src/alure.cpp

   1 /*
   2  * ALURE  OpenAL utility library
   3  * Copyright (c) 2009 by Chris Robinson.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to
   7  * deal in the Software without restriction, including without limitation the
   8  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   9  * sell copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 /* Title: Main and Miscellanious */
  25
  26 #include "config.h"
  27
  28 #include "main.h"
  29
  30 #include <string.h>
  31 #include <errno.h>
  32 #include <stdio.h>
  33 #include <time.h>
  34 #ifdef HAVE_WINDOWS_H
  35 #include <windows.h>
  36 #endif
  37
  38 #include <vector>
  39 #include <string>
  40 #include <map>
  41
  42 std::map<ALint,UserCallbacks> InstalledCallbacks;
  43 CRITICAL_SECTION cs_StreamPlay;
  44 alureStream::ListType alureStream::StreamList;
  45
  46 PFNALCSETTHREADCONTEXTPROC palcSetThreadContext;
  47 PFNALCGETTHREADCONTEXTPROC palcGetThreadContext;
  48
  49
  50 template<typename T>
  51 static inline void LoadALCProc(ALCdevice *dev, const char *name, T **ptr)
  52 { *ptr = reinterpret_cast<T*>(alcGetProcAddress(dev, name)); }
  53
  54
  55 #ifdef HAVE_GCC_CONSTRUCTOR
  56 static void init_alure(void) __attribute__((constructor));
  57 static void deinit_alure(void) __attribute__((destructor));
  58 static struct MyConstructorClass {
  59     ~MyConstructorClass()
  60     { alureStream::Clear(); };
  61 } MyConstructor;
  62 #elif defined(_WIN32) && !defined(ALURE_STATIC_LIBRARY)
  63 static void init_alure(void);
  64 static void deinit_alure(void);
  65 static struct MyConstructorClass {
  66     ~MyConstructorClass()
  67     { alureStream::Clear(); };
  68 } MyConstructor;
  69
  70 extern "C" BOOL APIENTRY DllMain(HINSTANCE module, DWORD reason, LPVOID /*reserved*/)
  71 {
  72     // Perform actions based on the reason for calling.
  73     switch(reason)
  74     {
  75         case DLL_PROCESS_ATTACH:
  76             DisableThreadLibraryCalls(module);
  77             init_alure();
  78             break;
  79
  80         case DLL_PROCESS_DETACH:
  81             deinit_alure();
  82             break;
  83     }
  84     return TRUE;
  85 }
  86 #else
  87 static void init_alure(void);
  88 static void deinit_alure(void);
  89
  90 static struct MyConstructorClass {
  91     MyConstructorClass()
  92     { init_alure(); };
  93     ~MyConstructorClass()
  94     { alureStream::Clear();
  95       deinit_alure(); };
  96 } MyConstructor;
  97 #endif
  98
  99 static void init_alure(void)
 100 {
 101     InitializeCriticalSection(&cs_StreamPlay);
 102
 103     // These calls actually just return references to the codecs' Decoder
 104     // objects. They aren't really used for anything other than to prevent the
 105     // compiler from removing the codec initializers.
 106     alure_init_wav();
 107     alure_init_aiff();
 108 #ifdef HAS_VORBISFILE
 109     alure_init_vorbisfile();
 110 #endif
 111 #ifdef HAS_FLAC
 112     alure_init_flac();
 113 #endif
 114 #ifdef HAS_SNDFILE
 115     alure_init_sndfile();
 116 #endif
 117 #ifdef HAS_FLUIDSYNTH
 118     alure_init_fluidsynth();
 119 #endif
 120 #ifdef HAS_DUMB
 121     alure_init_dumb();
 122 #endif
 123 #ifdef HAS_MODPLUG
 124     alure_init_modplug();
 125 #endif
 126 #ifdef HAS_MPG123
 127     alure_init_mpg123();
 128 #endif
 129
 130     if(alcIsExtensionPresent(NULL, "ALC_EXT_thread_local_context"))
 131     {
 132         LoadALCProc(NULL, "alcSetThreadContext", &palcSetThreadContext);
 133         LoadALCProc(NULL, "alcGetThreadContext", &palcGetThreadContext);
 134         if(!palcSetThreadContext || !palcGetThreadContext)
 135         {
 136             fprintf(stderr, "Alure lib: ALC_EXT_thread_local_context advertised, but missing function:\n"
 137                             "    alcSetThreadContext=%p\n"
 138                             "    alcGetThreadContext=%p\n",
 139                             palcSetThreadContext, palcGetThreadContext);
 140             palcSetThreadContext = NULL;
 141             palcGetThreadContext = NULL;
 142         }
 143     }
 144 }
 145
 146 static void deinit_alure(void)
 147 {
 148     alureUpdateInterval(0.0f);
 149     DeleteCriticalSection(&cs_StreamPlay);
 150 }
 151
 152
 153 #ifndef HAVE_WINDOWS_H
 154
 155 void EnterCriticalSection(CRITICAL_SECTION *cs)
 156 {
 157     int ret;
 158     ret = pthread_mutex_lock(cs);
 159     assert(ret == 0);
 160 }
 161 void LeaveCriticalSection(CRITICAL_SECTION *cs)
 162 {
 163     int ret;
 164     ret = pthread_mutex_unlock(cs);
 165     assert(ret == 0);
 166 }
 167 void InitializeCriticalSection(CRITICAL_SECTION *cs)
 168 {
 169     pthread_mutexattr_t attrib;
 170     int ret;
 171
 172     ret = pthread_mutexattr_init(&attrib);
 173     assert(ret == 0);
 174
 175     ret = pthread_mutexattr_settype(&attrib, PTHREAD_MUTEX_RECURSIVE);
 176 #ifdef HAVE_PTHREAD_NP_H
 177     if(ret != 0)
 178         ret = pthread_mutexattr_setkind_np(&attrib, PTHREAD_MUTEX_RECURSIVE);
 179 #endif
 180     assert(ret == 0);
 181     ret = pthread_mutex_init(cs, &attrib);
 182     assert(ret == 0);
 183
 184     pthread_mutexattr_destroy(&attrib);
 185 }
 186 void DeleteCriticalSection(CRITICAL_SECTION *cs)
 187 {
 188     int ret;
 189     ret = pthread_mutex_destroy(cs);
 190     assert(ret == 0);
 191 }
 192
 193 #endif
 194
 195
 196 static const ALchar *last_error = "No error";
 197 void SetError(const char *err)
 198 {
 199     last_error = err;
 200 }
 201
 202
 203 ALuint DetectBlockAlignment(ALenum format)
 204 {
 205     switch(format)
 206     {
 207 #define CHECK_RET(f,s) case (f): return (s)
 208         CHECK_RET(AL_FORMAT_MONO8, sizeof(ALubyte));
 209         CHECK_RET(AL_FORMAT_MONO16, sizeof(ALshort));
 210         CHECK_RET(AL_FORMAT_MONO_FLOAT32, sizeof(ALfloat));
 211         CHECK_RET(AL_FORMAT_MONO_DOUBLE_EXT, sizeof(ALdouble));
 212         CHECK_RET(AL_FORMAT_MONO_MULAW, sizeof(ALubyte)*1);
 213
 214         CHECK_RET(AL_FORMAT_STEREO8, sizeof(ALubyte)*2);
 215         CHECK_RET(AL_FORMAT_STEREO16, sizeof(ALshort)*2);
 216         CHECK_RET(AL_FORMAT_STEREO_FLOAT32, sizeof(ALfloat)*2);
 217         CHECK_RET(AL_FORMAT_STEREO_DOUBLE_EXT, sizeof(ALdouble)*2);
 218         CHECK_RET(AL_FORMAT_STEREO_MULAW, sizeof(ALubyte)*2);
 219
 220         CHECK_RET(AL_FORMAT_QUAD8, sizeof(ALubyte)*4);
 221         CHECK_RET(AL_FORMAT_QUAD16, sizeof(ALshort)*4);
 222         CHECK_RET(AL_FORMAT_QUAD32, sizeof(ALfloat)*4);
 223         CHECK_RET(AL_FORMAT_QUAD_MULAW, sizeof(ALubyte)*4);
 224
 225         CHECK_RET(AL_FORMAT_REAR8, sizeof(ALubyte)*2);
 226         CHECK_RET(AL_FORMAT_REAR16, sizeof(ALshort)*2);
 227         CHECK_RET(AL_FORMAT_REAR32, sizeof(ALfloat)*2);
 228         CHECK_RET(AL_FORMAT_REAR_MULAW, sizeof(ALubyte)*2);
 229
 230         CHECK_RET(AL_FORMAT_51CHN8, sizeof(ALubyte)*6);
 231         CHECK_RET(AL_FORMAT_51CHN16, sizeof(ALshort)*6);
 232         CHECK_RET(AL_FORMAT_51CHN32, sizeof(ALfloat)*6);
 233         CHECK_RET(AL_FORMAT_51CHN_MULAW, sizeof(ALubyte)*6);
 234
 235         CHECK_RET(AL_FORMAT_61CHN8, sizeof(ALubyte)*7);
 236         CHECK_RET(AL_FORMAT_61CHN16, sizeof(ALshort)*7);
 237         CHECK_RET(AL_FORMAT_61CHN32, sizeof(ALfloat)*7);
 238         CHECK_RET(AL_FORMAT_61CHN_MULAW, sizeof(ALubyte)*7);
 239
 240         CHECK_RET(AL_FORMAT_71CHN8, sizeof(ALubyte)*8);
 241         CHECK_RET(AL_FORMAT_71CHN16, sizeof(ALshort)*8);
 242         CHECK_RET(AL_FORMAT_71CHN32, sizeof(ALfloat)*8);
 243         CHECK_RET(AL_FORMAT_71CHN_MULAW, sizeof(ALubyte)*8);
 244
 245         CHECK_RET(AL_FORMAT_MONO_IMA4, 36);
 246         CHECK_RET(AL_FORMAT_STEREO_IMA4, 36*2);
 247 #undef CHECK_RET
 248     }
 249     return 0;
 250 }
 251
 252 ALuint DetectCompressionRate(ALenum format)
 253 {
 254     switch(format)
 255     {
 256     case AL_FORMAT_MONO8:
 257     case AL_FORMAT_MONO16:
 258     case AL_FORMAT_MONO_FLOAT32:
 259     case AL_FORMAT_MONO_DOUBLE_EXT:
 260     case AL_FORMAT_STEREO8:
 261     case AL_FORMAT_STEREO16:
 262     case AL_FORMAT_STEREO_FLOAT32:
 263     case AL_FORMAT_STEREO_DOUBLE_EXT:
 264     case AL_FORMAT_QUAD8:
 265     case AL_FORMAT_QUAD16:
 266     case AL_FORMAT_QUAD32:
 267     case AL_FORMAT_REAR8:
 268     case AL_FORMAT_REAR16:
 269     case AL_FORMAT_REAR32:
 270     case AL_FORMAT_51CHN8:
 271     case AL_FORMAT_51CHN16:
 272     case AL_FORMAT_51CHN32:
 273     case AL_FORMAT_61CHN8:
 274     case AL_FORMAT_61CHN16:
 275     case AL_FORMAT_61CHN32:
 276     case AL_FORMAT_71CHN8:
 277     case AL_FORMAT_71CHN16:
 278     case AL_FORMAT_71CHN32:
 279         return 1;
 280
 281     case AL_FORMAT_MONO_MULAW:
 282     case AL_FORMAT_STEREO_MULAW:
 283     case AL_FORMAT_QUAD_MULAW:
 284     case AL_FORMAT_REAR_MULAW:
 285     case AL_FORMAT_51CHN_MULAW:
 286     case AL_FORMAT_61CHN_MULAW:
 287     case AL_FORMAT_71CHN_MULAW:
 288         return 1;
 289
 290     case AL_FORMAT_MONO_IMA4:
 291     case AL_FORMAT_STEREO_IMA4:
 292         return 65;
 293     }
 294     fprintf(stderr, "Alure lib: Unhandled format: %#x\n", format);
 295     return 0;
 296 }
 297
 298 ALenum GetSampleFormat(ALuint channels, ALuint bits, bool isFloat)
 299 {
 300 #define CHECK_FMT_RET(f) do {                                                 \
 301     ALenum fmt = alGetEnumValue(#f);                                          \
 302     if(alGetError() == AL_NO_ERROR && fmt != 0 && fmt != -1)                  \
 303         return fmt;                                                           \
 304 } while(0)
 305     if(!isFloat)
 306     {
 307         if(bits == 8)
 308         {
 309             if(channels == 1) CHECK_FMT_RET(AL_FORMAT_MONO8);
 310             if(channels == 2) CHECK_FMT_RET(AL_FORMAT_STEREO8);
 311             if(alIsExtensionPresent("AL_EXT_MCFORMATS"))
 312             {
 313                 if(channels == 4) CHECK_FMT_RET(AL_FORMAT_QUAD8);
 314                 if(channels == 6) CHECK_FMT_RET(AL_FORMAT_51CHN8);
 315                 if(channels == 7) CHECK_FMT_RET(AL_FORMAT_61CHN8);
 316                 if(channels == 8) CHECK_FMT_RET(AL_FORMAT_71CHN8);
 317             }
 318             if(alIsExtensionPresent("AL_LOKI_quadriphonic"))
 319             {
 320                 if(channels == 4) CHECK_FMT_RET(AL_FORMAT_QUAD8_LOKI);
 321             }
 322             SetError("Unsupported 8-bit channel count\n");
 323             return AL_NONE;
 324         }
 325         if(bits == 16)
 326         {
 327             if(channels == 1) CHECK_FMT_RET(AL_FORMAT_MONO16);
 328             if(channels == 2) CHECK_FMT_RET(AL_FORMAT_STEREO16);
 329             if(alIsExtensionPresent("AL_EXT_MCFORMATS"))
 330             {
 331                 if(channels == 4) CHECK_FMT_RET(AL_FORMAT_QUAD16);
 332                 if(channels == 6) CHECK_FMT_RET(AL_FORMAT_51CHN16);
 333                 if(channels == 7) CHECK_FMT_RET(AL_FORMAT_61CHN16);
 334                 if(channels == 8) CHECK_FMT_RET(AL_FORMAT_71CHN16);
 335             }
 336             if(alIsExtensionPresent("AL_LOKI_quadriphonic"))
 337             {
 338                 if(channels == 4) CHECK_FMT_RET(AL_FORMAT_QUAD16_LOKI);
 339             }
 340             SetError("Unsupported 16-bit channel count\n");
 341             return AL_NONE;
 342         }
 343         SetError("Unsupported PCM bit depth\n");
 344         return AL_NONE;
 345     }
 346
 347     if(bits == 32 && alIsExtensionPresent("AL_EXT_FLOAT32"))
 348     {
 349         if(channels == 1) CHECK_FMT_RET(AL_FORMAT_MONO_FLOAT32);
 350         if(channels == 2) CHECK_FMT_RET(AL_FORMAT_STEREO_FLOAT32);
 351         if(alIsExtensionPresent("AL_EXT_MCFORMATS"))
 352         {
 353             if(channels == 4) CHECK_FMT_RET(AL_FORMAT_QUAD32);
 354             if(channels == 6) CHECK_FMT_RET(AL_FORMAT_51CHN32);
 355             if(channels == 7) CHECK_FMT_RET(AL_FORMAT_61CHN32);
 356             if(channels == 8) CHECK_FMT_RET(AL_FORMAT_71CHN32);
 357         }
 358         SetError("Unsupported float32 channel count\n");
 359         return AL_NONE;
 360     }
 361     if(bits == 64 && alIsExtensionPresent("AL_EXT_DOUBLE"))
 362     {
 363         if(channels == 1) CHECK_FMT_RET(AL_FORMAT_MONO_DOUBLE_EXT);
 364         if(channels == 2) CHECK_FMT_RET(AL_FORMAT_STEREO_DOUBLE_EXT);
 365         SetError("Unsupported double channel count\n");
 366         return AL_NONE;
 367     }
 368 #undef CHECK_FMT_RET
 369
 370     SetError("Unsupported float bit depth\n");
 371     return AL_NONE;
 372 }
 373
 374 extern "C" {
 375
 376 /* Function: alureGetVersion
 377  *
 378  * Stores the major and minor version of the library. If either major or minor
 379  * are NULL, that value is not provided.
 380  */
 381 ALURE_API void ALURE_APIENTRY alureGetVersion(ALuint *major, ALuint *minor)
 382 {
 383     if(major) *major = ALURE_VER_MAJOR;
 384     if(minor) *minor = ALURE_VER_MINOR;
 385 }
 386
 387 /* Function: alureGetErrorString
 388  *
 389  * Returns a string describing the last error encountered.
 390  */
 391 ALURE_API const ALchar* ALURE_APIENTRY alureGetErrorString(void)
 392 {
 393     const ALchar *ret = last_error;
 394     last_error = "No error";
 395     return ret;
 396 }
 397
 398
 399 /* Function: alureGetDeviceNames
 400  *
 401  * Gets an array of device name strings from OpenAL. This encapsulates
 402  * AL_ENUMERATE_ALL_EXT (if supported and 'all' is true) and standard
 403  * enumeration, with 'count' being set to the number of returned device
 404  * names.
 405  *
 406  * Returns:
 407  * An array of device name strings, or NULL on error.
 408  *
 409  * See Also:
 410  * <alureFreeDeviceNames>
 411  */
 412 ALURE_API const ALCchar** ALURE_APIENTRY alureGetDeviceNames(ALCboolean all, ALCsizei *count)
 413 {
 414     const ALCchar *list = NULL;
 415     if(all && alcIsExtensionPresent(NULL, "ALC_ENUMERATE_ALL_EXT"))
 416         list = alcGetString(NULL, ALC_ALL_DEVICES_SPECIFIER);
 417     else
 418         list = alcGetString(NULL, ALC_DEVICE_SPECIFIER);
 419     if(!list)
 420     {
 421         alcGetError(NULL);
 422         SetError("No device names found");
 423         return NULL;
 424     }
 425
 426     const ALCchar *cur = list;
 427     ALuint retlistLen = 0;
 428     while(*cur)
 429     {
 430         cur += strlen(cur)+1;
 431         retlistLen++;
 432     }
 433
 434     const ALCchar **retlist = new const ALCchar*[retlistLen+1];
 435     retlistLen = 0;
 436     cur = list;
 437     while(*cur)
 438     {
 439         ALCuint len = strlen(cur)+1;
 440         ALCchar *newstr = new ALCchar[len];
 441
 442         memcpy(newstr, cur, len);
 443         cur += len;
 444
 445         retlist[retlistLen] = newstr;
 446         retlistLen++;
 447     }
 448     retlist[retlistLen] = NULL;
 449
 450     *count = retlistLen;
 451     return retlist;
 452 }
 453
 454 /* Function: alureFreeDeviceNames
 455  *
 456  * Frees the device name array returned from alureGetDeviceNames.
 457  *
 458  * See Also:
 459  * <alureGetDeviceNames>
 460  */
 461 ALURE_API ALvoid ALURE_APIENTRY alureFreeDeviceNames(const ALCchar **names)
 462 {
 463     if(names)
 464     {
 465         for(ALCuint i = 0;names[i];i++)
 466             delete[] const_cast<ALCchar*>(names[i]);
 467         delete[] names;
 468     }
 469 }
 470
 471
 472 /* Function: alureInitDevice
 473  *
 474  * Opens the named device, creates a context with the given attributes, and
 475  * sets that context as current. The name and attribute list would be the same
 476  * as what's passed to alcOpenDevice and alcCreateContext respectively.
 477  *
 478  * Returns:
 479  * AL_FALSE on error.
 480  *
 481  * See Also:
 482  * <alureShutdownDevice>
 483  */
 484 ALURE_API ALboolean ALURE_APIENTRY alureInitDevice(const ALCchar *name, const ALCint *attribs)
 485 {
 486     ALCdevice *device = alcOpenDevice(name);
 487     if(!device)
 488     {
 489         alcGetError(NULL);
 490
 491         SetError("Device open failed");
 492         return AL_FALSE;
 493     }
 494
 495     ALCcontext *context = alcCreateContext(device, attribs);
 496     if(!context || alcMakeContextCurrent(context) == ALC_FALSE)
 497     {
 498         if(context)
 499             alcDestroyContext(context);
 500         alcCloseDevice(device);
 501
 502         SetError("Context setup failed");
 503         return AL_FALSE;
 504     }
 505     alcGetError(device);
 506
 507     return AL_TRUE;
 508 }
 509
 510 /* Function: alureShutdownDevice
 511  *
 512  * Destroys the current context and closes its associated device.
 513  *
 514  * Returns:
 515  * AL_FALSE on error.
 516  *
 517  * See Also:
 518  * <alureInitDevice>
 519  */
 520 ALURE_API ALboolean ALURE_APIENTRY alureShutdownDevice(void)
 521 {
 522     ALCcontext *context = alcGetCurrentContext();
 523     ALCdevice *device = alcGetContextsDevice(context);
 524     if(!context || !device)
 525     {
 526         alcGetError(device);
 527         SetError("Failed to get current device");
 528         return AL_FALSE;
 529     }
 530
 531     if(alcMakeContextCurrent(NULL) == ALC_FALSE)
 532     {
 533         alcGetError(NULL);
 534         SetError("Failed to unset current context");
 535         return AL_FALSE;
 536     }
 537
 538     alcDestroyContext(context);
 539     alcCloseDevice(device);
 540     alcGetError(NULL);
 541
 542     return AL_TRUE;
 543 }
 544
 545
 546 /* Function: alureGetSampleFormat
 547  *
 548  * Retrieves an OpenAL format for the given sample format. If bits is non-0,
 549  * floatbits must be 0, and if floatbits is non-0, bits must be 0. The
 550  * application should not rely on any particular format enum being returned as
 551  * it is dependant on the available extensions. The returned format will be
 552  * valid for the current context. Requires an active context.
 553  *
 554  * Returns:
 555  * An OpenAL format enum for the given sample format, or AL_NONE if one can't
 556  * be found.
 557  */
 558 ALURE_API ALenum ALURE_APIENTRY alureGetSampleFormat(ALuint channels, ALuint bits, ALuint floatbits)
 559 {
 560     if(alGetError() != AL_NO_ERROR)
 561     {
 562         SetError("Existing OpenAL error");
 563         return AL_NONE;
 564     }
 565
 566     if(bits && floatbits)
 567     {
 568         SetError("Both bit-types specified");
 569         return AL_NONE;
 570     }
 571
 572     if(bits)
 573         return GetSampleFormat(channels, bits, false);
 574     return GetSampleFormat(channels, floatbits, true);
 575 }
 576
 577
 578 /* Function: alureInstallDecodeCallbacks
 579  *
 580  * Installs callbacks to enable ALURE to handle more file types. The index is
 581  * the order that each given set of callbacks will be tried, starting at the
 582  * most negative number (INT_MIN) and going up. Negative indices will be tried
 583  * before the built-in decoders, and positive indices will be tried after.
 584  * Installing callbacks onto the same index multiple times will remove the
 585  * previous callbacks, and removing old callbacks won't affect any opened files
 586  * using them (they'll continue to use the old functions until properly closed,
 587  * although newly opened files will use the new ones). Passing NULL for all
 588  * callbacks is a valid way to remove an installed set, otherwise certain
 589  * callbacks must be specified. Callbacks that are not specified will assume
 590  * failure.
 591  *
 592  * Parameters:
 593  * open_file - This callback is expected to open the named file and prepare it
 594  *             for decoding. If the callbacks cannot decode the file, NULL
 595  *             should be returned to indicate failure. Upon success, a non-NULL
 596  *             handle must be returned, which will be used as a unique
 597  *             identifier for the decoder instance. This callback is required
 598  *             if open_memory is not specified.
 599  * open_memory - This callback behaves the same as open_file, except it takes a
 600  *               memory segment for input instead of a filename. The given
 601  *               memory will remain valid while the instance is open. This
 602  *               callback is required if open_file is not specified.
 603  * get_format - This callback is used to retrieve the format of the decoded
 604  *              data for the given instance. It is the responsibility of the
 605  *              function to make sure the returned format is valid for the
 606  *              current AL context (eg. don't return AL_FORMAT_QUAD16 if the
 607  *              AL_EXT_MCFORMATS extension isn't available). Returning 0 for
 608  *              samplerate or blocksize, or returning AL_NONE for format, will
 609  *              cause a failure. Returning AL_FALSE indicates failure. This
 610  *              callback is required.
 611  * decode - This callback is called to get more decoded data. Up to the
 612  *          specified amount of bytes should be written to the data pointer.
 613  *          The number of bytes written should be a multiple of the block size,
 614  *          otherwise an OpenAL error may occur during buffering. The function
 615  *          should return the number of bytes written. This callback is
 616  *          required.
 617  * rewind - This callback is for rewinding the instance so that the next decode
 618  *          calls for it will get audio data from the start of the sound file.
 619  *          If the stream fails to rewind, AL_FALSE should be returned.
 620  * close - This callback is called at the end of processing for a particular
 621  *         instance. The handle will not be used further and any associated
 622  *         data may be deleted.
 623  *
 624  * Returns:
 625  * AL_FALSE on error.
 626  */
 627 ALURE_API ALboolean ALURE_APIENTRY alureInstallDecodeCallbacks(ALint index,
 628       void*     (*open_file)(const ALchar *filename),
 629       void*     (*open_memory)(const ALubyte *data, ALuint length),
 630       ALboolean (*get_format)(void *instance, ALenum *format, ALuint *samplerate, ALuint *blocksize),
 631       ALuint    (*decode)(void *instance, ALubyte *data, ALuint bytes),
 632       ALboolean (*rewind)(void *instance),
 633       void      (*close)(void *instance))
 634 {
 635     if(!open_file && !open_memory && !get_format && !decode && !rewind && !close)
 636     {
 637         std::map<ALint,UserCallbacks>::iterator i = InstalledCallbacks.find(index);
 638         if(i != InstalledCallbacks.end())
 639             InstalledCallbacks.erase(i);
 640         return AL_TRUE;
 641     }
 642
 643     if((!open_file && !open_memory) || !get_format || !decode)
 644     {
 645         SetError("Missing callback functions");
 646         return AL_FALSE;
 647     }
 648
 649     UserCallbacks newcb;
 650     newcb.open_file = open_file;
 651     newcb.open_mem  = open_memory;
 652     newcb.get_fmt   = get_format;
 653     newcb.decode    = decode;
 654     newcb.rewind    = rewind;
 655     newcb.close     = close;
 656
 657     InstalledCallbacks[index] = newcb;
 658
 659     return AL_TRUE;
 660 }
 661
 662
 663 /* Function: alureSleep
 664  *
 665  * Rests the calling thread for the given number of seconds.
 666  *
 667  * Returns:
 668  * AL_FALSE on error.
 669  */
 670 ALURE_API ALboolean ALURE_APIENTRY alureSleep(ALfloat duration)
 671 {
 672     if(duration < 0.0f)
 673     {
 674         SetError("Invalid duration");
 675         return AL_FALSE;
 676     }
 677
 678     ALuint seconds = (ALuint)duration;
 679     ALdouble rest = duration - (ALdouble)seconds;
 680
 681 #ifdef HAVE_NANOSLEEP
 682
 683     struct timespec t, remainingTime;
 684     t.tv_sec = (time_t)seconds;
 685     t.tv_nsec = (long)(rest*1000000000);
 686
 687     while(nanosleep(&t, &remainingTime) < 0 && errno == EINTR)
 688         t = remainingTime;
 689
 690 #elif defined(HAVE_WINDOWS_H)
 691
 692     while(seconds > 0)
 693     {
 694         Sleep(1000);
 695         seconds--;
 696     }
 697     Sleep((DWORD)(rest * 1000));
 698
 699 #endif
 700
 701     return AL_TRUE;
 702 }
 703
 704
 705 /* Function: alureGetProcAddress
 706  *
 707  * Returns a pointer for the named ALURE function.
 708  *
 709  * Returns:
 710  * NULL on error.
 711  *
 712  * *Version Added*: 1.1
 713  */
 714 ALURE_API void* ALURE_APIENTRY alureGetProcAddress(const ALchar *funcname)
 715 {
 716     static const struct {
 717         const char *name;
 718         void *func;
 719     } FunctionList[] = {
 720 #define ADD_FUNCTION(x) { #x, (void*)x },
 721         ADD_FUNCTION(alureGetVersion)
 722         ADD_FUNCTION(alureGetErrorString)
 723         ADD_FUNCTION(alureGetDeviceNames)
 724         ADD_FUNCTION(alureFreeDeviceNames)
 725         ADD_FUNCTION(alureInitDevice)
 726         ADD_FUNCTION(alureShutdownDevice)
 727         ADD_FUNCTION(alureGetSampleFormat)
 728         ADD_FUNCTION(alureSleep)
 729         ADD_FUNCTION(alureCreateBufferFromFile)
 730         ADD_FUNCTION(alureCreateBufferFromMemory)
 731         ADD_FUNCTION(alureBufferDataFromFile)
 732         ADD_FUNCTION(alureBufferDataFromMemory)
 733         ADD_FUNCTION(alureCreateStreamFromFile)
 734         ADD_FUNCTION(alureCreateStreamFromMemory)
 735         ADD_FUNCTION(alureCreateStreamFromStaticMemory)
 736         ADD_FUNCTION(alureCreateStreamFromCallback)
 737         ADD_FUNCTION(alureGetStreamLength)
 738         ADD_FUNCTION(alureRewindStream)
 739         ADD_FUNCTION(alureDestroyStream)
 740         ADD_FUNCTION(alureSetStreamOrder)
 741         ADD_FUNCTION(alureSetStreamPatchset)
 742         ADD_FUNCTION(alureInstallDecodeCallbacks)
 743         ADD_FUNCTION(alureSetIOCallbacks)
 744         ADD_FUNCTION(alureGetProcAddress)
 745         ADD_FUNCTION(alurePlaySourceStream)
 746         ADD_FUNCTION(alurePlaySource)
 747         ADD_FUNCTION(alureStopSource)
 748 #undef ADD_FUNCTION
 749         { NULL, NULL }
 750     };
 751
 752     size_t i;
 753     for(i = 0;FunctionList[i].name;i++)
 754     {
 755         if(strcmp(FunctionList[i].name, funcname) == 0)
 756             break;
 757     }
 758
 759     if(!FunctionList[i].name)
 760         SetError("Function not found");
 761     return FunctionList[i].func;
 762 }
 763
 764 } // extern "C"