//定义一个结构体
struct dragon //定义dragon结构，代表画面上的恐龙，其结构成员x和y为贴图坐标，dir为目前恐龙的移动方向
{
int x,y;
int dir;
};

//定义常数
const int draNum = 12; //定义常数draNum，代表程序在画面上要出现的恐龙数目，在此设定为12个
//全局变量定义
HINSTANCE hInst;
HBITMAP draPic[4],bg; //draPic[4]储存恐龙上下左右移动的连续图案，bg为存储背景图
HDC hdc,mdc,bufdc;
HWND hWnd;
DWORD tPre,tNow;
int picNum;
dragon dra[draNum]; //按照draNum的值建立数组dra[]，产生画面上出现的恐龙。

//全局函数声明
ATOM MyRegisterClass(HINSTANCE hInstance);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
void MyPaint(HDC hdc);

//****WinMain函数，程序入口点函数**************************************
int APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
MSG msg;

MyRegisterClass(hInstance);

//初始化
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
}
GetMessage(&msg,NULL,NULL,NULL);//初始化msg
//消息循环
while( msg.message!=WM_QUIT )
{
if( PeekMessage( &msg, NULL, 0,0 ,PM_REMOVE) )
{
TranslateMessage( &msg );
DispatchMessage( &msg );
}
else
{
tNow = GetTickCount();
if(tNow-tPre >= 100)
MyPaint(hdc);
}
}

return msg.wParam;
}

//****设计一个窗口类，类似填空题，使用窗口结构体*************************
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wcex;

wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = (WNDPROC)WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = NULL;
wcex.hCursor = NULL;
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = NULL;
wcex.lpszClassName = "canvas";
wcex.hIconSm = NULL;

return RegisterClassEx(&wcex);
}

//****初始化函数*************************************
// 加载位图并设定各初始值
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
HBITMAP bmp;
hInst = hInstance;
int i;

hWnd = CreateWindow("canvas", "绘图窗口" , WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

if (!hWnd)
{
return FALSE;
}

MoveWindow(hWnd,10,10,640,480,true);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);

hdc = GetDC(hWnd);
mdc = CreateCompatibleDC(hdc);
bufdc = CreateCompatibleDC(hdc);