/*

Simple DirectMedia Layer

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.

*/

/* WinRT NOTICE:

A number of changes were warranted to SDL's XAudio2 backend in order to

get it compiling for Windows RT.

When compiling for WinRT, XAudio2.h requires that it be compiled in a C++

file, and not a straight C file. Trying to compile it as C leads to lots

of errors, at least with MSVC 2012 and Windows SDK 8.0, as of Nov 22, 2012.

To address this specific issue, a few changes were made to SDL_xaudio2.c:

1. SDL_xaudio2.c is compiled as a C++ file in WinRT builds. Exported

symbols, namely XAUDIO2_bootstrap, uses 'extern "C"' to make sure the

rest of SDL can access it. Non-WinRT builds continue to compile

SDL_xaudio2.c as a C file.

2. A macro redefines variables named 'this' to '_this', to prevent compiler

errors (C2355 in Visual C++) related to 'this' being a reserverd keyword.

This hack may need to be altered in the future, particularly if C++'s

'this' keyword needs to be used (within SDL_xaudio2.c). At the time

WinRT support was initially added to SDL's XAudio2 backend, this

capability was not needed.

3. The C-style macros to invoke XAudio2's COM-based methods were

rewritten to be C++-friendly. These are provided in the file,

SDL_xaudio2_winrthelpers.h.

4. IXAudio2::CreateSourceVoice, when used in C++, requires its callbacks to

be specified via a C++ class. SDL's XAudio2 backend was written with

C-style callbacks. A class to bridge these two interfaces,

SDL_XAudio2VoiceCallback, was written to make XAudio2 happy. Its methods

just call SDL's existing, C-style callbacks.

5. Multiple checks for the __cplusplus macro were made, in appropriate

places.

A few additional changes to SDL's XAudio2 backend were warranted by API

changes to Windows. Many, but not all of these are documented by Microsoft

at:

http://blogs.msdn.com/b/chuckw/archive/2012/04/02/xaudio2-and-windows-8-consumer-preview.aspx

1. Windows' thread synchronization function, CreateSemaphore, was removed

from Windows RT. SDL's semaphore API was substituted instead.

2. The method calls, IXAudio2::GetDeviceCount and IXAudio2::GetDeviceDetails

were removed from the XAudio2 API. Microsoft is telling developers to

use APIs in Windows::Foundation instead.

For SDL, the missing methods were reimplemented using the APIs Microsoft

said to use.

3. CoInitialize and CoUninitialize are not available in Windows RT.

These calls were removed, as COM will have been initialized earlier,

at least by the call to the WinRT app's main function

(aka 'int main(Platform::Array<Platform::String^>^)). (DLudwig:

This was my understanding of how WinRT: the 'main' function uses

a tag of [MTAThread], which should initialize COM. My understanding

of COM is somewhat limited, and I may be incorrect here.)

4. IXAudio2::CreateMasteringVoice changed its integer-based 'DeviceIndex'

argument to a string-based one, 'szDeviceId'. In Windows RT, the

string-based argument will be used.

*/

#if SDL_AUDIO_DRIVER_XAUDIO2

#ifdef __cplusplus

extern "C" {

#endif

#include "../../core/windows/SDL_windows.h"

#include "SDL_audio.h"

#include "../SDL_audio_c.h"

#ifdef __cplusplus

}

#endif

#if defined(__WINRT__)

# define SDL_XAUDIO2_HAS_SDK 1

#endif

#if defined(__WIN32__)

#else

# define SDL_XAUDIO2_HAS_SDK 1

#define INITGUID 1

#include <XAudio2.h>

/* Hidden "this" pointer for the audio functions */

#define _THIS SDL_AudioDevice *this

#ifdef __cplusplus

#define this _this

#include "SDL_xaudio2_winrthelpers.h"

#endif

struct SDL_PrivateAudioData

{

IXAudio2 *ixa2;

IXAudio2SourceVoice *source;

IXAudio2MasteringVoice *mastering;

Uint8 *mixbuf;

int mixlen;

Uint8 *nextbuf;

};

static void

XAUDIO2_DetectDevices(int iscapture, SDL_AddAudioDevice addfn)

{

IXAudio2 *ixa2 = NULL;

UINT32 devcount = 0;

UINT32 i = 0;

void *ptr = NULL;

if (iscapture) {

SDL_SetError("XAudio2: capture devices unsupported.");

} else if (XAudio2Create(&ixa2, 0, XAUDIO2_DEFAULT_PROCESSOR) != S_OK) {

SDL_SetError("XAudio2: XAudio2Create() failed.");

} else if (IXAudio2_GetDeviceCount(ixa2, &devcount) != S_OK) {

SDL_SetError("XAudio2: IXAudio2::GetDeviceCount() failed.");

IXAudio2_Release(ixa2);

}

for (i = 0; i < devcount; i++) {

XAUDIO2_DEVICE_DETAILS details;

if (IXAudio2_GetDeviceDetails(ixa2, i, &details) == S_OK) {

addfn(str);

SDL_free(str); /* addfn() made a copy of the string. */

}

}

}

IXAudio2_Release(ixa2);

}

static void STDMETHODCALLTYPE

VoiceCBOnBufferEnd(THIS_ void *data)

{

/* Just signal the SDL audio thread and get out of XAudio2's way. */

SDL_AudioDevice *this = (SDL_AudioDevice *) data;

}

static void STDMETHODCALLTYPE

VoiceCBOnVoiceError(THIS_ void *data, HRESULT Error)

{

/* !!! FIXME: attempt to recover, or mark device disconnected. */

SDL_assert(0 && "write me!");

}

/* no-op callbacks... */

static void STDMETHODCALLTYPE VoiceCBOnStreamEnd(THIS) {}

static void STDMETHODCALLTYPE VoiceCBOnVoiceProcessPassStart(THIS_ UINT32 b) {}

static void STDMETHODCALLTYPE VoiceCBOnVoiceProcessPassEnd(THIS) {}

static void STDMETHODCALLTYPE VoiceCBOnBufferStart(THIS_ void *data) {}

static void STDMETHODCALLTYPE VoiceCBOnLoopEnd(THIS_ void *data) {}

#if defined(__cplusplus)

class SDL_XAudio2VoiceCallback : public IXAudio2VoiceCallback

{

public:

STDMETHOD_(void, OnBufferEnd)(void *pBufferContext) {

VoiceCBOnBufferEnd(pBufferContext);

}

STDMETHOD_(void, OnBufferStart)(void *pBufferContext) {

}

STDMETHOD_(void, OnLoopEnd)(void *pBufferContext) {

VoiceCBOnLoopEnd(pBufferContext);

}

STDMETHOD_(void, OnStreamEnd)() {

VoiceCBOnStreamEnd();

}

STDMETHOD_(void, OnVoiceError)(void *pBufferContext, HRESULT Error) {

VoiceCBOnVoiceError(pBufferContext, Error);

}

STDMETHOD_(void, OnVoiceProcessingPassEnd)() {

VoiceCBOnVoiceProcessPassEnd();

}

STDMETHOD_(void, OnVoiceProcessingPassStart)(UINT32 BytesRequired) {

VoiceCBOnVoiceProcessPassStart(BytesRequired);

}

};

#endif

static Uint8 *

XAUDIO2_GetDeviceBuf(_THIS)

{

return this->hidden->nextbuf;

}

static void

XAUDIO2_PlayDevice(_THIS)

{

XAUDIO2_BUFFER buffer;

Uint8 *mixbuf = this->hidden->mixbuf;

Uint8 *nextbuf = this->hidden->nextbuf;

const int mixlen = this->hidden->mixlen;

IXAudio2SourceVoice *source = this->hidden->source;

HRESULT result = S_OK;

if (!this->enabled) { /* shutting down? */

return;

}

/* Submit the next filled buffer */

SDL_zero(buffer);

buffer.AudioBytes = mixlen;

buffer.pAudioData = nextbuf;

buffer.pContext = this;

if (nextbuf == mixbuf) {

nextbuf += mixlen;

} else {

nextbuf = mixbuf;

}

this->hidden->nextbuf = nextbuf;

result = IXAudio2SourceVoice_SubmitSourceBuffer(source, &buffer, NULL);

if (result == XAUDIO2_E_DEVICE_INVALIDATED) {

/* !!! FIXME: possibly disconnected or temporary lost. Recover? */

}

if (result != S_OK) { /* uhoh, panic! */

IXAudio2SourceVoice_FlushSourceBuffers(source);

this->enabled = 0;

}

}

static void

XAUDIO2_WaitDevice(_THIS)

{

if (this->enabled) {

}

}

static void

XAUDIO2_WaitDone(_THIS)

{

IXAudio2SourceVoice *source = this->hidden->source;

XAUDIO2_VOICE_STATE state;

SDL_assert(!this->enabled); /* flag that stops playing. */

IXAudio2SourceVoice_Discontinuity(source);

IXAudio2SourceVoice_GetState(source, &state);

while (state.BuffersQueued > 0) {

IXAudio2SourceVoice_GetState(source, &state);

}

}

static void

XAUDIO2_CloseDevice(_THIS)

{

if (this->hidden != NULL) {

IXAudio2 *ixa2 = this->hidden->ixa2;

IXAudio2SourceVoice *source = this->hidden->source;

IXAudio2MasteringVoice *mastering = this->hidden->mastering;

if (source != NULL) {

IXAudio2SourceVoice_Stop(source, 0, XAUDIO2_COMMIT_NOW);

IXAudio2SourceVoice_FlushSourceBuffers(source);

IXAudio2SourceVoice_DestroyVoice(source);

}

if (ixa2 != NULL) {

IXAudio2_StopEngine(ixa2);

}

if (mastering != NULL) {

IXAudio2MasteringVoice_DestroyVoice(mastering);

}

if (ixa2 != NULL) {

IXAudio2_Release(ixa2);

}

if (this->hidden->mixbuf != NULL) {

SDL_free(this->hidden->mixbuf);

}

if (this->hidden->semaphore != NULL) {

}

SDL_free(this->hidden);

this->hidden = NULL;

}

}

static int

XAUDIO2_OpenDevice(_THIS, const char *devname, int iscapture)

{

HRESULT result = S_OK;

WAVEFORMATEX waveformat;

int valid_format = 0;

SDL_AudioFormat test_format = SDL_FirstAudioFormat(this->spec.format);

IXAudio2 *ixa2 = NULL;

IXAudio2SourceVoice *source = NULL;

WCHAR devIdBuffer[256];

LPCWSTR devId = 0;

#if defined(__cplusplus)

static SDL_XAudio2VoiceCallback callbacks;

#else

static IXAudio2VoiceCallbackVtbl callbacks_vtable = {

VoiceCBOnVoiceProcessPassStart,

VoiceCBOnVoiceProcessPassEnd,

VoiceCBOnStreamEnd,

VoiceCBOnBufferStart,

VoiceCBOnBufferEnd,

VoiceCBOnLoopEnd,

VoiceCBOnVoiceError

};

static IXAudio2VoiceCallback callbacks = { &callbacks_vtable };

#endif // ! defined(__cplusplus)

#if defined(__WINRT__)

if (iscapture) {

SDL_SetError("XAudio2: capture devices unsupported.");

return 0;

} else if (XAudio2Create(&ixa2, 0, XAUDIO2_DEFAULT_PROCESSOR) != S_OK) {

SDL_SetError("XAudio2: XAudio2Create() failed.");

return 0;

}

XAUDIO2_DEBUG_CONFIGURATION debugConfig;

debugConfig.TraceMask = XAUDIO2_LOG_ERRORS; //XAUDIO2_LOG_WARNINGS | XAUDIO2_LOG_DETAIL | XAUDIO2_LOG_FUNC_CALLS | XAUDIO2_LOG_TIMING | XAUDIO2_LOG_LOCKS | XAUDIO2_LOG_MEMORY | XAUDIO2_LOG_STREAMING;

debugConfig.BreakMask = XAUDIO2_LOG_ERRORS; //XAUDIO2_LOG_WARNINGS;

debugConfig.LogThreadID = TRUE;

debugConfig.LogFileline = TRUE;

debugConfig.LogFunctionName = TRUE;

debugConfig.LogTiming = TRUE;

ixa2->SetDebugConfiguration(&debugConfig);

if (devname != NULL) {

UINT32 devcount = 0;

UINT32 i = 0;

if (IXAudio2_GetDeviceCount(ixa2, &devcount) != S_OK) {

IXAudio2_Release(ixa2);

SDL_SetError("XAudio2: IXAudio2_GetDeviceCount() failed.");

return 0;

}

for (i = 0; i < devcount; i++) {

XAUDIO2_DEVICE_DETAILS details;

if (IXAudio2_GetDeviceDetails(ixa2, i, &details) == S_OK) {

if (str != NULL) {

const int match = (SDL_strcmp(str, devname) == 0);

SDL_free(str);

if (match) {

wcsncpy_s(devIdBuffer, ARRAYSIZE(devIdBuffer), details.DeviceID, _TRUNCATE);

devId = (LPCWSTR) &devIdBuffer;

break;

}

}

}

}

if (i == devcount) {

IXAudio2_Release(ixa2);

SDL_SetError("XAudio2: Requested device not found.");

return 0;

}

}

/* Initialize all variables that we clean on shutdown */

this->hidden = (struct SDL_PrivateAudioData *)

SDL_malloc((sizeof *this->hidden));

if (this->hidden == NULL) {

IXAudio2_Release(ixa2);

SDL_OutOfMemory();

return 0;

}

SDL_memset(this->hidden, 0, (sizeof *this->hidden));

this->hidden->ixa2 = ixa2;

if (this->hidden->semaphore == NULL) {

XAUDIO2_CloseDevice(this);

SDL_SetError("XAudio2: CreateSemaphore() failed!");

return 0;

}

while ((!valid_format) && (test_format)) {

switch (test_format) {

case AUDIO_U8:

case AUDIO_S16:

case AUDIO_S32:

case AUDIO_F32:

this->spec.format = test_format;

valid_format = 1;

break;

}

test_format = SDL_NextAudioFormat();

}

if (!valid_format) {

XAUDIO2_CloseDevice(this);

SDL_SetError("XAudio2: Unsupported audio format");

return 0;

}

/* Update the fragment size as size in bytes */

SDL_CalculateAudioSpec(&this->spec);

/* We feed a Source, it feeds the Mastering, which feeds the device. */

this->hidden->mixlen = this->spec.size;

this->hidden->mixbuf = (Uint8 *) SDL_malloc(2 * this->hidden->mixlen);

if (this->hidden->mixbuf == NULL) {

XAUDIO2_CloseDevice(this);

SDL_OutOfMemory();

return 0;

}

this->hidden->nextbuf = this->hidden->mixbuf;

/* We use XAUDIO2_DEFAULT_CHANNELS instead of this->spec.channels. On

Xbox360, this means 5.1 output, but on Windows, it means "figure out

what the system has." It might be preferable to let XAudio2 blast

stereo output to appropriate surround sound configurations

instead of clamping to 2 channels, even though we'll configure the

Source Voice for whatever number of channels you supply. */

result = IXAudio2_CreateMasteringVoice(ixa2, &this->hidden->mastering,

XAUDIO2_DEFAULT_CHANNELS,

this->spec.freq, 0, devId, NULL);

if (result != S_OK) {

XAUDIO2_CloseDevice(this);

SDL_SetError("XAudio2: Couldn't create mastering voice");

return 0;

}

SDL_zero(waveformat);

if (SDL_AUDIO_ISFLOAT(this->spec.format)) {

waveformat.wFormatTag = WAVE_FORMAT_IEEE_FLOAT;

} else {

waveformat.wFormatTag = WAVE_FORMAT_PCM;

}

waveformat.wBitsPerSample = SDL_AUDIO_BITSIZE(this->spec.format);

waveformat.nChannels = this->spec.channels;

waveformat.nSamplesPerSec = this->spec.freq;

waveformat.nBlockAlign =

waveformat.nChannels * (waveformat.wBitsPerSample / 8);

waveformat.nAvgBytesPerSec =

waveformat.nSamplesPerSec * waveformat.nBlockAlign;

#ifdef __WINRT__

result = IXAudio2_CreateSourceVoice(ixa2, &source, &waveformat,

0,

1.0f, &callbacks, NULL, NULL);

#else

result = IXAudio2_CreateSourceVoice(ixa2, &source, &waveformat,

XAUDIO2_VOICE_NOSRC |

XAUDIO2_VOICE_NOPITCH,

1.0f, &callbacks, NULL, NULL);

#endif

if (result != S_OK) {

XAUDIO2_CloseDevice(this);

SDL_SetError("XAudio2: Couldn't create source voice");

return 0;

}

this->hidden->source = source;

/* Start everything playing! */

result = IXAudio2_StartEngine(ixa2);

if (result != S_OK) {

XAUDIO2_CloseDevice(this);

SDL_SetError("XAudio2: Couldn't start engine");

return 0;

}

result = IXAudio2SourceVoice_Start(source, 0, XAUDIO2_COMMIT_NOW);

if (result != S_OK) {

XAUDIO2_CloseDevice(this);

SDL_SetError("XAudio2: Couldn't start source voice");

return 0;

}

return 1; /* good to go. */

}

static void

XAUDIO2_Deinitialize(void)

{

}

static int

XAUDIO2_Init(SDL_AudioDriverImpl * impl)

{

#ifndef SDL_XAUDIO2_HAS_SDK

SDL_SetError("XAudio2: SDL was built without XAudio2 support (old DirectX SDK).");

return 0; /* no XAudio2 support, ever. Update your SDK! */

#else

/* XAudio2Create() is a macro that uses COM; we don't load the .dll */

IXAudio2 *ixa2 = NULL;

if (FAILED(WIN_CoInitialize())) {

SDL_SetError("XAudio2: CoInitialize() failed");

return 0;

}

if (XAudio2Create(&ixa2, 0, XAUDIO2_DEFAULT_PROCESSOR) != S_OK) {

SDL_SetError("XAudio2: XAudio2Create() failed");

return 0; /* not available. */

}

IXAudio2_Release(ixa2);

/* Set the function pointers */

impl->DetectDevices = XAUDIO2_DetectDevices;

impl->OpenDevice = XAUDIO2_OpenDevice;

impl->PlayDevice = XAUDIO2_PlayDevice;

impl->WaitDevice = XAUDIO2_WaitDevice;

impl->WaitDone = XAUDIO2_WaitDone;

impl->GetDeviceBuf = XAUDIO2_GetDeviceBuf;

impl->CloseDevice = XAUDIO2_CloseDevice;

impl->Deinitialize = XAUDIO2_Deinitialize;

return 1; /* this audio target is available. */

}

#if defined(__cplusplus)

extern "C"

#endif

AudioBootStrap XAUDIO2_bootstrap = {

"xaudio2", "XAudio2", XAUDIO2_Init, 0

};

#endif /* SDL_AUDIO_DRIVER_XAUDIO2 */