Play a MIDI voice (Dev C++ console program)

// sound a tugboat toot using a midi voice from the winmm.lib
// in case of Dev C++ link with libwinmm.a via
// Project>>Project Options>>Parameters>>Add Lib>>libwinmm.a
// BCX generated C code painstakingly modified for Dev C++ 
//
// Sound(Frequency,Duration[,Volume,Voice,Tempo])
// Volume = 0 to 127 (off to loudest)
// Voice = 0 to 127 (Shanai = 111, Tuba = 58, Accordion = 21)
// more midi voices: 
// Rock Organ = 18, Marimba = 12, Steel String Guitar = 25
// Choir Aahs = 52, Alto Sax = 65, Bird Tweet = 123, Sitar = 104
// FX 8 (sci-fi) = 103, FX 3 (crystal) = 98, Glockenspiel = 9 
//
// a Dev-C++ tested Console Application by  vegaseat  21nov2004

#include <cmath>
#include <windows.h>
#include <mmsystem.h>

using namespace std;

#define SNDQUE 10000

typedef struct _soundtype
{
  double  Freq;
  int     Dura;
  int     Vol;
  int     Voice;
  double  Tempo;
  int     sndTid;
} soundtype, *LPSOUNDTYPE;

static soundtype  SndPmtr[SNDQUE+1];
static int        gTenter;
static int        gTwait;
static int        gTexit;
static int        gTarray;
static BOOL       gTsig;
static HANDLE     gSThread = NULL;

double  Round (double,int);
double  Abs (double);
int     Sound (float,int=0,int=127,int=0,float=1);
// changed this from int PlaySnd(void) to:
DWORD WINAPI PlaySnd (LPVOID);


int main()
{
  // Tugboat whistle sound 95 hertz, 2000ms, 127 = loud, 111 = Shanai
  // experiment with your own sounds, it's fun ...
  Sound(95,2000,127,111);  // 2 second blast 
  Sound( 1,1000,  0,111);  // 1 second of silence 
  Sound(95,2000,127,111);  // 2 second blast 
  Sound( 1,1000,  0,111);  // 1 second of silence 
  Sound(95,2000,127,111);  // 2 second blast
      
  // wait till que is empty
  while(Sound(0) != 0)
  {
    Sleep(10);
  }
 
  return 0;
}


double Round (double n, int d)
{
  return (floor((n)*pow(10.0,(d))+0.5)/pow(10.0,(d)));
}


double Abs (double a)
{
  if (a < 0)  return -a;
  return  a;
}


int Sound (float Freq,int Dura,int Vol,int Voice,float Tempo)
{
  DWORD  dwThreadId;
  
  if (Freq == 0 && Dura < 1) return gTenter-gTexit;
  // silence
  if (Freq == 0) Vol = 0;
  if (Dura < 5) Dura = 5;
  gTenter++;
  gTsig = FALSE;
  if (gTenter >= SNDQUE)
  { 
    gTarray = gTenter % SNDQUE+1;
  }
  else 
  {               
    gTarray=gTenter;
  }
  SndPmtr[gTarray].Freq = Freq;
  SndPmtr[gTarray].Dura = Dura;
  SndPmtr[gTarray].Tempo = Tempo;
  SndPmtr[gTarray].Vol = Vol;
  SndPmtr[gTarray].Voice = Voice;
  SndPmtr[gTarray].sndTid = gTenter;
  if (gSThread == NULL && (Freq == Abs(Freq) || Freq == 0))
  {
      // "PlaySnd" needs casting (void *)
      gSThread = CreateThread(NULL,0,PlaySnd,(void *)"PlaySnd",0,&dwThreadId);
      Sleep(1);
      return 0;
  }
  if (Freq != Abs(Freq))
  {
    if (Freq == -1)
    {
      Freq = 0;
      SndPmtr[gTarray].Vol=0;
    }
    SndPmtr[gTarray].Freq=Abs(Freq);
    gTsig=TRUE;
    while(gSThread!=NULL)
    {
      Sleep(10);
    }
    gTexit = gTenter-1;
    gTwait = gTenter-1;
    gTsig = FALSE;
    return PlaySnd(0);  // needs some kind of argument
  }
  return 0;
}


DWORD WINAPI PlaySnd (LPVOID)
{
  soundtype  LocSndPar;
  int  lTarray;
  
  while(gTenter > gTexit && gTsig == FALSE)
  {
    gTwait++;
    if (gTwait >= SNDQUE)
      lTarray = gTwait % SNDQUE+1;
    else
      lTarray = gTwait;
    LocSndPar = SndPmtr[lTarray];
    int Note = 0;
    int Phrase = 0;
    HMIDIOUT hMidi;
    midiOutOpen(&hMidi,(UINT)-1,0,0,CALLBACK_NULL);
    midiOutShortMsg(hMidi,(256*LocSndPar.Voice)+192);
    // convert frequency to midi note
    Note = (int)Round((log(LocSndPar.Freq)-log(440.0))/log(2.0)*12+69,0);
    Phrase = (LocSndPar.Vol*256+Note)*256+144;
    midiOutShortMsg(hMidi,Phrase);
    Sleep((int)(LocSndPar.Dura*(1/LocSndPar.Tempo+0.0001)));
    Phrase = (LocSndPar.Vol*256+Note)*256+128;
    midiOutShortMsg(hMidi,Phrase);
    midiOutClose(hMidi);
    gTexit++;
  }
  CloseHandle(gSThread);
  gSThread = NULL;
  return 0;
}