OpenAL tutorial

//http://www.youtube.com/user/thecplusplusguy
//Playing 3D sound with OpenAL, and loading a wav file manually
#include <iostream>
#include <fstream>
#include <cstring>
#include <AL/al.h>
#include <AL/alc.h>
#include <SDL/SDL.h>

bool isBigEndian()
{
    int a=1;
    return !((char*)&a)[0];
}

int convertToInt(char* buffer,int len)
{
    int a=0;
    if(!isBigEndian())
        for(int i=0;i<len;i++)
            ((char*)&a)[i]=buffer[i];
    else
        for(int i=0;i<len;i++)
            ((char*)&a)[3-i]=buffer[i];
    return a;
}

char* loadWAV(const char* fn,int& chan,int& samplerate,int& bps,int& size)
{
    char buffer[4];
    std::ifstream in(fn,std::ios::binary);
    in.read(buffer,4);
    if(strncmp(buffer,"RIFF",4)!=0)
    {
        std::cout << "this is not a valid WAVE file"  << std::endl;
        return NULL;
    }
    in.read(buffer,4);
    in.read(buffer,4);  //WAVE
    in.read(buffer,4);  //fmt
    in.read(buffer,4);  //16
    in.read(buffer,2);  //1
    in.read(buffer,2);
    chan=convertToInt(buffer,2);
    in.read(buffer,4);
    samplerate=convertToInt(buffer,4);
    in.read(buffer,4);
    in.read(buffer,2);
    in.read(buffer,2);
    bps=convertToInt(buffer,2);
    in.read(buffer,4);  //data
    in.read(buffer,4);
    size=convertToInt(buffer,4);
    char* data=new char[size];
    in.read(data,size);
    return data;
}

int main(int argc,char** argv)
{
    int channel,sampleRate,bps,size;
    char* data=loadWAV("test.wav",channel,sampleRate,bps,size);
    ALCdevice* device=alcOpenDevice(NULL);
    if(device==NULL)
    {
        std::cout << "cannot open sound card" << std::endl;
        return 0;
    }
    ALCcontext* context=alcCreateContext(device,NULL);
    if(context==NULL)
    {
        std::cout << "cannot open context" << std::endl;
        return 0;
    }
    alcMakeContextCurrent(context);

    unsigned int bufferid,format;
    alGenBuffers(1,&bufferid);
    if(channel==1)
    {
        if(bps==8)
        {
            format=AL_FORMAT_MONO8;
        }else{
            format=AL_FORMAT_MONO16;
        }
    }else{
        if(bps==8)
        {
            format=AL_FORMAT_STEREO8;
        }else{
            format=AL_FORMAT_STEREO16;
        }
    }
    alBufferData(bufferid,format,data,size,sampleRate);
    unsigned int sourceid;
    alGenSources(1,&sourceid);
    alSourcei(sourceid,AL_BUFFER,bufferid);
    SDL_Init(SDL_INIT_EVERYTHING);
    SDL_Surface* screen=SDL_SetVideoMode(640,480,32,SDL_SWSURFACE);
    SDL_Event event;
    Uint32 start;
    bool running;
    bool b[4]={0,0,0,0};
    float x=0,z=0;
    while(running)
    {
        start=SDL_GetTicks();
        while(SDL_PollEvent(&event))
        {
            switch(event.type)
            {
                case SDL_QUIT:
                    running=false;
                    break;
                case SDL_KEYDOWN:
                    switch(event.key.keysym.sym)
                    {
                        case SDLK_UP:
                            b[0]=true;
                            break;
                        case SDLK_RIGHT:
                            b[1]=true;
                            break;
                        case SDLK_DOWN:
                            b[2]=true;
                            break;
                        case SDLK_LEFT:
                            b[3]=true;
                            break;
                        case SDLK_SPACE:
                            alSourcePlay(sourceid);
                            break;
                    }
                    break;
                case SDL_KEYUP:
                    switch(event.key.keysym.sym)
                    {
                        case SDLK_UP:
                            b[0]=false;
                            break;
                        case SDLK_RIGHT:
                            b[1]=false;
                            break;
                        case SDLK_DOWN:
                            b[2]=false;
                            break;
                        case SDLK_LEFT:
                            b[3]=false;
                            break;
                    }
                    break;
            }
        }

        if(b[0])
            z+=0.3;
        if(b[1])
            x+=0.3;
        if(b[2])
            z-=0.3;
        if(b[3])
            x-=0.3;
        alSource3f(sourceid,AL_POSITION,x,0,z);
        alSourcei(sourceid,AL_LOOPING,AL_TRUE);


        float f[]={1,0,0,0,1,0};
        alListenerfv(AL_ORIENTATION,f);


        if(1000/30.0>SDL_GetTicks()-start)
            SDL_Delay(1000/30.0-(SDL_GetTicks()-start));
    }

    alDeleteSources(1,&sourceid);
    alDeleteBuffers(1,&bufferid);

    alcDestroyContext(context);
    alcCloseDevice(device);
    delete[] data;
    return 0;
}