend *self); +static ALCboolean ALCnullBackend_start(ALCnullBackend *self); +static void ALCnullBackend_stop(ALCnullBackend *self); +static DECLARE_FORWARD2(ALCnullBackend, ALCbackend, ALCenum, captureSamples, void*, ALCuint) +static DECLARE_FORWARD(ALCnullBackend, ALCbackend, ALCuint, availableSamples) +static DECLARE_FORWARD(ALCnullBackend, ALCbackend, ClockLatency, getClockLatency) +static DECLARE_FORWARD(ALCnullBackend, ALCbackend, void, lock) +static DECLARE_FORWARD(ALCnullBackend, ALCbackend, void, unlock) +DECLARE_DEFAULT_ALLOCATORS(ALCnullBackend) + +DEFINE_ALCBACKEND_VTABLE(ALCnullBackend); + + +static void ALCnullBackend_Construct(ALCnullBackend *self, ALCdevice *device) +{ + new (self) ALCnullBackend{}; + ALCbackend_Construct(STATIC_CAST(ALCbackend, self), device); + SET_VTABLE2(ALCnullBackend, ALCbackend, self); + + ATOMIC_INIT(&self->killNow, AL_TRUE); +} + +static void ALCnullBackend_Destruct(ALCnullBackend *self) +{ + ALCbackend_Destruct(STATIC_CAST(ALCbackend, self)); + self->~ALCnullBackend(); +} + + +static int ALCnullBackend_mixerProc(void *ptr) +{ + ALCnullBackend *self = (ALCnullBackend*)ptr; + ALCdevice *device = STATIC_CAST(ALCbackend, self)->mDevice; + struct timespec now, start; + ALuint64 avail, done; + const long restTime = (long)((ALuint64)device->UpdateSize * 1000000000 / + device->Frequency / 2); + + SetRTPriority(); + althrd_setname(althrd_current(), MIXER_THREAD_NAME); + + done = 0; + if(altimespec_get(&start, AL_TIME_UTC) != AL_TIME_UTC) + { + ERR("Failed to get starting time\n"); + return 1; + } + while(!ATOMIC_LOAD(&self->killNow, almemory_order_acquire) && + ATOMIC_LOAD(&device->Connected, almemory_order_acquire)) + { + if(altimespec_get(&now, AL_TIME_UTC) != AL_TIME_UTC) + { + ERR("Failed to get current time\n"); + return 1; + } + + avail = (now.tv_sec - start.tv_sec) * device->Frequency; + avail += (ALint64)(now.tv_nsec - start.tv_nsec) * device->Frequency / 1000000000; + if(avail < done) + { + /* Oops, time skipped backwards. Reset the number of samples done + * with one update available since we (likely) just came back from + * sleeping. */ + done = avail - device->UpdateSize; + } + + if(avail-done < device->UpdateSize) + al_nssleep(restTime); + else while(avail-done >= device->UpdateSize) + { + ALCnullBackend_lock(self); + aluMixData(device, NULL, device->UpdateSize); + ALCnullBackend_unlock(self); + done += device->UpdateSize; + } + } + + return 0; +} + + +static ALCenum ALCnullBackend_open(ALCnullBackend *self, const ALCchar *name) +{ + ALCdevice *device; + + if(!name) + name = nullDevice; + else if(strcmp(name, nullDevice) != 0) + return ALC_INVALID_VALUE; + + device = STATIC_CAST(ALCbackend, self)->mDevice; + alstr_copy_cstr(&device->DeviceName, name); + + return ALC_NO_ERROR; +} + +static ALCboolean ALCnullBackend_reset(ALCnullBackend *self) +{ + SetDefaultWFXChannelOrder(STATIC_CAST(ALCbackend, self)->mDevice); + return ALC_TRUE; +} + +static ALCboolean ALCnullBackend_start(ALCnullBackend *self) +{ + ATOMIC_STORE(&self->killNow, AL_FALSE, almemory_order_release); + if(althrd_create(&self->thread, ALCnullBackend_mixerProc, self) != althrd_success) + return ALC_FALSE; + return ALC_TRUE; +} + +static void ALCnullBackend_stop(ALCnullBackend *self) +{ + int res; + + if(ATOMIC_EXCHANGE(&self->killNow, AL_TRUE, almemory_order_acq_rel)) + return; + althrd_join(self->thread, &res); +} + + +struct ALCnullBackendFactory final : public ALCbackendFactory { + ALCnullBackendFactory() noexcept; +}; + +ALCbackendFactory *ALCnullBackendFactory_getFactory(void); + +static ALCboolean ALCnullBackendFactory_init(ALCnullBackendFactory *self); +static DECLARE_FORWARD(ALCnullBackendFactory, ALCbackendFactory, void, deinit) +static ALCboolean ALCnullBackendFactory_querySupport(ALCnullBackendFactory *self, ALCbackend_Type type); +static void ALCnullBackendFactory_probe(ALCnullBackendFactory *self, enum DevProbe type, al_string *outnames); +static ALCbackend* ALCnullBackendFactory_createBackend(ALCnullBackendFactory *self, ALCdevice *device, ALCbackend_Type type); +DEFINE_ALCBACKENDFACTORY_VTABLE(ALCnullBackendFactory); + +ALCnullBackendFactory::ALCnullBackendFactory() noexcept + : ALCbackendFactory{GET_VTABLE2(ALCnullBackendFactory, ALCbackendFactory)} +{ +} + + +ALCbackendFactory *ALCnullBackendFactory_getFactory(void) +{ + static ALCnullBackendFactory factory{}; + return STATIC_CAST(ALCbackendFactory, &factory); +} + + +static ALCboolean ALCnullBackendFactory_init(ALCnullBackendFactory* UNUSED(self)) +{ + return ALC_TRUE; +} + +static ALCboolean ALCnullBackendFactory_querySupport(ALCnullBackendFactory* UNUSED(self), ALCbackend_Type type) +{ + if(type == ALCbackend_Playback) + return ALC_TRUE; + return ALC_FALSE; +} + +static void ALCnullBackendFactory_probe(ALCnullBackendFactory* UNUSED(self), enum DevProbe type, al_string *outnames) +{ + switch(type) + { + case ALL_DEVICE_PROBE: + case CAPTURE_DEVICE_PROBE: + alstr_append_range(outnames, nullDevice, nullDevice+sizeof(nullDevice)); + break; + } +} + +static ALCbackend* ALCnullBackendFactory_createBackend(ALCnullBackendFactory* UNUSED(self), ALCdevice *device, ALCbackend_Type type) +{ + if(type == ALCbackend_Playback) + { + ALCnullBackend *backend; + NEW_OBJ(backend, ALCnullBackend)(device); + if(!backend) return NULL; + return STATIC_CAST(ALCbackend, backend); + } + + return NULL; +} |