出于好玩,一个小代码:
#include <windows.h>
#include <cmath>
#define PI 3.1415926
class Pentacle
{
private:
   POINT points[5];
   POINT mittel;
   double length;
public:
   Pentacle(){}
   Pentacle(const POINT & mP, const double l);
   void createPentacle(const POINT & mP, const double l);
   void paint1(HDC, HWND);
   void paint2(HDC, HWND);
   void paint3(HDC, HWND);
};
Pentacle::Pentacle(const POINT & mP, const double l)
{
   mittel = mP;
   length = l;
   for(int i = 0; i<5; i++)
   {
      points[i].x = (LONG)(length/2/sin(36*PI/180)*sin(i*72*PI/180) + mittel.x);
      points[i].y = (LONG)(length/2/sin(36*PI/180)*cos(i*72*PI/180) + mittel.y);
   }
}
void Pentacle::createPentacle(const POINT & mP, const double l)
{
   mittel = mP;
   length = l;
   for(int i = 0; i<5; i++)
   {
      points[i].x = (LONG)(length/2/sin(36*PI/180)*sin(i*72*PI/180) + mittel.x);
      points[i].y = (LONG)(length/2/sin(36*PI/180)*cos(i*72*PI/180) + mittel.y);
   }
}
void Pentacle::paint1(HDC hDC, HWND hWnd)
{
   //PAINTSTRUCT ps;
   //HDC hDC = BeginPaint(hWnd, &ps);
   HPEN hPen = CreatePen(PS_SOLID, 2, RGB(255, 0, 0));
   SelectObject(hDC, hPen);
   POINT points[6];// = {{100,100}, {129,121}, {118,154},{82,154},{71,121},{100,100}};
   
   for(int i = 0; i<5; i++)
   {
      points[i] = Pentacle::points[i];
   }
   points[5] = Pentacle::points[0];
   
   Polyline(hDC, points, 6);
   DeleteObject(hPen);
   //EndPaint(hWnd, &ps);
}
void Pentacle::paint2(HDC hDC, HWND hWnd)
{
   POINT points[6];// = {{100,100}, {129,121}, {118,154},{82,154},{71,121},{100,100}};
   
   for(int i = 0; i<5; i++)
   {
      points[i] = Pentacle::points[i];
   }
   points[5] = Pentacle::points[0];
   
   HPEN hPen = CreatePen(PS_SOLID, 2, RGB(255, 0, 0));
   SelectObject(hDC, hPen);
   MoveToEx(hDC, points[0].x, points[0].y, NULL);
   LineTo(hDC, points[2].x, points[2].y);
   DeleteObject(hPen);
   hPen = CreatePen(PS_SOLID, 2, RGB(0, 255, 0));
   SelectObject(hDC, hPen);
   LineTo(hDC, points[4].x, points[4].y);
   DeleteObject(hPen);
   hPen = CreatePen(PS_SOLID, 2, RGB(0, 0, 255));
   SelectObject(hDC, hPen);
   LineTo(hDC, points[1].x, points[1].y);
   DeleteObject(hPen);
   hPen = CreatePen(PS_SOLID, 2, RGB(125, 125, 125));
   SelectObject(hDC, hPen);
   LineTo(hDC, points[3].x, points[3].y);
   DeleteObject(hPen);
   hPen = CreatePen(PS_SOLID, 2, RGB(0, 0, 125));
   SelectObject(hDC, hPen);
   LineTo(hDC, points[0].x, points[0].y);
   DeleteObject(hPen);
}
void Pentacle::paint3(HDC hDC, HWND hWnd)
{
   POINT points[6];// = {{100,100}, {129,121}, {118,154},{82,154},{71,121},{100,100}};
   
   for(int i = 0; i<5; i++)
   {
      points[i] = Pentacle::points[i];
   }
   points[5] = Pentacle::points[0];
   
   HBRUSH hBrush = CreateSolidBrush(RGB(0, 128, 255));
   SelectObject(hDC, hBrush);
   Polygon(hDC, points, 6);
   DeleteObject(hBrush);
}
/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
/*  Make the class name into a global variable  */
char szClassName[ ] = "WindowsApp";
int WINAPI WinMain (HINSTANCE hThisInstance,
                   
HINSTANCE hPrevInstance,
                   
LPSTR lpszArgument,
                   
int nFunsterStil)
{
    HWND
hwnd;              
/* This is the handle for our window */
    MSG
messages;           
/* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */
    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style =
CS_DBLCLKS;                
/* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);
    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName =
NULL;                
/* No menu */
    wincl.cbClsExtra =
0;                     
/* No extra bytes after the window class */
    wincl.cbWndExtra =
0;                     
/* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;
    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
          
0,                  
/* Extended possibilites for variation */
          
szClassName,         /*
Classname */
           "Pentacle",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
          
CW_USEDEFAULT,       /* Windows decides
the position */
          
CW_USEDEFAULT,       /* where the window
ends up on the screen */
          
544,                
/* The programs width */
          
375,                
/* and height in pixels */
          
HWND_DESKTOP,        /* The window
is a child-window to desktop */
          
NULL,               
/* No menu */
          
hThisInstance,       /* Program Instance
handler */
          
NULL                
/* No Window Creation data */
           );
    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);
    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }
    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}
/*  This function is called by the Windows function DispatchMessage()  */
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    HPEN hPen;
    POINT mittel;
    POINT points[6];
    int length;
    Pentacle myPentacle;
    switch
(message)                 
/* handle the messages */
    {
        case WM_DESTROY:
           
PostQuitMessage (0);       /* send a
WM_QUIT to the message queue */
            break;
        case WM_PAINT:
            hdc = BeginPaint(hwnd, &ps);
            mittel.x = 150;
            mittel.y = 150;
            length = 150;
         
            myPentacle.createPentacle(mittel, length);
            myPentacle.paint1(hdc, hwnd);
            myPentacle.paint3(hdc, hwnd);
            myPentacle.paint2(hdc, hwnd);
            EndPaint(hwnd, &ps);
            break;
       
default:                     
/* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }
    return 0;
}