/* Simple.c -- Displays a window on the screen and plays a MIDI note while executing.
	Uses these basic Win API low-level MIDI functions:
		midiOutGetNumDevs()		-- get the number of MIDI output devices in the system
		midiOutGetDevCaps()		-- get thecapabilities of a selected MIDI output device
		midiOutOpen()			-- open a selected MIDI output device
		midiOutShortMsg()		-- send a channel voice message
		midiOutClose()			-- close selected MIDI output device
*/

#include <windows.h>
#include <mmsystem.h>
#include <string.h>
#include <stdio.h>

#define NOTEON	0x90
#define	NOTEOFF 0x80


char szWinName[] =	"MyWin"; /* name of window class */ 
HINSTANCE hInst;

LRESULT CALLBACK WindowFunc(HWND, UINT, WPARAM, LPARAM);
BOOL CALLBACK TestProc(HWND, UINT, WPARAM, LPARAM);
UINT FAR PASCAL sendMIDIEvent( HMIDIOUT, BYTE, BYTE, BYTE );


int WINAPI WinMain(HINSTANCE hThisInst, HINSTANCE hPrevInst, LPSTR lpszArgs, int nWinMode)
{
	HWND hwnd;
	MSG msg;
	WNDCLASS wcl;


	/* Define a window class. */
	wcl.hInstance = hThisInst; /* handle to this instance */ 
	wcl.lpszClassName = szWinName; /* window class name */ 
	wcl.lpfnWndProc = WindowFunc; /* window function */ 
	wcl.style = 0; /* default style */
	wcl.hIcon = LoadIcon(NULL, IDI_APPLICATION); /* icon style */
	wcl.hCursor = LoadCursor(NULL, IDC_ARROW); /* cursor style */
	/* specify name of menu resource */ 
	wcl.lpszMenuName = "MYMENU"; /* main menu */
	wcl.cbClsExtra = 0; /* none needed */ 
	wcl.cbWndExtra = 0; /* information needed */
	/* Make the window white. */ 
	wcl.hbrBackground = GetStockObject(WHITE_BRUSH);

	/* Register the window class. */ 
	if(!RegisterClass (&wcl)) 
		return 0;

	/*	Now that a window class has beer registered, a window can he created. */
	hwnd = CreateWindow( szWinName, /* name of window class */
						"Using a List Box", /* title */
						WS_OVERLAPPEDWINDOW, /* window style - normal */
						CW_USEDEFAULT, /* X coordinate - let Windows decide */
						CW_USEDEFAULT, /* y coordinate - let Windows decide */
						CW_USEDEFAULT, /* width - let Windows decide */
						CW_USEDEFAULT, /* height - let Windows decide */
						NULL, /* no parent window */
						NULL, /* use menu registered with this class */
						hThisInst, /* handle of this instance of the program */
						NULL); /* no additional arguments */

	hInst = hThisInst; /* save the current instance handle */

	/* Display the window. */
	ShowWindow(hwnd, nWinMode);

	UpdateWindow(hwnd);


	/* Create the message loop. */ 
	// Start the message loop. 
	while(GetMessage(&msg, NULL, 0, 0))
	{
		TranslateMessage(&msg); // allow use of keyboard  
		DispatchMessage(&msg);	// return control to Windows
	}
	return msg.wParam;
}

//	This function is called by Windows 95 and is passed messages from the message queue.
//  It will set up the default device and handle menu selections

LRESULT CALLBACK WindowFunc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static HMIDIOUT	hMidiOut;
	static UINT numDevs, curDevice;	// curDevice will be initialized to 0
	static MIDIOUTCAPS devCaps;
	static LPMIDIOUTCAPS lpCaps = &devCaps;
	int iResult;


	switch(message)
	{
		case WM_CREATE:	// Open the first midi device in the device list
			numDevs = midiOutGetNumDevs();	// Get the number of devices
			midiOutGetDevCaps(curDevice, lpCaps, sizeof(MIDIOUTCAPS)); // Get device capabilities for first device (curDevice == 0)
			iResult = midiOutOpen(&hMidiOut, curDevice, /*(DWORD) hwnd*/(DWORD) NULL, (DWORD) NULL, /*CALLBACK_WINDOW*/ (DWORD) NULL);
										// Open first device
			if(iResult != MMSYSERR_NOERROR)
				MessageBox(hwnd, "Midi Device Could Not Be Opened", "Device Error", MB_OK); 
			sendMIDIEvent(hMidiOut, NOTEON, 60, 100); // Turn on middle C
			break;
		case WM_COMMAND:
			break;
		case WM_PAINT:
			{
				char str[5];
				HDC hdc;
				PAINTSTRUCT ps;
	
				hdc = BeginPaint(hwnd, &ps);
				wsprintf(str, "%d ", numDevs);	// Print the number of midi devices 
				TextOut(hdc, 5, 5, str, strlen(str));

				EndPaint(hdc, &ps);
			}
			break;	
		case WM_DESTROY: /* terminate the program */ 
			sendMIDIEvent(hMidiOut, NOTEOFF, 60, 100);	/* On exit turn off the note */
			midiOutClose(hMidiOut);
			PostQuitMessage(0);
			break;
		default:
		/* Let Windows 95 process any messages not specified in
			the preceding switch statement. */
		return DefWindowProc(hwnd, message, wParam, lParam);

	}
	return 0;
}

/* Straight out of Microsoft MM SDK doc */
/* Takes three bytes (a status byte and two data bytes) as input and converts to
	the four-byte type required by midiOutShortMsg() */

UINT FAR PASCAL sendMIDIEvent( HMIDIOUT hMidiOut, BYTE bStatus,
								BYTE bData1, BYTE bData2 )
{
	union {
		DWORD 		dwData;
		BYTE		bData[4];
	} u;

	u.bData[0] = bStatus;
	u.bData[1] = bData1;
	u.bData[2] = bData2;
	u.bData[3] = 0;

	return midiOutShortMsg( hMidiOut, u.dwData );
}