openal beep

beep.cpp

#include <cmath>
#include <iostream>
#include <thread>
using namespace std;

#include <AL/alut.h> // OpenAl


void init_al()
{
    const char *defname = alcGetString(NULL, ALC_DEFAULT_DEVICE_SPECIFIER);
    ALCdevice* dev = alcOpenDevice(defname);
    ALCcontext *ctx = alcCreateContext(dev, NULL);
    alcMakeContextCurrent(ctx);
}

void exit_al()
{
    ALCcontext* ctx = alcGetCurrentContext();
    ALCdevice* dev = alcGetContextsDevice(ctx);
    alcMakeContextCurrent(0);
    alcDestroyContext(ctx);
    alcCloseDevice(dev);
}

void Beep(float freq = 440, float seconds = 0.5)
{

    ALuint buf;
    alGenBuffers(1, &buf);

    unsigned sample_rate = 10000;
    size_t buf_size = seconds * sample_rate;
    short* samples = new short[buf_size];
    if(samples == 0)
    {
        cout<< "It seems there is no more heap memory. Sorry we cannot make a beep!";
    }
    for(unsigned i = 0; i < buf_size; i++)
        samples[i] = 32760*sin(2*M_PI*i*freq/sample_rate);

    alBufferData(buf,AL_FORMAT_MONO16,samples,buf_size,sample_rate);

    ALuint src;
    alGenSources(1,&src);
    alSourcei(src,AL_BUFFER,buf);
    alSourcePlay(src);
    alutSleep(seconds + 0.5);
    delete[] samples;

    alSourceStopv(1,&src); // new line
    alDeleteSources(1,&src); // new line
    alDeleteBuffers(1,&buf); // new line
}

int main()
{
    init_al();
    for(int i = 1; i < 1000; i++)
    {
        thread t(Beep, 440,0.5);
        t.detach();
        alutSleep(0.01);
        cout<< i << "\n";
    }
     exit_al();
}