#include <windows.h>
#include <tchar.h>


LRESULT CALLBACK    windowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
    case WM_SIZE:
        break;
    case WM_CLOSE:
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        break;
    }

    return  DefWindowProc( hWnd, msg, wParam, lParam );
}

int     WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd )
{
    //  1   注册窗口类
    ::WNDCLASSEXA winClass;
    winClass.lpszClassName  =   "Raster";
    winClass.cbSize         =   sizeof(::WNDCLASSEX);
    winClass.style          =   CS_HREDRAW | CS_VREDRAW | CS_OWNDC | CS_DBLCLKS;
    winClass.lpfnWndProc    =   windowProc;
    winClass.hInstance      =   hInstance;
    winClass.hIcon	        =   0;
    winClass.hIconSm	    =   0;
    winClass.hCursor        =   LoadCursor(NULL, IDC_ARROW);
    winClass.hbrBackground  =   (HBRUSH)(BLACK_BRUSH);
    winClass.lpszMenuName   =   NULL;
    winClass.cbClsExtra     =   0;
    winClass.cbWndExtra     =   0;
    RegisterClassExA(&winClass);

    //  2 创建窗口
    HWND    hWnd   =   CreateWindowExA(
        NULL,
        "Raster",
        "Raster",
        WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN | WS_CLIPSIBLINGS,
        0,
        0,
        480,
        320, 
        0, 
        0,
        hInstance, 
        0
        );

    UpdateWindow( hWnd );
    ShowWindow(hWnd,SW_SHOW);

    RECT    rt      =   {0};
    GetClientRect(hWnd,&rt);

    int     width   =   rt.right - rt.left;
    int     height  =   rt.bottom - rt.top;
    void*   buffer  =   0;

    HDC     hDC     =   GetDC(hWnd);
    HDC     hMem    =   ::CreateCompatibleDC(hDC);



    BITMAPINFO	bmpInfor;
    bmpInfor.bmiHeader.biSize			=	sizeof(BITMAPINFOHEADER);
    bmpInfor.bmiHeader.biWidth			=	width;
    bmpInfor.bmiHeader.biHeight			=	height;
    bmpInfor.bmiHeader.biPlanes			=	1;
    bmpInfor.bmiHeader.biBitCount		=	32;
    bmpInfor.bmiHeader.biCompression	=	BI_RGB;
    bmpInfor.bmiHeader.biSizeImage		=	0;
    bmpInfor.bmiHeader.biXPelsPerMeter	=	0;
    bmpInfor.bmiHeader.biYPelsPerMeter	=	0;
    bmpInfor.bmiHeader.biClrUsed		=	0;
    bmpInfor.bmiHeader.biClrImportant	=	0;

    HBITMAP	hBmp    =	CreateDIBSection(hDC,&bmpInfor,DIB_RGB_COLORS,(void**)&buffer,0,0);
    SelectObject(hMem,hBmp);


    memset(buffer,0,width * height * 4);
    MSG     msg =   {0};
    while(true)
    {
        if (msg.message == WM_DESTROY  
            ||msg.message == WM_CLOSE
            ||msg.message == WM_QUIT)
        {
            break;
        }
        if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) )
        { 
            TranslateMessage( &msg );
            DispatchMessage( &msg );
        }

        memset(buffer,0,width * height * 4);
        //! 修改其中一部分
        unsigned char*  rgba    =   (unsigned char*)buffer;
        int             pitch   =   width * 4;

        memset(rgba + pitch * 10,255, pitch);


        BitBlt(hDC,0,0,width,height,hMem,0,0,SRCCOPY);

    }

    return  0;
}