/*Sources are points emitting sound*/

    ALuint *Sources;

    /*Buffers hold sound data*/

    ALuint *Buffers;

    /*index for Sources and Buffers*/

    ALuint globalindex, globalsize, increment;

    ALboolean openalReady = AL_FALSE;

    ALboolean openal_close (void) {

        /*Stop all sounds, deallocate all memory and close OpenAL */

        ALCcontext *context;

        ALCdevice  *device;

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        alSourceStopv	(globalsize, Sources);

        alDeleteSources (globalsize, Sources);

        alDeleteBuffers (globalsize, Buffers);

        free(Sources);

        free(Buffers);

        context = alcGetCurrentContext();

        device  = alcGetContextsDevice(context);

        alcMakeContextCurrent(NULL);

        alcDestroyContext(context);

        alcCloseDevice(device);

        openalReady = AL_FALSE;

        return AL_TRUE;

    }

    ALboolean openal_ready(void) {

        return openalReady;

    }

    ALboolean openal_init(uint32_t memorysize) {	

        /*Initialize an OpenAL contex and allocate memory space for data and buffers*/

        ALCcontext *context;

        ALCdevice *device;

        const ALCchar *default_device;

        /*Position of the listener*/

        ALfloat ListenerPos[] = { 0.0, 0.0, 0.0 };

        /*Velocity of the listener*/

        ALfloat ListenerVel[] = { 0.0, 0.0, 0.0 };

        /*Orientation of the listener. (first 3 elements are "at", second 3 are "up")*/

        ALfloat ListenerOri[] = { 0.0, 0.0, -1.0,  0.0, 1.0, 0.0 };

        if(openalReady == AL_TRUE) {

            fprintf(stderr, "ERROR: OpenAL already initialized\n");

            return AL_FALSE;

        }

        default_device = alcGetString(NULL, ALC_DEFAULT_DEVICE_SPECIFIER);

        fprintf(stderr, "Using default device: %s\n", default_device);

        if ((device = alcOpenDevice(default_device)) == NULL) {

            fprintf(stderr, "ERROR: Failed to open sound device\n");

            return AL_FALSE;

        }

        context = alcCreateContext(device, NULL);

        alcMakeContextCurrent(context);

        alcProcessContext(context);

        if (AlGetError("ERROR %d: Creating a new contex\n") != AL_TRUE)

            return AL_FALSE;

        /*allocate memory space for buffers and sources*/

        globalsize = memorysize;

        increment  = memorysize;

        Buffers = (ALuint*) Malloc(sizeof(ALuint)*globalsize);

        Sources = (ALuint*) Malloc(sizeof(ALuint)*globalsize);

        /*set the listener gain, position (on xyz axes), velocity (one value for each axe) and orientation*/

        alListenerf (AL_GAIN,        1.0f       );

        alListenerfv(AL_POSITION,    ListenerPos);

        alListenerfv(AL_VELOCITY,    ListenerVel);

        alListenerfv(AL_ORIENTATION, ListenerOri);

        if (AlGetError("ERROR %d: Setting Listener properties\n") != AL_TRUE)

            return AL_FALSE;

        openalReady = AL_TRUE;

        alGetError();  /* clear any AL errors beforehand */

        return AL_TRUE;

    }

    ALboolean helper_realloc (void) {

        /*expands allocated memory when loading more sound files than expected*/

        fprintf(stderr, "OpenAL: Realloc in process %d\n", globalsize);

        globalsize += increment;

        Buffers = (ALuint*) Realloc(Buffers, sizeof(ALuint)*globalsize);

        Sources = (ALuint*) Realloc(Sources, sizeof(ALuint)*globalsize);

        return AL_TRUE;

    }

    ALint openal_loadfile (const char *filename){

        /*Open a file, load into memory and allocate the Source buffer for playing*/

        ALfloat SourcePos[] = { 0.0, 0.0, 0.0 }; /*Position of the source sound*/

        ALfloat SourceVel[] = { 0.0, 0.0, 0.0 }; /*Velocity of the source sound*/

        ALenum format;

        ALsizei bitsize, freq;

        char *data;

        uint32_t fileformat;

        ALenum error;

        FILE *fp;

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        /*when the buffers are all used, we can expand memory to accept new files*/

        if (globalindex == globalsize)

            helper_realloc();

        /*detect the file format, as written in the first 4 bytes of the header*/

        fp = Fopen (filename, "rb");

        if (fp == NULL)

            return -1;

        error = fread (&fileformat, sizeof(uint32_t), 1, fp);

        fclose (fp);

        if (error < 0) {

            fprintf(stderr, "ERROR: file %s is too short \n", filename);

            return -2;

        }

        /*prepare the buffer to receive data*/

        alGenBuffers(1, &Buffers[globalindex]);

        if (AlGetError("ERROR %d: Allocating memory for buffers\n") != AL_TRUE)

            return -3;

        /*prepare the source to emit sound*/

        alGenSources(1, &Sources[globalindex]);

        if (AlGetError("ERROR %d: Allocating memory for sources\n") != AL_TRUE)

            return -4;

        if (fileformat == 0x5367674F) /*check if ogg*/

            error = load_oggvorbis (filename, &format, &data, &bitsize, &freq);

        else {

            if (fileformat == 0x46464952) /*check if wav*/

                error = load_wavpcm (filename, &format, &data, &bitsize, &freq);

            else {

                fprintf(stderr, "ERROR: File format (%08X) not supported!\n", invert_endianness(fileformat));

                return -5;

            }

        }

        /*copy pcm data in one buffer*/

        alBufferData(Buffers[globalindex], format, data, bitsize, freq);

        free(data);		/*deallocate data to save memory*/

        if (AlGetError("ERROR %d: Writing data to buffer\n") != AL_TRUE)

            return -6;

        /*set source properties that it will use when it's in playback*/

        alSourcei (Sources[globalindex], AL_BUFFER,   Buffers[globalindex]  );

        alSourcef (Sources[globalindex], AL_PITCH,    1.0f                  );

        alSourcef (Sources[globalindex], AL_GAIN,     1.0f                  );

        alSourcefv(Sources[globalindex], AL_POSITION, SourcePos             );

        alSourcefv(Sources[globalindex], AL_VELOCITY, SourceVel             );

        alSourcei (Sources[globalindex], AL_LOOPING,  0                     );

        if (AlGetError("ERROR %d: Setting source properties\n") != AL_TRUE)

            return -7;

        alGetError();  /* clear any AL errors beforehand */

        /*returns the index of the source you just loaded, increments it and exits*/

        return globalindex++;

    }

    ALboolean openal_toggleloop (uint32_t index){

        /*Set or unset looping mode*/

        ALint loop;

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        if (index >= globalsize) {

            fprintf(stderr, "ERROR: index out of bounds (got %d, max %d)\n", index, globalindex);

            return AL_FALSE;

        }

        alGetSourcei (Sources[index], AL_LOOPING, &loop);

        alSourcei (Sources[index], AL_LOOPING, !((uint8_t) loop) & 0x00000001);

        if (AlGetError("ERROR %d: Getting or setting loop property\n") != AL_TRUE)

            return AL_FALSE;

        alGetError();  /* clear any AL errors beforehand */

        return AL_TRUE;

    }

    ALboolean openal_setvolume (uint32_t index, uint8_t percentage) {

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        /*Set volume for sound number index*/

        if (index >= globalindex) {

            fprintf(stderr, "ERROR: index out of bounds (got %d, max %d)\n", index, globalindex);

            return AL_FALSE;

        }

        if (percentage > 100)

            percentage = 100;

        alSourcef (Sources[index], AL_GAIN, (float) percentage/100.0f);

        if (AlGetError2("ERROR %d: setting volume for sound %d\n", index) != AL_TRUE)

            return AL_FALSE;

        alGetError();  /* clear any AL errors beforehand */

        return AL_TRUE;

    }

    ALboolean openal_setglobalvolume (uint8_t percentage) {

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        /*Set volume for all sounds*/		

        if (percentage > 100)

            percentage = 100;

        alListenerf (AL_GAIN, (float) percentage/100.0f);

        if (AlGetError("ERROR %d: Setting global volume\n") != AL_TRUE)

            return AL_FALSE;

        alGetError();  /* clear any AL errors beforehand */

        return AL_TRUE;

    }

    ALboolean openal_togglemute () {

        /*Mute or unmute sound*/

        ALfloat mute;

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        alGetListenerf (AL_GAIN, &mute);

        if (mute > 0) 

            mute = 0;

        else

            mute = 1.0;

        alListenerf (AL_GAIN, mute);

        if (AlGetError("ERROR %d: Setting mute property\n") != AL_TRUE)

            return AL_FALSE;

        alGetError();  /* clear any AL errors beforehand */

        return AL_TRUE;

    }

    ALboolean openal_fade (uint32_t index, uint16_t quantity, bool direction) {

        /*Fade in or out by calling a helper thread*/

        pthread_t thread;

        HANDLE Thread;

        DWORD threadID;

#endif

        fade_t *fade;

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        fade = (fade_t*) Malloc(sizeof(fade_t));

        fade->index = index;

        fade->quantity = quantity;

        if (index >= globalindex) {

            fprintf(stderr, "ERROR: index out of bounds (got %d, max %d)\n", index, globalindex);

            return AL_FALSE;

        }

        if (direction == FADE_IN)

#ifndef _WIN32

            pthread_create(&thread, NULL, helper_fadein, (void*) fade);

#else

            Thread = _beginthread(&helper_fadein, 0, (void*) fade);

#endif

        else {

            if (direction == FADE_OUT)

#ifndef _WIN32

                pthread_create(&thread, NULL, helper_fadeout, (void*) fade);

#else

                Thread = _beginthread(&helper_fadeout, 0, (void*) fade);

            else {

                fprintf(stderr, "ERROR: unknown direction for fade (%d)\n", direction);

                free(fade);

                return AL_FALSE;

            }

        }

        pthread_detach(thread);

        alGetError();  /* clear any AL errors beforehand */

        return AL_TRUE;

    }

    ALboolean openal_fadeout (uint32_t index, uint16_t quantity) {

        /*wrapper for fadeout*/

        return openal_fade(index, quantity, FADE_OUT);

    }

    ALboolean openal_fadein (uint32_t index, uint16_t quantity) {

        /*wrapper for fadein*/

        return openal_fade(index, quantity, FADE_IN);

    }

    ALboolean openal_setposition (uint32_t index, float x, float y, float z) {

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        if (index >= globalindex) {

            fprintf(stderr, "ERROR: index out of bounds (got %d, max %d)\n", index, globalindex);

            return AL_FALSE;

        }

        alSource3f(Sources[index], AL_POSITION, x, y, z);

        if (AlGetError2("ERROR %d: setting position for sound %d\n", index) != AL_TRUE)

            return AL_FALSE;

        return AL_TRUE;

    }

    ALboolean openal_playsound (uint32_t index){

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        /*Play sound number index*/

        if (index >= globalindex) {

            fprintf(stderr, "ERROR: index out of bounds (got %d, max %d)\n", index, globalindex);

            return AL_FALSE;

        }

        alSourcePlay(Sources[index]);

        if (AlGetError2("ERROR %d: Playing sound %d\n", index) != AL_TRUE)

            return AL_FALSE;

        alGetError();  /* clear any AL errors beforehand */

        return AL_TRUE;

    }

    ALboolean openal_pausesound(uint32_t index){

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        /*Pause sound number index*/

        if (index >= globalindex) {

            fprintf(stderr, "ERROR: index out of bounds (got %d, max %d)\n", index, globalindex);

            return AL_FALSE;

        }

        alSourcePause(Sources[index]);

        if (AlGetError2("ERROR %d: Pausing sound %d\n", index) != AL_TRUE)

            return AL_FALSE;

        return AL_TRUE;

    }

    ALboolean openal_stopsound(uint32_t index){

        if(openalReady == AL_FALSE) {

            fprintf(stderr, "ERROR: OpenAL not initialized\n");

            return AL_FALSE;

        }

        /*Stop sound number index*/

        if (index >= globalindex) {

            fprintf(stderr, "ERROR: index out of bounds (got %d, max %d)\n", index, globalindex);

            return AL_FALSE;

        }

        alSourceStop(Sources[index]);

        if (AlGetError2("ERROR %d: Stopping sound %d\n", index) != AL_TRUE)

            return AL_FALSE;

        alGetError();  /* clear any AL errors beforehand */

        return AL_TRUE;

    }