///////////////////////////////////////////////////////
///
///  このソースコードを引用・改変した結果如何なる
///　損害が発生しても、著者はは責任を負いません。
///  広島大学　脳外科　橋詰顕
///
////////////////////////////////////////////////////////
#define STRICT              //型チェックを厳密に行う
#define WIN32_LEAN_AND_MEAN //ヘッダーからあまり使われていない関数を省く
#include<windows.h>

//DirectDraw7用
#include<ddraw.h>
#pragma comment(lib,"ddraw.lib")
#pragma comment(lib,"dxguid.lib")

void hnsDeleteWindowMessage();
LPDIRECTDRAWSURFACE7 hnsMakeDirectDraw7BackSurface(LPDIRECTDRAWSURFACE7 pSurface);
LPDIRECTDRAW7 hnsMakeDirectDraw7Object(HWND hWindow,int WindowWidth,int WindowHeight);
void hnsMakeDirectDraw7PrimarySurface(LPDIRECTDRAW7 pDirectDraw,int BackBuffer,LPDIRECTDRAWSURFACE7 pSurface);
void hnsSetFullScreenVGA(HWND hWindow);
void hnsTaskLoop(HWND hWindow);
LRESULT CALLBACK WindowProcedure(HWND hWindow,UINT message,WPARAM wParameter,LPARAM lParameter);

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine,int iCmdShow)
{
	//WNDCLASSの設計
	WNDCLASS WindowClass;
	WindowClass.style=CS_HREDRAW | CS_VREDRAW;
	WindowClass.lpfnWndProc=WindowProcedure;
	WindowClass.cbClsExtra=0;
	WindowClass.cbWndExtra=0;
	WindowClass.hInstance=hInstance;
	WindowClass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
	WindowClass.hCursor=LoadCursor(NULL,IDC_ARROW);
	WindowClass.hbrBackground=(HBRUSH)GetStockObject(BLACK_BRUSH);//背景は黒
	WindowClass.lpszMenuName=NULL;
	WindowClass.lpszClassName="WindowClassName";

	//設計したWNDCLASSの登録
	if(!RegisterClass(&WindowClass))
	{
		MessageBox(NULL,"設計したWNDCLASSの設計に失敗しました","Error!",MB_ICONERROR);
		return 0;
	}

	//Windowの作成
	HWND hWindow=CreateWindow(
		"WindowClassName",						//window class name
		"Let's make MEG task",					//title
		//WS_OVERLAPPEDWINDOW | WS_VISIBLE,		//Window Style
		WS_POPUP | WS_VISIBLE,					//枠なし表示
		CW_USEDEFAULT,CW_USEDEFAULT,			//top left
		CW_USEDEFAULT,CW_USEDEFAULT,			//width,height
		NULL,									//parent window handle
		(HMENU)NULL,							//window menu handle
		hInstance,								//application handle
		NULL);									//creation parameter
	ShowWindow(hWindow,SW_SHOW);	

	MSG  message;
	
	//無限ループです。
	while(GetMessage(&message,NULL,0,0))
	{
		TranslateMessage(&message);
		DispatchMessage(&message);
	}

	return 0;	
}

void hnsDeleteWindowMessage()
{
	//Window Messageを取り除く
	MSG message;
	int flag=1;
	while (1)
	{
		flag=::PeekMessage(&message,NULL,WM_KEYFIRST,WM_KEYLAST,PM_REMOVE );
		if(flag==0){break;}
	}
}

LPDIRECTDRAWSURFACE7 hnsMakeDirectDraw7BackSurface(LPDIRECTDRAWSURFACE7 pSurface)
{   //pSurfaceはprimary surface,back surface,back surface,...の順で取得すること
	DDSCAPS2 DirectDrawSurfaceCaps;
	LPDIRECTDRAWSURFACE7 pBackSurface;
	ZeroMemory(&DirectDrawSurfaceCaps,sizeof(DirectDrawSurfaceCaps));
	DirectDrawSurfaceCaps.dwCaps=DDSCAPS_BACKBUFFER;
    HRESULT hResult=pSurface->GetAttachedSurface(&DirectDrawSurfaceCaps,&pBackSurface);
	if(FAILED(hResult)){return NULL;}
	return pBackSurface;
}

LPDIRECTDRAW7 hnsMakeDirectDraw7Object(HWND hWindow,int WindowWidth,int WindowHeight)
{
	HRESULT hResult;
	LPDIRECTDRAW7 pDirectDraw=NULL;
	hResult=DirectDrawCreateEx(NULL,(void**)&pDirectDraw,IID_IDirectDraw7,NULL);
	if(FAILED(hResult)){
		MessageBox(NULL,"DirectDraw objectは作成できませんでした","",MB_ICONERROR);
		return NULL;
	}
	pDirectDraw->SetCooperativeLevel(
		hWindow,
		DDSCL_EXCLUSIVE |  //Device占有
		DDSCL_ALLOWREBOOT | //CTRL + ALT + DEL の機能を許可する
		DDSCL_FULLSCREEN); //fullscreen
	hResult=pDirectDraw->SetDisplayMode(
		WindowWidth,WindowHeight,//dwWidth,dwHeight
		32,      //dwBPP Bit/Pixel  checkすること！
		0,       //dwRefeshRate 0:default refresh rate
		0);      //dwFlags
	if(FAILED(hResult)){
		MessageBox(NULL,"Display Modeの設定はできませんでした","",MB_ICONERROR);
		return NULL;
	}
	pDirectDraw->WaitForVerticalBlank(DDWAITVB_BLOCKBEGIN,0);//垂直描画開始にあわせる
	return pDirectDraw;
}


LPDIRECTDRAWSURFACE7 hnsMakeDirectDraw7PrimarySurface(LPDIRECTDRAW7 pDirectDraw,int BackBuffer)
{
	LPDIRECTDRAWSURFACE7 pPrimarySurface;
	DDSURFACEDESC2 DirectDrawSurfaceDesc;
	ZeroMemory(&DirectDrawSurfaceDesc,sizeof(DirectDrawSurfaceDesc));
	DirectDrawSurfaceDesc.dwSize=sizeof(DirectDrawSurfaceDesc);
	if(BackBuffer==0)
	{
		DirectDrawSurfaceDesc.dwFlags=DDSD_CAPS;
		DirectDrawSurfaceDesc.dwRefreshRate=0;//default?
		DirectDrawSurfaceDesc.ddsCaps.dwCaps=DDSCAPS_PRIMARYSURFACE;
	}
	else
	{
		DirectDrawSurfaceDesc.dwFlags=
			DDSD_CAPS |          //ddsCapsを有効に
			DDSD_BACKBUFFERCOUNT;//back bufferを有効に
		DirectDrawSurfaceDesc.ddsCaps.dwCaps=
			DDSCAPS_PRIMARYSURFACE |
			DDSCAPS_FLIP |
			DDSCAPS_COMPLEX;
		DirectDrawSurfaceDesc.dwBackBufferCount=BackBuffer;
	}
	HRESULT hResult=pDirectDraw->CreateSurface(&DirectDrawSurfaceDesc,&pPrimarySurface,NULL);
	if(FAILED(hResult)){return NULL;}
	return pPrimarySurface;
}

void hnsSetFullScreenVGA(HWND hWindow)
{

	static int WindowWidth=640;
	static int WindowHeight=480;
	LONG lResult;	//画面を640x480に変更できたかどうか	

	//画面を640x480にする
	DEVMODE DeviceMode;
	DeviceMode.dmSize		=sizeof(DEVMODE);
	DeviceMode.dmFields		=DM_PELSWIDTH | DM_PELSHEIGHT;
	DeviceMode.dmPelsWidth	=WindowWidth;
	DeviceMode.dmPelsHeight	=WindowHeight;
	
	//画面を元に戻す
	if(hWindow==NULL){
		ChangeDisplaySettings(&DeviceMode,NULL);
		return;
	}

	lResult=ChangeDisplaySettings(&DeviceMode,CDS_FULLSCREEN);
	if(lResult!=DISP_CHANGE_SUCCESSFUL)
	{
		MessageBox(hWindow,"full screenの変換は失敗しました","",MB_ICONERROR);
		return;
	}
	SetWindowPos(hWindow,HWND_TOPMOST,0,0,WindowWidth,WindowHeight,0);
}

void hnsTaskLoop(HWND hWindow)
{
	static int WindowWidth=640;
	static int WindowHeight=480;

	//DirectDraw objectの作成
	LPDIRECTDRAW7 pDirectDraw=hnsMakeDirectDraw7Object(hWindow,WindowWidth,WindowHeight);
	if(pDirectDraw==NULL)
	{
		return;//失敗したらやめる
	}
	//DirectDraw objectからprimary surfaceの作成
	LPDIRECTDRAWSURFACE7 pPrimarySurface=hnsMakeDirectDraw7PrimarySurface(pDirectDraw,1);
	if(pPrimarySurface==NULL)
	{
		pDirectDraw->Release();
		return;
	}
	//primary surfaceからback surfaceの作成
	LPDIRECTDRAWSURFACE7 pBackSurface=hnsMakeDirectDraw7BackSurface(pPrimarySurface);
	if(pPrimarySurface==NULL)
	{
		pPrimarySurface->Release();	
		pDirectDraw->Release();
		return;
	}

	//device contextに直接描画するのではなくmemory device contextを使う
	HDC hDeviceContext=GetDC(hWindow);
	HDC hMemoryDeviceContext=CreateCompatibleDC(hDeviceContext);//この時点では1x1 1bit
	HBITMAP hBitmap=CreateCompatibleBitmap(hDeviceContext,WindowWidth,WindowHeight);
	SelectObject(hMemoryDeviceContext,hBitmap);
	DeleteObject(hBitmap);
	ReleaseDC(hWindow,hDeviceContext);

	//文字描画の設定
	SetTextColor(hMemoryDeviceContext,RGB(255,255,255));
	SetBkMode(hMemoryDeviceContext,TRANSPARENT);
	SetBkColor(hMemoryDeviceContext,RGB(0,0,0));
	int CharacterSize=50;

	//fontの設定
	HFONT hFont=CreateFont(
		CharacterSize,CharacterSize/2,		//高さ・幅 2byte文字は*2が必要
		0,0,			//角度・ベースラインの角度
		FW_BOLD,			//太さ
		FALSE,				//斜体
		FALSE,				//下線
		FALSE,				//打消し線
		SHIFTJIS_CHARSET,	//文字セット
		OUT_DEFAULT_PRECIS,	//出力精度
		CLIP_DEFAULT_PRECIS,//クリッピング精度
		DEFAULT_QUALITY,	//出力品質
		VARIABLE_PITCH | FF_ROMAN,//ピッチとフォントファミリ
		"MS ゴシック");				//書体

	//fontの選択
	SelectObject(hMemoryDeviceContext,hFont);

	//文字列の作成
	char textbuffer[]="Hello World";

	//描画矩形領域の設定
	RECT rect;
	rect.left=0;
	rect.right=WindowWidth;
	rect.top=0;
	rect.bottom=WindowHeight;

	DrawText(
		hMemoryDeviceContext,
		textbuffer,
		-1,//文字列の長さは自動的に計算
		&rect,
		DT_CENTER | DT_VCENTER | DT_SINGLELINE);//横中央・縦中央 1列表示

	//hFontの解放
	DeleteObject(hFont);	

	//memory device contextからback surfaceへブロック転送
	HDC hSurfaceDeviceContext;
	pBackSurface->GetDC(&hSurfaceDeviceContext);
	BitBlt(hSurfaceDeviceContext,0,0,WindowWidth,WindowHeight,
		   hMemoryDeviceContext,0,0,SRCCOPY);

	//back surfaceの内容をprimary surfaceに転送
	pBackSurface->ReleaseDC(hSurfaceDeviceContext);//flipする前にdevice contextを消しておくこと!
	pPrimarySurface->Flip(NULL,DDFLIP_NOVSYNC);//次の走査線にできる限り近い物理的なフリップを実行する

	//memory device contextの解放
	DeleteDC(hMemoryDeviceContext);
	
	bool EscapeFlag=FALSE;

	//Window Messageを取り除く
	hnsDeleteWindowMessage();

	while(1)			//御法度の無限ループ
	{
		while(1)
		{
			if((GetAsyncKeyState(VK_ESCAPE)&0x8000)!=0){EscapeFlag=TRUE;break;}
		}
		if(EscapeFlag){break;}
	}	
	//Window Messageを取り除く
	hnsDeleteWindowMessage();

	//Direct Drawで作った部品を作成順の逆で解放
	pBackSurface->Release();
	pPrimarySurface->Release();
	pDirectDraw->Release();
}

LRESULT CALLBACK WindowProcedure(HWND hWindow,UINT message,WPARAM wParameter,LPARAM lParameter)
{
	switch(message)
	{
	case WM_CREATE:
		hnsSetFullScreenVGA(hWindow);
		break;
	case WM_KEYDOWN:
		switch(wParameter)
		{
		//ESCAPEキーをおすとWindowを破壊するWM_DESTROYメッセージを送る
		case VK_ESCAPE:
			PostMessage(hWindow,WM_DESTROY,0,0);
			break;
		//RETURNキーをおすとタスク開始
		case VK_RETURN:
			hnsTaskLoop(hWindow);
			hnsSetFullScreenVGA(hWindow);
			break;
		}
		break;
	case WM_DESTROY:
		//hnsSetFullScreenVGA(NULL); ない方がいいみたい
		PostQuitMessage(0);
		return 0;
	}
	return DefWindowProc(hWindow,message,wParameter,lParameter);
}