#include<windows.h>

// winmm.lib をリンクする
#pragma comment(lib,"winmm")

#define MIDIMSG(status,channel,data1,data2) ( (DWORD)((status<<4) | channel | (data1<<8) | (data2<<16)) )

LRESULT CALLBACK WindowProc(HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam)
{
	static HMIDIOUT hMidiOut;
	static BYTE note=0x3C,velocity=0x40;
	static BYTE program=0;

	HDC hdc;
	PAINTSTRUCT ps;
	char str[64];

	switch(uMsg){
		case WM_CREATE:
			midiOutOpen(&hMidiOut,MIDIMAPPER,NULL,0,CALLBACK_NULL);
			return 0;
		case WM_LBUTTONDOWN:	//鍵盤を押す
			midiOutShortMsg(hMidiOut,MIDIMSG(0x9,0x0,note,velocity));
			return 0;
		case WM_RBUTTONDOWN:	//鍵盤を離す
			midiOutShortMsg(hMidiOut,MIDIMSG(0x9,0x0,note,0));
			return 0;
		case WM_KEYDOWN:
			switch(wParam){
				case 'A':		//音色変更
					if(program>0) program--;
					midiOutShortMsg(hMidiOut,MIDIMSG(0xC,0,program,0));
					break;
				case 'F':		//音色変更
					if(program<0x7F) program++;
					midiOutShortMsg(hMidiOut,MIDIMSG(0xC,0,program,0));
					break;
				case VK_LEFT:	//音階変更
					if(note>0) note--;
					break;
				case VK_RIGHT:	//音階変更
					if(note<0x7F) note++;
					break;
				case VK_DOWN:	//打鍵強度変更
					if(velocity>0) velocity--;
					break;
				case VK_UP:		//打鍵強度変更
					if(velocity<0x7F) velocity++;
					break;
			}
			InvalidateRect(hWnd,NULL,TRUE);
			return 0;
		case WM_PAINT:
			hdc=BeginPaint(hWnd,&ps);
			wsprintf(str,"音色 = 0x%02X , 音階 = 0x%02X , 打鍵強度 = 0x%02X",program,note,velocity);
			TextOut(hdc,0,0,str,lstrlen(str));
			EndPaint(hWnd,&ps);
			return 0;
		case WM_DESTROY:
			midiOutReset(hMidiOut);
			midiOutClose(hMidiOut);
			PostQuitMessage(0);
			return 0;
	}
	return DefWindowProc(hWnd,uMsg,wParam,lParam);
}

int WINAPI WinMain(
	HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR lpCmdLine,int nCmdShow)
{
	WNDCLASS wc;
	MSG msg;

	wc.style		 = CS_HREDRAW | CS_VREDRAW;
	wc.lpfnWndProc	 = WindowProc;
	wc.cbClsExtra	 = 0;
	wc.cbWndExtra	 = 0;
	wc.hInstance	 = hInstance;
	wc.hIcon		 = LoadIcon(NULL,IDI_APPLICATION);
	wc.hCursor		 = LoadCursor(NULL,IDC_ARROW);
	wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
	wc.lpszMenuName	 = NULL;
	wc.lpszClassName = __FILE__;
	if(!RegisterClass(&wc)) return 0;

	HWND hWnd=CreateWindow(
		__FILE__,"MIDIを鳴らす",
		WS_OVERLAPPEDWINDOW | WS_VISIBLE,
		CW_USEDEFAULT,CW_USEDEFAULT,
		CW_USEDEFAULT,CW_USEDEFAULT, 
		NULL,NULL,hInstance,NULL);
	if(hWnd==NULL) return 0;

	BOOL bRet;
	while((bRet=GetMessage(&msg,NULL,0,0))!=0){
		if(bRet==-1) break;
		DispatchMessage(&msg);
	}

	return (int)msg.wParam;
}