5인용C++스터디/윈도우에그림그리기

GDI ¶

GDI(Graphics Device Interface)란 �� 리��를 ��는데 ��는 ��. ��디�� 린�� 는 부��. �� Windows�� 는 �� 램�� GDI를 �� 보를 �� 뿐 �� Windows �� GDI를 �� 메뉴, ��롤 바, ��, ��리�� 마�� .

DC ¶

DC(Device Context)는 GDI�� 내부�� 리��는 데�� 며 �� ��. ��림�� 리�� 는 �� 먼�� DC�� 대�� 들�� . ��램�� 들�� 는 �� Windows는 �� 를 �� . ��러면 ��들�� GDI �� 리�� 는 ��를 Windows�� .

��들 : �� 들��는 말�� 말��대�� 들��.

��를 들면 ��동��를 �� 동��들�� /�� 면�� 동��를 ��듯�� �� 들�� 를 �� ��.

DC ��들 �� ¶

DC ��들�� 는 �� 방�� WM_PAINT 메�� 리 �� BeginPaint�� EndPaint �� 는 ��.

hdc = BeginPaint (hwnd, &ps);
��른 명��들
EndPaint (hwnd, &ps);

��번�� 는 ��램�� 대�� 들��.
변�� ps는 PAINTSTRUCT �� . PAINTSTRUCT ��는 �� 리는 데 �� 는 ��보들�� .

WM_PAINT ¶

보�� 램�� WinMain�� UpdateWindow를 �� . �� 무��를 ��리�� .

WM_PAINT ��리는 �� BeginPaint�� 대�� .

hdc = BeginPaint (hwnd, &ps);

��리�� EndPaint를 �� .

EndPaint (hwnd, &ps);

�� 번�� 는 ��램�� 대�� 들��. ��번�� 는 PAINTSTRUCT �� 대�� . PAINTSTRUCT ��는 �� 리는 데 �� 는 ��보들�� .

WndProc�� BeginPaint를 �� GetClientRect를 ��.

GetClientRect(hwnd, &rect);

��번�� 는 ��램 �� 대�� 들��. ��번�� 는 RECT�� 대�� .

�� ¶

~cpp 
#include <windows.h>

LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrev, LPSTR lpCmdLine, int nCmdShow)
{
	HWND hWnd;
	WNDCLASS wc;
	MSG mSg;
	char szTitleName[]="Drawing Line";
	char szClassName[]="it is a class";

	wc.cbClsExtra=NULL;
	wc.cbWndExtra=NULL;
	wc.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
	wc.hCursor=LoadCursor(NULL,IDC_ARROW);
	wc.hIcon=LoadIcon(NULL,IDI_APPLICATION);
	wc.hInstance=hInst;
	wc.lpfnWndProc=WndProc;
	wc.lpszClassName=szClassName;
	wc.lpszMenuName=NULL;
	wc.style=NULL;

	RegisterClass(&wc);

	hWnd=CreateWindow(szClassName,szTitleName, WS_OVERLAPPEDWINDOW,100,90,320,240,NULL,NULL,hInst,NULL);

	ShowWindow(hWnd,nCmdShow);
	UpdateWindow(hWnd);

	while(GetMessage(&mSg,NULL,0,0))
	{
		TranslateMessage(&mSg);
		DispatchMessage(&mSg);
	}
	return mSg.wParam;
}

LRESULT CALLBACK WndProc(
						 HWND hWnd,
						 UINT uMsg,
						 WPARAM wParam,
						 LPARAM lParam)
{
	HDC hDC;
	HPEN hPen;
	PAINTSTRUCT ps;
	static int nSX,nSY,nEX,nEY;
	static POINT pt;
	static BOOL bTF;

	switch(uMsg)
	{
	case WM_LBUTTONDOWN:
		{
			bTF = TRUE;
			nSX=LOWORD(lParam);
			nSY=HIWORD(lParam);
		}
		return FALSE;

	case WM_LBUTTONUP:
		{
			bTF=FALSE;
			nEX=LOWORD(lParam);
			nEY=HIWORD(lParam);
			InvalidateRect(hWnd,NULL,FALSE);
		}
		return FALSE;

	case WM_PAINT:
		{
			if(bTF==FALSE)
			{
				hPen=CreatePen(PS_SOLID,0,RGB(0,0,0));
				hDC=BeginPaint(hWnd,&ps);
				SelectObject(hDC,hPen);
                                    SelectObject(hDC, GetStockObject(NULL_BRUSH));
 				MoveToEx(hDC,nSX,nSY,&pt);
				LineTo(hDC,nEX,nEY);
				DeleteObject(hPen);
				EndPaint(hWnd,&ps);
			}
		}
			return FALSE;
	case WM_DESTROY:
		PostQuitMessage(0);
		return FALSE;
		}
		return DefWindowProc(hWnd,uMsg,wParam,lParam);
	}

~cpp 
                               hPen=CreatePen(PS_SOLID,0,RGB(0,0,0)); 
                               hDC=BeginPaint(hWnd,&ps); 
                               Ellipse(hDC,nSX,nSY,nEX,nEY);
                               EndPaint(hWnd,&ps);

CreatePen() : �� 는 ��.
SelectObject() : CreatePen()�� 만�� .
LineTO() : �� 리는 ��.
DeleteObject() : CreatePen()�� 는 ��.

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