union uData
{
   bool b;
   char c;
   unsigned char uc;
   short s;
   unsigned short us;
   int i;
   unsigned int ui;
   float f;
   double d;
   long long int i64;
   unsigned long long int ui64;
   char *str;
   unsigned char *bytes;
};

int __stdcall DllMain(void *module, unsigned int reason, void *reserved)
{
    return 1;
}

#undef fb
#undef c
#undef g
#undef ref
#undef d

extern "C" __declspec(dllexport) void buck_conv_pwm(void **opaque, double t, union uData *data)
{
    double fb  = data[0].d;
    double c   = data[1].d;
    double ref = data[2].d;
    double &g  = data[3].d;
    double &d  = data[4].d;

    static double last_t = 0.0;
    double dt = t - last_t;
    last_t = t;

    if (dt == t)
    {
        dt = 0.0;
    }

    double Kp = 0.02;
    double Ki = 50.0;

    static double integral_term = 0.0;

    double error = ref - fb;

    integral_term = integral_term + (Ki * error * dt);

    if (integral_term > 0.90)
    {
        integral_term = 0.90;
    }
    else if (integral_term < 0.0)
    {
        integral_term = 0.0;
    }

    d = (Kp * error) + integral_term;

    if (d > 0.95)
    {
        d = 0.95;
    }
    else if (d < 0.05)
    {
        d = 0.05;
    }

    if (d > c)
    {
        g = 5.0;
    }
    else
    {
        g = 0.0;
    }
}