//===========================================================================
//  Revised 21 January 2012                                 MIDIRAMP FUNCTION
//===========================================================================

// PUT THIS WITH THE INCLUDES AT THE TOP:

#include <mmsystem.h>                                         // enables MIDI


// PUT THESE WITH THE VARIABLE DECLARATIONS:

int midiport = 0;
HMIDIOUT device;

union {
   public:
   unsigned long word;
   unsigned char data[4];
} message;

int instrument = 12;  // "marimba" but sounds like 13 xylophone
int note;


// FUNCTION:

//------------------------------------------------------- 2012.01.21 midiRamp
// Be aware that the range of notes is different for different instruments.
// This code does not take that into account.
int midiRamp(int part, int whole) {
	// only using the 47 MIDI notes which range from 35 to 81
        if (whole == 0) whole = 1;     // prevent divide by zero
        part = part % whole;           // keep part less than whole 
	note = (part * 47) / whole;
	note = note + 35;
	return note;
}


// FUNCTION CALL:

Sleep(milliseconds);                    // interval between notes
if (part == 0) continue;                // if we want 0 to be silent
note = midiRamp(part, whole);           // the call
message.data[0] = 0x90;                 // note on
message.data[1] = note;                 // note #
midiOutShortMsg(device, message.word);  // do it


// PUT ONLY THE CONTENTS IN THIS FIRST EVENT HANDLER

__fastcall TForm1::TForm1(TComponent* Owner)
	: TForm(Owner)
{
   midiOutOpen(&device, midiport, 0, 0, CALLBACK_NULL);
   message.data[0] = 0xC0;         // choose instrument command
   message.data[1] = instrument;   // instrument
   message.data[2] = 100;          // once set, no need to repeat
   message.data[3] = 0;            // once set, no need to repeat
   midiOutShortMsg(device, message.word);
}