学习windows编程 day4 之 多边矩形填充

#include <windows.h>
#include <math.h>

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);

#define R 200
#define PI 3.1415926

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    //声明全局数据：类名
    static TCHAR szClassName[] = TEXT("MyWindows");
    HWND hwnd;
    MSG msg;

    //注册窗口类
    WNDCLASS wndclass;

    wndclass.hInstance = hInstance;
    wndclass.lpszClassName = szClassName;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.lpfnWndProc = WndProc;
    wndclass.lpszMenuName = NULL;
    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.style = CS_HREDRAW;

    if (!RegisterClass(&wndclass))
    {
        MessageBox(NULL, TEXT("this program must run in Windows NT!"), szClassName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(
        szClassName,
        TEXT("MyFirstPractice"),
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        NULL,
        NULL,
        hInstance,
        NULL
        );

    ShowWindow(hwnd, nShowCmd);
    UpdateWindow(hwnd);

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    RECT rect;

    static HBRUSH hBrush, hOldBrush;
//    绘制一个多边形，可填充是需要顶点的个数polygon
    POINT apt1[4] = { 100, 200, 200, 100, 300, 200,200, 300 };
//    绘制一个封闭多边形polyline需要顶点数+1    注意：用线绘制的封闭图像不具有填充能力
//    POINT apt2[5] = { 400, 200, 500, 100, 600, 200, 500, 300, 400, 200 };
    POINT apt2[5];
    int cxClient, cyClient;    //星星的中心位置

    switch (message)
    {
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        GetClientRect(hwnd, &rect);

        cxClient = rect.right / 2;
        cyClient = rect.bottom / 2;

        //获取五个顶点
        //左上顶点
        apt2[0].x = cxClient - (int)(R*cos(PI / 5));
        apt2[0].y = cyClient - (int)(R*sin(PI / 5));

        //右上顶点
        apt2[1].x = cxClient + (int)(R*cos(PI / 5));
        apt2[1].y = cyClient - (int)(R*sin(PI / 5));

        //左下顶点
        apt2[2].x = cxClient - (int)(R*cos(PI / 5));
        apt2[2].y = cyClient + (int)(R*sin(PI / 5));

        //上顶点
        apt2[3].x = cxClient;
        apt2[3].y = cyClient - R;

        //右下顶点
        apt2[4].x = cxClient + (int)(R*cos(PI / 5));
        apt2[4].y = cyClient + (int)(R*sin(PI / 5));

         hBrush = CreateSolidBrush(RGB(255,255,0));
         hOldBrush = SelectObject(hdc, hBrush);

//        SetPolyFillMode(hdc, ALTERNATE);    //交替填充
        SetPolyFillMode(hdc, WINDING);    //螺旋填充，填充所有能够一笔完成的图形
// 
         Polygon(hdc, apt2, 5);
//         Polyline(hdc, apt2, 5);
// 
         SelectObject(hdc, hOldBrush);
         DeleteObject(hOldBrush);
        EndPaint(hwnd, &ps);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }


    return DefWindowProc(hwnd, message, wParam, lParam);
}