/*

Simple DirectMedia Layer

Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>

This software is provided 'as-is', without any express or implied

warranty. In no event will the authors be held liable for any damages

arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not

claim that you wrote the original software. If you use this software

in a product, an acknowledgment in the product documentation would be

appreciated but is not required.

2. Altered source versions must be plainly marked as such, and must not be

misrepresented as being the original software.

3. This notice may not be removed or altered from any source distribution.

*/

#include "../../SDL_internal.h"

#if SDL_AUDIO_DRIVER_NACL

#include "SDL_naclaudio.h"

#include "SDL_audio.h"

#include "SDL_mutex.h"

#include "../SDL_audio_c.h"

#include "../SDL_audiodev_c.h"

#include "ppapi/c/pp_errors.h"

#include "ppapi/c/pp_instance.h"

#include "ppapi_simple/ps.h"

#include "ppapi_simple/ps_interface.h"

#include "ppapi_simple/ps_event.h"

/* The tag name used by NACL audio */

#define NACLAUDIO_DRIVER_NAME "nacl"

#define SAMPLE_FRAME_COUNT 4096

/* Audio driver functions */

static void nacl_audio_callback(void* samples, uint32_t buffer_size, PP_TimeDelta latency, void* data);

/* FIXME: Make use of latency if needed */

static void nacl_audio_callback(void* stream, uint32_t buffer_size, PP_TimeDelta latency, void* data) {

const int len = (int) buffer_size;

SDL_AudioDevice* _this = (SDL_AudioDevice*) data;

SDL_AudioCallback callback = _this->spec.callback;

SDL_LockMutex(private->mutex); /* !!! FIXME: is this mutex necessary? */

/* Only do something if audio is enabled */

if (!SDL_AtomicGet(&_this->enabled) || SDL_AtomicGet(&_this->paused)) {

if (_this->stream) {

SDL_AudioStreamClear(_this->stream);

}

SDL_memset(stream, _this->spec.silence, len);

return;

}

SDL_assert(_this->spec.size == len);

if (_this->stream == NULL) { /* no conversion necessary. */

SDL_LockMutex(_this->mixer_lock);

callback(_this->spec.userdata, stream, len);

SDL_UnlockMutex(_this->mixer_lock);

} else { /* streaming/converting */

const int stream_len = _this->callbackspec.size;

while (SDL_AudioStreamAvailable(_this->stream) < len) {

callback(_this->spec.userdata, _this->work_buffer, stream_len);

if (SDL_AudioStreamPut(_this->stream, _this->work_buffer, stream_len) == -1) {

SDL_AudioStreamClear(_this->stream);

SDL_AtomicSet(&_this->enabled, 0);

break;

}

}

const int got = SDL_AudioStreamGet(_this->stream, stream, len);

SDL_assert((got < 0) || (got == len));

if (got != len) {

SDL_memset(stream, _this->spec.silence, len);

}

}

SDL_UnlockMutex(private->mutex);

}

static void NACLAUDIO_CloseDevice(SDL_AudioDevice *device) {

const PPB_Core *core = PSInterfaceCore();

const PPB_Audio *ppb_audio = PSInterfaceAudio();

SDL_PrivateAudioData *hidden = (SDL_PrivateAudioData *) device->hidden;

ppb_audio->StopPlayback(hidden->audio);

SDL_DestroyMutex(hidden->mutex);

core->ReleaseResource(hidden->audio);

}

static int

NACLAUDIO_OpenDevice(_THIS, void *handle, const char *devname, int iscapture) {

PP_Instance instance = PSGetInstanceId();

const PPB_Audio *ppb_audio = PSInterfaceAudio();

const PPB_AudioConfig *ppb_audiocfg = PSInterfaceAudioConfig();

private = (SDL_PrivateAudioData *) SDL_calloc(1, (sizeof *private));

if (private == NULL) {

SDL_OutOfMemory();

return 0;

}

private->mutex = SDL_CreateMutex();

_this->spec.freq = 44100;

_this->spec.format = AUDIO_S16LSB;

_this->spec.channels = 2;

_this->spec.samples = ppb_audiocfg->RecommendSampleFrameCount(

instance,

PP_AUDIOSAMPLERATE_44100,

SAMPLE_FRAME_COUNT);

/* Calculate the final parameters for this audio specification */

SDL_CalculateAudioSpec(&_this->spec);

private->audio = ppb_audio->Create(

instance,

ppb_audiocfg->CreateStereo16Bit(instance, PP_AUDIOSAMPLERATE_44100, _this->spec.samples),

nacl_audio_callback,

_this);

/* Start audio playback while we are still on the main thread. */

ppb_audio->StartPlayback(private->audio);

return 1;

}

static int

NACLAUDIO_Init(SDL_AudioDriverImpl * impl)

{

if (PSGetInstanceId() == 0) {

return 0;

}

/* Set the function pointers */

impl->OpenDevice = NACLAUDIO_OpenDevice;

impl->CloseDevice = NACLAUDIO_CloseDevice;

impl->OnlyHasDefaultOutputDevice = 1;

impl->ProvidesOwnCallbackThread = 1;

/*

* impl->WaitDevice = NACLAUDIO_WaitDevice;

* impl->GetDeviceBuf = NACLAUDIO_GetDeviceBuf;

* impl->PlayDevice = NACLAUDIO_PlayDevice;

* impl->Deinitialize = NACLAUDIO_Deinitialize;

*/

return 1;

}

AudioBootStrap NACLAUDIO_bootstrap = {

NACLAUDIO_DRIVER_NAME, "SDL NaCl Audio Driver",

NACLAUDIO_Init, 0

};

#endif /* SDL_AUDIO_DRIVER_NACL */

/* vi: set ts=4 sw=4 expandtab: */